People love to classify things. Pre-hominids seemed more primitive than prehistoric humans who had tamed fire. Natives armed with spears and arrows seem less technologically advanced than invaders armed with firearms. Steam power seems less technologically advanced than nuclear energy. So naturally historicaly-minded people tried to codify this into a scale of technological advancement, to conveniently classify various cultures at various times in their history. A scale of "tech levels" in other words.

Since many early researchers were regrettably Western-centric, they tended to visualize tech levels as a linear path (that is, the path followed by Western civilization). This is a gross simplification. Latter researchers studying a wider range of cultures (such as China) realized the linear path was a poor model. There is no particular reason why Louis Pasteur's germ theory of disease was formulated about the same time as the invention of the Gattling gun. In other cultures they might occur at widely separated historical periods.

A much better model is the multi-branched "tech tree." The technology required to make an iron sword has the prerequisite of a supply of iron and a furnace to heat it. Both of which require the technology of making fire. In addition iron requires the skills of prospecting and mining iron ore, plus the technology of smelting ore into ingots of pure metal. And so on.

The superiority of a tech tree over tech levels is that different cultures can travel over various branchces of a tech tree at different rates. So culture Alfa might have germ theory tech at the same time as gattling gun tech, but culture Bravo might develope gattling guns decades before germ theory.

The convoluted way that tech advances influence each other was the entire premise behind James Burke's documentary series Connections and The Day The Universe Changed, which you should watch if you haven't already.

The role-playing game Traveller popularized the use of tech levels in 1977. The tabletop boardgame Civilization popularized the use of tech trees in 1980. And pretty much every 4x game uses tech trees, with the items accessed by investing in tech research.

There is a chunky version of tech level displayed in the Kardashev scale. And do peruse the section on Alien Tech Levels.

Tech Levels


"Technological advance is an inherently iterative process. One does not simply take sand from the beach and produce a Dataprobe. We use crude tools to fashion better tools, and then our better tools to fashion more precise tools, and so on. Each minor refinement is a step in the process, and all of the steps must be taken."
Chairman Shen-Ji Yang, "Looking God in the Eye"

In Hollywood, people seem to believe that technology starts at fire and ends in people turning into energy; the interim would follow the exact same steps on every possible world. Often, this takes the form of people not from Earth creating exact replicas of Earth technology right down to the last detail — such as interface panels ripped right out of the Apollo missions on an alien space station. These copies are often similar enough that people who are from Earth often have no trouble at all using the device, or even interfacing their own hardware with it.

Similarly, seemingly distinct and diverse technologies will always develop at the same rate. An alien world with "Renaissance-era" technology (ignoring for the moment that the Renaissance spanned four centuries and giant changes in technology) in, say, firearms will also possess lenses, ships, building materials, and mathematical principles identical to those that Earth (read: the inter-continental trade powers of north-western Europe) possessed along with said firearms.

It's only rarely that a civilization will break off the path, and usually as a result of external forces providing them with something outside their capabilities (intentionally, accidentally or incidentally), such as a 1920s planet with fusion power, or a 1700s planet with radios. However, mastering this technology does not actually give them an understanding of related concepts, or even concepts which would be required to use this technology in the first place (thus averting Possession Implies Mastery).

Remember, don't think path, think tree, just as with the evolution of biological lifeforms. Except, in this case the distant descendants of unrelated branches can inspire and influence the future of others. For inspiring viewing, see the James Burke documentary series Connections, which shows the sometimes ludicrously unlikely places where inspiration and discovery come from, and the web-like connections between seemingly-unrelated inventions.

I, for one, can only look forward to the day that crystal-based technology paves the way for our conversion into energy.

See also: Enforced Technology Levels, Evolutionary Levels, In Spite of a Nail, and Tier System. Contrast Schizo Tech, Aliens Never Invented the Wheel, Sufficiently Advanced Bamboo Technology, Alternate Techline, Anachronism Stew and/or Fantasy Gun Control.

This has some actual reference in the real world Kardashev Scale (how much total energy one gets to play with, no matter how). The other wiki used to have a list. See Abusing the Kardashev Scale for Fun and Profit for some fun speculation.

For a huge list of examples click here

TECHNOLOGY LEVELS entry from TV Tropes

Note that when an interstellar colony is established, the tech levels can become scrambled due to the colony infrastructure problem (e.g., horses make more sense than automobiles if the colony has no oil wells to produce gasoline).

Corporal Anuraro showed me how to get into the canoe without swamping it. We don't have those things in Arizona. As they paddled me ashore, I thought about how silly the situation was. I was being paddled in a canoe, a device invented at least ten thousand years ago. I was carrying a pair of light-amplifying field glasses based on a principle not discovered until after I was born. Behind me was a steamboat that might have been moving up the Missouri River at the time of Custer's last stand, and I got to this planet in a starship.

From WEST OF HONOR by Jerry Pournelle (1976)


     A useful concept in science fiction gaming is the technology level (or “tech level”), denoting what a given world or society can create or do, technologically. On contemporary Earth, we tend to use decades as rough indicators of technology — the United States boasts a “twenty-first century” military, while poorer and less advanced countries have “1960s-era” forces.
     Technology classifications tend to either be very broad or very narrow. An example of a broad schema is the notion of “Ages”: Stone Age, Bronze Age, Iron Age, Industrial Age, Information Age, PostHuman Age, and so forth. Broad technology schemes cover centuries or millennia, and they describe a whole suite of interrelated technologies and social structures. This usually implies that cultures develop along a similar path. Broad tech classifications also encourage cinematic-style invention and gadgeteering — if you’re an Industrial Age mechanic you can fix anything from an early steamship to a World War II fighter plane.
     Narrow tech scales are more useful in eras when technology changes quickly. A real-world example of this is the Gulf War of 1990, in which the 1990s-tech Coalition forces just walked over the 1980s-tech Iraqi army — using equipment which, by the standards of 2002, is often inferior or obsolete. This sort of system is appropriate to Cyberpunk or technothriller-style SF, in which hackers breeze through last year’s defensive software, and getting a beta-test copy of new intrusion programs can make a kid from the projects into a heavy hitter in cyberspace — for a few weeks, anyway. Obviously, narrow tech bands make it harder for a specialist trained in one tech level to work in others, and a character’s skills can get rusty in just a few years if he doesn’t study and stay current in the field.

Tech Scales

     Most technology-rating schemes have a “signature” technology which is the ultimate yardstick. If you have technology X, then you are tech level Y. The signature technology in a tech level rating system says as much about the people devising the system as it does about the cultures described. Archaeologists once classified Earth cultures by their artifacts, giving rise to the system of Stone, Bronze, and Iron Age. This works for archaeologists because they learn about cultures by examining things left in middens and tombs. By contrast, the Russian astronomer Kardashev classified civilizations by energy output, because energy emissions are what astronomers can detect. A culture interested in trade would rate civilizations by what they can make, while an aggressive conquering empire would be interested in the military potential of alien planets. Frequently space flight or interstellar travel are major demarcations in tech level. Sometimes a system combines two or more signature technologies for higher resolution.

Creating A Tech Scale

     Gamemasters devising a tech scale need to make three decisions:
  • Will the scale be narrow or broad?
  • What will the signature technologies be?
  • How will the levels be identified and/or labeled?

Alternate Tech Paths

     Human beings invented sailing ships before gunpowder, balloons before the germ theory of disease, and steam power before rocketry. But there’s no reason things had to happen in that order. The Greek scientists of Alexandria devised toys which contained all the principles of steam power almost two millennia before James Watt. An Egyptian doctor might have mixed saltpeter, sulfur, and charcoal thousands of years before the Chinese invented gunpowder. Hot-air balloons were possible a thousand years before the Montgolfier Brothers.
     Gamemasters can have a lot of fun mixing and matching technologies. Early development of steam power allows naval battles between steam-powered Roman galleys firing catapults at each other. Early ballooning lets one have knights, castles, and aerial reconaissance. But don’t forget that some technologies depend on others — germ theory requires microscopes, airplanes need internal-combustion motors, and submarines aren’t practical until they can use electric batteries.
     More exotic alternate technology paths could skip entire areas of knowledge — one common way to make an alien civilization alien is to give them a technology based on biology rather than inanimate materials and machinery. Instead of making a device to do something, they would breed an organism for it. Or maybe the aliens lack some device common on Earth. H.G. Wells’s Martians, for example, didn’t have the wheel.

Varying Tech Paths

     Within a given civilization, it’s entirely possible for the tech levels to vary from place to place. For example, the most advanced nations or regions on a particular planet might have Tech Level Theta devices, whereas less advanced or more isolated locations might only have reached Tech Level Delta. Similarly, Kalidar IV might possess extremely advanced technology, while Haroldson’s Planet is much less developed technologically. Not only is this realistic, it’s dramatic — it provides the GM with a lot of potential story and character hooks, all centered around the issue of why the differences exist. Do the Tech Level Theta regions actively oppress their neighbors, preventing technological development from occurring? Are those areas inhabited by two different species, with the more advanced imposing a technology embargo on itself to keep from interfering with the other? Has Kalidar IV historically been a haven for scientists and free thinkers, while Haroldson’s Planet persecutes them... or is Haroldson’s Planet a young colony on the fringes of the Galactic Commonwealth, whereas Kalidar IV is a Commonwealth core world?
     Nor do tech levels have to be uniform from one type of technology to another. Ordinarily advances in one field tend to lead to advances in other fields, so that technology progresses in a broadly uniform sort of way. But that’s not inevitable. A civilization could have, for example, Tech Level 15 computers and communications equipment, but only Tech Level 10 weapons. Again, the intriguing question is why this state of affairs exists. By considering and answering that question, the GM and players can develop the setting further, creating more opportunities for adventures and enjoyable characters.

Obsolete And Advanced Technology

     Often technologies introduced at an earlier tech level remain in use for long periods. Humans still use automatic pistols designed before 1900 (and still manufacture some, with minor improvements). Axes and hammers are among the earliest known tools, and are still available at the hardware store. In general, characters get no penalty using equipment from an earlier tech level. There are exceptions to this: some technologies become so obsolete that characters accustomed to a more advanced tech landscape are completely unfamiliar with them. Firemaking is a good example — until the invention of matches just about everyone could kindle a fire with flint and steel; now it’s something to study in wilderness-survival courses or historical reenactment workshops.

From STAR HERO by James Cambias and Steven S. Long (2002)

(ed note: our hero Jason dinAlt has been marooned on an old Terran colony which had fallen into a dark ages and is slowly climbing its way up the tech levels. Though they do have a regrettable tendency to do things in the most inefficient manner possible. There are various clans, each with a monopoly on some technological advance whose secret they guard with their lives.)

Here was one of the ĉaroj (Esperanto word for "car", "cart", or "chariot") that Ijale had told him about: there could be no doubt of it. He could now understand how, to her uneducated eye, there could exist an uncertainty as to whether the thing was an animal or not. The vehicle was a good ten meters long, and was shaped roughly like a boat; it bore on the front a large and obviously false animal head covered with fur, and resplendent with rows of carved teeth and glistening crystal eyes. Hide coverings and not very realistic legs were hung on the thing, surely not enough camouflage to fool a civilized six-year-old.

This sort of disguise might be good enough to take in the ignorant savages, but the same civilized child would recognize this as a vehicle as soon as he saw the six large wheels underneath. They were cut with deep treads and made from some resilient-looking substance. No motive power was visible, but Jason almost hooted with joy at the noticeable smell of burnt fuel. This crude-looking contrivance had some artificial source of power, which might be the product of a local industrial revolution, or might have been purchased from off-world traders.

A post projected from the front of the deck, and one of the men fitted what could only be a tiller handle over the squared top of it. If this monolithic apparatus steered with the front pair of wheels it must be driven with the rear ones, so Jason flopped around on the deck until he could look towards the stern. A cabin, the width of the deck, was situated here, windowless and with a single inset door fitted with a grand selection of locks and bolts. Any doubt that this was the engine room was dispelled by the black metal smokestack that rose up through the cabin roof.

'We are leaving," Edipon screeched, and waved his thin arms in the air. "Bring in the entranceway. Narsisi, stand forward to indicate the way to the ĉaroj. Now—all pray as I go into the shrine to induce the sacred powers to move us towards Putl'ko." He started towards the cabin, then stopped to point to one of the club bearers. "Erebo, you lazy sod, did you remember to fill the watercup of the gods this time, for they grow thirsty?"

"I filled it, I filled it," Erebo muttered, chewing on a looted kreno. Preparations made, Edipon went into the recessed doorway and pulled a concealing curtain over it. There was much clanking and rattling as the locks and bolts were opened and he let himself inside. Within a few minutes a black cloud of greasy smoke rolled out of the smokestack and was whipped away by the wind. Almost an hour passed before the sacred powers were ready to move, and they announced their willingness to proceed by screaming and blowing their white breath up in the air. Four of the slaves screamed counterpoint and fainted, while the rest looked as if they would be happier dead.

Jason had had some experience with primitive machines before, so the safety valve on the boiler came as no great surprise. From the amount of smoke and the quantity of steam escaping from under the stern he didn't think the engine was very efficient, but primitive as it was it moved the ĉaroj and its load of passengers across the sand at a creeping yet steady pace.

(ed note: at the destination Jason is harnessed to a sort of pump along with the rest of the slaves.)

Jason turned his attention to the crude mechanism they were powering. A vertical shaft from the capstan turned a creaking wooden wheel that set a series of leather belts in motion. Some of them vanished through openings into a large stone building, while the strongest strap of all turned the rocker arm of what could only be a counterbalanced pump. This all seemed like a highly inefficient way to go about pumping water, since there must be natural springs and lakes somewhere around. The pungent smell that filled the yard was hauntingly familiar, and Jason had just reached the conclusion that water couldn't be the object of their labors when a throaty gurgling came from the standpipe of the pump and a thick black stream bubbled out.

"Petroleum—of course!" Jason said out loud.

This was the secret of the d'zertanoj, and the source of their power. Here in this guarded valley they labored to pump the crude oil that their masters used to power their big desert wagons. Or did they use crude oil for this? The petroleum was gurgling out in a heavy stream now, and was running down an open trough that disappeared through the wall into the same building as the turning belts. What barbaric devilishness went on in there? A thick chimney crowned the building and produced clouds of black smoke, while from the various openings in the wall came a tremendous stench that threatened to lift the top off his head.

     It was time for the hard sell. "You had better hear me—because I know that what comes out first is best. (in oil refining, the first fluid that comes out is gasoline or petrol. The fluids that come next (kerosene, diesel, and fuel oil) are inferior to gasoline)
     Jason's words were without meaning to the slaves as well as to the overseer, but their impact on Edipon was as dramatic as if he had stepped on a hot coal. He shuddered to a halt and wheeled about, and even at this distance Jason could see that a sickly grey tone had replaced the normal brown color of his skin.
     "What was that you said?" He hurled the words at Jason while his fingers half plucked a knife from his belt.
     "You heard what I said—and I don't think you want me to repeat it in front of all these strangers. I know what happens here because I come from a place far away where we do this kind of thing all the time. I can help you. I can show you how to get more of the best, and how to make your ĉaroj work better. Just try me. Only unchain me from this bar first and let's get to some place private where we can have a nice chat."

     "Not at all. It is science, though many times confused as being the same thing. I'll prove my point. You know that I could never have been inside of your mysterious building out there, and I imagine you can be sure no one has told me its secrets. Yet I'll bet that I can describe fairly accurately what is in there—not from seeing the machinery, but from knowing what must be done to oil in order to get the products you need. You want to hear?"
     'Proceed," Edipon said, sitting on a corner of the table and balancing the knife loosely in his palm.

     "I don't know what you call it, the device, but in the trade it is a pot still used for fractional distillation. Your crude oil runs into a tank of some kind, and you pipe it from there to a retort, some big vessel that you can seal airtight. Once it is closed, you light a fire under the thing and try to get all the oil to an even temperature. A gas rises from the oil and you take it off through a pipe and run it through a condenser, probably more pipe with water running over it. Then you put a bucket under the open end of the pipe and out of it drips the juice that you burn in your ĉaroj to make them move."

     Edipon's eyes opened wider and wider while Jason talked, until they seemed almost bulging from his head. "Demon!" he screeched, and tottered towards Jason with the knife extended. "You couldn't have seen, not through stone walls. Only my family have seen, no others—I'll swear to that!"
     "Keep cool, Edipon. I told you that we have been doing this stuff for years in my country. I'm not out to steal your secrets. In fact, they are pretty small potatoes where I come from, where every farmer has a still for cooking up his own mash and saving on taxes. I'll bet I can even put in some improvements for you, sight unseen. How do you monitor the temperature on your cooking brew? Do you have thermometers?"
     "What are thermometers?" Edipon asked.

     "That's what I thought. I can see where your bootleg joy-juice is going to take a big jump in quality, if you have anyone here who can do some simple glass-blowing. Though it might be easier to rig up a coiled bi-metallic strip. You're trying to boil off your various fractions, and unless you keep an even and controlled temperature you are going to have a mixed brew. The thing you want for your engines are the most volatile fractions, the liquids that boil off first, like gasoline and benzene. After that you raise the temperature and collect kerosene for your lamps, and so forth right on down the line until you have a nice mass of tar left to pave your roads with. How does that sound to you?"

     Edipon had forced himself into calmness, though a jumping muscle in his cheek betrayed his inner tension. "What you have described is the truth, though you were wrong on some small things. But I am not interested in your thermometer nor in improving our water-of-power. It has been good enough for my family for generations and it is good enough for me."
     "I suppose you think that line is original?"

     "But there is something that you might be able to do that would bring you rich rewards," Edipon went on. "You have seen our ĉaroj and ridden on one, and seen me go into the shrine to intercede with the sacred powers to make us move. Can you tell me what power moves the ĉaroj?"
     "I hope this is the final exam, Edipon, because you are stretching my powers of extrapolation. Stripping away the 'shrines' and 'sacred powers,' I would say that you go into the engine room to do a piece of work with very little praying involved. There could be a number of ways of moving those vehicles, but let's think of the simplest. This is top of the head now, so no penalties if I miss any of the fine points. Internal combustion is out. I doubt if you have the technology to handle it, plus the fact there was a lot of do about the water tank and it took you almost an hour to get under way. That sounds as if you were getting up a head of steam—The safety valve! I forgot about that.
     "So it is steam. You go in, lock the door, of course, then open a couple of valves until the fuel drips into the firebox, then you light it. Maybe you have a pressure gauge, or maybe you just wait until the safety valve pops to tell you if you have a head of steam. Which can be dangerous, since a sticking valve could blow the whole works right over the mountain. Once you have the steam, you crack a valve to let it into the cylinders and get the thing moving. After that you just enjoy the trip, of course making sure that the water is feeding to your boiler all right, that your pressure stays up, your fire is hot enough, all your bearings are lubricated, and the rest…"

     "Do you know what you have done?" Edipon asked excitedly. "Do you know what you have said? I don't know if you are right or not; I have never seen the inside of one of the Appsalan devil-boxes. You know more about their—what do you call it?—engine, than I do. I have only spent my life tending them and cursing the people of Appsala who keep the secret from us. But you will reveal it to us! We will build our own engines, and if they want water-of-power they will have to pay dearly for it."

(ed note: Putl'ko has a monopoly on the creation of gasoline (water-of-power), but has no idea how the ĉaroj steam engines operate. The Appsalans have a monopoly on that.)

     "Look at them!" Eclipon exclaimed, and pulled at his nose. 'The finest and most beautiful of constructions, striking fear into our enemies' hearts, carrying us fleetly across the sands, bearing on their backs immense loads, and only three of the damned things are able to move."
     "Engine trouble?" Jason asked lightly.
     Edipon cursed and fumed under his breath, and led the way to an inner courtyard where stood four immense black boxes painted with death heads, splintered bones, fountains of blood, and cabalistic symbols, all of a sinister appearance.
     "Those swine in Appsala take our water-of-power and give nothing in return. Oh yes, they let us use their engines, but after running for a few months the cursed things stop and will not go again, then we must bring them back to the city to exchange for a new one, and pay again and again."

     "A nice racket," Jason said, looking at the sealed covering on the engines. "Why don't you just crack into them and fix them yourself? They can't be very complex."
     "That is death!" Edipon gasped. "We have tried that, in my father's father's day, for we are not superstitious like the slaves, and we know that these are man-made not god-made. However, the tricky serpents of Appsala hide their secrets with immense cunning. If any attempt is made to break the covering, horrible death leaks out and fills the air. Men who breathe the air die, and even those who are only touched by it develop immense blisters and die in pain. The men of Appsala laughed when this happened to our people, and after that they raised the price even higher."
     Jason circled one of the boxes, examining it with interest. The thing was higher than his head and almost twice as long. A heavy shaft emerged through openings on opposite sides, probably the power takeoff for the wheels. Through an opening in the side he could see inset handles and two small colored disks, and above these were three funnel-shaped openings painted like mouths. By standing on tiptoe, Jason could look on top, but there was only a flanged, sooty opening there that must be for attaching a smokestack. There was only one more opening, a smallish one in the rear, and no other controls on the garish container.

     "I'm beginning to get the picture, but you will have to tell me how you work the controls."
     "Death before that!" Narsisi shouted. "Only my family—"
     'Will you shut up!" Jason shouted back. "Remember? You're not allowed to browbeat the help any more. There are no secrets here. Not only that, but I probably know more about this thing than you do, just by looking at it. Oil, water, and fuel go in these three openings, you poke a light in somewhere, probably in that smoky hole under the controls, and open one of those valves for fuel supply; another one is to make the engine go slower and faster, and the third is for your water feed. The disks are indicators of some kind."
     "It is as you say," Edipon said. "The mouths must always be filled, and woe betide if they go empty; for the powers will halt, or worse. Fire goes in here, as you guessed, and when the green finger (pressure gage) comes forward this lever may be turned for motion (engage the gearbox). The next is for great speed, or for going slow (shifting from low gear to high gear). The very last is under the sign of the red finger, which when it points indicates need (low water in the boiler indicator), and the handle (boiler water feed) must be turned and held turned until the finger retires. White breath comes from the opening in back. That is all there is."

     "About what I expected," Jason muttered, and examined the container wall, rapping it with his knuckles until it boomed. "They give you the minimum of controls to run the thing, so you won't learn anything about the basic principles involved. Without the theory, you would never know what the handles control, or that the green indicator comes out when you have operating pressure, and the red one when the water level is low in the boiler. Very neat. And the whole thing sealed up in a can and booby-trapped in case you have any ideas of going into business for yourself. The cover sounds as if it is doublewalled, and from your description I would say that it has one of the (WARNING next two links have disturbing images. Vesicant means "blister agent" and they are not kidding) vesicant war gases, like mustard gas, sealed inside there in liquid form. Anyone who tries to cut their way in will quickly forget their ambitions after a dose of that. Yet there must be a way to get inside the case and service the engine; they aren't just going to throw them away after a few months' use. And considering the level of technology displayed by this monstrosity, I should be able to find the tricks and get around any other built-in traps. I think I'll take the job."

"Really primitive," Jason sneered, and he kicked at the boxful of clumsy hand-forged tools. The work was of the crudest, the product of a sort of neolithic machine age. The distilling retort (which separates gasoline from petroleum) had been laboriously formed from sheet copper and clumsily riveted together. It leaked mightily, as did the soldered seams on the hand-formed pipe. Most of the tools were blacksmith's tongs and hammers for heating and beating out shapes on the anvil. The only things that gladdened Jason's heart were the massive drill press and lathe that worked off the slave-power drive belts. In the tool holder of the lathe was clamped a chip of some hard mineral that did a good enough job of cutting the forged iron and low-carbon steel. Even more cheering was the screw-thread advance on the cutting head, which was used to produce the massive nuts and bolts that secured the ĉaroj wheels to their shafts.

     The concealing hood (covering the ĉaroj steam engine) was made of thin metal that could not hide many secrets. He carefully scratched away some of the paint and discovered a crimped and soldered joint where the sides met, but no other revealing marks. After some time spent tapping all over with his ear pressed to the metal, he was sure that the hood was just what he had thought it was when he first examined the thing: a double-walled metal container filled with liquid. Puncture it and you were dead. It was there merely to hide the secrets of the engine, and served no other function. Yet it had to be passed to service the steam engine—or did it? The construction was roughly cubical, and the hood covered only five sides. What about the sixth, the base?
     "Now you're thinking, Jason," he said to himself, and knelt down to examine it. A wide flange, apparently of cast iron, projected all around, and was penetrated by four large bolt holes. The protective casing seemed to be soldered to the base, but there must be stronger concealed attachments, for it would not move even after he carefully scratched away some of the solder at the base. Therefore the answer had to be on the sixth side.

     Jason dug channels beneath it and forced them under. When this was done he took turns with Mikah in digging out the sand beneath, until the engine stood over a pit, supported only by the poles. Jason let himself down and examined the bottom of the machine. It was smooth and featureless.
     Once more he scratched away the paint with careful precision, until it was cleared around the edges. Here the solid metal gave way to solder and he picked at this until he discovered that a piece of sheet metal had been soldered at the edges and fastened to the bedplate. "Very tricky, these Appsalanoj," he said to himself, and attacked the solder with a knife blade. When one end was loose he slowly pulled the sheet of metal away, making sure that there was nothing attached to it, and that it had not been booby-trapped in any way. It came off easily enough and clanged down into the pit. The revealed surface was smooth hard metal.

     The following morning, under the frightened gaze of his guards, Jason tackled the underside of the baseplate. He had been thinking about it a good part of the night, and he put his theories to the test at once. By pressing hard on a knife he could make a good groove in the metal. It was not as soft as the solder, but seemed to be some simple alloy containing a good percentage of lead. What could it be concealing? Probing carefully with the point of the knife, he covered the bottom in a regular pattern. The depth of the metal was uniform except in two spots where he found irregularities; they were on the midline of the rectangular base, and equidistant from the ends and sides. Picking and scraping, he uncovered two familiar-looking shapes, each as big as his head.
     "Why—big nuts, of course. Threaded on the ends of bolts. But they are so big…"
     "They would have to be if they hold the entire metal case on. I think we are getting very close now to the mystery of how to open the engine—and this is the time to be careful. I still can't believe it is as easy as this to crack the secret. I'm going to whittle a wooden template of the nut, then have a wrench made. While I'm gone you stay down here and pick all the metal off the bolt and out of the screw threads. We can think this thing through for a while, but sooner or later I'm going to have to take a stab at turning one of those nuts. And I find it very hard to forget about that mustard gas."

     Making the wrench put a small strain on the local technology, and all of the old men who enjoyed the title of Masters of the Still went into consultation over it. One of them was a fair blacksmith, and after a ritual sacrifice and a round of prayers he shoved a bar of iron into the charcoal and Jason pumped the bellows until it glowed white hot. With much hammering and cursing, it was laboriously formed into a sturdy open-end wrench with an offset head to get at the countersunk nuts. Jason made sure that the opening was slightly undersized, then took the untempered wrench to the work site and filed the jaws to an exact fit. After being reheated and quenched in oil he had the tool that he hoped would do the job.
     Edipon must have been keeping track of the work progress, for he was waiting near the engine when Jason returned with the completed wrench.
     "I have been under," he announced, "and have seen the nuts that the devilish Appsalanoj have concealed within solid metal. Who would have suspected! It still seems to me impossible that one metal could be hidden within another. How could that be done?"
     "Easy enough. The base of the assembled engine was put into a form and the molten covering metal poured into it. It must have a much lower melting point than the steel of the engine, so there would be no damage. They just have a better knowledge of metal technology in the city, and counted upon your ignorance."
     "What do you do next?"
     "I take off the nuts and when I do there is a good chance that the poison-hood will be released and can simply be lifted off."
     "It is too dangerous for you to do. The fiends may have other traps ready when the nut is turned. I will send a strong slave to turn them while we watch from a distance. His death will not matter."
     "I'm touched by your concern for my health, but as much as I would like to take advantage of the offer, I cannot. I've been over the same ground and reached the reluctant conclusion that this is one job of work that I have to do myself. Taking off those nuts looks entirely too easy, and that's what makes me suspicious. out for any more trickery at the same time—and that is something that only I can do. Now I suggest you withdraw with the troops to a safer spot."

     Jason spat on his palms, controlled a slight shiver, and slid into the pit. The wrench fitted neatly over the nut, he wrapped both hands around it, and, bracing his leg against the pit wall, began to pull.
     And stopped. Three turns of thread on the bolt projected below the nut, scraped clean of metal by the industrious Mikah. Something about them looked very wrong, though he didn't know quite what. But suspicion was enough.
     "Mikah," he shouted, "Nip over to the petroleum works and get me one of their bolts threaded with a nut—any size, it doesn't matter."
     Jason warmed his hands by the stove until Mikah returned with the oily bolt. Back in the pit, he held it up next to the protruding section of Appsalan bolt and almost shouted with joy. The threads on the engine bolt were canted at a slightly different angle: where one ran up, the other ran down. The Appsalan threads had been cut in reverse, with a left-hand thread.
     Throughout the galaxy there existed as many technical and cultural differences as there were planets, but one of the few things they all had in common, inherited from their terrestrial ancestors, was a uniformity of thread. Jason had never thought about it before, but when he mentally ran through his experiences on different planets he realized that they were all the same. Screws went into wood, bolts went into threaded holes, and nuts all went onto bolts when you turned them with a clockwise motion. Counterclockwise removed them. In his hand was the crude d'zertano nut and bolt, and when he tried it it moved in the same manner. But the engine bolt did not: it had to be turned clockwise to remove it.

     Dropping the nut and bolt, he placed the wrench on the massive engine bolt and slowly applied pressure in what felt like the completely wrong direction—as if he were tightening, not loosening. It gave slowly, first a quarter-turn, then a half-turn. Bit by bit the projecting threads vanished, until they were level with the surface of the nut. It turned easily now, and within a minute it fell into the pit. He threw the wrench after it and scrambled out. Standing at the edge, he carefully sniffed the air, ready to run at the slightest smell of (poison) gas. There was nothing.
     The second nut came off as easily as the first, and with no ill effects. Jason pushed a sharp chisel between the upper case and the baseplate where he had removed the solder, and when he leaned on it the case shifted slightly, held down only by its own weight.

     "There is still the little matter of taking it off," he told them, "and I'm sure that grabbing and heaving is the wrong way. That was my first idea, but the people who assembled that thing had some bad trouble in store for anyone who tightened those nuts instead of loosening them. Until we find out what that is, we are going to tread very lightly. Do you have any big blocks of ice around here, Edipon? It is winter now, isn't it?"
     "Ice? Winter?" Edipon mumbled, "Of course it is winter. But what do you want ice for?"
     "You get it and I'll show you. Have it cut in nice flat blocks that I can stack I'm not going to lift off the hood—I'm going to drop the engine out from underneath it!"
     By the time the slaves had brought the ice down from the distant lakes Jason had rigged a strong wooden frame flat on the ground around the engine and pushed sharpened metal wedges under the hood; then he had secured the wedges to the frame. Now, if the engine was lowered into the pit, the hood would stay above, supported by the wedges. The ice would take care of this. Jason built a foundation of ice under the engine and then slipped out the supporting bars. As the ice slowly melted, the engine would be gently lowered into the pit.
     The weather remained cold, and the ice refused to melt until Jason had the pit ringed with smoking oil stoves. Water began to run down into the pit and Mikah went to work bailing it out, while the gap between the hood and the baseplate widened. The melting continued for the rest of the day and almost all of the night. Red-eyed and exhausted, Jason and Mikah supervised the soggy sinking, and when the d'zertanoj returned at dawn the engine rested safely in a pool of mud on the bottom of the pit: the hood was off.

     "They're tricky devils over there in Appsala, but Jason dinAlt wasn't born yesterday," he exulted. "Do you see that crock sitting there on top of the engine?" He pointed to a sealed container of thick glass, the size of a small barrel, filled with an oily greenish liquid; it was clamped down tightly with padded supports. "That's the booby-trap. The nuts I took off were on the threaded ends of two bars that held the hood on, but instead of being fastened directly to the hood they were connected by a crossbar that rested on top of that jug. If either nut was tightened instead of being loosened the bar would have bent and broken the glass. I'll give you exactly one guess as to what would have happened then."
     "The poison liquid!"
     "None other. And the double-walled hood is filled with it too. I doubt if the engine has many other surprises in store, but I'll be careful as I work on it."

     "You can fix it? You know what is wrong with it?" Edipon was trembling with joy.
     "In fact, one look was enough to convince that the job will be as easy as stealing krenoj from a blind man. The engine is as inefficient and clumsy in construction as your petroleum still. If you people put one tenth of the energy into research and improving your product as you do into hiding it from the competition, you would all be flying jets."
     The first engine proved to have a burnt-out bearing and Jason rebuilt it by melting down the original bearing metal and casting it in position. When he unbolted the head of the massive single cylinder he shuddered at the clearance around the piston; he could fit his fingers into the opening between the piston and the cylinder wall. By introducing cylinder rings, he doubled the compression and power output. When Edipon saw the turn of speed the rebuilt engine gave his ĉaroj, he hugged Jason to his bosom and promised him the highest reward. This turned out to be a small piece of meat every day to relieve the monotony of the kreno meals, and a doubled guard to make sure that his valuable property did not escape.

     Jason went out past the still silent sentry and headed back towards the refinery station. Instead of a club or a dagger, he was armed with a well-tempered broadsword that he had managed to manufacture under the noses of the guards. They had examined everything he brought from the worksite, since he had been working in the evenings in his room, but they ignored everything he manufactured as being beyond their comprehension. This primordial mental attitude had been of immense value, for in addition to the sword he carried a sack of molotails, a simple weapon of assault whose origin was lost in pre-history. Small crocks were filled with the most combustible of the refinery's fractions and were wrapped around with cloth that he had soaked in the same liquid. The stench made him dizzy, and he hoped that they would repay his efforts when the time came. He could only hope, for they were completely untried. In use, one lit the outer covering and threw them. The crockery burst on impact and the fuse ignited the contents. Theoretically.

(ed note: Jason escapes with his companions, helped by a slave who is a former mercenary. As fitting his profession, the mercenary proves to be very mercenary and betrays Jason to be captured by the Perssonoj clan. )

     "But they aren't getting my hand-made, super-charged steamobile!" he added with sudden vehemence, snatching up the crossbow. "Back, both of you, far back. They'll make a slave of me for my talents, but no free samples go with it. If they want one of these hot-red steam wagons they are going to have to pay for it!"
     Jason lay down fiat at the maximum range of the crossbow and his third quarrel hit the boiler. It went up with a most satisfactory bang and small pieces of metal and wood rained down all around. In the distance he heard shouting and the barking of dogs.

     (the mercenary said) "I have fought for the Perssonoj and they knew me, and I saw the Hertug himself and he believed me. The Perssonoj (clan) are very powerful in Appsala and have many powerful secrets, but they are not as powerful as the Trozelligoj (clan), who have the secret of the ĉaroj and the jetilo. I knew I could ask any price of the Perssonoj if I brought them the secret of the ĉaroj."

(Jason and companions are placed in the hold of a seagoing ship with the other slaves, and the ship sails to the big city Appsala containing all the warring clans. Jason watches through a knot-hole and gives sarcastic commentary)

     "Our voyage is nearing its close, and before us opens up the romantic and ancient city of Appsala, famed for its loathsome customs, murderous natives, and archaic sanitation facilities, of which the watery channel this ship is now entering seems to be the major cloaca. There are islands on both sides, the smaller ones covered with hovels so decrepit that in comparison the holes in the grounds of the humblest animals are as palaces, while the larger islands seem to be forts, each one walled and barbicaned, and presenting a warlike face to the world. There couldn't be that many forts in a town this size, so I am led to believe that each one is undoubtedly the guarded stronghold of one of the tribes, groups, or clans that our friend Judas told us about. Look on these monuments to ultimate selfishness and beware: this is the end product of the system that begins with slaveholders like the former Ch'aka with their tribes of kreno crackers, and builds up through familial hierarchies like the d'zertanoj, and reaches its zenith of depravity behind those strong walls. It is still absolute power that rules absolutely, each man out for all that he can get, the only way to climb being over the bodies of others, and all physical discoveries and inventions being treated as private and personal secrets to be hidden and used only for personal gain. Never have I seen human greed and selfishness carried to such extremes, and I admire Homo sapiens' capacity to follow through on an idea, no matter how it hurts."

     "But I must first know what is the specialty of your clan, if you know what I mean. For instance, the Trozelligoj make motors, and the d'zertanoj pump oil: what do your people do?"
     The Hertug thumped his chest. "We can talk across the width of the country, and always know where our enemies are. We can send magic to make light in a glass ball, or magic that will pluck the sword from an enemy's hand and drive terror into his heart."
     "It sounds as if your gang has the monopoly on electricity, which is good to hear. If you have some heavy forging equipment—"
     "Stop!" the Hertug interrupted. "Leave! Not the new slave, he stays here," he shouted when the soldiers seized Jason. The Hertug spoke to him again. "You used a sacred word. Who told it to you? Speak quickly, or you will be killed."
     "Didn't I tell you I knew everything? I can build a ĉaroj and, given a little time, I can improve on your electrical works, if your technology is on the same level as the rest of this planet."

     "Do you know what lies behind the forbidden portal?" the Hertug asked, pointing to a barred, locked, and guarded door at the other end of the room. "There is no way you can have seen what is there, but if you can tell me what lies beyond it I will know you are the wizard that you claim you are."
     "I have a very strange feeling that I have been over this ground once before." Jason sighed. "All right, here goes. You people here make electricity, maybe chemically, though I doubt if you would get enough power that way, so you must have a generator of some sort. That will be a big magnet, a piece of special iron that can pick up other iron, and you spin wire around fast next to it, and out comes electricity. You pipe this through copper wire to whatever devices you have—and they can't be very many. You say you talk across the country. I'll bet you don't talk at all, but send little clicks—I'm right, am I not?" The foot shuffling and the rising buzz from the adepts were sure signs that he was hitting close.
     "I have an idea for you: I think I'll invent the telephone. Instead of the old clickety-clack, how would you like to really talk across the country? Speak into a gadget here, and have your voice come out at the far end of the wire?"
     The Hertug's piggy little eyes blinked greedily. "It is said that in the old days this could be done, but we have tried and have failed. Can you do this thing?"
     "I can—if we can come to an agreement first. But before I make any promises I have to see your equipment."

     This brought mutters of complaint about secrecy, but in the end avarice won over taboo and the door to the holy of holies was opened for Jason. It was all Jason could do to keep himself from breaking into contemptuous laughter.
     A rotating shaft—undoubtedly slave-powered—entered the large chamber through the far wall and turned a ramshackle collection of belts and pulleys that eventually hooked up to a crude and ugly machine that rattled and squeaked and shook the floor under their feet. At first sight it baffled Jason, until he examined its components and realized what it was.
     "What else should I have expected?" he said to himself. "If there are two ways of doing anything, leave it to these people to use the worst one."
     The final, cartwheel-sized pulley was fixed to a wooden shaft that rotated at an impressive speed, except when one of the belts jumped out of place, which was something that occurred with monotonous regularity. This happened while Jason was watching, and the shaft instantly slowed so that he could see that iron rings studded with smaller, U-shaped pieces of iron, were fixed all along its length. These were half hidden inside a birdcage of looped wires that was suspended about the shaft. The whole thing looked like an illustration from a bronze age edition of First Steps in Electricity.

     "Does not your soul cringe in awe before these wonders?" the Hertug asked, noticing Jason's dropped jaw and glassy eye.
     "It cringes all right," Jason told him. "But only in pain from that ill-conceived collection of mechanical misconceptions."
     "Blasphemer!" the Hertug shrieked. "Slay him!"
     "Wait a minute!" Jason said, holding tight to the dagger arms of the two nearest sciuloj and interposing their bodies between his body and the others' blades. "Don't misunderstand. That's a great generator you have there, a seventh wonder of the world—though most of the wonder is how it manages to produce any electricity. A tremendous invention, years ahead of its time. However, I might be able to suggest a few minor modifications that would produce more electricity with less work. I suppose that you are aware that an electric current is generated in a wire when a magnetic field is moved across it?"
     "I do not intend to discuss theology with a non-believer," the Hertug said coldly.
     "Theology or science, call it what you will, the answers still come out the same. But did you ever stop to think that you could get an electrical current just as easily by moving the wire through the magnetic field, instead of the other way around? You can get the same current flow that way with about a tenth of the work."
     "We have always done it this way, and what was good enough for our ancestors—"
     "I know, I know, don't finish the quote. I seem to have heard it before on this planet."

     With the threat removed for the moment, Jason examined the large, ungainly apparatus that filled the far end of the room, this time making some attempt to control his horrified reactions. "I suppose that yon sacred wonder is your holy telegraph?"
     "None other," the Hertug said reverently. Jason shuddered.
     Copper wires came down from the ceiling above and terminated in a clumsily wound electromagnet positioned close to the flat iron shaft of a pendulum. When a current surged through the electromagnet it would attract the shaft; and when the current was turned off, the weight on the end of the pendulum would drag it back to somewhere near the vertical. A sharp metal scriber was fixed to the bottom of the weight, and the point of the scriber was dug into the wax coating of a long strip of copper. This strip ran in grooves so that it moved at right angles to the pendulum's swing, dragged forward by a weight-powered system of meshed wooden gears.
     While Jason watched, the rattling mechanism jerked into motion. The electromagnet buzzed, the pendulum jerked, the needle drew an incision across the wax, the gears squeaked, and the cord fastened to a hole in the end of the strip began to draw it forwards. Attentive sciuloj stood ready to put another wax-coated strip into position when the first one was finished.
     Close by, completed message strips were being made legible by pouring red liquid over them. This ran off the waxen surface but was trapped by the needle-scratched grooves. A shaky red line appeared running the length of the strips, with V-shaped extensions wherever the scribing needle had been deflected. These were carried to a long table where the coded information was copied off onto slates. Everything considered, it was a slow, clumsy, inept method of transmitting information. Jason rubbed his hands together.

     "Oh, Hertug of all the Perssonoj," he intoned, "I have looked on your holy wonders and stand in awe, indeed I do. Far be it for a mere mortal to improve on the works of the gods, at least not right now, but it is within my power to pass on to you certain other secrets of electricity that the gods have imparted to me."
     "Such as what?" the Hertug asked, eyes slitted.
     "Such as the—let's see, what is the Esperanto word for it—such as the akumulatoro (Esperanto for "accumulator"). Do you know of this?"
     "The word is mentioned in some of the older holy writings, but that is all we know of it." The Hertug was licking his lips now.
     "Then get ready to add a new chapter, because I'm going to provide you with a Leyden jar, free and gratis, along with complete instructions on how to make more. This is a way of putting electricity in a bottle, just as if it were water (capacitor). Then later we can go on to more sophisticated batteries. I'll need some special materials that I don't see here. A wide-mouthed glass jar and a good supply of tin."

     In theory, a Leyden jar is simple enough to manufacture—if all the materials are on hand. Getting the correct materials was Jason's biggest problem. The Perssonoj did no glass blowing themselves, but bought everything they needed from the Vitristoj clan, who labored at their secret furnaces. These glass blowers produced a few stock-size bottles, buttons, drinking glasses, knobby plate glass, and half a dozen other items. None of their bottles could be adapted to this use, and they were horrified at Jason's suggestion that they produce a new bottle to his specifications. The offer of hard cash drained away most of their dismay, and after studying Jason's clay model they reluctantly agreed to produce a similar bottle for a staggering sum. The Hertug grumbled mightily, but finally he paid over the required number of stamped and punctured gold coins strung on a wire.
     "Have faith, and all will be well," Jason reassured him, and he returned to browbeating the metal workers, who suffered as they tried to hammer sheet tin into thin foil.
     "It has arrived," the Hertug announced, and he and all the sciuloj stood around mumbling suspiciously while the wrappings were removed from the glass jar.
     "Not too bad," Jason said, holding it up to the light to see how thick the sides were. "Except that this is the large twenty-liter economy size—about four times as big as the model I sent them."
     "For a large price a large jar," the Hertug said. "That is only right. Why do you complain? Do you fear failure?"
     "I fear nothing. It's just a lot more trouble to build a model this size. It can also be dangerous; these Leyden jars can take quite a charge."

     Ignoring the onlookers, Jason coated the jar inside and out with his lumpy tinfoil, stopping about two-thirds of the way up from the bottom. He then whittled a plug from guini, a rubber-like material that had good insulating qualities, and drilled a hole through it. The Perssonoj watched, mystified, as he pushed an iron rod through this hole, then attached a short iron chain to the longer end, and fixed a round iron ball to the shorter.
     "Finished," he announced.
     "But—what does it do?" the Hertug asked, puzzled.
     "I demonstrate." Jason pushed the plug into the wide mouth of the jar so that the chain rested on the inner lining of tinfoil. He pointed to the ball that projected from the top. "This is attached to the negative pole of your generator; electricity flows down through the rod and chain and is collected on the tin lining. We run the generator until the jar is full, then disconnect the input. The jar will then hold an electrical charge that we can draw off by hooking up to the ball. Understand?"
     "Madness!" one of the older sciuloj cackled, and averted the infection of insanity by rotating his forefinger next to his temple.
     "Wait and see," Jason said, with a calmness he did not feel. He had built the Leyden jar from a dim memory of a textbook illustration studied in his youth, and there was no guarantee the thing would work. He grounded the positive pole of the generator, then did the same with the outer coating of the jar by running a wire from it to a spike driven down through a cracked floor tile into the damp soil below.
     "Let her roll!" he shouted and stepped back, arms folded.
     The generator groaned and rotated, but nothing visible happened. He let it go on for several minutes, since he had no idea of its output or of the jar's capacity, and a lot depended on the results of this first experiment. Finally the sneering asides of the sciuloj grew louder, so he stepped forward and disconnected the jar with a flip of a dry stick.
     "Stop the generator; the work is done. The akumulatoro is filled brimful with the holy force of electricity." He pulled over the demonstration unit he had prepared, a row of the crude incandescent light bulbs wired in series. There ought to be enough of a charge in the Leyden jar to overcome the weak resistance of the carbon filaments and light them up. He hoped.

     "Blasphemy!" screeched the same elderly sciulo, shuffling forward. "It is sacred writ that the holy force can only flow when the road is complete, and when the road of flow is broken no force shall move. Yet this outlander dares tell us that holiness now resides in this jar to which but one wire was connected. Lies and blasphemy!"
     "I wouldn't do that if I were you…" Jason suggested to the oldster, who was now pointing to the ball on top of the Leyden jar.
     "There is no force here-there can be no force here…" His voice broke off suddenly as he waved his finger an inch from the ball. A fat blue spark snapped between his fingertip and the charged metal, and the sciulo screamed hoarsely and dropped to the floor. One of his fellows knelt to examine him, then turned his frightened gaze to the jar.
     "He is dead," he breathed.
     "You can't say I didn't warn him," Jason said, then decided to press hard while luck was on his side. "It was he who blasphemed!" Jason shouted, and the old men cringed away. "The holy force was stored in the jar, and he doubted and the force struck him dead. Doubt no more, or you will all meet the same fate! Our work as sciuloj," he added, giving himself a promotion from slavery, "is to harness the powers of electricity for the greater glory of the Hertug. Let this be a reminder, lest we ever forget." They eyed the body, shuffled backwards, and got the idea very clearly.
     "The holy force can kill," the Hertug said, smiling down at the corpse and dry-washing his hands. "This is indeed wonderful news. I always knew it could give shocks and cause burns, but never knew it held this great power. Our enemies will shrink before us."

     “When will this be completed?” the Hertug asked, poking at the parts spread over Jason’s workbench.
     “Tomorrow morning, though I work all night, oh Hertug. But even before it is finished I have another gift for you, a way to improve your telegraph system.”
     “It needs no improvement! It is as it was in our forefathers’ days, and—”
     “I’m not going to change anything; forefathers always know best, I agree. I’ll just give you a new operating technique. Look at this—” and he held out one of the metal strips with the scribed wax coating. “Can you read the message?”
     “Of course, but it takes great powers of concentration, for it is a deep mystery.”
     “Not that deep; in one look I divined all its horrible simplicity.”
     “You blaspheme!”
     “Not really. Look here: that’s a B, isn’t it—two jiggles from the magic pendulum?”
     The Hertug counted on his fingers. “It is a B, you are correct. But how can you tell?”
     Jason concealed his scorn. “It was hard to figure out, but all things are as an open book to me. B is the second letter in the alphabet, so it is coded by two strokes. C is three—still easy; but you end up with Z, needing twenty-six bashes at the sending key, which is just a nonsensical waste of time. When all you have to do is modify your equipment slightly in order to send two different signals—let’s be original and call one a ‘dot’ and the other a ‘dash.’ Now, using these two signals, a short and a long impulse, we can transcribe every letter of the alphabet in a maximum of four increments. Understand?”
     “There is a buzzing in my head, and it is difficult to follow…”
     “Sleep on it. In the morning my invention will be finished, and at that time I will demonstrate my code.”
     The Hertug left, muttering to himself, and Jason finished the last windings on the armature for his new generator.

     “What do you call it?” the Hertug asked, walking around the tall, ornate wooden box.
     “This is an All Hail the Hertug Maker, a new source of worship, respect, and finance for Your Excellency. It is to be placed in the temple, or your local equivalent, where the public will pay for the privilege of doing you homage. Observe: I am a loyal subject who enters the temple. I give a donation to the priest and grasp this handle that projects from the side, and turn.” He began cranking lustily and the sound of turning gears and a growing whine came from the cabinet. “Now watch the top.”
     Projecting from the upper surface of the cabinet were two curved metal arms that ended in copper spheres separated by an air space. The Hertug gasped and recoiled as a blue spark snapped across the gap.
     “That will impress the peasants, won’t it?” Jason said. “Now—observe the sparks and notice their sequence. First three short sparks, then three long ones, then three short ones again.”
     He stopped cranking and handed the Hertug a clearly inscribed sheet of vellum, a doctored version of the standard interstellar code. “Notice. Three dots stand for H and three dashes signify A. Therefore as long as this handle is turned the machine sends out H.A.H. in code, signifying Huraoj al Heriug, All hail the Hertug! An impressive device that will keep the priests busy and out of mischief and your loyal followers entertained. While at the same time it will cry your praises with the voice of electricity, over and over, night and day.”
     The Hertug turned the handle and watched the sparks with glowing eyes. “It shall be unveiled in the temple tomorrow. But there are sacred designs that must be inscribed on it first. Perhaps some gold…”
     “Jewels too, the richer—looking the better. People aren’t going to pay to work a holy hand-organ unless it looks impressive.”
     Jason listened happily as the sparks crackled out. They might be saying H.A.H. in the local code, but it would be S.O.S. to an offworlder. And any spaceship with a decent receiver that entered the atmosphere of this planet should pick up the broad-spectrum radio waves from the spark gap. There might even be one hearing the message now, turning the loop of the direction finder, zeroing in on the signal. If he only had a receiver he could hear their answering message, but it didn’t matter, for shortly he would hear the roar of their rockets as they dropped on Appsala.

(ed note: predictably Jason is kidnapped by another clan)

     "Silence! Death is at hand!"
     "Ekskremento!" (Esperanto for "excrement") Jason sneered. "Your masks and threats are of about the same quality as those of the desert slavers. Let's get down to facts. You have been collecting rumors about me and they have got you interested. You have heard about the supercharged ĉaroj, and spies have told you about the electronic prayer wheel in the temple—maybe more. It all sounded so good that you wanted me for yourselves, and you tried the foolproof Appsalan dodge of a little money in the right places. And here I am."
     "Do you know to whom you talk?" the masked figure on the far right asked in a high-pitched, shaking voice. Jason examined the speaker carefully.
     "The Mastreguloj? I've heard about you. You are supposed to be the witches and warlocks of this town, with fire that burns in water, smoke that will burn the lungs, water that will burn the flesh, and so forth. My guess is that you are the local equivalents of chemists; and though there aren't supposed to be very many of you, you are nasty enough to keep the other tribes frightened."
     "Do you know what this contains?" the man asked, holding up a glass sphere with some yellowish liquid in it.
     "I don't know, and I couldn't care less."
     "It contains the magic burning water that will sear you and char you in an instant if it touches—"
     "Oh, come off it! There's nothing in there but some common acid, probably sulphuric, because the other acids are made from it, and there is also the strong clue of rotten egg reek that fills this room."
     "Die!" the man shrieked, and hurled a glass sphere at Jason's head.
     "Thanks," Jason said, catching the thing neatly in midair with his free hand. He slipped it inside his clothes as he pulled the door open.

     "Your trusted captain sold you out to the competition, who wanted me to work for them, but I didn't accept. I didn't think too much of their outfit and I left before they got around to making an offer. But I brought a sample back with me." Jason pulled out the glass sphere of acid and the guards dropped back, screaming, and even the Hertug went white.
     "The burning water!" he gasped.
     "Exactly. And as soon as I get some lead it is going to become part of the wet cell battery I was busy inventing."

     "How would you like to own all that?" Jason asked.
     "Speak on." The Hertug's little eyes glittered.
     "I mentioned this before, but now I mean it—seriously. I am going to reveal to you every secret of every other clan on this damned planet. I'm going to show you how the d'zertanoj distill oil, how the Mastreguloj make sulphuric acid, how the Trozelligoj build engines. Then I'm going to improve your weapons of war, and introduce as many new ones as I can. I will make war so terrible that it will no longer be possible. Of course it will still go on, but your troops will always win. You'll wipe out the competition, one by one, starting with the weakest ones, until you will be the master of this city, then of the whole planet. The riches of a world will be yours, and your evenings will be enlivened by the horrible deaths you will mete out to your enemies. What do you say?"

     But he had very little time to notice it, for he was working long hours at both research and production, a constantly exhausting task. Pure research and production development were expensive, and when the bills mounted too high the Hertug scratched in his beard and mumbled about the good old days. Then Jason had to drop everything and produce a fresh miracle or two. The arc light was one; then the arc furnace, which helped with the metallurgical work and made the Hertug very happy, particularly when he found out how good it was for torture and fed a captured Trozelligo into it until he told them what they wanted to know. When this novelty palled, Jason introduced electroplating, which helped fill the treasury both through jewelry sales and counterfeiting.
     After opening the Mastreguloj glass sphere with elaborate precautions, Jason satisfied himself that it did contain sulphuric acid, and he constructed a heavy, but effective, storage battery. Still angry over the kidnapping, he led an attack on a Mastreguloj barge and captured a large supply of acid, as well as assorted other chemicals. These he was testing whenever he had the time. He had followed a number of dead-end trails, but had been forced to abandon them. The formula for gunpowder escaped him, and this depressed him, though it cheered his assistants who had been raking through old manure piles for supplies of saltpeter.
     He had more success with ĉaroj and steam engines, because of previous experience, and developed a lightweight, sturdy marine engine. In his spare moments he invented movable type, the telephone, and the loudspeaker—which, with the addition of the phonograph record, did wonders for the religious revenue in production of spirit voices. He also made a naval propeller to go with his engine, and was busily perfecting a steam catapult. For his own pleasure he had set up a still in his rooms, with which he manufactured a coarse but effective brandy.
     "All in all, things aren't going too badly," he said, lolling back in his upholstered easy chair and sipping a glass of his latest and best. It had been a warm day, and more than a bit choking with the effluvia that rose from the canals, but now the evening sea breeze was cool and sweet as it blew in through the open windows. Under his belt was a fine steak, cooked on a charcoal grill of his own invention, served with mashed krenoj and bread baked from flour ground in his recently invented mill. Ijale was singing in the kitchen as she cleaned up, and Mikah was industriously running a brush through the pipes of the still, clearing away the dregs of the last batch.
     "Look, we have here a static culture that is never going to change without a large charge of explosive put in the proper place. That's me. As long as knowledge is classified as an official secret, there will be no advance. There will probably be slight modifications and improvements within these clans as they work on their specialties, but nothing of any vital importance. I'm ruining all that. I'm letting our Hertug have the information possessed by every other tribe, plus a lot of gadgets they don't know about yet. This destroys the normal check and balance that keeps these warring mobs roughly equal, and if he runs his war right—meaning my way—he can pick them off one by one…"

     Because the steam engine and propeller had already been installed in a ship and tested inside the sea gate, finishing the warship did not take very long. It was mostly a matter of bolting on the iron plates he had designed to shield it down to the waterline. The plating was thicker at the bow, and he saw to it that heavier internal bracing was installed. At first he had thought to install the steam catapult on the warship, but then had decided against it. A simpler way was better. The catapult was fitted into a large, flat-bottomed barge, along with the boiler, tanks of fuel, and a selection of carefully designed missiles.
     First came the warship, the "Dreadnaught," with Jason and the Hertug on its armored bridge; this towed the barge. In line astern were a great variety of vessels of all sizes, loaded with the troops. The entire city knew what was happening and the canals were deserted, while the Trozelligoj fortress was sealed, barred, and waiting. Jason let go a blast of the steam whistle, well out of arrow range of the enemy walls, and the fleet reluctantly halted.
     "Why don't we attack?" the Hertug asked.
     "Because we have them in range, while they can't reach us. See." Immense, iron-headed spears plunged into the water a good thirty meters from the bow of the ship.
     "Jetilo (Esperanto for "throw" or "cast") arrows." The Hertug shuddered. "I've seen them pass through the bodies of seven men without being slowed."
     "Not this time. I'm about to show you the glories of scientific warfare."

     The fire from the jetiloj was no more effective than the shouting soldiers on the walls who were clashing swords on shields and hurling curses, and it soon stopped. Jason transferred to the barge and saw that it was anchored firmly, pointing its bow directly at the fortress. While the steam pressure was building up, he aimed the centerline of the catapult and took a guess at the elevation.
     The device was simple, but powerful, and he had high hopes for it. On the platform, which could be rotated and elevated, was mounted a single large steam cylinder with its piston connected directly to the short arm of a long lever. When steam was admitted to the cylinder, the short but immensely powerful stroke of the piston was turned by mechanical advantage into flailing speed at the far end of the arm. This whipped up and crashed into a padded crossarm and was stopped, but whatever load was placed in the cup on the end of the arm went speeding off through the air. The mechanism had been tested and worked perfectly, though no shots had yet been fired.
     "Full pressure," Jason called out to his technicians. "Load one of the stones into the cup." He had prepared a variety of missiles, all of them weighing the same in order to simplify ranging problems. While the weapon was being loaded he checked the flexible steam lines once more: they had been the hardest thing to manufacture, and they still had a tendency to leak under pressure and continued use.
     "Here goes!" he shouted, and pulled down on the valve.
     The piston drove out with a satisfactory speed, the arm whipped up and crashed resoundingly into the stop-while the stone went whistling away, a dwindling dot. All the Perssonoj cheered. But the cheering stopped when the stone kept on going, clearing the topmost turret of the keep by a good fifty meters, and vanished on the other side. The Trozelligoj burst into raucous cheering of their own when it splashed harmlessly into the canal on the far side.
     "Just a ranging shot," Jason said offhandedly. "A little less elevation and I'll drop one like a bomb into their courtyard."
     He cracked the exhaust valves and gravity drew the long arm back to the horizontal, at the same time returning the piston for the next shot. Jason carefully shut the valve and cranked on the elevation wheel. A stone was loaded and he fired again.
     This time only the Trozelligoj in the fortress cheered as the stone mounted almost straight up, then dropped to sink one of the attacking boats less than fifty meters from the barge.
     "I do not think much of your devilish machine," the Hertug said. He had come back to watch the firing.
     "There are always field problems," Jason answered through tight lips. "Just watch the next shot." He decided to abandon any more attempts at fancy high trajectories, and to let fly head-on, for the machine was far more powerful than he had estimated. Cranking furiously on the elevation wheel, he raised the rear of the catapult until the stone would leave the cup almost parallel with the water.
     "This is the shot that tells," he announced with much more conviction than he felt, and crossed the fingers of his free hand as he fired. The stone hummed away and hit just below the top of the crenellated wall. It blasted out a great chunk of masonry and utterly demolished the soldiers who had been standing there. There were no more cheers heard from the besieged Trozeliigoj.

     "They cower in fear!" the Hertug screamed exultantly. "Attack!"
     "Not quite yet." Jason explained patiently. "You're missing the whole point of siege weapons. We do as much damage to them as we can before attacking—it helps the odds." He gave the aiming wheel a turn and the next missile bit a piece out of the wall further along. "And we change ammunition too, just to keep them on the jump."
     When the stones had worked along the wall and were beginning to tear holes in the main building, Jason raised the sights a bit. "Load on a special," he ordered. These were oil-soaked bundles of rags weighted with stones and bound about with ropes.
     When the special was seated in the cup he ignited it himself and did not shoot until it was burning well. The rapid journey through the air fanned it into a roaring blaze that burst expansively on the thatched roof of the enemy keep, which began immediately to crackle and smoke. "We'll try a few more of those," Jason said, happily rubbing his hands together.

     When Jason reached the bridge of the "Dreadnaught" he saw that the clumsy-looking Trozelligoj side-wheeler had thrashed through the sea gate and was heading directly towards them. Jason had heard blood chilling descriptions of this powerful weapon of destruction, and he was pleased to see that it was just a ramshackle and unarmored vessel, as he had expected. "Full speed ahead," he bellowed into the speaking tube, and took the wheel himself.
     The ships, head-on to each other, closed rapidly, and spears from the jetiloj, the oversize crossbows, rattled off the "Dreadnaught's" armor plate and splashed into the water. They did no harm and the two vessels still rushed towards each other on a collision course. The sight of the low, beetle-like and smoke-belching form of the "Dreadnaught" must have shaken the enemy captain, and he must have realized that collision at this speed could not do his ship much good, for he suddenly turned the ship away. Jason spun the wheel to follow the other, and kept his bow aimed at the ship's flank.
     "Brace yourselves—we're going to hit!" he shouted as the high dragon prow of the other ship flashed past, frightened faces at the rail. Then the metal ram of the "Dreadnaught's" bow hit squarely in the middle of the dripping boards of the port paddle wheel and crashed on deep into the ship's hull. The shuddering impact hurled them from their feet as the "Dreadnaught" slammed to a stop.
     "Reverse engines so we can pull free!" Jason ordered, and spun the wheel hard over.

     Jason transferred to the barge and planted some of the fire-bomb specials on the roof to keep the fire roaring. He followed these with half a dozen rounds of canister shotleather bags of fist-sized stones that burst when fired—and cleared away all the firefighters and soldiers who were foolish enough to expose themselves. Then he worked the heavy stones back along the wall, crumbling it even more, until his hurtling missiles reached the sea gate. It took just four shots to batter the heavy timber into splinters and leave the gates a sagging wreck. The way was open. Jason waved his arms and jumped for the boat. The whistle screamed three times and the waiting Perssonoj vessels began to move to the attack.

From DEATHWORLD 2 by Harry Harrison (1964)

(ed note: The protagonists are forced to land on a random asteroid and barely escape from their spacecraft before the malfunctioning atomic drive melts the entire ship into slag. As they explore the asteroid desperately trying to find a way to survive, they stumble over an ancient alien spacecraft of remarkably similar design to their lost ship. Unfortunately they find out the hard way that similar is not the same as identical, and tiny differences can have catastrophic consequences.)

"Why shouldn’t I be able to understand the drive?" retorted Cray. "It should he like ours, only a little more primitive—depending on how long this boat's been here.”

Grant shot him an amazed glance. "Do you still think this is a Terrestrial ship, and has been here only a few decades?” he asked.

“Sure. Any evidence otherwise?”

Grant pointed to the floor beneath their feet. All looked down, arid for the first time noticed that they left footprints in a thin, even layer of dust that coated the corridor floor.

"That means that the ship held its air for a longer time than I care to think about—long enough not only to reduce the various organic substances on board to dust, but at random currents to distribute it through the open spaces. Yet when we came the air was almost gone leaked out through the joints and valves, good as they were, so that there was not enough left to resist us when we pushed a twelve-foot piston against its pressure. Point one.”

The finger swung to the control board. “Point two.” He said nothing further, but all could see what he meant.

The center of the control room was occupied by a thick-walled hemisphere—a cup, if you like—swung in gimbals which permitted its flat side always to the uppermost with respect to the ship’s line of net acceleration. The control board occupied the inner surface and upper edge of this cup, all around the circumference; and in the center of the assembly was the pilot's seat—if it could be called a seat.

It was a dome-shaped structure protruding from the floor about two feet ; five broad, deep grooves were spaced equally about its sides, but did not quite reach the top. It looked somewhat like a jelly mold ; and the one thing that could be stated definitely about its history was that no human being had ever sat in it. Cray absorbed this evident fact with a gulp, as though he had not chewed it sufficiently.

The rest of the men stared silently at the seat. It was as though the ghost of the long-dead pilot had materialized there and held their frozen attention ; overwrought imaginations pictured him, or strove to picture him, as he might have looked. And they also tried to picture what emergency, what unexpected menace, had called upon him to leave the place where he had held sway—to leave it forever. All those men were intelligent and highly trained; but more than one pair of eyes explored the corridor the human invaders had just used, and its mate stretching on from the other side of the control room.

Cray swallowed again, and broke the silence. "I should be able to figure out the engines, anyway.” he said, “if they're atomics at all like ours. After all, they have to do the same things our did, and they must have corresponding operations and parts." (famous last words...)

The free-lance seekers had met the engineer at the entrance, to the engine room. Now the three moved inside, stepping out onto a catwalk similar to that in the control room. This chamber, however, was illuminated only by the hand torches of the men; and it was amazing to see how well they lit up the whole place, reflecting again and again from polished metal surfaces.

When one had seen the tube arrangement from outside the ship, it was not difficult to identify most of the clustered machines. The tube breeches, with their heavy injectors and disintegrators, projected in a continuous ring around the walls and in a solid group from the forward bulkhead. Heavily insulated leads ran from the tubes to the supplementary cathode ejectors. It seemed evident that the ship had been driven and steered by reaction jets of heavy-metal ions, as were the vessels of human make. All the machines were incased in heavy shields, which suggested that their makers were not immune to nuclear radiation.

“Not a had layout,” remarked Preble. “Found out whether they’ll run?”

Cray glared. “No!” he answered almost viciously. “Would you mind taking a look at their innards for us?”

Preble raised his eyebrows, and stepped across the twenty-foot space between the catwalk and the nearest tube breech. It was fully six feet across, though the bore was probably not more than thirty inches —the walls had to contain the windings for the field which kept the ion stream from actual contact with the metal. The rig which was presumably the injector-disintegrator unit was a three-foot bulge in the center, and the insulated feed tube led from it to a nearby fuel container. The fuel was probably either mercury or some other easily vaporized heavy metal, such as lead. All this seemed obvious and simple enough, and was similar in basic design to engines with which even Preble was familiar ; but there was a slight departure from convention in that the entire assembly, from fuel line to the inner hull, appeared to be one seamless surface of metal. Preble examined it closely all over, and found no trace of a joint.

“I see what you mean,” he said at last, looking up. “Are they all the same?” Cray nodded.

“They seem to be. We haven’t been able to get into any one of them—even the tanks are tight. They look like decent, honest atomics, but we’ll never prove it by looking at the outside.”

“But how did they service them?” asked Stevenson. “Surely they didn’t weld the cases on and hope their machines were good enough to run without attention. That’s asking too much, even from a race that built a hull that could hold air as long as this must have.”

“How could I possibly know?” growled Cray. “Maybe they went outside and crawled in through the jets to service ’em—only I imagine it’s some trick seal like the door of this room. After all, that was common sense, if you look at it right. The fewer moving parts, the less wear. Can anyone think of a way in which this breech mechanism could be fastened on, with an invisible joint, working from the same sort of common sense?”

Why no one got the answer then will always remain a mystery; but the engineer was answered by nothing but half a dozen thought expressions more or less hidden in space helmets. He looked around hopefully for a moment, then shrugged his shoulders. “Looks like we'll just have to puzzle around and hope for the best,” he concluded. “Jack and Don might as well go back to their own snooping—and for Heaven’s sake, if you get any more ideas, come a-runnin’.”

The light revealed, besides the tanks, converters, and tube breeches which had been so obvious in the forward engine room, several open cabitiets which had been mere bulges on the walls up forward. Tools and other bits of apparatus filled these and lay about on the floor. Light frameworks of metal, rather like small building scaffolds, inclosed two of the axial tube breeches; and more tools lay on these. It was the first scene they had encountered on the ship that suggested action and life rather than desertion and stagnation. Even the dust, present here as everywhere, could not eradicate the impression that the workers had dropped their tools for a brief rest, and would return shortly.

Preble went at once to the tubes upon which work had apparently been in progress. He was wondering, as he had been since first examining one, how they were opened for servicing. He had never taken seriously Cray’s remark that it might have been done from outside.

His eye caught the thing at once. The dome of metal that presumably contained the disintegrator and ionizing units had been disconnected from the fuel tank, as he had seen from across the room; but a closer look showed that it had been removed from the tube, as well, and replaced somewhat carelessly. It did not match the edges of its seat all around, now; it was displaced a little to one side, exposing a narrow crescent of flat metal on each of the two faces normally in complete contact. An idea of the position can be obtained by placing two pennies one on the other, and giving the upper one a slight sideward displacement.

The line of juncture of the two pieces was, therefore, visible all around. Unfortunately, the clamping device Preble expected to find was not visible anywhere. He got a grip—a very poor one, with his gloved hand—on the slightly projecting edge of the hemisphere, and tried to pull it free, without success; and it was that failure which gave him the right answer—the only possible way in which an air-tight and pressure-tight seal could be fastened solidly, even with the parts out of alignment, with nonmagnetic alloys. It was a method that had been used on Earth, though not on this scale; and he was disgusted at his earlier failure to see it.

Magnetism, of course, could not be used so near the ion projectors, since it would interfere with the controlling fields ; but there was another force, ever present and available—molecular attraction. The adjoining faces of the seal were plane, not merely flat. To speak of their accuracy in terms of the wave length of sodium light would be useless; a tenth-wave surface, representing hours of skilled human hand labor, would be jagged in comparison. Yet the relatively large area of these seals and the frequency with which the method appeared to have been used argued mass production, not painstaking polishing by hand.

But if the seal were actually wrung tight, another problem presented itself. How could the stirfaces be separated, against a force sufficient to confine and direct the blast of the ion rockets? No marks on the breech suggested the application of prying tools—and what blade could be inserted into such a seal?

Stevenson eatne over to see what was keeping Preble so quiet, and listened while the latter explained his discovery and problems.

“We can have a look through these cabinets,” the chemist remarked finally. “This seems to fit Sorrell’s idea of a tool-requiring job. Just keep your eyes and mind open.”

The open mind seemed particularly indicated. The many articles lying in and about the cabinets were undoubtedly tools, but their uses were far from obvious. They differed from man-made tools in at least one vital aspect. Many of our tools are devices for forcing: hammers, wrenches, clamps, pliers, and the like. A really good machine job would need no such devices. The parts would fit, with just enough clearance to eliminate undesired friction—and no more.

That the builders of the ship were superb designers and machinists was already evident. What sort of tools they would need was not so obvious. Shaping devices, of course; there were planers, cutters, and grinders among the littered articles. All were portable, but solidly built, and were easily recognized even by Preble and Stevenson. But what were the pairs of slender rods which clung together, obviously magnetized? What were the small, sealed-glass tubes; the long, grooved strips of metal and plastic; the featureless steel-blue spheres; the iridescent, oddly shaped plates of paper-thin metal? The amateur investigators could not even guess, and sent for professional help.

Cray and his assistants almost crooned with pleasure as they saw the untidy floor and cabinets; but an hour of careful examination and theorizing left them in a less pleasant mood. Cray conceded that the molecular attraction theory was most probably correct, but made no headway at all on the problem of breaking the seal. Nothing in the room seemed capable of insertion in the air-tight joint.

“Why not try sliding them apart?’’ asked Stevenson. “If they’re as smooth as all that, there should be no difficulty.”

Cray picked up a piece of metal. “Why don't you imagine a plane through this bar, and slide it apart along that?’’ he asked. “The crystals of the metal are practically as close together, and grip each other almost as tightly, in the other case. You’ll have to get something between them.”

The chemist, who should have known more physics, nodded. “But it's more than the lubricant that keeps the parts of an engine apart,” he said.

“No, the parts of one of our machines are relatively far apart, so that molecular attraction is negligible,” answered the machinist. “But —I believe you have something there. A lubricant might do it; molecules might conceivably work their way between those surfaces. Has anybody noticed anything in this mess that might fill the bill?”

“Yes,” answered Preble promptly, "these glass tubes. They contain liquid, and have been fused shut—which is about the only way you could seal in a substance such as you would need.”

He stepped to a cabinet and picked up one of the three-inch long, transparent cylinders. A short nozzle, its end melted shut, projected from one end. and a small bubble was visible in the liquid within. The bubble moved sluggishly when the tube was inverted, and broke up into many small ones when it was shaken. These recombined instantly when the liquid came to rest, which was encouraging. Evidently the stuff possessed a very low viscosity and surface tension.

Cray took the tube over to the breech which had been partly opened and carelessly closed so long ago, held the nozzle against the edge of the seal, and, after a moment’s hesitation, snapped off the tip with his gloved fingers. He expected the liquid to ooze out in the asteroid’s feeble gravity, but its vapor pressure must have been high, for it sprayed out in a heavy stream. Droplets rebounded from the metal and evaporated almost instantly; with equal speed the liquid which spread over the surface vanished. Only a tiny fraction of a percent, if that, could have found its way between the surfaces.

Cray stared tensely at the dome of metal as the tube emptied itself. After a moment, he dropped the empty cylinder and applied a sideways pressure.

A crescent, of shifting rainbow colors, appeared at the edge of the seal; and the dome slowly slid off to one side. The crescent did not widen, for the lubricant evaporated the instant it was exposed. Preble and Stevenson caught the heavy dome and eased its mass to the central catwalk.

The last of the rainbow film of lubricant evaporated from the metal, and the engineers crowded around the open breech. There was no mass of machinery inside; the disintegrators would, of course, be within the dome which had been removed. The coils which generated the fields designed to keep the stream of ionized vapor from contact with the tube walls were also invisible, being sealed into the tube lining. Neither of these facts bothered the men. for their own engines had been similarly designed. Cray wormed his way down the full length of the tube to make sure it was not field failure which had caused it to be opened in the first place; then the three specialists turned to the breech which had been removed.

The only visible feature of its flat side was the central port through which the metallic vapor of the exhaust had entered the tube; but application of another of the cylinders of lubricant, combined with the asteroid's gravity, caused most of the plate to fall away and reveal the disintegrator mechanism within. Preble. Stevenson, Grant, and McEachern watched for a while as piece of the disintegrator began to cover the floor of the room; but they finally realized that they were only getting in the way of men who seemed to know what they were doing, so a gradual retreat to the main corridor took place.

“Do you suppose they can find ant what was wrong with it ?” queried Stevenson.

“We should.” It was Cray’s voice on the radio. “The principle of this gadget is exactly like our own. The only trouble is that they've used that blasted molecularattraction fastening method everywhere. It's taking quite a while to get it apart.”

It’s odd that the technology of these beings should have been so similar to ours in principle, and yet so different in detail,” remarked Grant. “I’ve been thinking it over, and can’t come to any conclusion as to what the reason could be. I thought perhaps their sense organs were different from ours, but I have no idea how that could produce such results—not surprising, since I can’t imagine what sort of senses could exist to replace or supplement ours.”

“There’s something funny about part of this,” he said. “I think it’s a relay, working from your main controls, but that’s only a guess. It's not only connected to the electric part of the business, but practically built around the fuel inlet as well. By itself it’s all right; solienoid and moving core type. We've had it apart, too.”

“What do you plan to do?” asked Grant. “Have you found anything wrong with the unit as a whole?”

“No. we haven’t. It has occurred to me that the breech was unsealed for some purpose other than repair. It would make a handy emergency exit—and that might account for the careless way it was resealed. We were thinking of putting it back together, arranging the relay so that we can control it from here and test the whole tube. Is that all right with you?”

“If you think you can do it, go ahead,” replied Grant. “We haven’t got much to lose. I should say. Could you fix up the whole thing to drive by local control?”

“Possibly. Wait till we see what happens to this one.”

The four men glided back down the corridor to the engine room. The reassembly of the breech mechanism was far from completed, and Grant did not like to interrupt. He was, of course, reasonably familiar with such motors, and knew that their assembly was a delicate task even for an expert.

Cray's makeshift magnetic device for controlling the relay when the breech was sealed was a comment on the man's ingenuity. It was not his fault that none of the men noticed that the core of the relay was made of the same alloy as the great screw cocks which held the engineroom doors shut, and the small bolts on the doors in the cargo hold. It was, in fact, a delicate governor, controlling the relation between fuel flow and the breech field strength —a very necessary control, since the field had to be strong enough to keep the hot vapor from actual contact with the breech, but not strong enough to overcome the effect of the fields protecting the throat of the tube, which were at right angles to it. There was, of course, a similar governor in man-made motors, but it was normally located in the throat of the tube and was controlled by the magnetic effect of the ion stream. The device was not obvious, and of course was not of a nature which a human engineer would anticipate. It might have gone on operating normally for an indefinite period, if Cray had used any means whatever, except magnetic manipulation, to open and close the relay.

(ed note: They decide to make one of the alien rocket jets spray against the asteroid surface. This will make a bright flare which will attract the attention of a rescue ship that is in this sector of space.)

Cray nodded. “I can start it alone,” he said. “The rest of you go on out. I'll give you a couple of minutes, then turn it on for just a moment. I’ll give you time to send someone in if anything is wrong.”

Grant nodded approval, and led the other five men along the main corridor and out the air lock. They leaped to a position perhaps a hundred and fifty yards to one side of the ship, and waited.

The tube in question was one of the lowest in the bank of those parallel to the ship’s longitudinal axis. For several moments after the men had reached their position it remained lifeless; then a silent, barely visible ghost of flame jetted from its lip. This changed to a track of dazling incandescence at the point where it first contacted the rock of the asteroid ; and the watchers automatically snapped the glare shields into place on their helmets. These were all in place before anyone realized that the tube was still firing, cutting a glowing canyon into the granite and hurling a cloud of boiling silica into space. Grant stared for a moment, leaped for the air lock, and disappeared inside. As he entered the control room from the front, Cray burst in from the opposite end, making fully as good time as the captain. He didn’t even pause, but called out as he came:

“She wouldn't cut off, and the fuel flow is increasing. I can’t stop it. Get out before the breech gives—I didn't take time to close the engine-room door !"

Grant was in midair when the engineer spoke, but he grasped a stanchion that supported the catwalk, swung around it like a comet, and reversed his direction of flight before the other man caught up to him. They burst out of the air lock at practically the same instant.

By the time they reached the others, the tube fields had gone far out of balance. The lips of the jet tube were glowing blue-white and vanishing as the stream caught them; and the process accelerated as the men watched. The bank of stern tubes glowed brightly, began to drip, and boiled rapidly away; the walls of the engine room radiated a bright red. then yellow, and suddenly slumped inward. That was the last straw for the tortured disintegrator ; its own supremely resistant substance yielded to the lack of external cooling, and the device ceased to exist. The wreckage of the alien ship, glowing red now for nearly its entire length, gradually cooled as the source of energy ceased generating; but it would have taken supernatural intervention to reconstruct anything useful from the rubbish which had been its intricate mechanism. The men, who had seen the same thing happen to their own ship not twenty hours before, did not even try to do so.

The abruptness with which the accident had occurred left the men stunned.

(ed note: Happily, the melting of the alien ship was enough to attract the rescue ship and the crew is saved.)

From TECHNICAL ERROR by Hal Clement (1944)

Sample Level Charts

Traveller TL Historical Era
0 Stone Age (fire)
1 Bronze Age (3500 BC)
1 Iron Age (1200 BC)
1 Medieval Age (600 AD)
2 Age of Sail (1450 AD)
3 Industrial Revolution (1730 AD)
4 Mechanized Age (1880 AD)
5 Circa 1910 AD
6 Nuclear Age (1940 AD)
7 Circa 1970 AD
8 Digital Age (1990 AD)
9 Early Stellar (2050 AD)
10 (A) Early Stellar (2120 AD)
11 (B) Average Stellar
12 (C) Average Imperial
13 (D) Average Stellar
14 (E) High Stellar
15 (F) Imperial Maximum
16 (G) Darrian Historical Maximum

From Tech Level Comparison Chart

Quality of life Tech Comparison
000MusclesFingers and sticksRunnersMystics/HerbologyNatural (Caves, Huts)
11-31-3WaterAbacus / Geometry, TrigonometryLong Distance SignalingDiagnosisSettlements, Towns (Irrigation)
244WindAlgebraPrinting pressInternal AnatomyCities (Canals, Roads)
355Coal / SteamCalculusTelegraph, Audio RecordingSurgery Cement Structures
456ElectricityMechanical CalculatorsTelephoneVaccination, Antiseptics, AnestheticsCities in Rugged/Desert Terrain, Crude Terraform
566Petrochemicals, Internal combustionElectric CalculatorsRadio, RadarMass Vaccination, X-RaySealed/Conditioned Cities
667Nuclear FissionElectronic Computers (Large Model/1 bis)Television / Advanced Audio RecordingVirus, Crude ProstheticsSkyscrapers, Weather Predict, Underground Cities
777Solar energy, early Fuel CellsDesktop Computers, Expert systems, Model/2Early Satellite, Video recordingOrgan Transplant, Slow DrugsCities in Jungle Terrain
878GeothermalMassive Parallel / Low Data, Model/2bisFibre opticsArtificial Organs, MetabolicsOrbital Settlements, Early Weather Control
989Early Fusion, Improved BatteriesNon-Volatile / High Data, Vocal I/O, Model/3Video Telephone, Flat ScreenLimb Regeneration, Cryogenics, Fast DrugsArcologies, Orbital Cities
10910Fusion Plants 2KL MinimumEarly Synaptics, voice transcription, Model/4Holovision, Text TranscriptionAntiviral Vaccines, Cancer Cure, Growth QuickiningUnder-Sea/Under Ice Cities
11910Fusion Plants 1KL MinimumSynaptic Learning Processors, Hand Computers, Model/5Personal Global Communications Nerve Refusion, Artificial EyesGravitic Structure Support
121011Fusion Plants 250L Minimum, Advanced Fuel CellsLow Autonomous Robots, Model/6Real-time Multilingual TranslatorsBroad Spectrum Anti-toxins, Enhanced ProstheticsMajor Terraforming, Advanced Weather Control
131011Fusion output 3Kw per L, Miniature Super-BatteriesHolocrystal Storage, High Autonomous Robots, Model/7Holovideo RecordersCloning of Replacement Parts, ReanimationNon-mobile Gravitic Cities
141112Fusion Plants 100L MinimumComputer/Brain Implants, Model/8Early Meson CommunicatorsGenetic Engineering, Memory ErasureMobile Gravitic Cities
151212Fusion output 6Kw per LPseudo-Reality Computers, Pseudo Robots, Model/9Meson Communicators, Pseudo Reality CommunicationsAnagathics, Advanced Pseudobio ProstheticsComplex Terraforming Possible
161313Fusion output 7Kw per L, 80L MinimumLow Artificial Intelligence, Robots in all FacetsPersonal Meson Communicators, Personal HolovideoBrain Transplants, Crude Memory TransferGlobal Terraforming, Hostile Worlds
17 - -Early Antimatter PlantsHigh Artificial Intelligence, Self-Aware RobotsPocket Meson CommunicationsSelective Memory Erasure, Intelligent AnitbodiesTotal Terraforming to 800Km worlds
18 - -Antimatter 1Mw/L, 750L Fuel Pod MinimumRobots become Society's Basic WorkforcePartial Memory TransferTotal Terraforming to 4000Km worlds
19 - -Antimatter 2.5Mw/L, 200L Fuel Pod MinimumNon-Cryogenic Suspension, Advanced BioengineeringTotal Terraforming
20 - -Antimatter 15Mw/L, 40L Fuel Pod MinimumMatter Transport Eliminates Global Communication BarriersTotal Memory TransferMobile Worlds (Sublight)
21 - -Antimatter 50Mw/L, 5L Fuel Pod MinimumMatter Transport Eliminates Intra-System BarriersEarly Total RejuvenationMobile Worlds (Jump Space) & Rosettes
23 - -Dyson Spheres (with many Capsules)
25 - -Ability to create Ringworlds, access pocket universe
27 - -Rigid Dyson Spheres
35Create Pocket Universe
Transportation Tech Comparison
000Foot - AnimalsRaft / Canoe - -
11-31-3Wheel - Carts/ChariotsRowed Galleys, Crude Sailing Vessels - -
244Advanced Wheel - Moveable Axle, Replaceable RimsEarly Multi-Mast Sailing, Crude Navigation - -
355Extensive Road - High-Speed CoachMulti-Mast Sailing, NavigationHot Air Balloons -
456TrainsIronclads, SteamshipsDirigibles, Early Gliders -
566Ground Cars, Tracked VehiclesPersonal Self-Propelled Boats, Steel hulls, Early SubmersiblesAirplanes, SeaplanesEarly Rockets (unmanned)
667Amphibian Vehicles, ATVsAFVsSubmersibles, Scuba, Amphibian VehiclesEarly Jet, HelicoptersEarly Manned Rockets, Unmanned Rockets
777Hovercraft, High-Speed TrainsHydrofoils, HovercraftSupersonic Jet, Hang GlidersDeep Space Probes (Unmanned), Maneuver-1/2 (non-gravitic)
878Triphibian VehiclesTriphibian Vehicles, Early Artificial GillsTriphibian Vehicles, Hypersonic JetSpace Shuttles, Space Stations, Maneuver-3-5 (non-grav)
989Early Grav Vehicles, Ultra High-Speed TrainsEarly Grav Vehicles, Artificial GillsEarly Grav Vehicles, Rocket Assist SuborbitalJump-1 possible, Sublight Stellar
10910Grav VehiclesUH Grav ModulesGravitic Maneuver

Jump-1 certain

11910Personal G-Tubes, HV Grav ModulesJump-2, Thruster Technology
121011Personal Grav Belts, LT Grav ModulesJump-3
131011Grav Vehicles Merge with Orbital Spacecraft, Jump-4
16 - -Raw Material Only Short Range Matter Transport
17 - -Inanimate Only Short Range Matter Transport
18 - -Self-Aware Starships, living being portal based Matter Transport
21 - -Multi Parsec Range Starship-Sized Matter Transport Portals
Military Tech Comparison
- - -PersonalHeavy
000Club, SpearFur - -
11-31-3Early Weapons (Bow, Sword)Jack ArmourCatapultWood
244Early GunsSmall Cannons
355Rifled WeaponsCannons
456CartridgeMesh ArmourHowitzers, Gatling gunSoft Steel
566Explosive Grenade, ShotgunFilter MaskMortars
667Automatic (SMG)Nuclear Weapons, MissilesHard Steel
777Grenade LaunchersCloth Armour, Flack JacketBeam LasersComposite Laminate
878RAM Grenade Launchers, Early Laser CarbineParticle Accelerators, Target Desginated Missiles
989Laser WeaponsAblative ArmourLight Weight Composite Laminate
10910Advanced Combat RifleReflec, Combat Environment SuitPlasma Guns, RepulsorsCrystaliron
11910Combat ArmourMeson Guns
121011PGMP-12, Gauss RifleFusion GunsSuperdense Armour, Nuclear Dampers
131011PGMP-13, X-Ray LasersBattle DressX-Ray Lasers
141112FGMP-14Bonded Superdense
151212FGMP-15Early Black Globes
161313FGMP-16, Plasma Rifle, Neural GunNeural ShieldTractor BeamBlack Globes
17 - -Fusion Rifle, Plama PistolDisintegrators, Antimatter WarheadsCoherent Superdense
18 - -Disintegrator Rifle, Fusion PistolPersonal DamperLong Range Disintegrator/Tractor Beam
19 - -Disintegrator PistolProton Screen, Plastic Metal Armour
20 - -Relativity BeamWhite Globes, Proton Beam
21 - -Relativity RiflePersonal White GlobeJump ProjectorJump Damper

From GURPS Wiki Tech Level

TL Era Timespan Signature technologies
0 Stone Age Prehistory and later Counting; oral tradition.
1 Bronze Age 3500 B.C.+ Arithmetic; writing.
2 Iron Age 1200 B.C.+ Geometry; scrolls.
3 Medieval 600 A.D.+ Algebra; books.
4 Age of Sail 1450+ Calculus; movable type.
5 Industrial Revolution 1730+ Mechanical calculators; telegraph.
6 Mechanized Age 1880+ Electrical calculators; telephone and radio;
7 Nuclear Age 1940+ Mainframe computers; television.
8 Digital Age 1980+? Personal computers; global networks.
9 Microtech Age 2025+? Artificial intelligence; real-time virtuality.
10 Robotic Age 2070+ Nanotechnology or other advances start to blur distinctions between technologies...
11 Age of Exotic Matter
12 Whatever the GM likes!
TL Transportation Weapons and Armor Power Biotechnology/Medicine
0 Skis; dogsleds; dugout canoes. Wooden and stone weapons; primitive shields; hides for armor. Human muscle power; dogs. First aid; herbal remedies; primitive agriculture.
1 Bare horseback; the wheel (and chariots); ship-building; sails. Bronze weapons and armor. Donkeys; oxen; ponies. Surgery; animal husbandry; fermentation.
2 Saddle; roads; triremes. Iron weapons; iron armor (including mail); siege engines. Horses; water wheels. Bleeding the sick; chemical remedies.
3 Stirrups; oceangoing sailing ships (longships, roundships, etc.). Steel weapons; early firearms; plate armor; castles. Heavy horses and horse-collars; windmills. Crude prosthetics; anatomical science.
4 Stagecoach; three-masted sailing ships; precise navigation. Muskets and pikes; horse artillery; naval broadsides. Improved windmills; belt drives; clockwork. Optical microscope makes cells visible.
5 Steam locomotives; steamboats; early submersibles; balloons and early airships. Early repeating small arms; rifled cannon; ironclads. Steam engines; direct current; batteries. Germ theory of disease; safe anesthetics; vaccines.
6 Automobiles; continental railways; ocean liners; submarines; aircraft. Smokeless powder; automatic weapons; tanks; combat aircraft. Steam turbines; internal combustion; alternating current; hydroelectricity. Antibiotics; blood typing and safe transfusions; heredity; biochemistry.
7 Nuclear submarines; jet aircraft; helicopters; manned space flight. Ballistic body armor; guided munitions; combat jets; nuclear weapons. Gas turbines; fission; solar power. Discovery of DNA; organ transplants; pacemakers.
8 Satellite navigation; SSTO ("single stage to orbit") spacecraft. Smartguns; blinding lasers; unmanned combat vehicles. Fuel cells; advanced batteries. Genetically modified organisms; gene therapy; cloning.
9 Robot cars; space elevators; manned interplanetary space flight. Electrolasers; heavy laser weapons; battlesuits; combat robots; designer viruses. Micro fuel cells; deuterium-hydrogen fusion; high-temperature superconductors. Human genetic engineering; tissue engineering; artificial wombs; cybernetic implants
10 Fast interplanetary space flight. Compact laser and heavy particle-beam weapons; Gauss guns; nanotech armor; nanoviruses; antimatter bombs. Helium-3 fusion; antimatter. Brain transplants; uploading; bioroids; uplifted animals.
11 Manned interstellar space flight. Compact particle-beam weapons; disassemblers ("gray goo"); defensive nanites. Portable fusion power. Living machines; cellular regeneration.
12 Faster interstellar space flight. Gamma-ray lasers; "living metal" armor; black-hole bombs. Portable antimatter power. Full metamorphosis; regeneration.
^ Reactionless thrust; contragravity; faster-than-light (FTL) travel; matter transmission; parachronic technology; time machines. Monomolecular blades; force-field technology; gravitic weapons; nuclear dampers; disintegrators. Broadcast power; cold fusion; zero-point energy; total conversion; cosmic power. Fast-growth clone tanks; psi drugs; regeneration ray.

Tech Trees


A technology, tech, or research tree is a hierarchical visual representation of the possible sequences of upgrades a player can take (most often through the act of research) in strategy computer games. The diagram is tree-shaped in the sense that it branches between each 'level', allowing the player to choose one sequence or another. Each level is called a tier and is often used to describe the technological strength of a player. Typically, at the beginning of a session of a strategy game, a player will start at tier 1, and will only have a few options for technologies to research. Each technology that a player researches will open up one or more new options, but may or may not, depending on the computer game, close off the paths to other options. The tech tree is the representation of all possible paths of research a player can take, up to the culmination of said sequence.

Types of tech tree

Classic Research Technology Tree

     The Classic tech tree is the one where extensive research into new technologies must be conducted parallel to the progression of a game. Some real-time strategy (RTS) games as well as most turn-based strategy (TBS) games employ this type of tech tree. In these games, players typically have a 'command center', 'unit-training-facility' and 'research facility' at their disposal from the start, allowing them to both start research into more advanced technologies, or engaging in combat with enemies using the basic units (Warzone 2100, Master of Orion series, Civilization series, Space Empires series).

Allocation Technology Tree

     In some games, the requirement of an actual research facility is absent. In this case players can allocate research points, or in-game resources to purchase new technologies. In some games the allocation yields direct results, meaning that procuring the new technology isn't paired with allotted time for the research of said technology to complete.

Building-based Technology Tree

     In most RTS games the technology tree consists of buildings which must be built in a specific sequence, which in turn unlocks new technologies. These newly unlocked technologies can be more advanced unit, upgrades for research or more advanced buildings. (StarCraft, Command & Conquer Series.)

Prerequisites for technology advances

     In most types of strategy games, the player needs particular buildings in order to research specific technologies or build specific advanced units (StarCraft, Total Annihilation), while in other games upgrades/technologies are unlocked through research of their parent technology research (Warzone 2100). In many TBS games the prerequisite is one or more lower-level technologies, with no dependency on specific buildings (Master of Orion series, Civilization series, Space Empires series). Most strategy games however use both systems. both requiring dedicated buildings and in advanced cases pre requisite technology, sometimes culminating in a game ending super-weapon of some kind.


     The structures of tech trees vary quite widely. In the simplest cases (e.g. Master of Orion) there are several completely separate research areas and one could research all the way up to the highest level in one area without researching other areas (although this would often be far from ideal). In more complex cases[citation needed] (e.g. Civilization) every technology above the starting level has more than one prerequisite and one has to research most of the lower-level technologies in order to research any of the top-level technologies. And there are many possibilities between these two variants, for example in Space Empires researching to a specified level in one field may enable the player both to research to a higher level in that field and to start research in a new field which was previously not available.
     Major 4X games like Civilization and Master of Orion have a much larger technology tree than most other strategy games; as an extreme example, Space Empires III has over 200 technologies.

Are all technologies available?

     Some RTSs make different techs available to different races or cultures (especially StarCraft; but many RTSs have special units or buildings for different cultures, e.g. Age of Empires expansion pack and later versions, Red Alert 2). Most TBSs make all technologies available to all cultures (e.g. Civilization). Master of Orion (original version) is a complex special case in this respect: the full tree is the same for all; but in each game each player gets a subset of the full tech tree that depends on which race was selected.

Balance between civilian and military techs

     In many RTS games tech advances are almost exclusively military (e.g. StarCraft). But in most TBS and some RTS games the research and production costs of top-end military techs are so high that you have to build up your economy and your research productivity first (RTS - Age of Empires and Empire Earth, where one of the most significant costs is going up an epoch; TBS - the Civilization series and Master of Orion series).

From the Wikipedia entry for TECHNOLOGY TREE

Section of the tech tree for FreeCiv. Note the complex dependencies between technologies. Use horizontal scroll bar to pan the tree.


Research and technology

4X games typically feature a technology tree, which represents a series of advancements that players can unlock to gain new units, buildings, and other capabilities. Technology trees in 4X games are typically larger than in other strategy games, featuring a larger selection of choices. Empires must generate research resources and invest them in new technology. In 4X games, the main prerequisite for researching an advanced technology is knowledge of earlier technology. This is in contrast to non-4X real-time strategy games, where technological progress is achieved by building structures that grant access to more advanced structures and units.

Research is important in 4X games because technological progress is an engine for conquest. Battles are often won by superior military technology or greater numbers, with battle tactics playing a smaller part. In contrast, military upgrades in non-4X games are sometimes small enough that technologically basic units remain important throughout the game.

From the Wikipedia entry for 4X

A staple of almost every strategy game is the ability for you to unlock new abilities for your units, or new unit classes entirely, by spending time and resources on scientific research instead of just bashing your opponent into submission with your existing ones.

Exactly how the tech tree works varies greatly depending on the game genre.

In Real-Time Strategy games, research is usually represented by specialized units or structures, with the pace of new tech development decided by how many of these the player has on the field. Research units often have weak attacking abilities (If they can attack at all) and must be protected from harm. Smart players and AIs will, of course, constantly be after these units.

New technologies typically allow for better armor to take more damage before dying, faster ground speeds, weapons that do more damage per hit, and increased sight and accuracy bonuses.

Tech upgrades are usually dressed to look genre-appropriate for the game. Researching advanced radar tech for your helicopters in one game will be instantly recognizable as granting your Paladins "Holy Sight" in another (or, in some cases, the same game).

Another key feature is that they usually follow a set order in which they must be researched. To give your troops armor-piercing shell upgrades, you may have to first research the advanced artillery tech, which in turn can't be done until you've finished researching basic cannon tech, etc...

Some games allow players greater influence over their gaming economies, and they can pour extra money into certain research projects to get them done faster while completing less urgent ones at their leisure.

Other times the development speed is static, and all that's required is that the player have enough gold, tiberium, wood, mana or whatever is needed to pay the upgrade costs for that tech.

The use of tech trees in 4X games is quite different. Tech trees typically do not have an on-map representation. They are a function of the empire itself. In such games, each empire's cities (or equivalent) provides some portion of research that is pooled until the civilization researches a particular technology. The rewards for a tech are improvements for "cities", new units or unit equipments, bonuses for a civilization researching them, or other such things.

Some Role Playing Games have the similar "Feat Tree", where at character creation time and at every Nth Level Up the player gets to choose new traits and abilities (feats) for their character, with some feats requiring other feats to unlock. Refer to Skill Scores and Perks for more information.

Tech trees are one of the big points where historians pick at games. It's a hierarchical view of science, research, and history. When compared with actual history, tech trees are wrong. On the other hand, the few attempts at doing something different have wound up pulled from any final version, with good reason.

Either way, researched technologies in many games, most often Real-Time Strategy, have an annoying habit of disappearing once the current level/mission is completed, forcing you to spend time researching them all again in the very next round.

See also You Have Researched Breathing, Reinventing the Wheel. A Tech Tree may be prone to Interface Spoilers, or conversely, it may become a Guide Dang It to make an informed decision.

For a huge list of examples click here

TECH TREE entry from TV Tropes

     “It’s clear enough for me to like it. You’d be surprised at the way the first part of the program ties in with stuff I’ve been working on for a long time. As for the other — untrammeled research into the completely unknown — you realize, of course, that if MetEnge participates fifty-fifty, DesDes will be on a non-retainer basis all the time you are out and will have to split fifty-fifty.”
     “But there isn’t going to be anything the least bit commercial about it!” Barbara protested.
     “You’re wrong there, young lady. Research always has paid off big, in hard dollars."

From SUBSPACE EXPLORERS by E. E. "Doc" Smith (1965)

Everybody has heard of the Long Range Foundation, but it happened that Pat and I had just done a term paper on non-profit corporations and had used the Long Range Foundation as a type example.

We got interested in the purposes of the Long Range Foundation. Its coat of arms reads: “Bread Cast Upon the Waters,” and its charter is headed: “Dedicated to the Welfare of Our Descendants.”

The charter goes on with a lot of lawyers’ fog but the way the directors have interpreted it has been to spend money only on things that no government and no other corporation would touch. It wasn’t enough for a proposed project to be interesting to science or socially desirable; it also had to be so horribly expensive that no one else would touch it and the prospective results had to lie so far in the future that it could not be justified to taxpayers or shareholders. To make the LRF directors light up with enthusiasm you had to suggest something that cost a billion or more and probably wouldn’t show results for ten generations, if ever … something like how to control the weather (they’re working on that) or where does your lap go when you stand up.

The funny thing is that bread cast upon waters does come back seven hundred fold; the most preposterous projects made the LRF embarrassing amounts of money — “embarrassing” to a non-profit corporation that is. Take space travel: it seemed tailor-made, back a couple of hundred years ago, for LRF, since it was fantastically expensive and offered no probable results comparable with the investment: There was a time when governments did some work on it for military reasons, but the Concord of Bayreuth in 1980 put a stop even to that.

So the Long Range Foundation stepped in and happily began wasting money. It came at a time when the corporation unfortunately had made a few billions on the Thompson mass-converter when they had expected to spend at least a century on pure research; since they could not declare a dividend (no stockholders), they had to get rid of the money somehow and space travel looked like a rat hole to pour it down.

Even the kids know what happened to that: Ortega’s torch made space travel inside the solar system cheap, fast, and easy, and the one-way energy screen made colonization practical and profitable; the LRF could not unload fast enough to keep from making lots more money.

I did not think all this that evening; LRF was just something that Pat and I happened to know more about than most high school seniors … more than Dad knew, apparently, for he snorted and answered, “The Long Range Foundation, eh? I’d almost rather you were from the government. If boondoggles like that were properly taxed, the government wouldn’t be squeezing head taxes out of its citizens.”

This was not a fair statement, not a “flat-curve relationship,” as they call it in Beginning Mathematical Empiricism. Mr. McKeefe had told us to estimate the influence, if any, of LRF on the technology “yeast-form” growth curve; either I should have flunked the course or LRF had kept the curve from leveling off early in the 21st century — I mean to say, the “cultural inheritance,” the accumulation of knowledge and wealth that keeps us from being savages, had increased greatly as a result of the tax-free status of such non-profit research corporations. I didn’t dream up that opinion; there are figures to prove it. What would have happened if the tribal elders had forced Ugh to hunt with the rest of the tribe instead of staying home and whittling out the first wheel while the idea was bright in his mind?

From TIME FOR THE STARS by Robert Heinlein (1956)

Warning Signs for Tomorrow

Anders Sandberg has created a brilliant set of "warning signs" to alert people of futuristic hazards. Some are satirical, but they are all very clever. There are larger versions of the signs here.

Rate of Technological Advance

Arms Race

In early pulp science fiction there were a couple of examples of tech level climbing that was totally out of control. An arms race on steroids. Arguably the most egregious was E. E. "Doc" Smith's Skylark of Space series, although John W. Campbell Jr's Mightiest Machine series gives it a run for the money. The super scientist hero and the super scientist villain frantically try to jump to the next tech step so they can vaporize their nemesis. But somehow their nemesis is only wounded, not atomized. Then its the nemesis' turn to make a tech jump.

In the first novel of the Skylark of Space series, the heroic Richard Seaton makes his first tech jump by inventing a potent power source and building a crude starship. By the last novel Seaton and his rival destroy an entire galaxy, star by star. That's a lot of tech jumps.

"Doc" Smith's Lensman novels were a bit milder. They started out with space battles with large numbers of ships. About mid-way they were mass-producing Death Stars.

Such novels also have a comically shorted research and development cycle. We are talking only a month or two between demonstrating the effect in the lab to cranking out the new weapons for use on the battlefield. In reality it is more like years. The classic cautionary tale is Superiority by Arthur C. Clarke, which is required reading for some M.I.T. courses.


The thing about John Campbell is that he liked things big. He liked big men with big ideas working out big applications of their big theories. And he liked it fast. His big men built big weapons within days; weapons that were, moreover, without serious shortcomings, or at least, with no shortcomings that could not be corrected as follows: “Hmm, something’s wrong — oh, I see — of course.” Then, in two hours, something would be jerry-built to fix the jerry-built device.

On the other hand, in the real world during World War 2, the British Royal Navy and the US Navy started the war with biplanes. By the end of the war, the Nazis were fielding jet fighter planes and ballistic missiles. Not to mention the US ending the war with atomic bombs. This was over a mere six year period.

In my long and misspent youth I tried to make a tabletop wargame based on the Skylark of Space series. That's when I discovered the flaw in the situation: the novels have the arms race impossibly balanced. When each protagonist makes a tech level advance it is always just enough to threaten their opponent but not enough so they can squish him like a bug (which would prematurely end the series). Outside of a novel (where things are scripted) and into a wargame, it is far to easy for one player to jump up several tech levels at once and render their opponent helpless. Makes for a frustrating game.

"First we got The Bomb and that was good
'Cause we love peace and motherhood
Then Russia got The Bomb, but that's OK;
'Cause the balance of power is maintained that way
Who's next?"Tom Lehrer, "Who's Next?", That Was the Year That Was

This is what happens when (nation-)states attempt to prove that My Kung-Fu Is Stronger Than Yours or build a Bigger Stick.

If a military conflict goes on for any appreciable length of time in a high-tech setting, each side will be struggling to become and remain stronger than the other - often by producing better equipment and weapons. Sometimes, this process of Serial Escalation goes way over the top (especially with Soviet Superscience).

Truth in Television, naturally, with first and last decades of the Cold War between the USA and the Soviet Union as the Trope Codifier and the inspiration for many Arms Races in fiction. As a result, these Arms Races usually have rapid inventions of Nuclear Weapons-parallels, Space Weaponry, Mutually Assured Destruction, and other Cold War-era tropes. The Trope Namer comes from E. E. “Doc” Smith's Lensman novels. Over the course of a decades-long struggle (that was only the surface of a deeper, eons-old war between cosmic beings using mortals as pawns), Civilization and Boskone went from ordinary starship battles to star-powered lasers, antimatter bombs, planets used as missiles, antimatter planets used as missiles, faster-than-light missiles, faster-than-light antimatter planet missiles...

If somebody tries to argue this as evidence that competition and the constant drive to survive and build Bigger Sticks to kill each other motivates technological evolution, he is likely to be a Social Darwinist.

Moore's Law is this trope applied specifically to computer technology, stating that every eighteen months, roughly, we see a doubling of transistor density (and thus hardware capabilities).

See also: Plot Leveling, So Last Season, Sorting Algorithm of Evil, Serial Escalation, Space Cold War.

Not to be confused with the rather less bloody Escalating War.

(ed note: see TV Trope page for list of examples)


Recently I have become fascinated by the development of early bombers during the First World War. Driven by the exigencies of the world’s first large-scale industrialized war (the Russo-Japanese War was an industrialized war, but not on the scale of the First World War), aircraft developed rapidly. I have focused on the same rapidity of technological development previously emphasizing the modernity of weapons systems during the Second World War. In The Dialectic of Stalemate I wrote:

“When the Second World War ended, there were operable jet fighters, ballistic missiles, electronic computers, and atomic weapons. None of these existed when the war began.”

True enough, but the essential ideas behind these weapons systems were already in play. An idea can be implemented in any number of ways (admittedly some more efficacious than others), and exactly how an idea is implemented is a matter of technology and engineering — in other words, implementation is an accident of history. As soon as the idea has its initial implementation, we are clever enough to usually see the implications of that idea rather quickly, and thus technology is driven to keep up with the intrinsic potentiality of the idea.

Once the proof of concept of heavier-than-air flight was realized, the rest fell into place like pieces of a puzzle. Aircraft would be armed; they would seek to destroy other aircraft, and prevent themselves from being destroyed; and they would seek to destroy targets on the ground. Hence the idea of aircraft in warfare rapidly moves to fighters and bombers. The pictures above are of the Zeppelin-Staaken — not the first enclosed bomber, but among the first (the Russians, I believe, made the first enclosed bomber, the Sikorsky Ilya Muromets).

The Zeppelin-Staaken was an enormous craft with a wingspan almost equal to that of a B-29 and a crew of many men. In fact, these early German bombers were called Riesenflugzeug (or R-planes) — gigantic aircraft. An early testimonial from a Zeppelin-Staaken crew member vividly conveys the sense of flying the R-planes:

“Inside the fuselage the pale glow of dim lights outlined the chart table, the wireless equipment, and the instrument panel. Under us, the black abyss.”
—Trenches: Battleground WWI, episode 5, “Fight On, Fly On”

The technology and engineering of flight during the First World War was not sufficiently advanced to make a decisive strategic difference, but they had the idea of what was possible, and they attempted to put it into practice. The idea of bombers, coordinated by radio, executing a strategic precision airstrike was already present during the First World War.

During the Second World War, the technology had advanced to the point that strategic bombing was decisive, and, in fact, it was at one point the only possible war that the UK could wage against Germany. The evolutionary development continues to the present day. Contemporary precision munitions are finally beginning to converge on true precision air strikes that were first imagined (and attempted) during the First World War.

The point here is that, once the idea is in place, the rest is mere technology and engineering — in other words, implementation. The corollary of the essential idea coupled with with contingent implementation is the fact that the wars of industrial-technological civilization, there are no secrets.

William Langewiesche in his book Atomic Bazaar: The Rise of the Nuclear Poor emphasized that the early atomic scientists knew that there were no “secrets” per se, because the atomic bomb was the result of science, and anyone who would engage in science, technology, and engineering on a sufficiently large scale can build a nuclear weapon.

This thesis should be generalized and extrapolated beyond the science of nuclear weapons. Precision munitions, aviation, targeting, and all the familiar line items of a current military budget are refined and perfected by science and technology. For all practical purposes, all war has become science, and science is no secret. Any sufficiently diligent and well-funded people can produce a body of scientific knowledge that could be put into practice building weapons systems.

One might suppose, from the regimes of state security that have become so prevalent, that secrecy is of the essence of technological warfare. While this impression is encouraged, it is false. Secrecy is no more central to competition in technological warfare than it is central to industrial competition. That is to say, secrecy has a role to play, but the role that secrecy plays is not quite the role that official secrecy claims might lead one to believe.

Wittgenstein in his later work — no less pregnantly aphoristic than the Tractatus — said that nothing is hidden. And so it is in the age of industrial-technological civilization: Nothing is hidden. Everything is, in principle, out in the open and available for public inspection. This is the very essence of science, for science progresses through the repeatability of its results. That is to say, science is essentially an iterative enterprise.

Wittgenstein also said in his later period that philosophy leaves the world as it is. That is to say, philosophy is is no sense revolutionary. And so too with the philosophy of war, which in its practical application is strategic doctrine: strategic doctrine leaves the world as it is.

The perennial verities of war remain. These are largely untouched by technology, because all parties to modern, scientific war have essentially the same technology, so that they fight on the same level. Military powers contending for victory seek technological advantages when and where they can get them, but these advantages are always marginal and temporary. Soon the adversary has the same science, and soon after that the same technology.

The true struggle is the struggle of ideas — the struggle of mind against mind, contending to formulate the decisive idea first. As I said above, once the idea is in place, everything else follows from the idea. But it is the idea that is the necessary condition of all that follows.

War, then, is simply the war of ideas.


In several posts I have described what I called the STEM cycle, which typifies our industrial-technological civilization. The STEM cycle involves scientific discoveries employed in new technologies, which are in turn engineered into industries which supply new instruments to science resulting in further scientific discoveries. For more on the STEM cycle you can read my posts The Industrial-Technological Thesis, Industrial-Technological Disruption, The Open Loop of Industrial-Technological Civilization, Chronometry and the STEM Cycle, and The Institutionalization of the STEM Cycle.

Industrial-technological civilization is a species of the genus of scientific civilizations (on which cf. David Hume and Scientific Civilization and The Relevance of Philosophy of Science to Scientific Civilization). Ultimately, it is the systematic pursuit of science that drives industrial-technological civilization forward in its technological progress. While it is arguable whether contemporary civilization can be said to embody moral, aesthetic, or philosophical progress, it is unquestionable that it does embody technological progress, and, almost as an epiphenomenon, the growth of scientific knowledge. And while knowledge may not grow evenly across the entire range of human intellectual accomplishment, so that we cannot loosely speak of “intellectual progress,” we can equally unambiguously speak of scientific progress, which is tightly-coupled with technological and industrial progress.

Now, it is a remarkable feature of science that there are no secrets in science. Science is out in the open, as it were (which is one reason the appeal to embargoed evidence is a fallacy). There are scientific mysteries, to be sure, but as I argued in Scientific Curiosity and Existential Need, scientific mysteries are fundamentally distinct from the religious mysteries that exercised such power over the human mind during the epoch of agrarian-ecclesiastical civilization. You can be certain that you have encountered a complete failure to understand the nature of science when you hear (or read) of scientific mysteries being assimilated to religious mysteries.

That there are no secrets in science has consequences for the warfare practiced by industrial-technological civilization, i.e., industrialized war based on the application of scientific method to warfare and the exploitation of technological and industrial innovations. While, on the one hand, all wars since the first global industrialized war have been industrialized war, since the end of the Second World War, now seventy years ago, on the other hand, no wars have been mass wars, or, if you prefer, total wars, as a result of the devolution of warfare.

Today, for example, any competent chemist could produce phosgene or mustard gas, and anyone who cares to inform themselves can learn the basic principles and design of nuclear weapons. I made this point some time ago in Weapons Systems in an Age of High Technology: Nothing is Hidden. In that post I wrote:

Wittgenstein in his later work — no less pregnantly aphoristic than the Tractatus — said that nothing is hidden. And so it is in the age of industrial-technological civilization: Nothing is hidden. Everything is, in principle, out in the open and available for public inspection. This is the very essence of science, for science progresses through the repeatability of its results. That is to say, science is essentially an iterative enterprise.

Although science is out in the open, technology and engineering are (or can be made) proprietary. There is no secret science or sciences, but technologies and industrial engineering can be kept secret to a certain degree, though the closer they approximate science, the less secret they are.

I do not believe that this is well understood in our world, given the pronouncements and policies of our politicians. There are probably many who believe that science can be kept secret and pursued in secret. Human history is replete with examples of the sequestered development of weapons systems that rely upon scientific knowledge, from Greek Fire to the atom bomb. But if we take the most obvious example — the atomic bomb — we can easily see that the science is out in the open, even while the technological and engineering implementation of that science was kept secret, and is still kept secret today. However, while no nation-state that produces nuclear weapons makes its blueprints openly available, any competent technologist or engineer familiar with the relevant systems could probably design for themselves the triggering systems for an implosion device. Perhaps fewer could design the trigger for a hydrogen bomb — this came to Stanislaw Ulam in a moment of insight, and so represents a higher level of genius, but Andrei Sakharov also figured it out — however, a team assembled for the purpose would also certainly hit on the right solution if given the time and resources.

Science nears optimality with it is practiced openly, in full view of an interested public, and its results published in journals that are read by many others working in the field. These others have their own ideas — whether to extend research already preformed, reproduce it, or to attempt to turn it on its head — and when they in turn pursue their research and publish their results, the field of knowledge grows. This process is exponentially duplicated and iterated in a scientific civilization, and so scientific knowledge grows.

When Lockheed’s Skunkworks recently announced that they were working on a compact fusion generator, many fusion scientists were irritated that the Skunkworks team did not publish their results. The fusion research effort is quite large and diverse (something I wrote about in One Hundred Years of Fusion), and there is an expectation that those working in the field will follow scientific practice. But, as with nuclear weapons, a lot is at stake in fusion energy. If a private firm can bring proprietary fusion electrical generation technology to market, it stands to be the first trillion dollar enterprise in human history. With the stakes that high, Lockheed’s Skunkworks keeps their research tightly controlled. But this same control slows down the process of science. If Lockheed opened its fusion research to peer review, and others sought to duplicate the results, the science would be driven forward faster, but Lockheed would stand to lose its monopoly on propriety fusion technology.

Fusion science is out in the open — it is the same as nuclear science — but particular aspects and implementations of that science are pursued under conditions of industrial secrecy. There is no black and white line that separates fusion science from fusion technology research and fusion engineering. Each gradually fades over into the other, even when the core of each of science, technology, and engineering can be distinguished (this is an instance of what I call the Truncation Principle).

The stakes involved generate secrecy, and the secrecy involved generates industrial espionage. Perhaps the best known example of industrial espionage of the 20th century was the acquisition of the plans for the supersonic Concorde, which allowed the Russians to get their “Konkordski” TU-144 flying before the Concorde itself flew. Again, the science of flight and jet propulsion cannot be kept secret, but the technological and engineering implementations of that science can be hidden to some degree — although not perfectly. Supersonic, and now hypersonic, flight technology is a closely guarded secret of the military, but any enterprise with the funding and the mandate can eventually master the technology, and will eventually produce better technology and better engineering designs once the process is fully open.

Because science cannot be effectively practiced in private (it can be practiced, but will not be as good as a research program pursued jointly by a community of researchers), governments seek the control and interdiction of technologies and materials. Anyone can learn nuclear science, but it is very difficult to obtain fissionables. Any car manufacturer can buy their rival’s products, disassemble them, and reserve engineer their components, but patented technologies are protected by the court system for a certain period of time. But everything in this process is open to dispute. Different nation-states have different patent protection laws. When you add industrial espionage to constant attempts to game the system on an international level, there are few if any secrets even in proprietary technology and engineering.

The technologies that worry us the most — such as nuclear weapons — are purposefully retarded in their development by stringent secrecy and international laws and conventions. Moreover, mastering the nuclear fuel cycle requires substantial resources, so that mostly limits such an undertaking to nation-states. Most nation-states want to get along to go along, so they accept the limitations on nuclear research and choose not to build nuclear weapons even if they possess the industrial infrastructure to do so. And now, since the end of the Cold War, even the nation-states with nuclear arsenals do not pursue the development of nuclear technology; so-called “fourth generation nuclear weapons” may be pursued in the secrecy of government laboratories, but not with the kind of resources that would draw attention. It is very unlikely that they are actually being produced.

Why should we care that nuclear technology is purposefully slowed and regulated to the point of stifling innovation? Should we not consider ourselves fortunate that governments that seem to love warfare have at least limited the destruction of warfare by limiting nuclear weapons? Even the limitation of nuclear weapons comes at a cost. Just as there is no black and white line separating science, technology, and engineering, there is no black and white line that separates nuclear weapons research from other forms of research. By clamping down internationally on nuclear materials and nuclear research, the world has, for all practical purposes, shut down the possibility of nuclear rockets. Yes, there are a few firms researching nuclear rockets that can be fueled without the fissionables that could also be used to make bombs, but these research efforts are attempts to “design around” the interdictions of nuclear technology and nuclear materials.

We have today the science relevant to nuclear rocketry; to master this technology would require practical experience. It would mean designing numerous designs, testing them, and seeing what works best. What works best makes its way into the next iteration, which is then in its turn improved. This is the practical business of technology and engineering, and it cannot happen without an immersion into practical experience. But the practical experience in nuclear rocketry is exactly what is missing, because the technology and materials are tightly controlled.

Thus we already can cite a clear instance of how existential risk mitigation becomes the loss of an existential opportunity. A demographically significant spacefaring industry would be an existential opportunity for humanity, but if the nuclear rocket would have been the breakout technology that actualized this existential opportunity, we do not know, and we may never know. Nuclear weapons were early recognized as an existential risk, and our response to this existential risk was to consciously and purposefully put a brake on the development of nuclear technology. Anyone who knows the history of nuclear rockets, of the NERVA and DUMBO programs, of the many interesting designs that were produced in the early 1960s, knows that this was an entire industry effectively strangled in the cradle, sacrificed to nuclear non-proliferation efforts as though to Moloch. Because science cannot be kept secret, entire industries must be banned.

by J. N. Nielsen (2015)

Research And Development

When climbing a tech tree, most governments figure this can be safely left to the private sector. They might give some seed money to worthy research projects, or help fund expensive projects like the Large Hadron Collider, but otherwise tech funding is somebody else's problem.

But in times of war in general, and in space opera style hyper-accelerated arms races in particular, this becomes a matter of a nation's life or death.

Research and development budget are always a cruel dilemma for any military. How do you divide your budget between [1] purchasing military assets that are obsolete but are available now, and [2] assets that are cutting edge high tech but are still being researched?

This is a familiar problem for any player of 4x strategy games. In such games more powerful military assets and secret weapons are represented by a "tech tree". Players must allocate their budget between purchasing research on how to build new unit types and purchasing examples of existing old unit types. On the one hand the more you spend on research, the more unstoppable a super-dreadnought warship you will (eventually) be able to construct. But on the other hand your opponent might spend their budget on swarms of primitive warships which none the less are more effective than your pitifully small fleet.


There are two aspects to the military procurement dilemma. First:

A gigantic technological race is in progress ... a new form of strategy is developing in peacetime, a strategy of which the phrase "arms race" used prior to the old great conflicts is hardly more than a faint reflection.

There are no battles in this strategy; each side is merely trying to outdo in performance the equipment of the other. It has been termed "logistic strategy". Its tactics are industrial, technical, and financial. It is a form of indirect attrition; instead of destroying enemy resources, its object is to make them obsolete, thereby forcing on him enormous expenditure...

A silent and apparently peaceful war is therefore in progress, but it could well be a war which of itself could be decisive.

—General d'Armee Andre Beaufre

If we do not engage in this "silent and apparently peaceful war," we will be defeated. However:

A common argument against investment in technological weapons is the engineering maxim, "If it works, it's obsolete." True, whatever one buys, if you had waited a few years something better would be available; but if this is carried to extremes, nothing will ever be built.

Whenever a new field of technology opens up, the people who use it must learn how. They must become operationally effective. Had we waited until third-generation missiles were available before we constructed any, we would not be alive today. We certainly would have had no experienced crews to man the missiles we would only now be constructing.

A time comes when systems must be built, even though we know they will be obsolete in future years...

The fallacy that prototypes and research are all that are needed should have been laid to rest by the experience of the French in 1939. The French Army had—and had possessed for quite a long time— prototypes of aircraft, armor, and antitank weapons much better than those of the German Army. The French did not have these weapons in their inventory because still better ones were coming. While they waited for the best weapons, they lost their country. Military action must be routine. It cannot be extraordinary, planned months in advance like a space spectacular. Operational experience with a weapons system is required before operational employment doctrines can be perfected. Troops must be trained, logistics bases developed, maintenance routines learned, idiosyncrasies—and modern technological gadgetry is full of them—must be discovered. This cannot be done if the latest technology is confined to the drawing board or laboratory.

S. T. Possony and J. E. Pournelle, The Strategy of Technology, 1970

There is no simple escape from this dilemma. Suppose that you are the Secretary of Defense, and you must recommend a military budget.

You have several choices.

1. Make severe cutbacks in the defense budget. This will leave more money in the hands of the taxpayers, and allow more investment in the nation's economy. Without a strong economy we are finished anyway; while if the economy is sufficiently strong, we will be able to afford a much larger defense establishment.

2. Invest in military research and development. This can be coupled with (1). Some military research will aid the civilian economy anyway. We mean here real development studies, not merely paper studies and patches.

3. Buy the weapons available today, so that the troops can become familiar with them and learn to maintain them; so that they become operational weapons systems.

These choices come up time after time. You have a billion dollars: do we invest that in development of military lasers, or do we buy a new aircraft carrier? The choice is not obvious. Without forces in being, small conflicts become big, and small wars can grow into large ones.

You have a sum of money. You may spend it on two wings of the best existing military aircraft, and thus have a force within two years.

You can also spend it to procure two wings of much better advanced aircraft to be delivered in ten years. If you choose the second option, your over-all military capabilities will probably be enhanced due to new technology developed as part of the procurement.

That's ten years from now. Meanwhile, you will NOT have the best equipment for the period of 2 through 8 years.

In combat, there are few prizes for second place, and none at all for what you would have had next year.

There are, however, persons not of good will who will muddy the waters: who will attack R&D spending on the grounds that the money is needed for operational weapons systems, then attack the operational systems because they are obsolete. They are poltroons; and alas, their name is legion, for they are many.

From MEN OF WAR, THERE WILL BE WAR VOL II edited by Jerry Pournelle (1984)

Technology Readiness Level

4x strategy games and poorly written science fiction assumes that once a new weapon or warship has been researched, it is instantly ready to start production next day. In the real world there are always bugs and glitches to deal with, which slows things up. Not to mention the time required training the troops in how to use the blasted things.

(The original 4X game was the tabletop boardgame Stellar Conquest (1975). This was the first SF boardgame I ever played and {modest cough} the first one I drew illustrations for.)

The classic cautionary tale is Sir Arthur C. Clarke's famous short story Superiority, which is required reading in some courses taught at M.I.T.. My take on the story is:

Voltaire said "Perfect is the enemy of good". Shakespeare said "striving to better, oft we mar what's well". Aristotle spoke of the Golden Mean to avoid extremes in any direction.

More practically:

Pareto principle
Also known as 80–20 rule, the law of the vital few, and the principle of factor sparsity. It commonly takes 20% of the full time to complete 80% of a task while to complete the last 20% of a task takes 80% of the effort. Achieving absolute perfection may be impossible and so, as increasing effort results in diminishing returns, further activity becomes increasingly inefficient.
Cult Of The Imperfect
This was formulated by Sir Robert Alexander Watson-Watt in World War 2, while he struggled to create early warning radar in Britain to counter the rapid growth of the German Luftwaffe. He said "Give them the third best to go on with; the second best comes too late, the best never comes."
George Stigler's Observation
Economist George Stigler said that "If you never miss a plane, you're spending too much time at the airport."

The thing about John Campbell is that he liked things big. He liked big men with big ideas working out big applications of their big theories.

And he liked it fast. His big men built big weapons within days; weapons that were, moreover, without serious shortcomings, or at least, with no shortcomings that could not be corrected as follows: “Hmm, something’s wrong — oh, I see — of course.” Then, in two hours, something would be jerry-built to fix the jerry-built device.

(ed note: any project manager can tell you that never happens)

The big applications were, usually, in the form of big weapons to fight big wars on tremendous scales. Part of it was, of course, Campbell’s conscious attempt to imitate and surpass Edward E. (“Doc”) Smith. The world-shaking, escalating conflicts in Campbell’s stories, as in The Space Beyond in this collection, is a reflection of the escalating conflict on the printed page between John and Doc.

From BIG, BIG, BIG by Isaac Asimov (1976)

The situation was now both serious and infuriating. With stubborn conservatism and complete lack of imagination, the enemy continued to advance with his old-fashioned and inefficient but now vastly more numerous ships. It was galling to realize that if we had only continued building, without seeking new weapons, we would have been in a far more advantageous position.

There were many acrimonious conferences at which Norden defended the scientists while everyone else blamed them for all that had happened. The difficulty was that Norden had proved every one of his claims: he had a perfect excuse for all the disasters that had occurred.

And we could not now turn back — the search for an irresistible weapon must go on. At first it had been a luxury that would shorten the war. Now it was a necessity if we were to end it victoriously.

From SUPERIORITY by Sir Arthur C. Clarke (1951)

The research process is also more complicated than one would think. In reality it has quite a few phases.

Technology readiness level is a scale used to measure how close a new technology is to being ready for actual use in the field on a real mission.

In the old (almost unplayable) tabletop game Star Empires each player had a limited number of research teams, symbolized by playing counters. Each one could research a single advance, some army weapon, artillery weapon, spacecraft weapon, missile warhead, warship type, etc. that was the next item in its respective tech tree.

If the tech advance was of difficulty One, you'd assign it to research team Alfa, pay the initial research cost, and place Alfa's counter on Research Flow Chart One in the square marked "S" for "start". Once the team has managed to traverse the flow chart to the space marked "F" for "finish" your interstellar empire would own that tech advance, and would instantly be able to start cranking out the new weapon from your factories.

But traversing the flow chart is a bit of a challenge.

Each turn, for all research teams with counters on the flow chart, you'd pay this turns research cost for that unit, and roll a ten-sided die. Examining the square the counter is currently occupying, you'd find the out-going arrow with the number rolled and move the counter accordingly. Some loop back to the same square so the team does not move. Others move to a new square. If the new square is the F square, the team is successful.

And if the square is a little skull-and-cross-bones symbol, the entire team is killed in a lab accident and removed. Next turn you'll have to spend money to recruit a replacement research team.

If, however, your research project is of difficulty Four, you'll have to use the flow chart below. Egad. This shows why game designers in the 1970s were desperate for somebody to invent personal computers. There were intermediate complexity flow charts for difficulty Two and three, but this is insane for a manual tabletop game.



A common failing of with those who write future histories is a failure to take into account Future Shock, that is, the rapid progress of technological advancement. Refer to the "Apes or Angels" argument. Consider that one hundred years ago the paper clip had just been invented, Marconi had invented the wireless radio, the Wright brothers had invented the airplane, and the latest cutting edge material was Bakelite. Assuming that technology continues to advance at the same rate, all of our flashy technological marvels of today will look just as quaint and obsolete in the year 2100. And in 2500, they will look like something made by Galileo.

Remember, this assumes that the rate of technological progress remains the same. The evidence suggests that the rate is increasing.

Authors who do not want to deal with such break-neck advances in technology will have to invent a way to put on the brakes to progress.


When it comes to futures histories in various SF novels, the main failing I have noted is a failure of scope. While you may read novels with orbital beanstalks, immortality drugs, virtual people living in digital cyber-reality, nanotechnology, transhumanity and post-humans, Dyson spheres, teleportation, zero-point energy, matter duplicators, time travel, cloning, and cyborgs; you almost never find an individual novel that has all of these things (although Greg Egan's DIASPORA comes close, and the Orion's Arm project comes even closer).

This is because future history SF novels are not meant to predict the future, so much as they are meant to illuminate a specific point the author is trying to make.

I am once again stunned at the insistence that Star Trek has to be allegorically relevant, but if it must, I'd prefer it take on more scientific/ethical issues, like a justification for banning genetic enhancement. or how a society with FTL, molecular replication, and teleportation has managed to sidestep a technological singularity.

Star Trek is considered by many to be the public face of SF, it's flagship. I hold by my belief that to retain that title it needs to take it up a level: travel out into some heretofore unexplored quadrant and find that it is heavily populated by Type II Kardashev cultures, Lovecraftian ancients, Kirby-esque star gods, Matrioshka brain AIs trying to tap reality's source-code, post-singularity societies like Banks Culture, Wright's Oecumene, or Hamilton's Edenists, etc.

In short, Trek needs to catch up with the rest of science fiction.

Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape- descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea.


INVENTOR n. A person who makes an ingenious arrangement of wheels, levers and springs, and believes it civilization.

From THE DEVIL'S DICTIONARY by Ambrose Bierce (1911)


Naturally, the more specific the details of your future technology that you describe in your SF story, the bigger the risk that it is going to sound quite silly in the decades to come. This is called "Zeerust", and of course TV Tropes has a page devoted to it just chock full of entertaining examples and associated tropes (food pills, jet pack, video phone, flying car, etc).

My favorite example is "Into the Meteorite Orbit" by Frank K. Kelly (1933).

It starts out so good. It predicts air-traffic controllers, the 22nd century as being dominated by the energy crisis, it even has the hero finding a recorded message on his video-telephone.

Then the reader's willing suspension of disbelief crashes and burns as the hero pulls the wax cylinder out of the video-telephone, puts it in the replay unit, and places the needle on the groove. Oops.

And then there were the slide-rules in a short story by A. E. Van Vogt, complete with a radio link to the ship's computer.

In "How to Build a Future", John Barnes suggests as a general rule one shouldn't try predicting technological advances past 500 years or so. After about 500 years of technological epochs, the current technology approaches 100% magic as compared to the starting technology, as per his explanation below:


My experienced-based general rule is that five hundred years is the absolute maximum.


I need not tell an SF audience that technological advance has dramatic effects. There are a lot of different ways to model it; this time I used the “shopping list” approach—gadgets are invented at a steady rate, but they are economically deployed (that is, come into actual widespread use) in bursts. Schumpeter suggested deployment might correlate with the upswing in the Kondratiev wave; it’s also a truism that war brings rapid technical development.

To express this, I simply assume significant new inventions go onto a “shopping list” or “technological backlog” of potential technology, and move off the list and into real deployment at a rate that varies between 0 and 100 percent, depending on the Kondratiev cycle value and the values of warfare indicators (see below).

As you can see in figure 2, this gives a fairly credible situation: technology sometimes stagnates as nothing new is deployed for a long time, and at other times skyrockets, especially after a long hiatus. This gave me as much information as I really wanted: eight major surges of technological innovation between now and the beginning of interstellar colonization. (A “major surge” is something on the order of the highly innovative periods 1900-20 or 1940-65.)

To envision the surges, I use a general rule that has no justification other than gut feeling. Each new surge is 90 percent what you might have expected from the last one, plus 10 percent magic (in its Clarke’s Law sense). So from the viewpoint of 1920, 90 percent of the gadgets of the (roughly) Manhattan Project through Apollo Project boom would be imaginable (indeed, some, like TV, were abortively available in the previous boom). But 10 percent (lasers, nuclear power, transistors) would be absolutely incomprehensible—magic.

I further arbitrarily assume that the major discoveries for the next surge have all been made as of today.

The graph shows a major surge in the 2000s and 2010s, Surge Zero, which should deploy everything in SF that seems pretty likely right now. Everything.

Does that feel like a real explosion in the brain, like Bruce Sterling or William Gibson at their dazzling best? All the same it’s only the start.

Surge One must be an immense extension of everything in Surge Zero, plus a 10 percent addition of things that work according to as-yet-undiscovered principles. Surge Two must be extensions on everything in Surge One (including the 10 percent of magic) plus 10 percent new magic. From our viewpoint it’s now 19 percent magic.

And Surge Three … well, you see where this gets to. Since the Inward Turn starts at the end of Surge Seven, 52 percent of significant new technology in the culture we’re imagining must be stuff we currently would not find comprehensible.

Realistically, the world should be half magic. Who’d have thought calculations, the lifeblood of hard SF, could drive us that far into fantasy?

Magic Percentage
% Magic010192734414752576165697275

From HOW TO BUILD A FUTURE by John Barnes (1990)

(ed note: Robert Heinlein originally wrote this in 1952. In 1980 he updated it)

      Most science fiction consists of big-muscled stories about adventures in space, atomic wars, invasions by extra-terrestrials, and such. All very well—but now we will take time out for a look at ordinary home life half a century hence. Except for tea leaves and other magical means, the only way to guess at the future is by examining the present in the light of the past. Let's go back half a century and visit your grandmother before we attempt to visit your grandchildren.

     1900: Mr. McKinley is President and the airplane has not yet been invented. Let's knock on the door of that house with the gingerbread, the stained glass, and the cupola.
     The lady of the house answers. You recognize her—your own grandmother, Mrs. Middleclass. She is almost as plump as you remember her, for she "put on some good, healthy flesh" after she married.
     She welcomes you and offers coffee cake, fresh from her modern kitchen (running water from a hand pump; the best coal range Pittsburgh ever produced). Everything about her house is modern—hand-painted china, souvenirs from the Columbian Exposition, beaded portières, shining baseburner stoves, gas lights, a telephone on the wall.
     There is no bathroom, but she and Mr. Middleclass are thinking of putting one in. Mr. Middleclass's mother calls this nonsense, but your grandmother keeps up with the times. She is an advocate of clothing reform, wears only one petticoat, bathes twice a week, and her corsets are guaranteed rust proof. She has been known to defend female suffrage—but not in the presence of Mr. Middleclass.

     Nevertheless, you find difficulty in talking with her. Let's jump back to the present (1950) and try again.
     The automatic elevator takes us to the ninth floor, and we pick out a door by its number, that being the only way to distinguish it.
     "Don't bother to ring," you say? What? It's your door and you know exactly what lies beyond it—

     Very well, let's move a half century into the future (to 2000) and try another middle class home.
     It's a suburban home not two hundred miles from the city. You pick out your destination from the air while the cab is landing you—a cluster of hemispheres that makes you think of the houses Dorothy found in Oz.
     You set the cab to return to its hangar and go into the entrance hall. You neither knock nor ring. The screen has warned them before you touched down on the landing flat and the autobutler's transparency is shining with: PLEASE RECORD A MESSAGE.
     Before you can address the microphone a voice calls out, "Oh, it's you! Come in, come in." There is a short wait, as your hostess is not at the door. The autobutler flashed your face to the patio—where she was reading and sunning herself—and has relayed her voice back to you.
     She pauses at the door, looks at you through one-way glass, and frowns slightly; she knows your old-fashioned disapproval of casual nakedness. Her kindness causes her to disobey the family psychiatrist; she grabs a robe and covers herself before signaling the door to open.
     The psychiatrist was right; you have thus been classed with strangers, tradespeople, and others who are not family intimates. But you must swallow your annoyance; you cannot object to her wearing clothes when you have sniffed at her for not doing so.
     There is no reason why she should wear clothes at home. The house is clean—not somewhat clean, but clean—and comfortable. The floor is warm to bare feet; there are no unpleasant drafts, no cold walls. All dust is precipitated from the air entering this house. All textures, of floor, of couch, of chair, are comfortable to bare skin. Sterilizing ultra-violet light floods each room whenever it is unoccupied, and, several times a day, a "whirlwind" blows house-created dust from all surfaces and whisks it out. These auto services are unobtrusive because automatic cut-off switches prevent them from occurring whenever a mass in a room is radiating at blood temperature.
     Such a house can become untidy, but not dirty. Five minutes of straightening, a few swipes at children's fingermarks, and her day's housekeeping is done. Oftener than sheets were changed in Mr. McKinley's day, this housewife rolls out a fresh layer of sheeting on each sitting surface and stuffs the discard down the oubliette. This is easy; there is a year's supply on a roll concealed in each chair or couch. The tissue sticks by pressure until pulled loose and does not obscure the pattern and color.

     You go into the family room, sit down, and remark on the lovely day. "Isn't it?" she answers. "Come sunbathe with me."
     The sunny patio gives excuse for bare skin by anyone's standards; thankfully she throws off the robe and stretches out on a couch. You hesitate a moment. After all, she is your own grandchild, so why not? You undress quickly, since you left your outer wrap and shoes at the door (only barbarians wear street shoes in a house) and what remains is easily discarded. Your grandparents had to get used to a mid-century beach. It was no easier for them.
     On the other hand, their bodies were wrinkled and old, whereas yours is not. The triumphs of endocrinology, of cosmetics, of plastic surgery, of figure control in every way are such that a woman need not change markedly from maturity until old age. A woman can keep her body as firm and slender as she wishes—and most of them so wish. This has produced a paradox: the United States has the highest percentage of old people in all its two and a quarter centuries, yet it seems to have a larger proportion of handsome young women than ever before.
     (Don't whistle, son! That's your grandmother—)
     This garden is half sunbathing patio, complete with shrubs and flowers, lawn and couches, and half swimming pool. The day, though sunny, is quite cold—but not in the garden, and the pool is not chilly. The garden appears to be outdoors, but is not; it is covered by a bubble of transparent plastic, blown and cured on the spot. You are inside the bubble; the sun is outside; you cannot see the plastic.

     She invites you to lunch; you protest. "Nonsense!" she answers, "I like to cook." Into the house she goes. You think of following, but it is deliciously warm in the March sunshine and you are feeling relaxed to be away from the city. You locate a switch on the side of the couch, set it for gentle massage, and let the couch knead your troubles away. The couch notes your heart rate and breathing; as they slow, so does it. As you fall asleep it stops.
     Meanwhile your hostess has been "slaving away over a hot stove." To be precise, she has allowed a menu selector to pick out an 800-calorie, 4-ration-point luncheon. It is a random-choice gadget, somewhat like a slot machine, which has in it the running inventory of her larder and which will keep hunting until it turns up a balanced meal. Some housewives claim that it takes the art out of cookery, but our hostess is one of many who have accepted it thankfully as an endless source of new menus. Its choice is limited today as it has been three months since she has done grocery shopping. She rejects several menus; the selector continues patiently to turn up combinations until she finally accepts one based around fish disguised as lamb chops.
     Your hostess takes the selected items from shelves or the freezer. All are prepared; some are pre-cooked. Those still to be cooked she puts into her—well, her "processing equipment," though she calls it a "stove." Part of it traces its ancestry to diathermy equipment; another feature is derived from metal enameling processes. She sets up cycles, punches buttons, and must wait two or three minutes for the meal to cook. She spends the time checking her ration accounts.
     Despite her complicated kitchen, she doesn't eat as well as her great grandmother did—too many people and too few acres.
     Never mind; the tray she carries out to the patio is well laden and beautiful. You are both willing to nap again when it is empty. You wake to find that she has burned the dishes and is recovering from her "exertion" in her refresher. Feeling hot and sweaty from your nap you decide to use it when she comes out. There is a wide choice offered by the 'fresher, but you limit yourself to a warm shower growing gradually cooler, followed by warm air drying, a short massage, spraying with scent, and dusting with powder. Such a simple routine is an insult to a talented machine.
     Your host arrives home as you come out; he has taken a holiday from his engineering job and has had the two boys down at the beach. He kisses his wife, shouts, "Hi, Duchess!" at you, and turns to the video, setting it to hunt and sample the newscasts it has stored that day. His wife sends the boys in to 'fresh themselves then says, "Have a nice day, dear?"
     He answers, "The traffic was terrible. Had to make the last hundred miles on automatic. Anything on the phone for me?"
     "Weren't you on relay?"
     "Didn't set it. Didn't want to be bothered." He steps to the house phone, plays back his calls, finds nothing he cares to bother with—but the machine goes ahead and prints one message; he pulls it out and tears it off.
     "What is it?" his wife asks.
     "Telestat from Luna City—from Aunt Jane."
     "What does she say?"
     "Nothing much. According to her, the Moon is a great place and she wants us to come visit her."
     "Not likely!" his wife answers. "Imagine being shut up in an air-conditioned cave."
     "When you are Aunt Jane's age, my honey lamb, and as frail as she is, with a bad heart thrown in, you'll go to the Moon and like it. Low gravity is not to be sneezed at—Auntie will probably live to be a hundred and twenty, heart trouble and all."
     "Would you go to the Moon?" she asks.
     "If I needed to and could afford it." He turns to you. "Right?"
     You consider your answer. Life still looks good to you—and stairways are beginning to be difficult. Low gravity is attractive even though it means living out your days at the Geriatrics Foundation on the Moon. "It might be fun to visit," you answer. "One wouldn't have to stay."

     Hospitals for old people on the Moon? Let's not be silly—
     Or is it silly? Might it not be a logical and necessary outcome of our world today?
     Space travel we will have, not fifty years from now, but much sooner. It's breathing down our necks. As for geriatrics on the Moon, for most of us no price is too high and no amount of trouble is too great to extend the years of our lives. It is possible that low gravity (one sixth, on the Moon) may not lengthen lives; nevertheless it may—we don't know yet—and it will most certainly add greatly to comfort on reaching that inevitable age when the burden of dragging around one's body is almost too much, or when we would otherwise resort to an oxygen tent to lessen the work of a worn-out heart.
     By the rules of prophecy, such a prediction is probable, rather than impossible.
     But the items and gadgets suggested above are examples of timid prophecy.
     What are the rules of prophecy, if any?

     Look at the graph shown here. The solid curve is what has been going on this past century. It represents many things—use of power, speed of transport, numbers of scientific and technical workers, advances in communication, average miles traveled per person per year, advances in mathematics, the rising curve of knowledge. Call it the curve of human achievement.
     What is the correct way to project this curve into the future? Despite everything, there is a stubborn "common sense" tendency to project it along dotted line number one—like the patent office official of a hundred years back who quit his job "because everything had already been invented." Even those who don't expect a slowing up at once tend to expect us to reach a point of diminishing returns (dotted line number two).
     Very daring minds are willing to predict that we will continue our present rate of progress (dotted line number three—a tangent).
     But the proper way to project the curve is dotted line number four—for there is no reason, mathematical, scientific, or historical, to expect that curve to flatten out, or to reach a point of diminishing returns, or simply to go on as a tangent. The correct projection, by all facts known today, is for the curve to go on up indefinitely with increasing steepness.
     The timid little predictions earlier in this article actually belong to curve one, or, at most, to curve two. You can count on the changes in the next fifty years at least eight times as great as the changes of the past fifty years.
     The Age of Science has not yet opened

AXIOM: A "nine-days' wonder" is taken as a matter of course on the tenth day.
AXIOM: A "common sense" prediction is sure to err on the side of timidity.
AXIOM: The more extravagant a prediction sounds the more likely it is to come true.
     So let's have a few free-swinging predictions about the future.
     Some will be wrong—but cautious predictions are sure to be wrong.

     1. 1950 Interplanetary travel is waiting at your front door—C.O.D. It's yours when you pay for it.
     1965 And now we are paying for it and the cost is high. But, for reasons understandable only to bureaucrats, we have almost halted development of a nuclear-powered spacecraft when success was in sight. Never mind; if we don't another country will. By the end of this century space travel will be cheap.
     1980 And now the Apollo-Saturn Man-on-the-Moon program has come and gone, and all we have now in the U.S.A. as a new man-in-space program is the Space Shuttle—underfinanced and two years behind schedule.
     Is space travel dead? No, because the United States is not the only nation on this planet. Today both Japan and Germany seem to be good bets—countries aware that endless wealth is out there for the taking. USSR seems to be concentrating on the military aspects rather than on space travel, and the People's Republic of China does not as yet appear to have the means to spare—but don't count out either nation; the potential is there, in both cases.
     And don't count out the United States! Today most of our citizens regard the space program as a boondoggle (totally unaware that it is one of the very few Federal programs that paid for themselves, manyfold). But we are talking about twenty years from now, 2000 A.D. Let's see it in perspective. Exactly thirty years ago George Pal and Irving Pichel and I—and ca. 200 others—were making the motion picture Destination Moon. I remember sharply that most of the people working on that film started out thinking that it was a silly fantasy, an impossibility. I had my nose rubbed in it again and again, especially if the speaker was unaware that I had written it. (Correction: written the first version of it. By the time it was filmed, even the banker's wife was writing dialog.)
     As for the general public—A trip to the Moon? Nonsense!
     That was thirty years ago, late 1949.
     Nineteen years and ten months later Apollo 11 landed on the Moon.
     Look again at the curves. With respect to space travel (and industry, power, and colonization) we have dropped to that feeble curve #1—but we could shift back to curve #4 overnight if our President and/or Congress got it through their heads that not one but all of our crisis problems can be solved by exploiting space. Employment, inflation, pollution, population, energy, running out of nonrenewable resources—there is pie in the sky for the U.S.A. and for the entire planet including the impoverished "Third World."
     I won't try to prove it here. See The Third Industrial Revolution by G. Harry Stine and see A Step Farther Out by Dr. Jerry Pournelle—and accept my assurance that I have known both authors well for twenty-odd years, know that each has years of experience in aerospace, and that each has both the formal education and the continuing study—and the horse sense!—to be a true expert in this matter.
     From almost total disbelief about space travel (99.9+%) to a landing on the Moon in twenty years . . . from President Kennedy's announcement of intention to that Lunar landing in only seven years … and still twenty years to go until the year 2000—we can still shift to curve #4 (and get rich) almost overnight. By 2000 A.D. we could have O'Neill colonies, self-supporting and exporting power to Earth, at both Lagrange-4 and Lagrange-5, transfer stations in orbit about Earth and around Luna, a permanent base on Luna equipped with an electric catapult—and a geriatrics retirement home.
     However, I am not commissioned to predict what we could do but to predict (guess) what is most likely to happen by 2000 A.D.
     Our national loss of nerve, our escalating anti-intellectualism, our almost total disinterest in anything that does not directly and immediately profit us, the shambles of public education throughout most of our nation (especially in New York and California) cause me to predict that our space program will continue to dwindle. It would not surprise me (but would distress me mightily!) to see the Space Shuttle canceled.
     In the meantime some other nation or group will start exploiting space—industry, power, perhaps Lagrange-point colonies—and suddenly we will wake up to the fact that we have been left at the post. That happened to us in '57; we came up from behind and passed the competition. Possibly we will do it again. Possibly—
     But I am making no cash bets.

     3. 1950 The most important military fact of this century is that there is no way to repel an attack from outer space.
     1965 I flatly stand by this one. True, we are now working on Nike-Zeus and Nike-X and related systems and plan to spend billions on such systems—and we know that others are doing the same thing. True, it is possible to hit an object in orbit or trajectory. Nevertheless this prediction is as safe as predicting tomorrow's sunrise. Anti-aircraft fire never stopped air attacks; it simply made them expensive. The disadvantage in being at the bottom of a deep "gravity well" is very great; gravity gauge will be as crucial in the coming years as wind gauge was in the days when sailing ships controlled empires. The nation that controls the Moon will control the Earth—but no one seems willing these days to speak that nasty fact out loud.
     1980 I have just heard a convincing report that the USSR has developed lasers far better than ours that can blind our eyes-in-the-sky satellites and, presumably, destroy our ICBMs in flight. Stipulate that this rumor is true: It does not change my 1950 assertion one iota. Missiles tossed from the Moon to the Earth need not be H-bombs or any sort of bomb—or even missile-shaped. All they need be is massive . . . because they arrive at approximately seven miles per second. A laser capable of blinding a satellite and of disabling an ICBM to the point where it can't explode would need to be orders of magnitude more powerful in order to volatilize a house-size chunk of Luna. For further details see my The Moon Is a Harsh Mistress.

     5. 1950 In fifteen years the housing shortage will be solved by a "breakthrough" into new technology which will make every house now standing as obsolete as privies.
     1965 Here I fell flat on my face. There has been no breakthrough in housing, nor is any now in prospect—instead the ancient, wasteful methods of building are now being confirmed by public subsidies. The degree of our backwardness in the field is hard to grasp; we have never seen a modern house. Think what an automobile would be if each one were custom-built from materials fetched to your home—what would it look like, what would it do, and how much would it cost. But don't set the cost lower than $100,000 or the speed higher than 10 m/h, if you want to be realistic about the centuries of difference between the housing industry and the automotive industry.
     I underestimated (through wishful thinking) the power of human stupidity—a fault fatal to prophecy.
     1980 I'm still flat on my face with my nose rubbed in the mud; the situation is worse than ever. See "A Bathroom of Her Own". And that figure of $100,000 just above was with gold at $35 per troy ounce—so change it to one million dollars—or call it 2700 troy ounces of gold. Or forget it. The point is that it would be very nearly impossible to build even a clunker automobile at any price if we built them the way we build houses.
     We have the technology to build cheap, beautiful, efficient, flexible (modular method) houses, extremely comfortable and with the durability of a Rolls Royce. But I cannot guess when (if ever) the powers that be (local bureaucrats, unions, building materials suppliers, county and state officials) will permit us poor serfs to have modern housing.

     6. 1950 We'll all be getting a little hungry by and by.
     1965 No new comment.
     1980 Not necessarily. In 1950 I was too pessimistic concerning population. Now I suspect that the controlling parameter is oil. In modern agriculture oil is the prime factor—as power for farm machinery (obviously) but also for insecticides and for fertilizers. Since our oil policies in Washington are about as boneheaded—counterproductive—as they can be, I have no way to guess how much food we can raise in 2000 A.D. But no one in the United States should be hungry in 2000 A.D.—unless we are conquered and occupied.

     7. 1950 The cult of the phony in art will disappear. So-called "modern art" will be discussed only by psychiatrists.
     1965 No new comment.
     1980 One may hope. But art reflects culture and the world is even nuttier now than it was in 1950; these are the Crazy Years. But, while "fine" art continues to look like the work of retarded monkeys, commercial art grows steadily better.

     8. 1950 Freud will be classed as a pre-scientific, intuitive pioneer and psychoanalysis will be replaced by a growing, changing "operational psychology" based on measurement and prediction.
     1965 No new comment.
     1980 This prediction is beginning to come true. Freud is no longer taken seriously by informed people. More and more professional psychologists are skilled in appropriate mathematics; most of the younger ones understand inductive methodology and the nature of scientific confirmation and are trying hard to put rigor into their extremely difficult, still inchoate subject. For some of the current progress see Dr. Pournelle's book.
     By 2000 A.D. we will know a great deal about how the brain functions . . . whereas in 1900 what little we knew was wrong.
     I do not predict that the basic mystery of psychology—how mass arranged in certain complex patterns becomes aware of itself—will be solved by 2000 A.D. I hope so but do not expect it.

     9. 1950 Cancer, the common cold, and tooth decay will all be conquered; the revolutionary new problem in medical research will be to accomplish "regeneration," i.e., to enable a man to grow a new leg, rather than fit him with an artificial limb.
     1965 In the meantime spectacular progress has been made in organ transplants—and the problem of regeneration is related to this one. Biochemistry and genetics have made a spectacular breakthrough in "cracking the genetic code." It is a tiny crack, however, with a long way to go before we will have the human chromosomes charted and still longer before we will be able to "tailor" human beings by gene manipulation. The possibility is there—but not by year 2000. This is probably just as well. If we aren't bright enough to build decent houses, are we bright enough to play God with the architecture of human beings?
     1980 I see no reason to change this prediction if you will let me elaborate (weasel) a little. "The common cold" is a portmanteau expression for upper respiratory infections which appear to be caused by a very large number of different viruses. Viruses are pesky things. It is possible to immunize against them, e.g., vaccination against smallpox, a virus disease. But there are almost no chemotherapies, medicines, against viruses. That is why "the common cold" is treated much the same way today as in 1900, i.e., support the patient with bed rest, liquids, aspirin to make him more comfortable, keep him warm. This was standard in 1900 and it is still standard in 1980.
     It is probable that your body makes antibodies against the virus of any cold you catch. But this gives you no protection against that virus's hundreds of close relatives found in any airport, theater, supermarket, or gust of dust off the street. In the meantime, while his kinfolk take turns making you miserable, virus #1 has mutated and you have no antibodies against the mutation.
     Good news: Oncology (cancer), immunology, hematology, and "the common cold" turn out to be strongly interrelated subjects; research in all these is moving fast—and a real breakthrough in any one might mean a breakthrough in all.

     10. 1950 By the end of this century mankind will have explored this solar system, and the first ship intended to reach the nearest star will be a building.
     1965 Our editor suggested that I had been too optimistic on this one—but I still stand by it. It is still thirty-five years to the end of the century. For perspective, look back thirty-five years to 1930—the American Rocket Society had not yet been founded. Another curve, similar to the one herewith in shape but derived entirely from speed of transportation, extrapolates to show faster-than-light travel by year 2000. I guess I'm chicken, for I am not predicting FTL ships by then, if ever. But the prediction still stands without hedging.
     1980 My money is still on the table at twenty years and counting. Senator Proxmire can't live forever. In the last 10½ years men have been to the Moon several times; much of the Solar system has been most thoroughly explored within the limits of "black box" technology and more will be visited before this year is out.
     Ah, but not explored by men—and the distances are so great. Surely they are . . . by free-fall orbits, which is all that we have been using. But there are numerous proposals (and not all ours!) for constant-boost ships, proposals that require R&D on present art only—no breakthroughs (I respectfully disagree).
     Reach for your pocket calculator and figure how long it would take to make a trip to Mars and back if your ship could boost at one-tenth gee (that don't sound like much, but it is still a freaking torchship. The tell-tale term is "constant boost"). We will omit some trivia by making it from parking orbit to parking orbit, use straight-line trajectories, and ignore the Sun's field—we'll be going uphill to Mars, downhill to Earth; what we lose on the roundabouts we win on the shys.
     These casual assumptions would cause Dan Alderson, ballistician at Jet Propulsion Laboratory, to faint. But after he comes out of his faint he would agree that our answers would be of correct close order of magnitude—and all I'm trying to prove is that even a slight constant boost makes an enormous difference in touring the Solar System. (Late in the 21st century we'll offer the Economy Tour: Ten Planets in Ten Days.)
     There are an unlimited number of distances between rather wide parameters for an Earth-Mars-Earth trip but we will select one that is nearly minimum (it's cheating to wait in orbit at Mars for about a year in order to take the shortest trip each way . . . and unthinkable to wait years for the closest approach). We'll do this Space Patrol style: There's Mars, here we are at L-5; let's scoot over, swing around Mars, and come straight home. Just for drill.
     Conditions: Earth-surface gravity (one "gee") is an acceleration of 32.2 feet per second squared, or 980.7 centimeters per second squared. Mars is in or near opposition (Mars is rising as Sun is setting). We will assume that the round trip is 120,000,000 miles. If we were willing to wait for closest approach we could trim that to less than 70,000,000 miles . . . but we might have to wait as long as 17 years. So we'll take a common or garden variety opposition—one every 26 months—for which the distance to Mars is about 50- to 60,000,000 miles and never over 64 million.
     (With Mars in conjunction on the far side of the Sun, we could take the scenic route of over 500 million miles—how much over depends on how easily you sunburn. I suggest a minimum of 700 million miles.)
     You now have all necessary data to figure the time it takes to travel Earth-Mars-Earth in a constant-boost ship—any constant-boost ship—when Mars is at opposition. (If you insist on the scenic route, you can't treat the trajectory approximations as straight lines and you can't treat space as flat but a bit uphill. You'll need Alderson or his equal and a big computer, not a pocket calculator; the equations are very hairy and sometimes shoot back.)
     But us two space cadets are doing this by eyeballing it, using Tennessee windage, an aerospace almanac, a Mickey Mouse watch, and an SR-50 Pop discarded years ago.
     We need just one equation: Velocity equals acceleration times elapsed time: v = at
     This tells us that our average speed is ½at—and from that we know that the distance achieved is the average speed times the elapsed time: d = ½at2
       If you don't believe me, check any physics text, encyclopedia, or nineteen other sorts of reference books—and I did that derivation without cracking a book but now I'm going to stop and find out whether I've goofed—I've had years of practice in goofing. (Later—seems okay.)
     Just two things to remember: 1) This is a 4-piece trip—boost to midpoint, flip over and boost to brake; then do the same thing coming home. Treat all four legs as being equal or 30,000,000 miles, so figure one of them and multiply by four (Dan, stop frowning; this is an approximation . . . done with a Mickey Mouse watch.)
     2) You must keep your units straight. If you start with centimeters, you are stuck with centimeters; if you start with feet, you are stuck with feet. So we have ¼ of the trip equals 5280 × 30,000,000 = 1.584 × 1011 feet, or 4.827 × 1012 centimeters.
     One last bit: Since it is elapsed time we are after, we will rearrange that equation (d = ½at2) so that you can get the answer in one operation on your trusty-but-outdated pocket calculator . . . or even on a slide rule, as those four-significant-figures data are mere swank; I've used so many approximations and ignored so many minor variables that I'll be happy to get answers correct to two significant figures.

     d / ½a = t2

     this gives us

     t = √d / ½a

     d is 30,000,000 miles expressed in feet, or 158,400,000,000. Set that into your pocket calculator. Divide it by one half of one tenth of gee, or 1.61. Push the square root button. Multiply by 4. You now have the elapsed time of the round trip expressed in seconds so divide by 3600 and you have it in hours, and divide that by 24 and you have it in days.
     At this point you are supposed to be astonished and to start looking for the mistake. While you are looking, I'm going to slide out to the refrigerator.
     There is no mistake. Work it again, this time in metric. Find a reference book and check the equation. You will find the answer elsewhere in this book but don't look for it yet; we'll try some other trips you may take by 2000 A.D. if you speak Japanese or German—or even English if Proxmire and his ilk fail of reelection.
     Same trip, worked the same way, but at only one percent of gee. At that boost I would weigh less than my shoes weigh here in my study.
     Hmmph! Looks as if one answer or the other must be wrong.
     Bear with me. This time we'll work it at a full gee, the acceleration you experience lying in bed, asleep. (See Einstein's 1905 paper.)
     (Preposterous. All three answers must be wrong.)
     Please stick with me a little longer. Let's run all three problems for a round trip to Pluto—in 2006 A.D., give or take a year. Why 2006? Because today Pluto has ducked inside the orbit of Neptune and won't reach perihelion until 1989—and I want it to be a bit farther away; I've got a rabbit stashed in the hat.
     Pluto ducks outside again in 2003 and by 2006 it will be (give or take a few million miles) 31.6 A.U. from the Sun, figuring an A.U. at 92,900,000 miles or 14,950,000,000,000 centimeters as we'll work this both ways, MKS and English units. (All right, all right—1.495 × 1013 centimeters; it gets dull here at this typewriter.)
     Now work it all three ways, a round trip of 63.2 A.U. at a constant boost of one gravity, one tenth gravity, and one hundredth of a gee—and we'll dedicate this to Clyde Tombaugh, the only living man to discover a new planet—through months of tedious and painstaking examination of many thousands of films.
     Some think that Pluto was once a satellite and its small size makes this possible. But it is not a satellite today. It is both far too big and hundreds of millions of miles out of position to be an asteroid. It can't be a comet. So it's a planet—or something so exotic as to be still more of a prize.
     Its size made it hard to find and thus still more of an achievement. But Tombaugh continued the search for seventeen weary years and many millions more films. If there is an Earth-size planet out there, it is at least three times as distant as Pluto, and a gas giant would have to be six times as far. Negative data win no prizes but they are the bedrock of science.
     Until James W. Christy on 22 June 1978 discovered Pluto's satellite, Charon, it was possible for us romantics to entertain the happy thought that Pluto was loaded with valuable heavy metals; the best estimate of its density made this plausible. But the mass of a planet with a satellite can be calculated quite easily and accurately, and from that, its density.
     The new figure was much too low, only half again as heavy as water. Methane snow? Perhaps.
     So once again a lovely theory is demolished by an awkward fact.
     Nevertheless Pluto remains a most mysterious and most intriguing heavenly body. A planet the size and mass of Mars might not be too much use to us out there . . . but think of it as a fuel dump. Many stories and many nonfictional projections speak of using the gas giants and/or the rings of Saturn as sources of fuel. But if Pluto is methane ice or water ice or frozen hydrogen or all three, as a source of fuel—conventional, or fusion, or even reaction mass—Pluto has one supremely important advantage over the gas giants: Pluto is not at the bottom of a horridly deep gravity well.
     Finished calculating? Good. Now see why I wanted our trip to Pluto to be a distance of 31.6 A.U.:
     N.B.: All trips are Earth parking orbit to Earth parking orbit without stopping at the target planet (Mars or Pluto). I assume that Hot Pilot Tom Corbett will handle his gravity-well maneuvers at Mars and at Pluto so as not to waste mass-energy—but that's his problem. Now about that assumption of "flat space" only slightly uphill: The Sun has a fantastically deep gravity well; its "surface" gravity is 28 times as great as ours and its escape speed is 55+ times as great—but at the distance of Earth's orbit that grasp has attenuated to about one thousandth of a gee, and at Pluto at 31.6 A.U. it has dropped off to a gnat's whisker, one millionth of gee.
     (No wonder it takes 2½ centuries to swing around the Sun. By the way, some astronomers seem positively gleeful that today Pluto is not the planet farthest from the Sun. The facts: Pluto spends nine-tenths of its time outside Neptune's orbit, and it averages being 875,000,000 miles farther out than Neptune—and at maximum is nearly 2 billion miles beyond Neptune's orbit (1.79 × 109 miles)—friends, that's more than the distance from here to Uranus, nearly four times as far as from here to Jupiter. When Pluto is out there—1865 or 2114 A.D.—it takes light 6 hours and 50 minutes to reach it. Pluto—the Winnuh and still Champeen! Sour grapes is just as common among astronomers as it is in school yards.)

4.59 days@1 gee vs.4.59 weeks
14.5 days@1/10 gee vs.14.5 weeks
45.9 days@1/100 gee vs.45.9 weeks
145 days@1/1000 gee vs.145 weeks

     —and the rabbit is out of the hat. You will have noticed that the elapsed-time figures are exactly the same in both columns, but in days for Mars, weeks for Pluto—i.e., with constant-boost ships of any sort Pluto is only 7 times as far away for these conditions as is Mars even though in miles Pluto is about 50 times as far away. 
     If you placed Pluto at its aphelion (stay alive another century and a quarter—quite possible), at one gee the Pluto round trip would take 5.72 weeks, at 1/10 gee 18.1 weeks, at 1/100 gee 57.2 weeks—and at 1/1000 gee 181 weeks, or 3 yrs & 25 wks.
     I have added on the two illustrations at 1/1000 of one gravity boost because today (late 1979 as I write) we do not as yet know how to build constant-boost ships for long trips at 1 gee, 1/10 gee, or even 1/100 gee; Newton's Third Law of Motion (from which may be derived all the laws of rocketry) has us (temporarily) stumped. But only temporarily. There is E = mc2, too, and there are several possible ways of "living off the country" like a foraging army for necessary reaction mass. Be patient; this is all very new. Most of you who read this will live to see constant-boost ships of 1/10 gee or better—and will be able to afford vacations in space—soon, soon! I probably won't live to see it, but you will. (No complaints, Sergeant—I was born in the horse & buggy age; I have lived to see men walk on the Moon and to see live pictures from the soil of Mars. I've had my share!)
     But if you are willing to settle today for a constant-boost on the close order of magnitude of 1/1000 gee, we can start the project later this afternoon, as there are several known ways of building constant-boost jobs with that tiny acceleration—even light-sail ships.
     I prefer to talk about light-sail ships (or, rather, ships that sail in the "Solar wind") because those last illustrations I added (1/1000 gee) show that we have the entire Solar System available to us right now; it is not necessary to wait for the year 2000 and new breakthroughs.
     Ten weeks to Mars . . . a round trip to Pluto at 31.6 A.U. in 2 years and 9 months . . . or a round trip to Pluto's aphelion, the most remote spot we know of in the Solar System (other than the winter home of the comets).
     Ten weeks—it took the Pilgrims in the Mayflower nine weeks and three days to cross the Atlantic.
     Two years and nine months—that was a normal commercial voyage for a China clipper sailing out of Boston in the last century . . . and the canny Yankee merchants got rich on it.
     Three years and twenty-five weeks is excessive for the China trade in the 19th century . . . but no one will ever take that long trip to Pluto because Pluto does not reach aphelion until 2113 and by then we'll have ships that can get out there (constant boost with turnover near midpoint) in three weeks
     Please note that England, Holland, Spain, and Portugal all created worldwide empires with ships that took as long to get anywhere and back as would a 1/1000-gee spaceship. On the high seas or in space it is not distance that counts but time. The magnificent accomplishments of our astronauts up to now were made in free fall and are therefore analogous to floating down the Mississippi on a raft. But even the tiniest constant boost turns sailing the Solar System into a money-making commercial venture.

     11. 1950 Your personal telephone will be small enough to carry in your handbag. Your house telephone will record messages, answer simple inquiries, and transmit vision.
     1965 No new comment.
     1980 This prediction is trivial and timid. Most of it has already come true and the telephone system will hand you the rest on a custom basis if you'll pay for it. In the year 2000, with modern telephones tied into home computers (as common then as flush toilets are today) you'll be able to have 3-dimensional holovision along with stereo speech. Arthur C. Clarke says that this will do away with most personal contact in business. I agree with all of Mr. Clarke's arguments and disagree with his conclusion; with us monkey folk there is no substitute for personal contact; we enjoy it and it fills a spiritual need.
     Besides that, the business conference is often an excuse to loaf on the boss's time and the business convention often supplies some of the benefits of the Roman Saturnalia.
     Nevertheless I look forward to holovideostereophones without giving up personal contacts.

     12. 1950 Intelligent life will be found on Mars.
     1965 Predicting intelligent life on Mars looks pretty silly after those dismal photographs. But I shan't withdraw it until Mars has been thoroughly explored. As yet we really have no idea—and no data—as to just how ubiquitous and varied life may be in this galaxy; it is conceivable that life as we don't know it can evolve on any sort of a planet . . . and nothing in our present knowledge of chemistry rules this out. All the talk has been about life-as-we-know-it—which means terrestrial conditions.
     But if you feel that this shows in me a childish reluctance to give up thoats and zitidars and beautiful Martian princesses until forced to, I won't argue with you—I'll just wait.
     1980 The photographs made by the Martian landers of 1976 and their orbiting companions make the prediction of intelligent Martian life look even sillier. But the new pictures and the new data make Mars even more mysterious. I'm a diehard because I suspect that life is ubiquitous—call that a religious opinion if you wish. But remember two things: Almost all discussion has been about Life-as-we-know-it . . . but what about Life-as-we-don't-know-it? If there were Martians around the time that those amazing gullies and canyons were formed, perhaps they went underground as their atmosphere thinned. At present, despite wonderful pictures, our data are very sparse; those two fixed landers are analogous to two such landing here: one on Canadian tundra, the other in Antarctica—hardly sufficient to solve the question: Is there intelligent life on Sol III?
     (Is there intelligent life in Washington, D.C.?)
     Whistling in the dark—I think I goofed on this one. But if in fact Mars is uninhabited, shortly there will be a land rush that will make the Oklahoma land stampede look gentle. Since E = mc2 came into our lives, all real estate is potentially valuable; it can be terraformed to suit humans. There has been so much fiction and serious, able nonfiction published on how to terraform Mars that I shan't add to it, save to note one thing:
     Power is no problem. Sunshine at that distance has dropped off to about 43% of the maximum here—but Mars gets all of it and gets it all day long save for infrequent dust storms . . . whereas the most that Philadelphia (and like places) ever gets is 35%—and overcast days are common. Mars won't need solar power from orbit; it will be easier to do it on the ground.
     But don't be surprised if the Japanese charge you a very high fee for stamping their visa into your passport plus requiring deposit of a prepaid return ticket or, if you ask for immigrant's visa, charge you a much, much higher fee plus proof of a needed colonial skill.
     For there is intelligent life in Tokyo.

     13. 1950 A thousand miles an hour at a cent a mile will be commonplace; short hauls will be made in evacuated subways at extreme speed.
     1965 I must hedge number thirteen; the "cent" I meant was scaled by the 1950 dollar. But our currency has been going through a long steady inflation, and no nation in history has ever gone as far as we have along this route without reaching the explosive phase of inflation. Ten-dollar hamburgers? Brother, we are headed for the hundred-dollar hamburger—for the barter-only hamburger.
     But this is only an inconvenience rather than a disaster as long as there is plenty of hamburger.
     1980 I must scale that "cent" again. In 1950 gold was $35/troy ounce; this morning the London fix was $374/troy ounce. Just last week my wife and I flew San Francisco to Baltimore and return. We took neither the luxury class nor any of the special discounted fares; we simply flew what we could get.
     Applying the inflation factor—35/374—our tickets cost a hair less than one cent a mile in 1950 dollars. From here on I had better give prices in troy ounces of gold, or in Swiss francs; not even the Man in the White House knows where this inflation is going. About those subways: possible, even probable, by 2000 A.D. But I see little chance that they will be financed until the dollar is stabilized—a most painful process our government hates to tackle.

     14. 1950 A major objective of applied physics will be to control gravity.
     1965 This prediction stands. But today physics is in a tremendous state of flux with new data piling up faster than it can be digested; it is anybody's guess as to where we are headed, but the wilder you guess, the more likely you are to hit it lucky. With "elementary particles" of nuclear physics now totaling about half the number we used to use to list the "immutable" chemical elements, a spectator needs a program just to keep track of the players. At the other end of the scale, "quasars"—quasi-stellar bodies—have come along; radio astronomy is now bigger than telescopic astronomy used to be; and we have redrawn our picture of the universe several times, each time enlarging it and making it more complex—I haven't seen this week's theory yet, which is well, as it would be out of date before this gets into print. Plasma physics was barely started in 1950; the same for solid-state physics. This is the Golden Age of physics—and it's an anarchy.
     1980 I stick by the basic prediction. There is so much work going on both by mathematical physicists and experimental physicists as to the nature of gravity that it seems inevitable that twenty years from now applied physicists will be trying to control it. But note that I said "trying"—succeeding may take a long time. If and when they do succeed, a spinoff is likely to be a spaceship that is in no way a rocket ship—and the Galaxy is ours! (Unless we meet that smarter, meaner, tougher race that kills us or enslaves us or eats us—or all three.)
     Particle physics: the situation is even more confusing than in 1965. Physicists now speak of more than 200 kinds of hadrons, "elementary" heavy particles. To reduce this confusion a mathematical construct called the "quark" was invented. Like Jell-O quarks come in many colors and flavors . . . plus spin, charm, truth, and beauty (or top and bottom in place of truth and beauty—or perhaps "truth" doesn't belong in the list, and no jokes, please, as the physicists aren't joking and neither am I). Put quarks together in their many attributes and you can account for (maybe) all those 200-odd hadrons (and have a system paralleling the leptons or light particles as a bonus).
     All very nice . . . except that no one has ever been able to pin down even one quark. Quarks, if they exist, come packaged in clumps as hadrons—not at random but by rules to account for each of that mob of hadrons.
     Now comes Kenneth A. Johnson, Ph.D. (Harvard '55), Professor of Physics at the Massachusetts Institute of Technology (which certainly places him in the worldwide top group of physicists) with an article (Scientific American, July 1979, p. 112, "The Bag Model of Quark Confinement"), an article which appears to state that quarks will never be pinned down because they are in sort of an eternal purdah, never to be seen even as bubble tracks.
     Somehow it reminds me of the dilemma when the snark is a boojum.
     I'm not poking fun at Dr. Johnson; he is very learned and trying hard to explain his difficult subject to the unlearned such as I.
     But, in the meantime I suggest reading The Hunting of the Snark while waiting patiently for 2000 A.D. We have a plethora of data; perhaps in twenty more years the picture will be simplified. Perhaps—

18. 1950 Fish and yeast will become our principal sources of proteins. Beef will be a luxury; lamb and mutton will disappear.      1965 I'll hedge number eighteen a little. Hunger is not now a problem in the USA and need not be in the year 2000—but hunger is a world problem and would at once become an acute problem for us if we were conquered . . . a distinct possibility by 2000. Between our present status and that of subjugation lies a whole spectrum of political and economic possible shapes to the future under which we would share the worldwide hunger to a greater or lesser extent. And the problem grows. We can expect to have to feed around half a billion Americans circa year 2000—our present huge surpluses would then represent acute shortages even if we never shipped a ton of wheat to India.
     1980 It would now appear that the USA population in 2000 A.D. will be about 270,000,000 instead of 500,000,000. I have been collecting clippings on demography for forty years; all that the projections have in common is that all of them are wrong. Even that figure of 270,000,000 may be too high; today the only reason our population continues to increase is that we oldsters are living longer; our current birthrate is not sufficient even to replace the parent generation.

     19. 1950 Mankind will not destroy itself, nor will "Civilization" be destroyed.
     1965 I stand by prediction number nineteen.
     1980 I still stand by prediction number nineteen. There will be wars and we will be in some of them—and some may involve atomic weapons. But there will not be that all-destroying nuclear holocaust that forms the background of so many SF stories. There are three reasons for this: The United States, the Soviet Union, and the People's Republic of China.
     Why? Because the three strongest countries in the world (while mutually detesting each the other two) have nothing to gain and everything to lose in an all-out swapping of H-bombs. Because Kremlin bosses are not idiots and neither are those in Beijing (Peiping)(Peking).
     If another country—say Israel, India, or the South African Republic—gets desperate and tosses an A- or H-bomb, that country is likely to receive three phone calls simultaneously, one from each of the Big Three: "You have exactly three minutes to back down. Then we destroy you."
     After World War II I never expected that our safety would ever depend on a massive split in Communist International—but that is exactly what has happened.

     1950 Here are things we won't get soon, if ever:
     Travel through time.
     Travel faster than the speed of light.
     "Radio" transmission of matter.
     Manlike robots with manlike reactions.
     Laboratory creation of life.
     Real understanding of what "thought" is and how it is related to matter.
     Scientific proof of personal survival after death.
     Nor a permanent end to war. (I don't like that prediction any better than you do.)

     1950 Prediction of gadgets is a parlor trick anyone can learn; but only a fool would attempt to predict details of future history (except as fiction, so labeled); there are too many unknowns and no techniques for integrating them even if they were known.
     Even to make predictions about overall trends in technology is now most difficult. In fields where before World War II there was one man working in public, there are now ten, or a hundred, working in secret. There may be six men in the country who have a clear picture of what is going on in science today. There may not be even one. 
     This is in itself a trend. Many leading scientists consider it a factor as disabling to us as the nonsense of Lysenkoism is to Russian technology. Nevertheless there are clear-cut trends which are certain to make this coming era enormously more productive and interesting than the frantic one we have just passed through. Among them are:
     Cybernetics: The study of communication and control of mechanisms and organisms. This includes the wonderful field of mechanical and electronic "brains"—but is not limited to it. (These "brains" are a factor in themselves that will speed up technical progress the way a war does.)
     Semantics: A field which seems concerned only with definitions of words. It is not; it is a frontal attack on epistemology—that is to say, how we know what we know, a subject formerly belonging to long-haired philosophers.
     New tools of mathematics and logic, such as calculus of statement, Boolean logic, morphological analysis, generalized symbology, newly invented mathematics of every sort—there is not space even to name these enormous fields, but they offer us hope in every field—medicine, social relations, biology, economics, anything.
     Biochemistry: Research into the nature of protoplasm, into enzyme chemistry, viruses, etc., give hope not only that we may conquer disease, but that we may someday understand the mechanisms of life itself. Through this, and with the aid of cybernetic machines and radioactive isotopes, we may eventually acquire a rigor of chemistry. Chemistry is not a discipline today; it is a jungle. We know that chemical behavior depends on the number of orbital electrons in an atom and that physical and chemical properties follow the pattern called the Periodic Table. We don't know much else, save by cut-and-try, despite the great size and importance of the chemical industry. When chemistry becomes a discipline, mathematical chemists will design new materials, predict their properties, and tell engineers how to make them—without ever entering a laboratory. We've got a long way to go on that one!
     Nucleonics: We have yet to find out what makes the atom tick. Atomic power?—yes, we'll have it, in convenient packages—when we understand the nucleus. The field of radioisotopes alone is larger than was the entire known body of science in 1900. Before we are through with these problems, we may find out how the universe is shaped and why. Not to mention enormous unknown vistas best represented by ?????
     Some physicists are now using two time scales, the T-scale, and the tau-scale. Three billion years on one scale can equal an incredibly split second on the other scale—and yet both apply to you and your kitchen stove. Of such anarchy is our present state in physics.
     For such reasons we must insist that the Age of Science has not yet opened. 

     (Still 1950) The greatest crisis facing us is not Russia, not the Atom Bomb, not corruption in government, not encroaching hunger, not the morals of young. It is a crisis in the organization and accessibility of human knowledge. We own an enormous "encyclopedia"—which isn't even arranged alphabetically. Our "file cards" are spilled on the floor, nor were they ever in order. The answers we want may be buried somewhere in the heap, but it might take a lifetime to locate two already known facts, place them side by side and derive a third fact, the one we urgently need.
     Call it the Crisis of the Librarian.
     We need a new "specialist" who is not a specialist, but a synthesist. We need a new science to be the perfect secretary to all other sciences.
     But we are not likely to get either one in a hurry and we have a powerful lot of grief before us in the meantime.
     Fortunetellers can always be sure of repeat customers by predicting what the customer wants to hear . . . it matters not whether the prediction comes true. Contrariwise, the weatherman is often blamed for bad weather.
     Brace yourself.
     In 1900 the cloud on the horizon was no bigger than a man's hand—but what lay ahead was the Panic of 1907, World War I, the panic following it, the Depression, Fascism, World War II, the Atom Bomb, and Red Russia.
     Today the clouds obscure the sky, and the wind that overturns the world is sighing in the distance.
     The period immediately ahead will be the roughest, cruelest one in the long, hard history of mankind. It will probably include the worst World War of them all. It might even end with a war with Mars, God save the Mark! Even if we are spared that fantastic possibility, it is certain that there will be no security anywhere, save that which you dig out of your own inner spirit.

     But what of that picture we drew of domestic luxury and tranquility for Mrs. Middleclass, style 2000 A.D.?
     She lived through it. She survived.
     Our prospects need not dismay you, not if you or your kin were at Bloody Nose Ridge, at Gettysburg—or trudged across the Plains. You and I are here because we carry the genes of uncountable ancestors who fought—and won—against death in all its forms. We're tough. We'll survive. Most of us.
     We've lasted through the preliminary bouts; the main event is coming up.
     But it's not for sissies.

     The last thing to come fluttering out of Pandora's Box was Hope—without which men die.
     The gathering wind will not destroy everything, nor will the Age of Science change everything. Long after the first star ship leaves for parts unknown, there will still be outhouses in upstate New York, there will still be steers in Texas, and—no doubt—the English will still stop for tea.

Afterthoughts, fifteen years later—(1965)     Today the forerunners of synthesists are already at work in many places. Their titles may be anything; their degrees may be in anything—or they may have no degrees. Today they are called "operations researchers," or sometimes "systems development engineers," or other interim tags. But they are all interdisciplinary people, generalists, not specialists—the new Renaissance Man. The very explosion of data which forced most scholars to specialize very narrowly created the necessity which evoked this new non-specialist. So far, this "unspecialty" is in its infancy; its methodology is inchoate, the results are sometimes trivial, and no one knows how to train to become such a man. But the results are often spectacularly brilliant, too—this new man may yet save all of us.

     I'm an optimist. I have great confidence in Homo sapiens.
     We have rough times ahead—but when didn't we? Things have always been "tough all over." H-bombs, Communism, race riots, water shortage—all nasty problems. But not basic problems, merely current ones.
     We have three basic and continuing problems: The problem of population explosion; the problem of data explosion; and the problem of government.
     Population problems have a horrid way of solving themselves when they are not solved rationally; the Four Horsemen of the Apocalypse are always saddled up and ready to ride. The data explosion is now being solved, mostly by cybernetics and electronics men rather than by librarians—and if the solutions are less than perfect, at least they are better than what Grandpa had to work with. The problem of government has not been solved either by the "Western Democracies" or the "People's Democracies," as of now. (Anyone who thinks the people of the United States have solved the problem of government is using too short a time scale.) The peoples of the world are now engaged in a long, long struggle with no end in sight, testing whether one concept works better than another; in that conflict millions have already died and it is possible that hundreds of millions will die in it before year 2000. But not all.
     I hold both opinions and preferences as to the outcome. But my personal preference for a maximum of looseness is irrelevant; what we are experiencing is an evolutionary process in which personal preference matters, at most, only statistically. Biologists, ecologists in particular, are working around to the idea that natural selection and survival of the fittest is a notion that applies more to groups and how they are structured than it does to individuals. The present problem will solve itself in the cold terms of evolutionary survival, and in the course of it both sides will make changes in group structure. The system that survives might be called "Communism" or it might be called "Democracy" (the latter is my guess)—but one thing we can be certain of: it will not resemble very closely what either Marx or Jefferson had in mind. Or it might be called by some equally inappropriate neologism; political tags are rarely logical.
     For Man is rarely logical. But I have great confidence in Man, based on his past record. He is mean, ornery, cantankerous, illogical, emotional—and amazingly hard to kill. Religious leaders have faith in the spiritual redemption of Man; humanist leaders subscribe to a belief in the perfectibility of Man through his own efforts; but I am not discussing either of these two viewpoints. My confidence in our species lies in its past history and is founded quite as much on Man's so-called vices as on his so-called virtues. When the chips are down, quarrelsomeness and selfishness can be as useful to the survival of the human race as is altruism, and pig-headedness can be a trait superior to sweet reasonableness. If this were not true, these "vices" would have died out through the early deaths of their hosts, at least a half million years back.
     I have a deep and abiding confidence in Man as he is, imperfect and often unlovable—plus still greater confidence in his potential. No matter how tough things are, Man copes. He comes up with adequate answers from illogical reasons. But the answers work.
     Last to come out of Pandora's Box was a gleaming, beautiful thing—eternal Hope.
     (1980—I see no point in saying more. R.A.H.)

From WHERE TO? by Robert Heinlein (1952, updated 1980)

Over Engineering

Some engineers are prone to creeping featurism, that urge to add just one more bell or whistle that will really make the design perfect. The old adage is: "There comes a time in the history of any project when it becomes necessary to shoot the engineers and begin production"

Worse is when the engineers have made an unconscious assumption that metaphorically puts the cart before the horse, which frustrates them when the problem becomes more insoluble the harder they try. The solution here is to take a step back and try "thinking outside the box", i.e., Lateral thinking.

Worst of all is when the engineers fail to consider whether the project was a good idea in the first place. In Jurassic Park, Ian said "Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should." And that's when the screaming starts.

Arthur C. Clarke had an example of the over-engineering trap. Solve this problem: allow a farmer to direct a draft-horse to turn left or right on command.

Solution 1: genetically engineer the horse to enhance its intelligence. Teach the horse a college level of English language comprehension, so that the horse can understand commands like "It is time to vector your course in the widdershins direction", "go thataway, stupid!", or whatever phrasing suits the passing fancy of the farmer at that moment. Problem will be solved after a few decades of over engineering, and each draft-horse will cost a quarter of a billon dollars.

Solution 2: take an off-the-shelf draft-horse. Teach it that "Haw" means turn left and "Gee" means turn right. Teach the farmer to employ this user interface when directing the horse. Problem solved.

The point is that trying to accomodate any whim of the farmer is an NP-hard problem. A little training of the lazy farmer vastly simplifies the problem.


Overengineering (or over-engineering) is the act of designing a product to be more robust or have more features than necessary for its intended use, or for a process to be unnecessarily complex or inefficient.

Overengineering is often done to increase a factor of safety, add function, or overcome perceived design flaws that most users would accept. Overengineering can be desirable when safety or performance is critical (e.g. in aerospace vehicles), or when extremely broad functionality is required (e.g. diagnostic tools), but it is generally criticized in terms of value engineering as wasteful of resources such as materials, time and money. As a design philosophy, it is the opposite of the minimalist ethos of "less is more" and a violation of the KISS principle.

Overengineering generally occurs in high-end products or specialized markets. In one form, products are overbuilt and have performance far in excess of expected normal operation (a city car that can travel at 300 km/h, or a home video recorder with a projected lifespan of 100 years), and hence are more expensive, bulkier, and heavier than necessary. Alternatively, they may become overcomplicated – the extra functions may be unnecessary, and potentially reduce the usability of the product by overwhelming end users.

Overengineering can decrease the productivity of the design team because of the need to build and maintain unwanted features.

A related issue is market segmentation – making different products for different market segments. In this context, a particular product may be more or less suited (and thus considered over- or under-engineered) for a particular market segment.

From the Wikipedia entry for OVERENGINEERING

I studied my four chronometric dials, tapping the face of each with my fingernail to ensure they were working. Already the hand on the second of the dials, which measured thousands of days, had begun to drift away from its rest position.

These dials—faithful, mute servants—were adapted from steam pressure gauges. They worked by measuring a certain shear tension in a quartz bar doped with Plattnerite, a tension induced by the twisting effects of time travel. The dials counted days—not years, or months, or leap years, or movable feasts!—and that was by conscious design. As soon as I began my investigations into the practicalities of this business of traveling into time, and in particular the need to measure my machine's position in it, I spent some considerable time trying to build a practical chronometric gauge capable of producing a display in common measures: centuries, years, months and days. I soon found I was likely to spend longer on that project than on the rest of the Time Machine put together!

I developed an immense impatience with the peculiarities of our antique calendar system, which has come from a history of inadequate adjustments: of attempts to fix seed-time and midwinter that go back to the beginnings of organized society.

Our calendar is a historical absurdity, without even the redeeming feature of accuracy at least on the cosmological timescales which I intended to challenge.

At any event, after all this, I abandoned my attempts to build a calendar-based chronometric gauge, and reverted to a simple count of days. I have always had a ready mind with figures, and did not find it hard to convert, mentally, my dials' day-count to years. On my first voyage, I had traveled to Day 292,495,934, which—allowing for leap year adjustments—turned out to be a date in the year A.D. 802,701. Now, I knew, I must travel forwards until my dials showed Day 292,495,940—the precise day on which I had lost Weena, and much of my self-respect, in the flames of that forest!

"Ha!—here we are; once more, it is the Sixteenth of June, A.D. 1938." He began to unravel his constraints. I got out of my chair and took a closer look at that "clock." I found that—although the hands made up a conventional clock face—the device also featured several little chronometric dials. I snorted and tapped the glass face of the thing with my finger. I said to Moses, "Look at this! It is a chronometric clock, but it shows years and months—overengineering, Moses; a characteristic of Government projects. I'm surprised it doesn't feature little dolls with raincoats and sun-hats, to show the passing of the seasons!"

From THE TIME SHIPS by Stephen Baxter (1995)

Evolvable hardware

Evolution is a remarkable designer. After all, it designed us, and every other living thing we know of.

It wasn't long before artificial intelligence researchers tried implementing evolution using computer software. Thus was born the science of the Evolutionary Algorithm. You create a data structure which acts like a gene, start with an enviroment populated with random genes, let them perform for a while, evaluate which were best at doing the task, delete the low performers and replace with new randoms, cross-breed the rest and throw in a few random mutations, and do a fresh cycle. Instant software evolution.

In 1996 Doctor Adrian Thompson had the brainstorm of using such evolutionary algorithms to design hardware. Thus was born the science of Evolvable Hardware. Since an algoritm instead of a human mind is doing the designing, the result tend to be somewhat alien. But effective.

Dr. Thompson's started with a field-programmable gate array (FPGA), which is basically a "programmable" integrated circuit. By sending special commands the user can change how the internal components are connected (actually how they are "virtually" connected, but don't worry about that). The task was to configure the FPGA so it would respond "YES" if you fed it a 1 kHz wave and "NO" if you fed it a 10 kHz wave ("yes" defined as outputting +5 volts and "no" defined as outputting 0 volts).

This was a bit of a challenge for the poor evolvable hardware algorithm. Humans build circuits to do such detection using some kind of electronic clock, but the FPGA has none. It would have to evolve the equivalent of a clock.

Halfway through the evolving, it was approaching a solution, but the output was weird. A FPGA is a digital device so it generally outputs +5v or 0v. But this was was outputting "fuzzy" values. A human engineer knows that a FPGA is a digital on-off device so it designs with that in mind. But the algorithm doesn't know that so it designs pragmatically. It worked with what the FPGA could actually do, not what it was supposed to do.

Finally the algorithm was successful and the FPGA performed as desired.

But when Dr. Thompson looked closer, things got weird again.

Part of the FPGA had been programmed with a circuit which was not connected to the main circuit. Dr. Thompson figured it was superfluous and removed it. And the FPGA promptly lost the ability to tell the two waves apart. When Dr. Thompson added the superfluous circuit back in, the FPGA started working again.

What the heck??

Dr. Thompson eventually figured out the cursed superfluous circuit was influencing the main circuit through electromagnetic coupling. It works, but it is very very alien.

Which is one of the reasons why Dr. Thompson's technique is not used today. For contractual and legal liability reasons chip designers want designs that they understand and can test rigorously. Neither of which is true of the weird designs created by Dr. Thompson's algorithm.

A final problem was when Dr. Thompson loaded the program arrangement from the algorithm into an FPGA of the same type it didn't work! It not only used properties of that type of FPGA, it also used specific quirks of that particular FPGA chip.

In 2003 Jason Lohn et al decided to create an X-band antenna for NASA's Space Technology 5 mission using established antenna evolvable algorithms.

They used two genetic algorithms to create two different antennae, then tested to see which was better. Genetic Algorithm 1 was a standard which created non-branching antennae, that is, the result looks like a twisted piece of wire. Genetic Algorithm 2 was a new one evolving "rod-structured robot morphologies", that is, the result looks like a little tree.

And yes, both look rather alien.


     Legend had it that the Progenitors had called for a perpetual search for knowledge before they departed for parts unknown, aeons ago. But, in practice, most species looked to the Library and only the Library for knowledge. Its store grew only slowly.
     What was the point of researching what must have been discovered a thousand times over by those who came before?
     It was simple, for instance, to choose advanced spaceship designs from Library archives and follow them blindly, understanding only a small fraction of what was built. Earth had a few such ships, and they were marvels.
     The Terragens Council, which handled relations between the races of Earth and the Galactic community, once almost succumbed to that tempting logic. Many humans urged co-opting of Galactic models that older races had themselves co-opted from ancient designs. They cited the example of Japan, which in the nineteenth century had faced a similar problem — how to survive amongst nations immeasurably more powerful than itself. Meiji Japan had concentrated all its energy on learning to imitate its neighbors, and succeeded in becoming just like them, in the end.
     The majority on the Terragens Council, including nearly all of the cetacean members, disagreed. They considered the Library a honey pot — tempting, and possibly nourishing, but also a terrible trap.
     They feared the "Golden Age" syndrome … the temptation to "look backward" — to find wisdom in the oldest, dustiest texts, instead of the latest journal.
     Except for a few races, such as the Kanten and Tymbrimi, the Galactic community as a whole seemed stuck in that kind of a mentality. The Library was their first and last recourse for every problem. The fact that the ancient records almost always contained something useful didn't make that approach any less repugnant to many of the wolflings of Earth, including Tom, Gillian, and their mentor, old Jacob Demwa.
     Coming out of a tradition of bootstrap technology, Earth's leaders were convinced there were things to be gained from innovation, even this late in Galactic history. At least it felt better to believe that. To a wolfling race, pride was an important thing.
     Orphans often have little else.

     But here was evidence of the power of the Golden Age approach. Everything about this ship spoke silkily of refinement. Even in wreckage, it was beautifully simple in its construction, while indulgent and ornate in its embellishments. The eye saw no welds. Bracings and struts were always integral to some other purpose. Here one supported a stasis flange, while apparently also serving as a baffled radiator for excess probability. Orley thought he could detect other overlaps, subtleties that could only have come with aeons of slow improvement on an ancient design.

From STARTIDE RISING by David Brin (1983)

The puppeteer ship was a robot. Beyond the airlock the lifesystem was all one big room. Four crash couches, as varied in design as their intended occupants, faced each other in a circle around a refreshment console.…

There were no corners. The curved wall merged into floor and ceiling; the couches and the refreshment console all looked half melted. In the puppeteer world there would be nothing hard or sharp, nothing that could draw blood or raise a bruise.

From RINGWORLD by Larry Niven (1970)

The hyperdrive shunt ran nearly the length of the ship, beneath the floor. Louis had to recognize the machinery from first principles. It was not of human manufacture; it had the half-melted look of most puppeteer construction. So: the ship had faster-than-light capability. It seemed he was slated for a long trip.

From RINGWORLD ENGINEERS by Larry Niven (1979)

Steam Engine Time

"Steam Engine Time" is a science fictional concept that when the time is ripe for Invention X it will be independently created by isolated individuals all over the world. Apparently the term was coined by Charles Fort.

Wikipedia calls it Multiple Discovery or Simultaneous Invention Hypothesis, as opposed to the more traditional Heroic Theory Of Invention And Scientific Development Hypothesis. Wikipedia also has an impressive list of multiple discoveries. Kevin Kelly calls it Technological Inevitability, the concept that some inventions are meant to be.

In science fiction, a good example is Harry Harrison's "In Our Hands, The Stars" (expanded into The Daleth Effect). SPOILERS: a scientist invents a reactionless drive which will turn a submarine into instant spaceship. The scientist does not want the invention falling into the hands of the military (of any and all nations) because it would be a horrific war weapon. Most of the novel is about the desperate efforts of the scientist to keep it secret and the desperate attempts of all the militaries of the world to seize the secret. Much death and destruction ensue. But the punch line comes when the invention is independently discovered by scientists all over the world. It seems that for the world it has become "Daleth Effect Time".

When the time is ripe for certain things, these things appear in different places in the manner of violets coming to light in early spring.

Farkas Bolyai

A period of time when many inventors all over the world, despite isolation from each other, and with no contact with each other in any way, begin inventing a similar technology with a coincidental commonality of ideas.

The invention of the steam engine didn't occur in only one place but was invented independently and in isolation by many inventors all over the world.

Another example of steam engine time includes the independent invention of the aeroplane by people in isolation from each other in many different regions of the world, leading to arguments about "who" invented the aeroplane first.

From STEAM ENGINE TIME entry in Urban Dictionary, by Wataru108 (2008)

For example, he (Charles Fort) was uncomfortable with the notion of “invention” and wondered whether Watt really invented the steam engine or the Wright brothers invented the flying machine. In his book New Lands, Fort wrote: “One of the greatest of secrets that have eventually been found out was for ages blabbed by all the pots and kettles in the world—but that the secret of the steam engine could not reveal itself until came the time for its co-ordination with the other phenomena and the requirements of the Industrial Age.”


There’s an idea in the science-fiction community called steam-engine time, which is what people call it when suddenly twenty or thirty different writers produce stories about the same idea. It’s called steam-engine time—because nobody knows why the steam engine happened when it did. Ptolemy demonstrated the mechanics of the steam engine, and there was nothing technically stopping the Romans from building big steam engines. They had little toy steam engines, and they had enough metalworking skill to build big steam tractors. It just never occurred to them to do it. When I came up with my cyberspace idea, I thought, I bet it’s steam-engine time for this one, because I can’t be the only person noticing these various things. And I wasn’t. I was just the first person who put it together in that particular way, and I had a logo for it, I had my neologism.


The actual phrase was first coined by the collector of weird, Charles Fort, in 1931, who wrote in his early fantasy novel Lo!: “A tree cannot find out, as it were, how to blossom, until comes blossom-time. A social growth cannot find out the use of steam engines, until comes steam-engine-time.”

Steam-engine-time is another name for technological determinism, which is another way to say simultaneous independent invention, Turns out simultaneous parallel discovery and invention are the norm in science and technology rather than the exception (see my previous post).

When it is steam-engine-time, steam engines will occur everywhere. But not before. Because all the precursor and supporting ideas and inventions need to be present. The Romans had the idea of steam engines, but not of strong iron to contain the pressure, nor valves to regulate it, nor the cheap fuel to power it. No idea – even steam engines — are solitary. A new idea rests on a web of related previous ideas. When all the precursor ideas to cyberspace are knitted together, cyberspace erupts everywhere. When it is robot-car-time, robot cars will come. When it is steam-engine-time, you can’t stop steam engines.

From STEAM-ENGINE-TIME by Kevin Kelly (2011)

This phenomenon of simultaneous discovery—what science historians call “multiples”—turns out to be extremely common. One of the first comprehensive lists of multiples was put together by William Ogburn and Dorothy Thomas, in 1922, and they found a hundred and forty-eight major scientific discoveries that fit the multiple pattern. Newton and Leibniz both discovered calculus. Charles Darwin and Alfred Russel Wallace both discovered evolution. Three mathematicians “invented” decimal fractions. Oxygen was discovered by Joseph Priestley, in Wiltshire, in 1774, and by Carl Wilhelm Scheele, in Uppsala, a year earlier. Color photography was invented at the same time by Charles Cros and by Louis Ducos du Hauron, in France. Logarithms were invented by John Napier and Henry Briggs in Britain, and by Joost Bürgi in Switzerland.

“There were four independent discoveries of sunspots, all in 1611; namely, by Galileo in Italy, Scheiner in Germany, Fabricius in Holland and Harriott in England,” Ogburn and Thomas note, and they continue:

The law of the conservation of energy, so significant in science and philosophy, was formulated four times independently in 1847, by Joule, Thomson, Colding and Helmholz. They had been anticipated by Robert Mayer in 1842. There seem to have been at least six different inventors of the thermometer and no less than nine claimants of the invention of the telescope. Typewriting machines were invented simultaneously in England and in America by several individuals in these countries. The steamboat is claimed as the “exclusive” discovery of Fulton, Jouffroy, Rumsey, Stevens and Symmington.

For Ogburn and Thomas, the sheer number of multiples could mean only one thing: scientific discoveries must, in some sense, be inevitable. They must be in the air, products of the intellectual climate of a specific time and place.

From IN THE AIR by Malcolm Gladwell (2008)

The Sword on the Starship

RocketCat sez

Yeah, I know I know, you just luv the idea of a thick coating of Errol Flynn - swashbuckling flavor on top of your science fiction. If you are an elderly geezer you probably got imprinted like a baby duck on Buster Crabbe - Flash Gordon serials, Alex Raymond - comic strips, or Edgar Rice Burroughs - John Carter of Barsoom novels. If you are a young sprat you probably imprinted on a light saber.

I'm trying to cut you some slack here, but I'm only barely restraining myself from giving you an atomic wedgie. To be brutally honest the concept is about as scientifically accurate as a Harry Potter movie.

But if you the author simply must include such feldercarb in your work, because you are catering to the masses or being deliberately post-ironic, I'll throw you a bone and give some threadbare fig-leaves to use.

Some space opera writers are fascinated with the romantic concept of star conquerors charging out of their interstellar star ships on horseback, waving long-swords (the technical term is Medieval Futurism). While cinematically interesting, the concept is obviously scientifically silly, surely somebody advanced enough to run an FTL starship can manage to tinker together a laser pistol (or at least a submachine gun).

Note this trope is somewhat incompatible with the concept of tech levels, that is, a linear path of technological achievements. To use it you must instead use the concept of a tech tree, one with really huge short-cut to starship technology.

There are several related entries on the TV Tropes website: Elegant Weapon for a More Civilized Age, Archaic Weapon for an Advanced Age, Guns Are Worthless, Rock Beats Laser, and Heroes Prefer Swords.

The cold unromantic fact of the matter is that such wildly disparate technology levels as starship for transport but only swords for weapons is totally illogical:


(ed note: Sprague de Camp is of the opinion that such wide technological incongruities as swords on starships are romantic as space operas but make zero sense scientifically)

Forsooth, many have written begiling tales of swordplay laid on Mars, not to mention Venus and assorted extra-solar planets. In fact, I am reading one, Gardner Fox's WARRIOR OF LLARN, right now.

The trouble with most of these stories, including Fox's, is that the authors try to combine two incompatable elements. For one, they want the glamor of antiquity. Therefore they fill their imaginary worlds with impenetrable jungles, fearsome monsters, glittering palaces, haughty emperors, beautiful princesses, sinister temples, villainous priests, cowering slaves, deadly duels, gladitorial combats, ghastly ghosts, frightful demons, lethal magic, gallant steeds, and of course a lavish assortment of swords and other hand-to-hand weapons.

But, at the same time, the writers want to cash in on the fictional appeal of super-science. So, along with this display of picturesque archaism, they mingle elements from the technological present and future: guns, disintegrators and other lethal ray projectors, mechanical air and ground vechicles, and other scientific gadgets. At this point, pop goes the illusion they have striven so hard to build up. For, their fictional milieu is as anachronistic, or technologically incongruous, as it would be to have a contemporary American businessman wear Gothic armor to his office or light his cigarette by rubbing sticks.

True, such incongruities do exist in the real world. Today you can see a Peruvian Indian jogging along on his mule and holding a transistor to his ear. (ed note: for all you young whipper-snappers, this was written in those ancient days of yore when a pocket-sized transistor FM radio was considered cutting-edge high-tech) But a mixture of the technics of different eras is always an unstable and rapidly changing state of affairs, because people compelled to mix with those of a technologically more advanced culture soon adopt the gadgets of the others, as far as they can do so without much disturbing their basic cultural attitudes, social organizations, and traditional way of life. Even when these things are disturbed, the people may eventually adopt the new discoveries when they get used to them.

To judge by the record of our own species, most people are not conservative about adopting more effective methods of killing their foes and getting from place to place. In recent centuries, for instance, primitive people who found themselves fighting Westerners did their damndest to obtain Western weapons. In the wars of the Peruvian Indians against the Conquistadores, many Indian chiefs went into battle wearing armor looted from dead Spaniards. Once the primitives had enough guns, they quickly shelved their bows and spears. The Plains Indians made little use of either in their wars with the whites in the 1870s and 80s.

By and large, the weapon with the longest effective range drives out the others, as the bow superseded the sling and the javelin, and the gun supplanted the bow. True, in civilized nations, the gun took several centuries to drive out the sword. The reason is that early guns took so long to reload that, if the gunner missed his first shot, his enemy could be upon him with a hand weapon before he could fire another. Therefore the gun's longer range was not always effective, and a reserve hand weapon was desirable.

This situation began to change with the development of the flint-lock in late +XVII. Now, instead of several minutes, it took a well-drilled soldier only fifteen seconds to load and fire. The development of the breech-loader with a metallic cartridge case in the 1850s shrank the interval between shots down to about five seconds, and the repeating rifle of the 1860s shortened it to less than two seconds. With each advance, the massed infantry charge became more costly. Pickett's charge at Gettysburg showed what happened to troops who tried it.

This was pretty much the end of the sword as a practical weapon. In the 1850s and 60s an explorer, setting out for inner Africa, often carried a sword as a back-up weapon. Richard F. Burton found his sword useful in his wild night-time fight with a whole tribe of Somalis in 1854.

By the end of the (20th) century, however, the sword had become an absurd anachronism, even though there were still a few cavalry charges. The last I know of was on 20 March 1942, when Sandeman's cavalry detachment charged a Japanese position near Toungoo, Burma. Needless to say, Sandeman and his gallant Sikhs were all killed before the could get within slashing distance.

The American soldiers fighting the Plains Indians abandoned their sabers, since they so seldom got close enough to their foes to use them — although Custer's men, before they were wiped out, had occasion to wish that they had brought theirs along. Of the 320,000 American casualties in the Kaiserian War, two were saber wounds. Cossacks and Japanese officers might continue to carry swords down through the Hitlerian War, but such pious archaisms had as much to do with serious fighting as a modern British knighthood has to do with medieval chivalry.

My point is that people who have weapons like radar-sighted, aluminum-alloy, radium rifles of Burroughs' Martians, with ranges of hundreds of miles, would not fool around with swords and spears, as Burroughs' people do, any more than the Plains Indians did when they got rifles. Nor will they go galumphing around on thoats, gawrs, drals, or other beasts of burden when the equivalents of automobiles and airplanes are available. Remember how quickly the Plains Indians adopted the horse.

Of course, one might find oneself in a fix where the more archaic weapon would be the more effective. In WW2, a marine friend of mine in the Pacific theater killed one enemy with a dagger and another with a machete, which is a sword of sorts. But one cannot carry enough gear to meet every possible contingency; and, 99 times out of 100, a modern repeating firearm will beat any ancient panoply that could be brought against it.

Furthermore, if your hero lives in a pre-gunpowder world where hand-to-hand weapons prevail, and he expects to have to do some serious fighting, he will try to provide himself not only with a sword but also with the best defenses that he can afford and that the armor-makers of the time can produce. This may range from an ox-hide shield of the Zulu type, or a jacket to which scales of boiled leather have been sewn, up to the marvelous suits of steel plate of late +XVI and early +XVII, which represent the all-time culmination of armor.

The precise details of our hero's defense depend partly on the technology of his world and partly on the circumstances under which he expects to fight. These factors determine whether or not he carries a shield; whether his armor is of leather, wood, coconut fiber, cloth, copper, bronze, iron, steel, or even a steel alloy; and whether it takes the form of scale mail, ring mail, chain mail, strap armor, or plate. Does he give battle on land or sea, alone or in an army, afoot or on horseback? If he expects to fight mounted, he must consider how much weight his mount can carry. In classical Greece the heaviest-armored men were foot soldiers, because the small horses of that era could not bear a man in full armor. By the Middle Ages, the development of larger breeds of horse reversed this relationship.

In any case, be sure that a hero in his right mind, knowing he faces hand-to-hand combat, will not go into action stripped to a loin cloth like a Burroughs Martian. Not, that is, if he can jolly well help it!

So, if you really want to build a convincing fantasy world, as the people on the Pacificon II panel prescribed, make up your mind what technological level your world shall have. If it is the ancient, pre-industrial world, that's fine; if the contemporary world, that's fine; if a world of super-science, that's fine. But don't mix them, unless the older technology is shown as crumbling before the new, as it always has, or unless the older activity is preserved in the form of sport. Many modern sports — hunting, fishing, sailing a sailboat, riding a horse, fighting with swords, shooting a bow, or throwing a javelin — were once serious occupations, on which a man's life might depend. But for serious adventuring — well, even Tarzan's son had the sense to hang on to his rifle and ammunition on his way to rescue his noble parents from the sinister prehensile-tailed priests of the mysterious valley of Pal-ul-don. This gun came in right handy, too.

From "RANGE" by Sprague de Camp, Amra v.2 #33 (1965)

(ed note: Poul Anderson had this comment on de Camp's analysis)

I have no argument with Sprague's interesting essay, but might amplify his remarks a trifle.

First, he modestly omits one legitimate way in which you can put your superscientific hero in a sword-swinging type of sitiuation. That's when, because of shipwreck, secrecy, technological blockade, or whatever, said hero has to get out and mingle with the backwards natives (oops, I mean underdeveloped patriots!) on their own terms à la Krishna.

Poul Anderson

      The twin moons brooded over the red deserts of Mars and the mined city of Khua-Loanis. The night wind sighed around the fragile spires and whispered at the fretted lattice windows of the empty temples, and the red dust made it like a city of copper.

     It was close to midnight when the distant rumble of racing hooves reached the city, and soon the riders thundered in under the ancient gateway. Tharn, Warrior Lord of Loanis, leading his pursuers by a scant twenty yards, realized wearily that his lead was shortening, and raked the scaly flanks of his six-legged vorkl with cruel spurs. The faithful beast gave a low cry of despair as it tried to obey and failed.

     In front of Tharn in the big double saddle sat Lehni-tal-Loanis, Royal Lady of Mars, riding the ungainly animal with easy grace, leaning forward along its arching neck to murmur swift words of encouragement into its flattened ears. Then she lay back against Tharn’s mailed chest and turned her lovely face up to his, flushed and vivid with the excitement of the chase, amber eyes aflame with love for her strange hero from beyond time and space.

     “We shall win this race yet, my Tharn," she cried. “Yonder through that archway lies the Temple of the Living Vapor, and once there we can defy all the Hordes of Varnis!” Looking down at the unearthly beauty of her, at the subtle curve of throat and breast and thigh, revealed as the wind tore at her scanty garments, Tharn knew that even if the Swordsmen of Varnis struck him down his strange odyssey would not have been in vain.

     But the girl had judged the distance correctly and Thain brought their snorting vorkl to a sliding, rearing halt at the great doors of the Temple, just as the Swordsmen reached the outer archway and jammed there in a struggling, cursing mass. In seconds they had sorted themselves out and came streaming across the courtyard, but the delay had given Tharn time to dismount and take his stand in one of the great doorways. He knew that if he could hold it for a few moments while Lehni-tal-Loanis got the door open, then the secret of the Living Vapor would be theirs, and with it mastery of all the lands of Loanis.

     The Swordsmen tried first to ride him down, but the doorway was so narrow and deep that Tharn had only to drive his sword-point upward into the first vorkl’s throat and leap backward as the dying beast fell. Its rider was stunned by the fall, and Tharn bounded up onto the dead animal and beheaded the unfortunate Swordsman without compunction. There were ten of his enemies left and they came at him now on foot, but the confining doorway prevented them from attacking more than four abreast, and Tharn’s elevated position upon the huge carcass gave him the advantage he needed. The fire of battle was in his veins now, and he bared his teeth and laughed in their faces, and his reddened sword wove a pattern of cold death which none could pass.

     Lehni-tal-Loanis, running quick cool fingers over the pitted bronze of the door. found the radiation lock and pressed her glowing opalescent thumb-ring into the socket, gave a little sob of relief as she heard hidden tumblers falling. With agonizing slowness the ancient mechanism began to open the door; soon Tharn heard the girls clear voice call above the clashing steel, “Inside, my Tharn, the secret of the Living Vapor is ours!”

     But Tharn, with four of his foes dead now, and seven to go, could not retreat from his position on top of the dead vorkl without grave risk of being cut down, and Lehni-tal-Loanis, quickly realizing this, sprang up beside him, drawing her own slim blade and crying, “Aie, my love! l will be your left arm!”

     Now the cold hand of defeat gripped the hearts of the Swordsmen of Varnis: two, three, four more of them mingled their blood with the red dust of the courtyard as Tharn and his fighting princess swung their merciless blades in perfect unison. It seemed that nothing could prevent them now from winning the mysterious secret of the Living Vapor, but they reckoned without the treachery of one of the remaining Swordsmen. Leaping backward out of the conflict he flung his sword on the ground in disgust. “Aw, the Hell with it!” he grunted, and unclipping a proton gun from his belt he blasted Lehni-tal-Loanis and her Warrior Lord out of existence with a searing energy-beam.

From THE SWORDSMEN OF VARNIS by Clive Jackson (1950)

But if you as an author insist upon putting swords in starships, there are a few possible thread-bare excuses you can use:

A related notion is a high-tech interstellar empire threatened by "barbarians" waiting in their FTL longboat starships at the rim of the empire. Just like a galactic Roman Empire. One wonders about the tech assumptions though. Either starships are relatively cheap (ponder the idea of "barbarians" fielding aircraft carriers as a comparison) or the smallest feudal units are pretty good sized. These can be accomodated by STARSHIPS ARE INHERITED, HARVESTED COBBLER TECHNOLOGY, and HOW DID WE MISS THAT?.

No Guns: Illegal Or Immoral

For some bizzare legal or cultural reason firearms and anything more advanced are not allowed.

Barsoom novels by Edgar Rice Burrough (1912)
The Martians have firearms which fire explosive radium bullets. However, there is a nearly unbreakable cultural taboo against fighting a foe with unequal weapons. When a foe attacks with a weapon in hand, you can only use weapons of equal or lesser effectiveness. No "Raiders of the Lost Ark" allowed, if your foe pulls out a sword it is not fair to just shoot him. If you do pull out a greater weapon, your opponent will attack with enhanced ferocity due to your rank villainy.
Traveller RPG (1977)
Swords are used on planets with high Law Levels because on such worlds it is illegal for civilians to carry firearms. Cutlasses are used when pirates invade starships because guns tend to perforate the hull and let all the air out (in reality you'll have about an hour before the pressure becomes dangerously low). On merchant starships there are racks for cutlasses next to the airlocks so the crew can repel boarders.
Deathstalker series by Simon Green (1995)
A bolt from a disruper pistol is deadly, but the blasted weapon takes two minutes to recharge. Just like a camera strobe with a weak battery and a large capacitor. People fire their single bolt then unsheathe their sword. Swordplay ensues while user waits for the blasted gun to charge up.

There are no slugthrowers firing bullets available because their relatively low price would allow them to be purchased by the "lower classes" of society, and the aristocracy frowns on that sort of thing.

No Guns: Technological Gizmo

There exists some commonly available gadget which disable all firearms within a wide radius. Pulling the pistol's trigger just makes sad clicking noises.

A related notion is the "nuclear damper" which hand-wavingly prevents nuclear warheads from exploding. This is commonly used by science fiction authors who want to write military stories with firearms and tanks but no nukes. Military science fiction stories with guns can be engrossing. Military science fiction stories about nuclear war have a plot like "The atomic war lasted 10 minutes and the entire planet died. The end."

The Reign of the Ray by Fletcher Pratt (1929)
A scientist name Robert Adams alters a Coolidge tube and invents a ray that can detonate explosives at a distance. The Russians start their attack to invade Europe before the Adams Ray can be mass produced, and the United States rush deliver Ray units to the European front. The Russians capture some ray units and reverse engineer them. Now both sides have to do battle with no firearms, bombs, aircraft, or any other internal combustion engines. The war has to be fought with swords, bayonets, and sabre-armed cavalry.
First Lensman by E. E. "Doc" Smith (1950)
The Galactic Patrol and the pirates use combat armor equipped with force fields. Since the defensive field's resistance goes up with the weapon velocity, bullets and ray-guns are useless. Therefore, both sides uses space axes.
Dorsai! by Gordon R. Dickson (1960)
     Each man carried a handgun and knife in addition to his regular armament; but they were infantry, spring-rifle men. Weapon for weapon, any thug in the back alley of a large city had more, and more modern firepower; but the trick with modern warfare was not to outgun the enemy, but carry weapons he could not gimmick. Chemical and radiation armament was too easily put out of action from a distance. Therefore, the spring-rifle with its five thousand-sliver magazine and its tiny, compact, non-metallic mechanism which could put a sliver in a man-sized target at a thousand meters time after time with unvarying accuracy.
     Yet, thought Donal, pacing between the silent men in the faint darkness of pre-dawn, even the spring-rifle would be gimmickable one of these days. Eventually, the infantryman would be back to the knife and short sword. And the emphasis would weigh yet again more heavily on the skill of the individual soldier.
Dune novels by Frank Herbert (1965)
The Holtzman effect personal force fields will stop bullets safely and will stop laser bolts with the unfortunate side effect of a thermonuclear explosion. Only swords and other blades will penetrate, and only slow moving swords at that.

Herbert notes that the size of the thermonuclear explosion is totally random, independent of the size of the laser bolt or forcefield. In other words this is an arbitrary author fiat whose sole purpose is to bring sword and knife fighting back into fashion, don't try to bring logic and science into it.

When Herbert adds the Butlerian Jihad it makes the universe of ten thousand years from now look remarkably medieval. Which is a good thing if the author does not want to be forced to write a high-tech cyberpunk post-Singularity novel.

According to the DUNE Wiki: "The Holtzman Shield is a potent literary device: it makes some directed-energy weaponry impossible against any worthwhile opponent, and also proves traditional projectile-based firearms and missiles ineffective, adding to the feudal atmosphere, and enforces the usage of mêlée weaponry despite other more advanced technology."
Shear-thickening fluid Body Armor (2007)
In yet another example of life imitating science fiction, modern day Shear-thickening fluid Body Armor is having a similar effect to the fictional Holtzman effect personal force fields in the Dune novels. STF armor render bullets ineffectual, but can be easily punctured by a slow knife stab.
O.K. Connery (1967)
In this comedy movie take-off of James Bond spy flicks, the terrorist organization THANATOS use their dreaded Magnetic Wave to turn off all mechanical devices world wide. In particular it renders firearms inoperative. But protagonist Neil Connery manages to foil their evil plot, with help of a team of Scottish archers.
The Forever War by Joe Haldeman (1974)
The "stasis field" alters the laws of physics so nothing can move faster than 16.3 m/s. Inside a stasis field soldiers are forced to use melee weapons or bow and arrows; lasers, chemical explosives, nuclear warheads, and other high-tech weapons will not work. They also have to wear insulated armor or they are instantly killed by the stasis field bringing the biochemical basis of their body's metabolism to screeching halt.
The Trigger by Arthur Clarke and Michael Kube-McDowell (1999)
Scientist accidentally invent a device which will detonate all explosives and gunpowder with a large radius. Criminals learn how to exploit this (e.g., faultless at-range detonator) so the scientists develop the device to the point where exposure will render all explosives and gunpowder in range permanently inert and useless. Criminals start using bow and arrow. The scientists foolishly try to develop the device further, and to their horror realize they've made the ultimate genocide machine.

      Then, as soon as the intrinsic velocities could possibly be matched, board and storm! With Dronvire of Rigel Four in the lead, closely followed by Costigan, Northrop, Kinnison the Younger, and a platoon of armed and armored Space Marines!
     Samms and the two scientists did not belong in such a melee as that which was to come, and knew it. Kinnison the Elder did not belong, either, but did not know it. In fact, be cursed fluently and bitterly at having to stay out—nevertheless, out he stayed.
     Dronvire, on the other hand, did not like to fight. The very thought of actual, bodily, hand-to-hand combat revolted every fiber of his being. In view of what the spy-ray men were reporting, however, and of what all the Lensmen knew of pirate psychology, Dronvire had to get into that control room first, and he had to get there fast.
     And if he had to fight, he could; and, physically, he was wonderfully well equipped for just such activity. To his immense physical strength, the natural concomitant of a force of gravity more than twice Earth's, the armor which so encumbered the Tellurian bafflers was a scarcely noticeable impediment. His sense of perception, which could not be barred by any material substance, kept him fully informed of every development in his neighborhood. His literally incredible speed enabled him not merely to parry a blow aimed at him, but to bash out the brains of the would-be attacker before that blow could be more than started. And whereas a human being can swing only one space-axe or fire only two ray-guns at a time, the Rigellian plunged through space toward what was left of the pirate vessel, swinging not one or two space-axes, but four; each held in a lithe and supple, but immensely strong, tentacular "hand".
     Why axes? Why not Lewistons, or rifles, or pistols? Because the space armor of that day could withstand almost indefinitely the output of two or three hand-held projectors; because the resistance of its defensive fields varied directly as the cube of the velocity of any material projectile encountering them. Thus, and strangely enough, the advance of science had forced the re-adoption of that long-extinct weapon.

From FIRST LENSMAN by E. E. "Doc" Smith (1950)

      “Yessir, except for those damned swords.” For use in the stasis field. “No way we can orient them that they won’t be bent. Just hope they don’t break.”
     I couldn’t begin to understand the principles behind the stasis field; the gap between present-day physics and my master’s degree in the same subject was as long as the time that separated Galileo and Einstein. But I knew the effects.
     Nothing could move at greater than 16.3 meters per second inside the field, which was a hemispherical (in space, spherical) volume about fifty meters in radius. Inside, there was no such thing as electro-magnetic radiation; no electricity, no magnetism, no light. From inside your suit, you could see your surroundings in ghostly monochrome—which phenomenon was glibly explained to me as being due to “phase transference of quasi-energy leaking through from an adjacent tachyon reality,” so much phlogiston to me.
     The result of it, though, was to make all conventional weapons of warfare useless. Even a nova bomb was just an inert lump inside the field. And any creature, Terran or Tauran, caught inside the field without the proper insulation would die in a fraction of a second.

     At first it looked as though we had come upon the ultimate weapon. There were five engagements where whole Tauran bases were wiped out without any human ground casualties. All you had to do was carry the field to the enemy (four husky soldiers could handle it in Earth-gravity) and watch them die as they slipped in through the field’s opaque wall. The people carrying the generator were invulnerable except for the short periods when they might have to turn the thing off to get their bearings.
     The sixth time the field was used, though, the Taurans were ready for it. They wore protective suits and were armed with sharp spears, with which they could breach the suits of the generator-carriers. From then on the carriers were armed.

     Inside the base, we relied on individual lasers, microton grenades, and a tachyon-powered repeating rocket launcher that had never been tried in combat, one per platoon. As a last resort, the stasis field was set up beside the living quarters. Inside its opaque gray dome, as well as enough paleolithic weaponry to hold off the Golden Horde, we’d stashed a small cruiser, just in case we managed to lose all our spacecraft in the process of winning a battle. Twelve people would be able to get back to Stargate.
     It didn’t do to dwell on the fact that the other survivors would have to sit on their hands until relieved by reinforcements or death.

     We had more than a half hour before the drones would strike. I could evacuate everybody to the stasis field, and they would be temporarily safe if one of the nova bombs got through. Safe, but trapped. How long would it take the crater to cool down, if three or four—let alone sixteen—of the bombs made it through? You couldn’t live forever in a fighting suit, even though it recycled everything with remorseless efficiency. One week was enough to make you thoroughly miserable. Two weeks, suicidal. Nobody had ever gone three weeks, under field conditions.
     Besides, as a defensive position, the stasis field could be a death-trap. The enemy has all the options since the dome is opaque; the only way you can find out what they’re up to is to stick your head out. They didn’t have to wade in with primitive weapons unless they were impatient. They could keep the dome saturated with laser fire and wait for you to turn off the generator. Meanwhile harassing you by throwing spears, rocks, arrows into the dome—you could return fire, but it was pretty futile.
     Of course, if one man stayed inside the base, the others could wait out the next half hour in the stasis field. If he didn’t come get them, they’d know the outside was hot.

     The Taurans started firing rockets, but most of them seemed to be going too high. I saw two of us get blown away before I got to my halfway point; found a nice big rock and hid behind it. I peeked out and decided that only two or three of the Taurans were close enough to be even remotely possible laser targets, and the better part of valor would be in not drawing unnecessary attention to myself. I ran the rest of the way to the edge of the field and stopped to return fire. After a couple of shots, I realized that I was just making myself a target; as far as I could see there was only one other person who was still running toward the dome.
     A rocket zipped by, so close I could have touched it. I flexed my knees and kicked, and entered the dome in a rather undignified posture.
     Inside, I could see the rocket that had missed me drifting lazily through the gloom, rising slightly as it passed through to the other side of the dome. It would vaporize the instant it came out the other side, since all of the kinetic energy it had lost in abruptly slowing down to 16.3 meters per second would come back in the form of heat.

     Nine people were lying dead, facedown just inside of the field’s edge. It wasn’t unexpected, though it wasn’t the sort of thing you were supposed to tell the troops.
     Their fighting suits were intact—otherwise they wouldn’t have made it this far—but sometime during the past few minutes’ rough-and-tumble, they had damaged the coating of special insulation that protected them from the stasis field. So as soon as they entered the field, all electrical activity in their bodies ceased, which killed them instantly. Also, since no molecule in their bodies could move faster than 16.3 meters per second, they instantly froze solid, their body temperature stabilized at a cool 0.426 degrees Absolute.
     I decided not to turn any of them over to find out their names, not yet. We had to get some sort of defensive position worked out before the Taurans came through the dome. If they decided to slug it out rather than wait.

     With elaborate gestures, I managed to get everybody collected in the center of the field, under the fighter’s tail, where the weapons were racked.
     There were plenty of weapons, since we had been prepared to outfit three times this number of people. After giving each person a shield and short-sword, I traced a question in the snow:

Good Archers?
Raise hands.

     I got five volunteers, then picked out three more so that all the bows would be in use. Twenty arrows per bow. They were the most effective long-range weapons we had; the arrows were almost invisible in their slow flight, heavily weighted and tipped with a deadly sliver of diamond-hard crystal.
     I arranged the archers in a circle around the fighter (its landing fins would give them partial protection from missiles coming in from behind) and between each pair of archers put four other people: two spear-throwers, one quarterstaff, and a person armed with a battle-ax and a dozen throwing knives. This arrangement would theoretically take care of the enemy at any range, from the edge of the field to hand-to-hand combat.

     Actually, at some 600-to-42 odds, they could probably walk in with a rock in each hand, no shields or special weapons, and still beat the sh*t out of us.

     Assuming they knew what the stasis field was. Their technology seemed up to date in all other respects.

     For several hours nothing happened. We got about as bored as anyone could, waiting to die. No one to talk to, nothing to see but the unchanging gray dome, gray snow, gray spaceship and a few identically gray soldiers. Nothing to hear, taste or smell but yourself.
     Those of us who still had any interest in the battle were keeping watch on the bottom edge of the dome, waiting for the first Taurans to come through. So it took us a second to realize what was going on when the attack did start. It came from above, a cloud of catapulted darts swarming in through the dome some thirty meters above the ground, headed straight for the center of the hemisphere.
     The shields were big enough that you could hide most of your body behind them by crouching slightly; the people who saw the darts coming could protect themselves easily. The ones who had their backs to the action, or were just asleep at the switch, had to rely on dumb luck for survival; there was no way to shout a warning, and it took only three seconds for a missile to get from the edge of the dome to its center.
     We were lucky, losing only five. One of them was an archer, Shubik. I took over her bow and we waited, expecting a ground attack immediately.

     It didn’t come. After a half hour, I went around the circle and explained with gestures that the first thing you were supposed to do, if anything happened, was to touch the person on your right. He’d do the same, and so on down the line.
     That might have saved my life. The second dart attack, a couple of hours later, came from behind me. I felt the nudge, slapped the person on my right, turned around and saw the cloud descending. I got the shield over my head, and they hit a split second later.
     I set down my bow to pluck three darts from the shield and the ground attack started.

     It was a weird, impressive sight. Some three hundred of them stepped into the field simultaneously, almost shoulder-to-shoulder around the perimeter of the dome. They advanced in step, each one holding a round shield barely large enough to hide his massive chest. They were throwing darts similar to the ones we had been barraged with.
     I set up the shield in front of me—it had little extensions on the bottom to keep it upright—and with the first arrow I shot, I knew we had a chance. It struck one of them in the center of his shield, went straight through and penetrated his suit.
     It was a one-sided massacre. The darts weren’t very effective without the element of surprise—but when one came sailing over my head from behind, it did give me a crawly feeling between the shoulder blades.
     With twenty arrows I got twenty Taurans. They closed ranks every time one dropped; you didn’t even have to aim. After running out of arrows, I tried throwing their darts back at them. But their light shields were quite adequate against the small missiles.

     We’d killed more than half of them with arrows and spears, long before they got into range of the hand-to-hand weapons. I drew my sword and waited. They still outnumbered us by better than three to one.
     When they got within ten meters, the people with the chakram throwing knives had their own field day. Although the spinning disc was easy enough to see and took more than a half second to get from thrower to target, most of the Taurans reacted in the same ineffective way, raising up the shield to ward it off. The razor-sharp, tempered heavy blade cut through the light shield like a buzz saw through cardboard.

     The first hand-to-hand contact was with the quarterstaffs, which were metal rods two meters long that tapered at the ends to a double-edged, serrated knife blade. The Taurans had a cold-blooded—or valiant, if your mind works that way—method for dealing with them. They would simply grab the blade and die. While the human was trying to extricate his weapon from the frozen death-grip, a Tauran swordsman, with a scimitar over a meter long, would step in and kill him.
     Besides the swords, they had a bolo-like thing that was a length of elastic cord that ended with about ten centimeters of something like barbed wire, and a small weight to propel it. It was a dangerous weapon for all concerned; if they missed their target it would come snapping back unpredictably. But they hit their target pretty often, going under the shields and wrapping the thorny wire around ankles.

     I stood back-to-back with Private Erikson, and with our swords we managed to stay alive for the next few minutes. When the Taurans were down to a couple of dozen survivors, they just turned around and started marching out. We threw some darts after them, getting three, but we didn’t want to chase after them. They might turn around and start hacking again.
     There were only twenty-eight of us left standing. Nearly ten times that number of dead Taurans littered the ground, but there was no satisfaction in it.
     They could do the whole thing over, with a fresh 300. And this time it would work.

     We moved from body to body, pulling out arrows and spears, then took up places around the fighter again. Nobody bothered to retrieve the quarterstaffs. I counted noses: Charlie and Diana were still alive (Hilleboe had been one of the quarterstaff victims), as well as two supporting officers. Wilber and Szydlowska. Rudkoski was still alive but Orban had taken a dart.
     After a day of waiting, it looked as though the enemy had decided on a war of attrition rather than repeating the ground attack. Darts came in constantly, not in swarms anymore, but in twos and threes and tens. And from all different angles. We couldn’t stay alert forever; they’d get somebody every three or four hours.
     We took turns sleeping, two at a time, on top of the stasis field generator. Sitting directly under the bulk of the fighter, it was the safest place in the dome.
     Every now and then, a Tauran would appear at the edge of the field, evidently to see whether any of us were left. Sometimes we’d shoot an arrow at him, for practice.
     The darts stopped falling after a couple of days. I supposed it was possible that they’d simply run out of them. Or maybe they’d decided to stop when we were down to twenty survivors.

     There was a more likely possibility. I took one of the quarterstaffs down to the edge of the field and poked it through, a centimeter or so. When I drew it back, the point was melted off. When I showed it to Charlie, he rocked back and forth (the only way you can nod in a suit); this sort of thing had happened before, one of the first times the stasis field hadn’t worked. They simply saturated it with laser fire and waited for us to go stir-crazy and turn off the generator. They were probably sitting in their ships playing the Tauran equivalent of pinochle.

     I tried to think. It was hard to keep your mind on something for any length of time in that hostile environment, sense-deprived, looking over your shoulder every few seconds. Something Charlie had said. Only yesterday. I couldn’t track it down. It wouldn’t have worked then; that was all I could remember. Then finally it came to me.
     I called everyone over and wrote in the snow:

Get nova bombs from ship.
Carry to edge of field.
Move field.

     Szydlowska knew where the proper tools would be aboard ship. Luckily, we had left all of the entrances open before turning on the stasis field; they were electronic and would have been frozen shut. We got an assortment of wrenches from the engine room and climbed up to the cockpit. He knew how to remove the access plate that exposed a crawl space into the bomb-bay. I followed him in through the meter-wide tube.
     Normally, I supposed, it would have been pitch-black. But the stasis field illuminated the bomb-bay with the same dim, shadowless light that prevailed outside. The bomb-bay was too small for both of us, so I stayed at the end of the crawl space and watched.
     The bomb-bay doors had a “manual override” so they were easy; Szydlowska just turned a hand-crank and we were in business. Freeing the two nova bombs from their cradles was another thing. Finally, he went back down to the engine room and brought back a crowbar. He pried one loose and I got the other, and we rolled them out the bomb-bay.

     Sergeant Anghelov was already working on them by the time we climbed back down. All you had to do to arm the bomb was to unscrew the fuse on the nose of it and poke something around in the fuse socket to wreck the delay mechanism and safety restraints.
     We carried them quickly to the edge, six people per bomb, and set them down next to each other. Then we waved to the four people who were standing by at the field generator’s handles. They picked it up and walked ten paces in the opposite direction. The bombs disappeared as the edge of the field slid over them.

     There was no doubt that the bombs went off. For a couple of seconds it was hot as the interior of a star outside, and even the stasis field took notice of the fact: about a third of the dome glowed a dull pink for a moment, then was gray again. There was a slight acceleration, like you would feel in a slow elevator. That meant we were drifting down to the bottom of the crater. Would there be a solid bottom? Or would we sink down through molten rock to be trapped like a fly in amber—didn’t pay to even think about that. Perhaps if it happened, we could blast our way out with the fighter’s gigawatt laser.

From THE FOREVER WAR by Joe Haldeman (1974)

No Guns: Magic Psionic Power

Certain psionically talented adepts (aka "wizards") can use their mysterious magic powers to prevent firearms from functioning, or at least can easily deflect the bullets or beams into a harmless direction.

Flight Into Yesterday by Charles Harness (1949)
The Thieves are the futuristic Robin-Hoods: robbing from the rich to free the slaves. They have a force field created by their brain waves that stop bullets. Tragically the screen resistance is proportional to the velocity of the missile, so it don't work no good on swords. But this is great for Medieval Futurism science fiction. Other science fiction authors were quick to copy the idea, after Harness' short story was published.
Sargasso of Lost Starships by Poul Anderson (1952)
The aliens have superhuman psychic powers that can deflect blaster bolts or bullets. But they can't stop a sword or a spear because those have too much inertia for the psychic power to cope with. Unfortunately for the aliens, the human invader figure this out quite quickly.
Star Wars movies (1977)
Lightsabers are laserized swords but to make oneself immune to blaster bolts you have to Trust The Force, Luke! Only the precognition granted by the Force will allow the Jedi or Sith to get the blade in place fast enough to deflect the bolt. Of course they will be worthless against a .45 automatic. The lightsaber blade will just convert the solid bullet into a molten metal bullet with all of its kinetic energy still intact and still heading right for your face.

(ed note: in this dystopian future, most of the population are slaves while the few rich aristocrats are not. The Thieves rob from the rich and use the money to buy freedom for slaves. The Thieves have a secret mental force field which stops bullets but is ineffectual against swords)

      In a bound he was at the bedroom door that opened to the guard annex, had slammed it noisily behind electronic bolts. He listened momentarily to the angry voices on the other side.
     “Bring a beam-cutter !” came a hoarse cry. The door would be down in short order.
     Simultaneously a heavy blow struck him in the left shoulder, and the bedroom sparkled with sudden light. He whirled, crouching, and appraised coolly the man in bed who had shot him.
     Shey’s voice was a strange mixture of sleepiness, alarm and indignation. “A Thief!” he cried, tossing the gun away. “Lead-throwers are no good against a Thief’s body-screen. And I have no blade here." He licked pudgy lips. “Remember,” he giggled nervously, “your Thief code forbids injuring an unarmed man. My purse is on the perfume table.”

     “Kim was unarmed, of course?”
     “Of course. And when I told him that he was an enemy of the state and that it was my duty to shoot him he laughed.”
     "And so you shot him.”
     “Through the heart. He fell. I left the room to order his body removed. When I returned with a house slave he—or his corpse—had vanished. Had a confederate carried him away? Had I really killed him? Who knows? Anyway the thefts began the next day.”
     "He was the first Thief?”
     “We don’t really know, of course. All we know is that all Thieves seemed invulnerable to police bullets. Was Muir wearing the same type of protective screen when I shot him ? I don’t suppose I’ll ever know.”
     “Just what is the screen? Kim never discussed it with me.”
     “There again we don’t know. The few Thieves we’ve taken alive don’t know, either. Under Shey’s persuasion they indicated that it was a velocity-response field based electrically on their individual encephalographic patterns, and was maintained by their cerebral waves. What it really does is spread the bullet impact over a wide area. It converts the momentum of the bullet into the identical momentum of a pillow.
     “But the police have actually killed screen-protected Thieves, haven’t they?”
     “True. We have semi-portable Kades rifles that fire short-range heat beams. And then, of course, plain artillery with atomic explosive shells the screen remains intact but the Thief dies rather quickly of internal injuries. But you’re fully acquainted with the main remedy.
     “The sword.”
     “Precisely. Since the screen resistance is proportional to the velocity of the missile it offers no protection against the comparatively slow-moving things, such as the rapier, the hurled knife or even a club. And all this talk of rapiers reminds me that I have business with the Minister of Police before meeting Shey. You will come with me and we’ll watch Thurmond at rapier practice for a few minutes.”
     “I didn’t know your vaunted Minister of Police required practise. Isn’t he the best blade in the Imperium?”
     “The very best. And practice will keep him that way.”

From FLIGHT INTO YESTERDAY by Charles Harness (1949)

No Guns: Forgot How To Make Them

Which gets rid of the guns, but leaves open the burning question of "so why didn't you also forget how to make starships?" Possible answers are in the sub sections below


      While Axxal prepared the sledge, Jorry distributed weapons. Each crewman was already armed with the customary personal weapons of his people, but Jorry supplemented these. On such an expedition as this, he wanted his crew outfitted with the best arms available in the galaxy, Axxal and Dolul were each given a pair of pistols. While they strapped them on and filled their pockets with shells, Jorry broke open a long crate and lifted out three short-range projectile rifles.

     These were the most powerful weapons in space. Most of the warrior races mistrusted the crude firearms of the period and preferred to rely on blades. Their doubt was well-founded. The ordinary firearms of the twenty-seventh century were crudely made, and jammed or misfired at crucial moments; a man was foolish to trust his life to them. But these weapons, made by the artisans of Rugatcz V from authentic Old Earth models, were as close to flawless as the work of humans could be. Jorry trusted in them. One rifle he slung over his own shoulder, the second he gave to Bral, the third to Collen. Bral hefted his rifle and looked dubiously at the captain.

     “Take it, Bral, and use it. I know you’d prefer your ax, but a rifle has a longer range,” Jorry said. “You’ve used one before, I know.”
     The Skeggjatt spoke as if he were making a shameful mission. “Yes, many times. But I can handle anything we may meet on this planet with my ax. You’ve seen me use it.”
     “It’s not a question of fighting skill, Bral, I just don’t want anything getting that close. These rifles will drop an attacker fifty meters off. That’s a comfortable margin.”

     For a time, before he realized how close the Quespodons and their allies were to rising, Jorry had also contemplated a simple outright seizure of power. It could have been easily done. A stock of firearms was hidden aboard the Seraph, and as far as Jorry could determine, these were the only weapons on Xhanchos except for the swords and javelins of Gariv’s troops. Thus armed, Jorry, Axxal, and a small band of rebels could not be withstood. Six of them could conquer a world like this one.

     The lack of advanced weaponry in the galaxy, and the great disparity of arms from world to world, were glaring anomalies of intersystem travel, but few starfarers dwelt on the situation or its implications. They simply accepted existing conditions, as they accepted the powerful ships whose workings were a mystery to them.

From UNDER A CALCULATING STAR by John Morressy (1975)
Using Inherited Technology

If you really must have swords on starships, the Deus ex machina solution is postulate that the high-tech items are ultra-advanced indestructable self-repairing technology that any moron can use. And they were not created by the current starship users, they were inherited.


...Let's consider Situation Two now; it's far more stable and leads to many more promising consequences. For my investigations into this area, I can thank Poul — hence my comments about his own excess of modesty. He had a delightful scene in a Planet yarn years back, where a sword-swinging spaceman argued that the stars couldn't be light-years apart because he could get from one to the other in a week or two. He'd set up a borderline case of the item under consideration: what one might call an inheritance situation. And the reason why this hasn't been examined more closely in the previous articles in Amra is probably because on Earth it's occurred only rarely and over a small area for a short space of time.

To the quick of the ulcer: a society (community, whatever) busy using up someone else's resources and not its own is a perfect setting in which to combine the most contrasting gadgetry. In the story just referred to, and in heaven knows how many more of that sort, the inheritors are the derelict descendants of a star-spanning galactic empire.


For instance, it takes the resources of a major industrial power to crash a can of instruments on the moon, or to operate an eighty-thousand-ton ocean liner or a fleet of jet aircraft. Unless something incredible happens, and I don't mean a faster-than-light drive, it's going to take the resources of an industrialized planet to maintain a spacefleet. A galactic empire will contain so many planets so highly industrialized and so densely populated that some part of it will survive any major crash and probably make the whole shebang into a galaxy-sized parallel with present-day Earth.

Not good enough. How do we get the local planetary populations down to peasant-agriculture numbers? How do we reduce the odds against knowledge of fifty-percent-plus are of contemporary (star-flying) technology disappearing altogether over an entire chunk of the galaxy?...

...I got it clear in my mind that the ships were surviving because they were built to last, while planet-bound engineering was mainly the product of the inhabitants, isolated on the fringe of the galaxy, and probably a century or two behind the state of the art at the Hub when the empire collapsed (which brings me approximately level with Asimov in his Foundation stories, though he was using the argument to a different end).

And then I got it, belatedly because as I said the Earthside parallels are extremely rare. I can only think of such instances as people mining ancient monuments for building stone and lacking either the patience or the skill to square a true block themselves when the store runs dry.

Suppose the early explorers of the galaxy find caches of starships belonging to a vanished race, in such enormous quantities that they can spread across the stars like seed from a puffball. Good: this provides all the necessary incongruities. You can go as far and as fast as you like; you don't have to take a cross-section of Earthside technology in every ship; and when you get where you're going you start with the local resources only. Maybe you don't make a very good job of it. In that case, when some next-door system gets into an expansionist mood you rather welcome being taken over and garrisoned by legionaries who bring advanced medicine (we should have invited Mrs. Jones who knows first aid!) — and maybe you do well enough yourself to launch out in the conquest game yourself.

But at no point does human knowledge of the borrowed technology catch up with the application of it. This is no surprise though — out of the next hundred people you see drive past you, how many do you think could change a spark plug or grind a valve? In certain previously advanced areas of the galaxy understanding will be achieved; maybe humans get to the theory underlying the stardrive ... but where from there? To build the tools to build the machines to apply the theory, and that may take generations.

From INTERSTELLAR EMPIRE by John Brunner (1965)

(ed note: This may or may not be the story John Brunner was referring to, but it is along the same lines)

Many men — risking indictment as warlocks or sorcerers—had tried to probe the secrets of the Great Destroyer and compute the speed of these mighty spacecraft of antiquity. Some had even claimed a speed of 100,000 miles per hour for them. But since the starships made the voyage from Earth to the agricultural worlds of Proxima Centauri in slightly less than twenty-eight hours, such calculations would place the nearest star-system an astounding two million eight hundred thousand miles from Earth — a figure that was as absurd to all Navigators as it was inconceivable to laymen.

(Ed note: 2,800,000 miles is a pathetic 1/50th the mean distance between Earth and Mars. To travel from Earth to Proxima Centauri in 28 hours would require the starship to be travelling about 1320 times the speed of light, which is a far far cry from 100,000 mph.)

From "THE REBEL OF VALKYR" by Alfred Coppel (Planet Stories, Fall, 1950)

(ed note: Starships built by former Human galactic empire)

There was much for Axxal and all his fellow inhabitants of that era to learn; but they had no living teachers. The driveships that bore them from system to system had all been built centuries before. They were products of a technology that collapsed forever when the humans of Old Earth, the greatest technicians in the history of the galaxy, had scattered throughout the stars like grains of sand flung into a hurricane. The ships endured, but the civilization that had produced them was forgotten, its records lost, scattered among a thousand wor1ds as fragments of myth and legend. The Wroblewski coils, the very heart of the lightspeed drive, worked on as efficiently as they had on their maiden voyages six centuries before, but the principle that underlay them was long forgotten. If a part broke or wore out—a rare occurrence—the crew or even the passengers, provided they could read, could replace it by following the ancient manuals. But the manuals did not explain purpose or function; The driveships were designed to carry fugitives by the millions from a festering planet; they were made literally foolproof. And needing no knowledge of their vessels’ operations, the pioneers sought none.

In the great age of exodus, during the twenty-first and twenty-second centuries of the Galactic Standard Calendar, the factories of Old Earth turned out driveships in profusion. Enough were built, and in sufficient variety, to carry starfarers for centuries to come.

The first wave of pioneers settled where they landed, so shaken by the experience of deep-space travel that they drove all thought of it from their minds and rejected the history that had driven them to the stars. Their grandchildren, the second wave of voyagers, accepted the great ships as the figures in the ancient tales accepted flying carpets and winged steeds. The things moved, and took them to the fringes of the galaxy. They did not care to inquire how; they went.

So Axxal found himself in a position somewhat analogous to that of an Old Earth caveman placed in the cab of a nineteenth-century locomotive, or at the helm of a twenty-first-century space ferry. This immense and frightening construction moved; with some study, he could learn to control it; but for all he knew or could determine, it was propelled by spirits.

Axxal’s mind was not as quick, nor as complicated, as Jorry’s, but it was a methodical mind, a good tool for the slow and patient unraveling of a many-faceted but tangible problem. He applied himself to the workings of the Seraph; traced intricate circuits from source to destination; learned what they did, though he could not yet fathom how; even puzzled out what gave the Seraph a stable atmosphere and planetary gravity. With extreme difficulty, he deciphered the shifting points of light in the vision tank that formed the forward bulkhead, and grasped the rudiments of interstellar navigation. Heretofore, he had only been able to aim the Seraph at preprogramed destinations; now he saw that it was possible to choose his destination from any world on the charts.

The lack of advanced weaponry in the galaxy, and the great disparity of arms from world to world, were glaring anomalies of intersystem travel, but few starfarers dwelt on the situation or its implications. They simply accepted existing conditions, as they accepted the powerful ships whose workings were a mystery to them. Some thoughtful men wondered at the incongruity of multi-lightspeed driveships manned by crews whose most powerful weapon was a cutlass or pistol; of healers who could replace a severed limb, and bloody tournaments in which men slaughtered one another by the hundreds in observance of traditions whose origin was long forgotten; of the great machine on Watson that served as repository for the legal wisdom of scores of civilizations, while on hundreds of worlds, justice was sought in the muttering of a seer or the casting of carven stones. Such things existed side by side in the same galaxy. A lightspeed traveler could go from the most sophisticated civilization to the most primitive in a single journey from system to system. This time, Jorry had thought to turn the backwardness of Xhanchos and its rulers to his advantage, and pluck an easy kingdom for himself.

From UNDER A CALCULATING STAR by John Morressy (1975)

(ed note: Starships built by former Human galactic empire)

(ed note: In The Warlock of Rhada one thousand years after the fall of the first galactic empire, warriors are armed with swords and ride horses, but by golly the starships still work. Built to last.)

The starship Gloria in Coelis, grounded on the sandy plain to the west of Lord Ulm of Vara's keep, was ancient. Though the men who presently flew her were the wisest of their time, they had no really clear notion of how the vessel operated, when it was built or how fast it traveled. From time out of mind, the Order of Navigators had trained its priests in the techniques of automated starflight by rote. Even now, as the Gloria's two million metric tons depressed the soil of the Varan plain, the duty Navigators on the starship's bridge, were chanting the Te Deum Stella, the Litany for Preflight, this ritual being one of the first taught to young novice Navigators on the cloister-planets of Algol.

Though the three junior priests on the bridge were chanting the voice commands that activated the immense ship's systems, in fact only the propulsion units (sealed after manufacture in the time of the Empire) responded. The priests did not know that the vessel's life-support systems and its many amenities had ceased to function more than a thousand years earlier. The interior of the starship was lit by torches burning in wall-sconces, water and food were stored aboard in wooden casks, and the ship's atmosphere was replenished not by the scrubber units, as originally intended, but by the air that was taken aboard through the open ports and hatchways. The starships were capable of almost infinite range, for the engines operated on solar-phoenix units. But the length of any star voyage was limited by the food and water supply and by the fouling of the air by the hundreds of men and horses of the warbands the starships most often carried.

The bridge had been depolarized, and from within this consecrated area where only a Navigator might pass, the duty crew could see the squat towers and thick walls of Lord Vim's keep. The warband, almost a thousand armed men, was mustering on the plain below the north tower, preparing to file into the vaulted caverns within the kilometer-long ship.

Brother Anselm, a novice who spoke with the heavy Slavic accents of the Pleiades Region, had the Conn. This honor was a small one, for the ship was not under way, but the engine cores were still humming from the recent voyage from Aurora, and Anseim, a fervent young man, imagined that the voice of the Holy Star was in them — and speaking directly to him.

He half-closed his eyes and chanted, "Planetary Mass two-third nullified and cores engaged for atmospheric flight at minus thirty and counting."

Brother Gwill, a thinly made and sour young Altairi, made the response, pressing the glowing computer controls in the prescribed sequence. "Cores One and Three at Energy Point Three, for the Glory of Heaven. Cores Two, Four, and Five coming into phase as the Lord of the Great Sky Commands."

"Hallelujah, Core Energy rising on scan curve," Anselm declared with fervid devotion…

…"Null-grav power to main buss at Energy Point Five in the Name of the Holy Name."

"Null-gee to main buss at my hack, if it is pleasing to the Spirit," Gwill responded. In spite of himself he could not suppress a shiver of anticipation. At Energy Point Five, the power of the cores was fed into the lifting system and the vast star ship would begin to lose mass. The tonnage that interacted with planetary gravity to give the ship its great weight when at rest would begin to dissipate into a spatio-temporal anomaly, changing the molecular structure by reversing the atomic polarities of all matter within the Core field. The men who designed and built the starships understood this effect only imperfectly, and the Navigators who now flew them across the Great Sky understood it not at all. But the visual and physical effects of the change in matter within the Core fields was spectacular and awesome. As the Null-grav buss was activated, the skin of the ship would begin to shimmer and glow, surplus energy accumulated by kinesis and radiation from the Vyka Sun expending itself as light and molecular motion until the starship actually began to move. It was a sight that created consternation among the common folk of all the Great Sky, and even Navigators, who were accustomed to the phenomena, gave thought to the miraculous and holy nature of the great ships that were their domain.

Anselm murmured to Brother Collis, "Gloria in Excelsis, let the ship's pressure rise to ambient."

"Ambient it is and blessed be the Holy Star," Collins said rapidly. He pressed the prescribed buttons on the Support Console and waited the required thirty heartbeats. Nothing happened, nor did the young novice expect anything to happen. The display screen remained dark. "We are hold, hold, hold, may it be pleasing to God," he reported in the familiar rising chant. "Hold on pressure, hold on flow, hold on storage."…

…The three priests made the sign of the Star and Anselm in dictated that Brother Gwill should make the Query.

The novice punched in the coded sequence that was one of the first things memorized by all Navigators and meant, in effect, "Are we where we should be?" Ordinarily, for a short atmospheric flight, the Query was omitted from the Litany, but nothing was ever left out when Brother Anseim was in charge of the countdown.

The ship's computer flashed its reply on the display-screen: "Position coordinates D788990658-RA008239657. Province of Vega, Area 10, Aldrin. Planetary coordinates 23° 17' north latitude, 31° 12' west longitude, inertial navigation system engaged."

In spite of their familiarity with the ways of the holy starships, the three novices felt a tingling thrill at the appearance of the strangely shaped sigils in the ancient Anglic runes of the Empire. They had only the vaguest notion of what the ship meant by addressing them in these mystical words, in these phrases of the ancient world. But the background color on the display screen was the Color of Go — emerald green — and that told them that the Gloria in Coelis was, once again, ready for flight.

The Rhadan warlock Cavour (Early Second Empire period) once suggested that starships could attain velocities in excess of 200,000 kilometers per standard hour. Not only did he run the fatal risk of the displeasure of the Order of Navigators by these calculations (in an earlier age he would have been burned), but he earned the derision of his contemporaries. His computations, based on the known elapsed time for flight between the Rimworlds and Earth, resulted in a hypothetical diameter for the galaxy of 12,800,000 kilometers. Even Cavour, a learned man for his day, was shaken by this immense figure, and recanted.

Interregnal investigators, such few as there were, believed that a figure of 666,666 kilometers represented the exact diameter of what they called "The Great Sky."

-Matthias ben Mullerium, The History of the Rhadan Republic, Late Second Stellar Empire period

From THE WARLOCK OF RHADA by Robert Cham Gilman (AKA Alfred Coppel) (1985)

(ed note: Starships built by alien Forerunners)

"The story of the Empire," he commenced, and heard in imagination the crashing of worlds like bowling-balls being hurled down a skittle-alley, "is shrouded in mystery. Ten thousand years have eroded history away.

"We know that we were borrowers. We inherited the abandoned property — most significantly, the interstellar ships — of a people that matured and died in the galactic hub while we were struggling outward from our legendary planet of origin. We know that this chance bequest allowed our race to spread among millions of stars like an epidemic.

"Details beyond this bare outline, however, can never be reclaimed. It is as though one were to blink and find a century had passed. Blink now, and man is creeping along the galactic rim, in those areas which were later to be regarded as the home of mutants and pirates. Blink once more, and the Empire's writ runs all the way to the threshold of the Big Dark."

"How did you come here? By the regular space-lines?"

"Blazes, no. In this corner of the galaxy, shipping schedules are down to monthly, sometimes bi-monthly frequencies. I should sit on my butt while they get around to organizing a: crew and lifting their creaky old tubs? No, I have my own ship now."

"Your own ship?" Spartak echoed in surprise. "You've done well. I've not heard of a privately owned starship before."

"Don't picture any ship of the line," Vix grunted. "I have an Imperial scout, probably one of the original ships they tell me we found when we came out into space the very first time. I've never dared compute how old she must be."

"Twenty thousand years," Spartak said positively.

"Twenty—?" It was Vix's turn to be astonished. "Oh, never!"

"If it's one of the original Imperial vessels, it must be. According to what events you take as marking the establishment and the collapse of the Empire, it lasted something between eight and a half and nine thousand years. By the time we came out to collect them, the various artifacts our predecessors left behind were already at least as old as the whole lifespan of the Empire."

"This is something I've never got straight in my mind," Vix said slowly. He seemed to be groping for some subject of conversation which would be sufficiently neutral to let him get to know this stranger-brother of his, who had adopted a way of life so alien to his temperament and yet now had to be his companion and confidant. "I guess you must have put in a deal of study on it—hm?"

"I did when I first came to Annanworld," Spartak agreed. "I had this over-ambitious idea that I was going to find out how the Empire originally arose. But the records simply don't exist. What little had . been recorded was either destroyed or simply rotted away. We've never had the skills required to build something to last ten thousand years. Even an Empire!"

"But—well, at least you can tell me how it is we're still flying ships supposed to be as old as you just said?"

"We've made some intelligent guesses. The best and most likely is that at some time in their own history the people who left the ships behind lost interest in physical activity, and built sufficient ships and some few other items to last out their—well, maybe their lifespan. Or else they went to another galaxy because they'd studied this one from rim to rim and exhausted it and themselves. But they'd built well. It took us ten thousand years to use up what they left behind."

"It's not used up yet, not by a long way," Vix countered.

Yes, but what time couldn't do to those ships, we've done deliberately. It costs to buy a ship, but it doesn't cost anything to run one, for they're self-fuelling and almost indestructible. The Argian fleet numbered one hundred and one million vessels at the height of Imperial power, and there must have been almost one thousand times as many as that in service throughout the galaxy. Yet now—as you just said—there are so few ships you may wait a month for passage on what used to be a flourishing Imperial starlane."

"We're building some ships of our own, though."

"Where? Not in Imperial space, Vix. Out on the Rim, where the Imperial writ never ran. I sometimes think I'd like to go out there, to see what human endeavor can do by itself, without accidental help from a vanished race."

From THE ALTAR ON ASCONEL by John Brunner (1965)

(ed note: Starships built by alien Forerunners)

So there was Gateway, getting bigger and bigger in the ports of the ship up from Earth:

An asteroid. Or perhaps the nucleus of a comet. About ten kilometers through, the longest way. Pear-shaped. On the outside it looks like a lumpy charred blob with glints of blue. On the inside it's the gateway to the universe.

Sheri Loffat leaned against my shoulder, with the rest of our bunch of would-be prospectors clustered behind us, staring. "Rob. Look at the cruisers!"

"They find anything wrong," said somebody behind us, "and they blow us out of space."

"They won't find anything wrong," said Sheri, but she ended her remark with a question mark. Those cruisers looked mean, circling jealously around the asteroid, watching to see that whoever comes in isn't going to steal the secrets that are worth more than anyone could ever pay.

We hung to the porthole braces to rubberneck at them. Foolishness, that was. We could have been killed. There wasn't really much likelihood that our ship's matching orbit with Gateway or the Brazilian cruiser would take much delta-V, but there only had to be one quick course correction to spatter us. And there was always the other possibility, that our ship would rotate a quarterturn or so and we'd suddenly find ourselves staring into the naked, nearby sun. That meant blindness for always, that close. But we wanted to see.

The Brazilian cruiser didn't bother to lock on. We saw flashes back and forth, and knew that they were checking our manifests by laser. That was normal. I said the cruisers were watching for thieves, but actually they were more to watch each other than to worry about anybody else. Including us. The Russians were suspicious of the Chinese, the Chinese were suspicious of the Russians, the Brazilians were suspicious of the Venusians. They were all suspicious of the Americans.

So the other four cruisers were surely watching the Brazilians more closely than they were watching us. But we all knew that if our coded navicerts had not matched the patterns their five separate consulates at the departure port on Earth had filed, the next step would not have been an argument. It would have been a torpedo.

It's funny. I could imagine that torpedo. I could imagine the cold-eyed warrior who would aim and launch it, and how our ship would blossom into a flare of orange light and we would all become dissociated atoms in orbit… Only the torpedoman on that ship, I'm pretty sure, was at that time an armorer's mate named Francy Hereira. We got to be pretty good buddies later on. He wasn't what you'd really call a cold-eyed killer. I cried in his arms all the day after I got back from that last trip, in my hospital room, when he was supposed to be searching me for contraband. And Francy cried with me.

The cruiser moved away and we all surged gently out, then pulled ourselves back to the window with the grips, as our ship began to close in on Gateway.

"Looks like a case of smallpox," said somebody in the group.

It did; and some of the pockmarks were open. Those were the berths for ships that were out on mission. Some of them would stay open forever, because the ships wouldn't be coming back. But most of the pocks were covered with bulges that looked like mushroom caps.

Those caps were the ships themselves, what Gateway was all about.

The ships weren't easy to see. Neither was Gateway itself. It had a low albedo to begin with, and it wasn't very big: as I say, about ten kilometers on the long axis, half that through its equator of rotation. But it could have been detected. After that first tunnel rat led them to it, astronomers began asking each other why it hadn't been spotted a century earlier. Now that they know where to look, they find it. It sometimes gets as bright as seventeenth magnitude, as seen from Earth. That's easy. You would have thought it would have been picked up in a routine mapping program.

The thing is, there weren't that many routine mapping programs in that direction, and it seems Gateway wasn't where they were looking when they looked.

Stellar astronomy usually pointed away from the sun. Solar astronomy usually stayed in the plane of the ecliptic — and Gateway has a right-angle orbit. So it fell through the cracks.

The piezophone clucked and said, "Docking in five minutes. Return to your bunks. Fasten webbing."

We were almost there.

Sheri Loffat reached out and held my hand through the webbing. I squeezed back. We had never been to bed together, never met until she turned up in the bunk next to mine on the ship, but the vibrations were practically sexual. As though we were about to make it in the biggest, best way there ever could be; but it wasn't sex, it was Gateway.

When men began to poke around the surface of Venus they found the Heechee diggings.

They didn't find any Heechees. Whoever the Heechees were, whenever they had been on Venus, they were gone. Not even a body was left in a burial pit to exhume and cut apart. All there was, was the tunnels, the caverns, the few piddling little artifacts, the technological wonders that human beings puzzled over and tried to reconstruct.

Then somebody found a Heechee map of the solar system. Jupiter was there with its moons, and Mars, and the outer planets, and the Earth-Moon pair. And Venus, which was marked in black on the shining blue surface of the Heechee-metal map. And Mercury, and one other thing, the only other thing marked in black besides Venus: an orbital body that came inside the perihelion of Mercury and outside the orbit of Venus, tipped ninety degrees out of the plane of the ecliptic so that it never came very close to either. A body which had never been identified by terrestrial astronomers. Conjecture: an asteroid, or a comet — the difference was only semantic — which the Heechees had cared about specially for some reason.

Probably sooner or later a telescopic probe would have followed up that clue, but it wasn't necessary. Then The Famous Sylvester Macklen — who wasn't up to that point the famous anything, just another tunnel rat on Venus — found a Heechee ship and got himself to Gateway, and died there. But he managed to let people know where he was by cleverly blowing up his ship. So a NASA probe was diverted from the chromosphere of the sun, and Gateway was reached and opened up by man.

Inside were the stars.

Inside, to be less poetic and more literal, were nearly a thousand smallish spacecraft, shaped something like fat mushrooms. They came in several shapes and sizes. The littlest ones were button-topped, like the mushrooms they grow in the Wyoming tunnels after they've dug all the shale out, and you buy in the supermarket. The bigger ones were pointy, like morels. Inside the caps of the mushrooms were living quarters and a power source that no one understood. The stems were chemical rocket ships, kind of like the old Moon Landers of the first space programs.

No one had ever figured out how the caps were driven, or how to direct them.

That was one of the things that made us all nervous: the fact that we were going to take our chances with something nobody understood. You literally had no control, once you started out in a Heechee ship. Their courses were built into their guidance system, in a way that nobody had figured out; you could pick one course, but once picked that was it — and you didn't know where it was going to take you when you picked it, any more than you know what's in your box of Cracker-Joy until you open it.

But they worked. They still worked, after what they say is maybe half a million years.

The first guy who had the guts to get into one and try to start it up succeeded. It lifted out of its crater on the surface of the asteroid. It turned fuzzy and bright, and was gone.

And three months later, it was back, with a starved, staring astronaut inside, aglow with triumph. He had been to another star! He had orbited a great gray planet with swirling yellow clouds, had managed to reverse the controls — and had been brought back to the very same pockmark, by the built-in guidance controls.

So they sent out another ship, this time one of the big, pointy morel-shaped ones, with a crew of four and plenty of rations and instrumentation. They were gone only about fifty days. In that time they had not just reached another solar system, they had actually used the lander to go down to the surface of a planet. There wasn't anything living there … but there had been.

They found the remnants. Not a lot. A few beat-up pieces of trash, on a corner of a mountaintop that had missed the general destruction that had hit the planet. Out of the radioactive dust they had picked up a brick, a ceramic bolt, a half-melted thing that looked as though it had once been a chromium flute.

Then the star rush began … and we were part of it.

Having seen him, I knew Gateway in a way I had not known it from the statistics. The statistics are clear enough, and we all studied them, all of us who came up as prospectors, and all of that vastly larger number who only wished they could. About eighty percent of flights from Gateway come up empty. About fifteen percent don't come back at all. So one person in twenty, on the average, comes back from a prospecting trip with something that Gateway — that mankind in general — can make a profit on. Most of even those are lucky if they collect enough to pay their costs for getting here in the first place.

And if you get hurt while you're out … well, that's tough. Terminal Hospital is about as well equipped as any anywhere. But you have to get there for it to do you any good. You can be months in transit. If you get hurt at the other end of your trip — and that's where it usually happens — there's not much that can be done for you until you get back to Gateway. By then it can be too late to make you whole, and likely enough too late to keep you alive.

From GATEWAY by Frederik Pohl (1976)

John Brunner is of the opinion that at a bare minimum, a technologically primitive culture can only utilize high-tech items from a more advanced culture if they have some people who are "cobblers." These are tinkerers who can see the functionality of the high-tech components, and reproduce the functionality using native low-tech solutions.


Speaking as one who misguidedly thought that writing swords-and-spaceship stories was easy (it used to be, but then I started asking awkward questions of myself), I read both Sprague de Camp's "Range" and Poul Anderson's comment theron with considerable interest. I got to the point where the latter was accusing the former of modesty in omitting the Krishna-type situation as a legitimate means of mating these ingredients, and realized that Poul was doing the same in his turn...

...There are two more ways, not examined in detail in the Amra discussion, in which this paradoxical situation can arise. First, and right under our noses, is the one implied by the horse-doesn't-need-United-Steel argument in respect of modes of transportation. We've had it in scores of After-the-Bomb stories. Modern technology requires an interlocking structure of cohesive and cooperative enterprise in which a catastrophic milieu would vanish and might not appear in its original form...

...One can select out from a body of techniques a certain rather limited group which are within the competence of a single man or a small team — for example the Afghan rifles — and provided one condition is met those techniques can then survive as folk knowledge...

...The condition which must be met is this: among the isolated team or community continuing the technique must be at least one cobbler. I mean by that someone who will make do — who can cut through the fog of traditional methods which surrounds most modern technology and see that even if such-and-such isn't available, so-and-so will do the job. What do those Afghans put in their rifles? Cordite? Maybe — if they have a source of supply from a factory. But for all their handcrafting skill, I don't see them processing nitroglycerine over a cooking fire. More likely, they're packing their cartridges with a rather inefficient black powder.

In your post-nuclear-holocaust situation, to give a parallel instance, you'll be able to keep cars and jeeps moving provided you have somebody around who can bake the gas out of wood, or compress methane boiled off by stable-dung, and plumb a gas-supply into the induction manifold using scrap tubing and insulated tape...

...So: Situation One aforementioned is a catastrophic one, during which for a comparatively brief time a maximal range of incongruities coexist...

(for situation two, go here)

From INTERSTELLAR EMPIRE by John Brunner (1965)

Poul Anderson used this in his novel THE HIGH CRUSADE. In the year 1345 CE an alien starship from the Wersgorix Empire scouts Terra for future conquest, but the alien crew managed to get captured by Sir Roger (Baron de Tourneville) and his knights. By dastardly design the starship takes the knights to the planet Tharixan instead of their desired destination. At one point the knights want to neutralize an alien castle. They have nuclear warheads but no missiles. Some cobbler figures out that a DIY trebuchet will take the place of a missile to deliver warheads.

This works remarkably well, being a good example of Rock Beats Laser. Since the aliens rely upon metal detectors they do not notice the wooden trebuchets advancing to the castle, and the missile detectors on the antimissile defenses of course do not detect any missiles because there aren't any. The nuclear warheads are lobbed in with no resistance and the castle is vaporized by a cluster of nuclear mushroom clouds.

Poul Anderson also pointed out that unscruplous individuals can actually harvest cobbler technology to sell to barbarians.

Harvesting Cobbler Technology

A "cobbler" is a local person who can adapt stranger's high technology to the lower tech base of the locals. So local Afghan tribesmen observed stranger Europeans armed with rifles. When the Afghans tried to make their own rifles, the cordite used in the bullets was beyond the capablilities of the Afghan's tech base. So an Afghan cobbler adapted the concept by using easy-to-make gunpowder instead of cordite.

The main reason to harvest cobbler technology is in order to create space barbarians for fun and profit.


(ed note: The aliens of the planet Trillia were visited by Terrans in starships. Unfortunately the Trillians did not have anything the Terrans considered valuable trade goods. The Trillians could not purchase Terran starships, so they slowly researched how to make their own crude ships. They cobbled, in other words. One fine day a Trillian named Witweet is kidnapped at blaster-point by some Terran criminals, who want his aid in stealing a crude Trillian starship. Witweet is puzzled as to why the Terrans would want a cobbled Trillian starship in the first place.)

First it called briefly at a neighboring star, on one of whose planets were intelligent beings that had developed a promising set of civilizations. But, again, quite a few such lay closer to home.

The era of scientific expansion was followed by the era of commercial aggrandizement. Merchant adventurers began to appear in the sector. They ignored Paradox, which had nothing to make a profit on, but investigated the inhabited globe in the nearby system. In the language dominant there at the time, it was called something like Trillia, which thus became its name in League Latin. The speakers of that language were undergoing their equivalent of the First Industrial Revolution, and eager to leap into the modern age.

Unfortunately, they had little to offer that was in demand elsewhere. And even in the spacious terms of the Polesotechnic League, they lived at the far end of a long haul. Their charming arts and crafts made Trillia marginally worth a visit, on those rare occasions when a trader was on such a route that the detour wasn't great. Besides, it was as well to keep an eye on the natives. Lacking the means to buy the important gadgets of Technic society, they had set about developing these for themselves.

"Dog your hatch!" The vocalizer made meaningless noises and Harker realized he had shouted in Anglic. He went back to Lenidellian-equivalent. "I don't propose to waste time. My partners and I did not come here to trade as we announced. We came to get a Trillian spaceship. The project is important enough that we'll kill if we must. Make trouble, and I'll blast you to greasy ash. It won't bother me. And you aren't the only possible pilot we can work through, so don't imagine you can block us by sacrificing yourself. I admit you are our best prospect. Obey, cooperate fully, and you'll live. We'll have no reason to destroy you." He paused. "We may even send you home with a good piece of money. We'll be able to afford that."

The bottling of his fur might have made Witweet impressive to another Trillian. To Harker, he became a ball of fuzz in a kimono, an agitated tail and a sound of coloratura anguish. "But this is insanity . . . if I may say that to a respected guest. . . . One of our awkward, lumbering, fragile, unreliable prototype ships—when you came in a vessel representing centuries of advancement—? Why, why, why, in the name of multiple sacredness, why?"

"I'll tell you later," the man said.

The port was like nothing in Technic civilization, unless on the remotest, least visited of outposts. After all, the Trillians had gone in a bare fifty years from propeller-driven aircraft to interstellar spaceships. Such concentration on research and development had necessarily been at the expense of production and exploitation. What few vessels they had were still mostly experimental. The scientific bases they had established on planets of next-door stars needed no more than three or four freighters for their maintenance.

Thus a couple of buildings and a ground-control tower bounded a stretch of ferrocrete on a high, chilly plateau; and that was Trillia's spaceport. Two ships were in. One was being serviced, half its hull plates removed and furry shapes swarming over the emptiness within. The other, assigned to Witweet, stood on landing jacks at the far end of the field. Shaped like a fat torpedo, decorated in floral designs of pink and baby blue, it was as big as a Dromond-class hauler. Yet its payload was under a thousand tons. The primitive systems for drive, control, and life support took up that much room.

"May I, in turn, humbly request enlightenment as to your reason for . . . sequestering . . . a spacecraft ludicrously inadequate by every standards of your oh, so sophisticated society?"

"We don't actually want the ship as such, except for demonstration purposes," Harker said. "What we want is the plans, the design. Between the vessel itself, and the service manuals aboard, we have that in effect."

Witweet's ears quivered. "Do you mean to publish the data for scientific interest? Surely, to beings whose ancestors went on to better models centuries ago—if, indeed, they ever burdened themselves with something this crude—surely the interest is nil. Unless . . . you think many will pay to see, in order to enjoy mirth at the spectacle of our fumbling efforts?" He spread his arms. "Why, you could have bought complete specifications most cheaply; or, indeed, had you requested of me, I would have been bubbly-happy to obtain a set and make you a gift." On a note of timid hope: "Thus you see, dear boy, drastic action is quite unnecessary. Let us return. I will state you remained aboard by mistake—"

Olafsson guffawed. Dolgorov said, "Not even your authorities can be that sloppy-thinking." Harker ground out his cigarette on the deck, which made the pilot wince, and explained at leisured length:

"We want this ship precisely because it's primitive. Your people weren't in the electronic era when the first human explorers contacted you. They, or some later visitors, brought you texts on physics. Then your bright lads had the theory of such things as gravity control and hyperdrive. But the engineering practice was something else again.

"You didn't have plans for a starship. When you finally got an opportunity to inquire, you found that the idealistic period of Technic civilization was over and you must deal with hardheaded entrepreneurs. And the price was set 'way beyond what your whole planet could hope to save in League currency. That was just the price for diagrams, not to speak of an actual vessel. I don't know if you are personally aware of the fact—it's no secret—but this is League policy. The member companies are bound by an agreement.

"They won't prevent anyone from entering space on his own. But take your case on Trillia. You had learned in a general way about, oh, transistors, for instance. But that did not set you up to manufacture them. An entire industrial complex is needed for that and for the million other necessary items. To design and build one, with the inevitable mistakes en route, would take decades at a minimum, and would involve regimenting your entire species and living in poverty because every bit of capital has to be reinvested. Well, you Trillians were too sensible to pay that price. You'd proceed more gradually. Yet at the same time, your scientists, all your more adventurous types were burning to get out into space.

"I agree your decision about that was intelligent too. You saw you couldn't go directly from your earliest hydrocarbon-fueled engines to a modern starship—to a completely integrated system of thermonuclear powerplant, initiative-grade navigation and engineering computers, full-cycle life support, the whole works, using solid-state circuits, molecular-level and nuclear-level transitions, forcefields instead of moving parts—an organism, more energy than matter. No, you wouldn't be able to build that for generations, probably.

"But you could go ahead and develop huge, clumsy, but workable fission-power units. You could use vacuum tubes, glass rectifiers, kilometers of wire, to generate and regulate the necessary forces. You could store data on tape if not in single molecules, retrieve with a cathode-ray scanner if not with a quantum-field pulse, compute with miniaturized gas-filled units that react in microseconds if not with photon interplays that take a nanosecond.

"You're like islanders who had nothing better than canoes till someone happened by in a nuclear-powered submarine. They couldn't copy that, but they might invent a reciprocating steam engine turning a screw—they might attach an airpipe so it could submerge—and it wouldn't impress the outsiders, but it would cross the ocean too, at its own pace; and it would overawe any neighboring tribes."

He stopped for breath.

"I see," Witweet murmured slowly. His tail switched back and forth. "You can sell our designs to sophonts in a proto-industrial stage of technological development. The idea comes from an excellent brain. But why could you not simply buy the plans for resale elsewhere?"

"The damned busybody League." Dolgorov spat.

"The fact is," Olafsson said, "spacecraft—of advanced type—have been sold to, ah, less advanced peoples in the past. Some of those weren't near industrialization, they were Iron Age barbarians, whose only thought was plundering and conquering. They could do that, given ships which are practically self-piloting, self-maintaining, self-everything. It's cost a good many lives and heavy material losses on border planets. But at least none of the barbarians have been able to duplicate the craft thus far. Hunt every pirate and warlord down, and that ends the problem. Or so the League hopes. It's banned any more such trades."

He cleared his throat. "I don't refer to races like the Trillians, who're obviously capable of reaching the stars by themselves and unlikely to be a menace when they do," he said. "You're free to buy anything you can pay for. The price of certain things is set astronomical mainly to keep you from beginning overnight to compete with the old-established outfits. They prefer a gradual phasing-in of newcomers, so they can adjust.

"But aggressive, warlike cultures, that'd not be interested in reaching a peaceful accommodation—they're something else again. There's a total prohibition on supplying their sort with anything that might lead to them getting off their planets in less than centuries. If League agents catch you at it, they don't fool around with rehabilitation like a regular government. They shoot you."

Harker grimaced. "I saw once on a telescreen interview," he remarked, "Old Nick van Rijn said he wouldn't shoot that kind of offenders. He'd hang them. A rope is reusable."

"And this ship can be copied," Witweet breathed. "A low industrial technology, lower than ours, could tool up to produce a modified design, in a comparatively short time, if guided by a few engineers from the core civilization."

"I trained as an engineer," Harker said. "Likewise Leo; and Einar spent several years on a planet where one royal family has grandiose ambitions."

"But the horror you would unleash!" wailed the Trillian. He stared into their stoniness. "You would never dare go home," he said.

"Don't want to anyway," Harker answered. "Power, wealth, yes, and everything those will buy—we'll have more than we can use up in our lifetimes, at the court of the Militants. Fun, too." He smiled. "A challenge, you know, to build a space navy from zero. I expect to enjoy my work."

"Will not the, the, the Polesotechnic League . . . take measures?"

"That's why we must operate as we have done. They'd learn about a sale of plans, and then they wouldn't stop till they'd found and suppressed our project. But a non-Technic ship that never reported in won't interest them. Our destination is well outside their sphere of normal operations. They needn't discover any hint of what's going on—till an interstellar empire too big for them to break is there. Meanwhile, as we gain resources, we'll have been modernizing our industry and fleet."

"It's all arranged," Olafsson said. "The day we show up in the land of the Militants, bringing the ship we described to them, we'll become princes."

"Kings, later," Dolgorov added. "Behave accordingly, you xeno. We don't need you much. I'd soon as not boot you through an airlock."

Witweet spent minutes just shuddering.

From A LITTLE KNOWLEDGE by Poul Anderson (1971). Collected in David Falkyn: Star Trader
How Did We Miss That?

There is an even more unbelievable solution to the "sword on the starship" problem in Harry Turtledove's "The Road Not Taken". Joshua Munn points out that there is a similar situation in David Brin's "Just a Hint"

(ed note: An alien battlefleet of the Roxolan empire discovers Terra and moves to invade)

      Captain Togram was using the chamberpot when the Indomitable broke out of hyperdrive. As happened all too often, nausea surged through the Roxolan officer. He raised the pot and was abruptly sick into it.
     Sighing again, he stowed the chamberpot in its niche. The metal cover he slid over it did little to relieve the stench. After sixteen days in space, the Indomitable reeked of ordure, stale food, and staler bodies. It was no better in any other ship of the Roxolan fleet, or any other. Travel between the stars was simply like that. Stinks and darkness were part of the price the soldiers paid to make the kingdom grow.
     Togram picked up a lantern and shook it to rouse the glowmites inside. They flashed silver in alarm. Some races, the captain knew, lit their ships with torches or candles, but glowmites used less air, even if they could only shine intermittently.
     Ever the careful soldier, Togram checked his weapons while the light lasted. He always kept all four of his pistols loaded and ready to use; when landing operations began, one pair would go on his belt, the other in his boottops. He was more worried about his sword. The perpetually moist air aboard ship was not good for the blade. Sure enough, he found a spot of rust to scour away.
     As he polished the rapier, he wondered what the new system would be like. He prayed for it to have a habitable planet. The air in the Indomitable might be too foul to breathe by the time the ship could get back to the nearest Roxolan-held planet. That was one of the risks starfarers took. It was not a major one—small yellow suns usually shepherded a life-bearing world or two—but it was there.
     He wished he hadn't let himself think about it; like an aching fang, the worry, once there, would not go away. He got up from his pile of bedding to see how the steerers were doing.
     As usual with them, both Ransisc and his apprentice Olgren were complaining about the poor quality of the glass through which they trained their spyglasses. "You ought to stop whining," Togram said, squinting in from the doorway. "At least you have light to see by." After seeing so long by glowmite lantern, he had to wait for his eyes to adjust to the harsh raw sunlight flooding the observation chamber before he could go in.

     "Go report it to Warmaster Slevon, and ask him if his devices have picked up any hyperdrive vibrations except for the fleet's."
     "Not a hyperdrive emanation but ours in the whole system!" Olgren grinned. Ransisc and Togram both pounded him on the back, as if he were the cause of the good news and not just its bearer.
     The captain's smile was even wider than Olgren's. This was going to be an easy one, which, as a professional soldier, he thoroughly approved of. If no one hereabouts could build a hyperdrive, either the system had no intelligent life at all or its inhabitants were still primitives, ignorant of gunpowder, fliers, and other aspects of warfare as it was practiced among the stars.
     He rubbed his hands. He could hardly wait for landfall.

     "Only that you don't have enough perspective. Egelloc on Roxolan has almost a million people, and from space it's next to invisible at night. It's nowhere near as bright as those lights, either. Remember, this is a primitive planet. I admit it looks like there's intelligent life down there, but how could a race that hasn't even stumbled across the hyperdrive build cities ten times as great as Egelloc?"

(ed note: On Terra the military of all nations have been mobilized. But they cannot figure out why the aliens are ignoring their radio messages. The Terrans do not know that the aliens haven't invented radio communication yet. Heck, the aliens haven't discovered electricity yet.)

     "I have one of the alien vessels on radar," the SR-81 pilot reported. "It's down to 80,000 meters and still descending." He was at his own plane's operational ceiling, barely half as high as the ship entering atmosphere.
     "For God's sake, hold your fire," ground control ordered. The command had been drummed into him before he took off, but the brass were not about to let him forget. He did not really blame them. One trigger-happy idiot could ruin humanity forever.
     "I'm beginning to get a visual image," he said, glancing at the head-up display projected in front of him. A moment later he added, "It's one damn funny-looking ship, I can tell you that already. Where are the wings?"
     "We're picking up the image now too," the ground control officer said. "They must use the same principle for their in-atmosphere machines as they do for their spacecraft: some sort of antigravity that gives them both lift and drive capability."
     The alien ship kept ignoring the SR-81, just as all the aliens had ignored every terrestrial signal beamed at them. The craft continued its slow descent, while the SR-81 pilot circled below, hoping he would not have to go down to the aerial tanker to refuel.
     "One question answered," he called to the ground. "It's a warplane." No craft whose purpose was peaceful would have had those glaring eyes and that snarling, fang-filled mouth painted on its belly. Some USAF ground-attack aircraft carried similar markings.

     At last the alien reached the level at which the SR-81 was loitering. The pilot called the ground again. "Permission to pass in front of the aircraft?" he asked. "Maybe everybody's asleep in there and I can wake 'em up."
     After a long silence, ground control gave grudging ascent. "No hostile gestures," the controller warned.
     "What do you think I'm going to do, flip him the finger?" the pilot muttered, but his radio was off. Acceleration pushed him back in his seat as he guided the SR-81 into a long, slow turn that would carry it about half a kilometer in front of the vessel from the spacefleet.
     His airplane's camera gave him a brief glimpse of the alien pilot, who was sitting behind a small, dirty windscreen.
     The being from the stars saw him, too. Of that there was no doubt. The alien jinked like a startled fawn, performing maneuvers that would have smeared the SR-81 pilot against the walls of his pressure cabin—if his aircraft could have matched them in the first place.
     "I'm giving pursuit!" he shouted. Ground control screamed at him, but he was the man on the spot. The surge from his afterburner made the pressure he had felt before a love pat by comparison.
     Better streamlining made his plane faster than the craft from the starships, but that did not do him much good. Every time its pilot caught sight of him, the alien ship danced away with effortless ease. The SR-81 pilot felt like a man trying to kill a butterfly with a hatchet.
     To add to his frustration, his fuel warning light came on. In any case, his aircraft was designed for the thin atmosphere' at the edge of space, not the increasingly denser air through which the alien flew. He swore, but he had to pull away.

(ed note: On board the alien ship)

     "You've just made a luof very happy," Togram said. Ransisc chuckled. The Roxolani brought the little creatures along to test new planets' air. If a luof could breathe it in the airlock of a flyer, it would also be safe for the animal's masters .
     "The luof lived, boys!" Togram said with a broad smile.
     His company raised a cheer that echoed deafeningly in the barracks room. "We're going down!" they whooped. Ears stood high in excitement. Some soldiers waved plumed hats in the fetid air. Others, of a bent more like their captain's, went over to their pallets and began seeing to their weapons.
     "How tough are they going to be, sir?" a gray-furred veteran named Ilingua asked as Togram went by. "I hear the flier pilot saw some funny things."
     Togram's smile got wider. "By the heavens and hells, Ilingua, haven't you done this often enough to know better than pay heed to rumors you hear before planetfall?"
     As inconspicuously as he could, the captain let out a sigh. He did not know what to believe himself, and he had listened to the pilot's report. How could the locals have flying machines when they did not know contragravity? Togram had heard of a race that used hot air balloons before it discovered the better way of doing things, but no balloon could have reached the altitude the locals' flier had achieved, and no balloon could have changed direction, as the pilot had violently insisted this craft had done.

(ed note: The US Army sends a unit to the landing site)

     The truck rolled northward, part of a convoy of trucks, MICV's, and light tanks that stretched for miles. An entire regiment was heading into Los Angeles, to be billeted by companies in different parts of the sprawling city. Cox approved of that; it made it less likely that he would personally come face-to-face with any of the aliens.
     "Sandy," he said to Amoros, who was squeezed in next to him, "even if I'm wrong and the aliens aren't friendly, what the hell good will hand weapons do? It'd be like taking on an elephant with a safety pin."

(ed note: The alien ship lands at Los Angeles)

     "There's a spot that looks promising," he said. "The greenery there in the midst of the buildings in the eastern—no, the western—part of the city. That should give us a clear landing zone, a good campground, and a base for landing reinforcements."
     "Let's see what you're talking about," Ransisc said, elbowing him aside. "Hmm, yes, I see the stretch you mean. That might not be bad. Olgren, come look at this. Can you find it again in the Warmaster's spyglass? All right then, go point it out to him. Suggest it as our setdown point."
     The apprentice hurried away. Ransisc bent over the eyepiece again. "Hmm," he repeated. "They build tall down there, don't they?"
     "I thought so," Togram said. "And there's a lot of traffic on those roads. They've spent a fortune cobblestoning them all, too; I didn't see any dust kicked up."
     A runner appeared in the doorway. "Captain Togram, your company will planet from airlock three."
     "Three," Togram acknowledged, and the runner trotted off to pass orders to other ground troop leaders. The captain put his plumed hat on his head (the plume was scarlet, so his company could recognize him in combat), checked his pistols one last time, and ordered his troopers to follow him.
     He felt the slightest of jolts as the Indomitable's fliers launched themselves from the mother ship. There would be no luofi aboard them this time, but musketeers to terrorize the natives with fire from above, and jars of gunpowder to be touched off and dropped. The Roxolani always strove to make as savage a first impression as they could. Terror doubled their effective numbers.

(ed note: The Army unit watches the alien ship land)

     The starship landed in the open quad between New Royce, New Haines, New Kinsey, and New Powell Halls. It towered higher than any of the two-story red brick buildings, each a reconstruction of one overthrown in the earthquake of 2034. Cox heard saplings splinter under the weight of the alien craft. He wondered what it would have done to the big trees that had fallen five years ago along with the famous old halls.
     "Take as much cover as you can," Lieutenant Shotton ordered quietly. The platoon scrambled into flowerbeds, snuggled down behind thin tree trunks. Out on Hilgard Avenue, diesels roared as armored fighting vehicles took positions with good lines of fire.
     It was all such a waste, Cox thought bitterly. The thing to do was to make friends with the aliens, not to assume automatically they were dangerous.
     Something, at least, was being done along those lines. A delegation came out of Murphy Hall and slowly walked behind a white flag from the administration building toward the starship. At the head of the delegation was the mayor of Los Angeles: the President and governor were busy elsewhere. Billy Cox would have given anything to be part of the delegation instead of sprawled here on his belly in the grass. If only the aliens had waited until he was fifty or so, had given him a chance to get established.
     Sergeant Amoros nudged him with an elbow. "Look there, man. Something's happening—"
     Amoros was right. Several hatchways which had been shut were swinging open, allowing Earth's air to mingle with the ship's.
     The westerly breeze picked up. Cox's nose twitched. He could not name all the exotic odors wafting his way, but he recognized sewage and garbage when he smelled them. "God, what a stink!" he said.

(ed note: On board the alien ship the alien troops ready to deploy)

     "By the gods, what a stink !" Togram exclaimed. When the outer airlock doors went down, he had expected real fresh air to replace the stale, overused gases inside the Indomitable. This stuff smelled like smoky peat fires, or lamps whose wicks hadn't quite been extinguished. And it stung! He felt the nictitating membranes flick across his eyes to protect them.
     "Deploy!" he ordered, leading his company forward. This was the tricky part. If the locals had nerve enough, they could hit the Roxolani just as the latter were coming out of their ship, and cause all sorts of trouble. Most races without hyperdrive though, were too overawed by the arrival of travelers from the stars to try anything like that. And if they didn't do it fast, it would be too late.
     They weren't doing it here. Togram saw a few locals, but they were keeping respectful distance. He wasn't sure how many there were. Their mottled skins—or was that clothing?—made them hard to notice and count. But they were plainly warriors, both by the way they acted and by the weapons they bore.
     His own company went into its familiar two-line formation, the first crouching, the second standing and aiming their muskets over the heads of the troops in front.
     "Ah, there we go." Togram said happily. The bunch approaching behind the white banner had to be the local nobles. The mottling, the captain saw, was clothing, for these beings wore entirely different earments, somber except for strange, narrow neckcloths. They were taller and skinnier than Roxolani, with muzzleless faces.
     "Ilingua!" Togram called. The veteran trooper led the right flank squad of the company.
     "Your troops, quarter-right face. At the command, pick off the leaders there. That will demoralize the rest," Togram said, quoting standard doctrine.
     "Slowmatches ready!" Togram said. The Roxolani lowered the smoldering cords to the touch holes of their muskets. "Take your aim!" The guns moved, very slightly. "Fire!"

(ed note: the US army troops return fire)

     Flames spurted from the aliens' guns. Great gouts of smoke puffed into the sky. Something that sounded like an angry wasp buzzed past Cox's ear. He heard shouts and shrieks from either side. Most of the mayor's delegation was down, some motionless, others thrashing.
     There was a crash from the starship, and another one an instant later as a roundshot smashed into the brickwork of Dodd Hall. A chip stung Cox in the back of the neck. The breeze brought him the smell of fireworks, one he had not smelled for years.

     "Reload!" Togram yelled. "Another volley, then at 'em with the bayonet!" His troopers worked frantically, measuring powder charges and ramming round bullets home.

     "So that's how they wanna play!" Amoros shouted. "Nail their hides to the wall!" The tip of his little finger had been shot away. He did not seem to know it.
     Cox's Neo-Armalite was already barking, spitting a stream of hot brass cartridges, slamming against his shoulder. He rammed in clip after clip, playing the rifle like a hose. If one bullet didn't bite, the next would.
     Others from the platoon were also firing. Cox heard bursts of automatic weapons fire from different parts of the campus, too, and the deeper blasts of rocket-propelled grenades and field artillery. Smoke not of the aliens' making began to envelop their ship and the soldiers around it.
     One or two shots came back at the platoon, and then a few more, but so few that Cox, in stunned disbelief, shouted to his sergeant, "This isn't fair!"
     "F**k 'em!" Amoros shouted back. "They wanna throw their weight around, they take their chances. Only good thing they did was knock over the mayor. Always did hate that old crackpot."

     The harsh tac-tac-tac did not sound like any gunfire Togram had heard. The shots came too close together, making a horrible sheet of noise. And if the locals were shooting back at his troopers, where were the thick, choking clouds of gunpowder smoke over their position?
     He did not know the answer to that. What he did know was that his company was going down like grain before a scythe. Here a soldier was hit by three bullets at once and fell awkwardly, as if his body could not tell in which direction to twist. There another had the top of his head gruesomely removed.
     The volley the captain had screamed for was stillborn. Perhaps a squad's worth of soldiers moved toward the locals, the sun glinting bravely off their long, polished bayonets. None of them got more than a half-sixteen of paces before falling.
     Ilingua looked at Togram, horror in his eyes, his ears flat against his head. The captain knew his were the same. "What are they doing to us?" Ilingua howled.
     Togram could only shake his head helplessly. He dove behind a corpse, fired one of his pistols at the enemy. There was still a chance, he thought—how would these demonic aliens stand up under their first air attack?
     A flier swooped toward the locals. Musketeers blasted away from firing ports, drew back to reload.
     "Take that, you w****sons!" Togram shouted. He did not, however, raise his fist in the air. That, he had already learned, was dangerous.

     "Incoming aircraft!" Sergeant Amoros roared. His squad, those not already prone, flung themselves on their faces. Cox heard shouts of pain through the combat din as men were wounded.
     The Cottonmouth crew launched their shoulder-fired AA missile at the alien flying machine. The pilot must have had reflexes like a cat's. He sidestepped his machine in midair; no plane built on Earth could have matched that performance. The Cottonmouth shot harmlessly past.
     The flier dropped what looked like a load of crockery. The ground jumped as the bombs exploded. Cursing, deafened, Billy Cox stopped worrying whether the fight was fair.
     But the flier pilot had not seen the F-29 fighter on his tail. The USAF plane released two missiles from point-blank range, less than a mile. The infrared seeker found no target and blew itself up, but the missile that homed on radar streaked straight toward the flier. The explosion made Cox bury his face in the ground and clap his hands over his ears.

     Hope died in Togram's hearts when the first flier fell victim to the locals' aircraft. The rest of the Indomitable's machines did not last much longer. They could evade, but had even less ability to hit back than the Roxolan ground forces. And they were hideously vulnerable when attacked in their pilots' blind spots, from below or behind.
     One of the starship's cannon managed to fire again, and quickly drew a response from the traveling fortresses Togram got glimpses of as they took their positions in the streets outside this parklike area.
     When the first shell struck, the luckless captain thought for an instant that it was another gun going off aboard the Indomitable. The sound of the explosion was nothing like the crash a solid shot made when it smacked into a target. A fragment of hot metal buried itself in the ground by Togram's hand. That made him think a cannon had blown up, but more explosions on the ship's superstructure and fountains of dirt flying up from misses showed it was just more from the locals' fiendish arsenal.
     Something large and hard struck the captain in the back of the neck The world spiraled down into blackness.

     "Cease fire!" The order reached the field artillery first, then the infantry units at the very front line. Billy Cox pushed up his cuff to look at his watch, stared in disbelief. The whole firefight had lasted less than twenty minutes.
     He looked around. Lieutenant Shotton was getting up from behind an ornamental palm. "Let's see what we have," he said. His rifle still at the ready, he began to walk slowly toward the starship. It was hardly more than a smoking ruin. For that matter, neither were the buildings around it. The damage to their predecessors had been worse in the big quake, but not much.
     Alien corpses littered the lawn. The blood splashing the bright green grass was crimson as any man's. Cox bent to pick up a pistol. The weapon was beautifully made, with scenes of combat carved into the grayish wood of the stock. But he recognized it as a single-shot piece, a small arm obsolete for at least two centuries. He shook his head in wonderment.
     Sergeant Amoros lifted a conical object from where it had fallen beside a dead alien. "What the hell is this?" he demanded.
     Again Cox had the feeling of being caught up in something he did not understand. "It's a powder horn", he said.
     "Like in the movies? Pioneers and all that good s**t?"
     "The very same."
     "Damn," Amoros said feelingly. Cox nodded in agreement.
     Along with the rest of the platoon, they moved closer to the wrecked ship. Most of the aliens had died still in the two neat rows from which they had opened fire on the soldiers.

     When Togram woke up on his back, he knew something was wrong. Roxolani always slept prone. For a moment he wondered how he had got to where he was …too much water-of-life the night before? His pounding head made that a good possibility.
     Then memory came flooding back. Those damnable locals with their sorcerous weapons! Had his people rallied and beaten back the enemy after all? He vowed to light votive lamps to Edieva. mistress of battles, for the rest of his life if that were true.
     The room he was in began to register. Nothing was familiar, from the bed he lay on to the light in the ceiling that glowed bright as sunshine and neither smoked nor flickered. No, he did not think the Roxolani had won their fight.

     Despite that contretemps, they did eventually make progress on the language. Togram had picked up snatches of a good many tongues in the course of his adventurous life; that was one reason he had made captain in spite of low birth and paltry connections.
     "Why did your people attack us?" she asked one day, when she had come far enough in Roxolanic to be able to frame the question.
     He knew he was being interrogated, no matter how polite she sounded. He had played that game with prisoners himself. His ears twitched in a shrug. He had always believed in giving straight answers; that was one reason he was only a captain. He said, "To take what you grow and make and use it for ourselves. Why would anyone want to conquer anyone else?"
     "Why indeed?" she murmured, and was silent a little while; his forthright reply seemed to have closed off a line of questioning. She tried again: "How are your people able to walk—I mean, travel—faster than light, when the rest of your arts are so simple?"
     His fur bristled with indignation.
     "They are not! We make gunpowder, we cast iron and smelt steel, we have spyglasses to help our steerers guide us from star to star. We are no savages huddling in caves or shooting at each other with bows and arrows."
     His speech, of course, was not that neat or simple. He had to backtrack, to use elaborate circumlocutions, to play act to make Hildachesta understand. She scratched her head in the gesture of puzzlement he had come to recognize. She said, "We have known all these things you mention for hundreds of years, but we did not think anyone could walk—damn, I keep saying that instead of 'travel'—faster than light. How did your people learn to do that?"
     "We discovered it for ourselves," he said proudly. "We did not have to learn it from some other starfaring race, as many folk do."
     "But how did you discover it?" she persisted.
     "How do I know? I'm a soldier; what do I care for such things? Who knows who invented gunpowder or found out about using bellows in a smithy to get the fire hot enough to melt iron? These things happen, that's all."
     She broke off the questions early that day.

     "It's humiliating," Hilda Chester said. "If these fool aliens had waited a few more years before they came, we likely would have blown ourselves to kingdom come without ever knowing there was more real estate around. From what the Roxolani say, races that scarcely know how to work iron fly starships and never think twice about it."
     "I don't quite understand it myself," she said. "Apart from the hyperdrive and contragravity, the Roxolani are backward, almost primitive. And the other species out there must be the same, or someone would have overrun them long since."
     Ebbets said, "Once you see it, the drive is amazingly simple. The research crews say anybody could have stumbled over the principle at almost any time in our history. The best guess is that most races did come across it, and once they did, why, all their creative energy would naturally go into refining and improving."
     "But we missed it," Hilda said slowly,"and so our technology developed in a different way."
     "That's right. That's why the Roxolani don't know anything about controlling electricity, to say nothing of atomics. And the thing is, as well as we can tell so far, the hyperdrive and contragravity don't have the ancillary applications the electromagnetic spectrum does. All they do is move things from here to there in a hurry."
     "That should be enough at the moment," Hilda said. Ebbets nodded. There were almost nine billion people jammed onto the Earth, half of them hungry. Now, suddenly, there were places for them to go and a means to get them there.
     "I think," Ebbets said musingly, "we're going to be an awful surprise to the people out there."
     It took Hilda a second to see what he was driving at. "If that's a joke, it's not funny. It's been a hundred years since the last war of conquest."
     "Sure—they've gotten too expensive and too dangerous. But what kind of fight could the Roxolani or anyone else at their level of technology put up against us? The Aztecs and Incas were plenty brave. How much good did it do them against the Spaniards?"

     "Ransisc!" Togram exclaimed as the senior steerer limped into his cubicle. Ransisc was thinner than he had been a few moons before, aboard the misnamed Indomitable. His fur had grown out white around several scars Togram did not remember.
     His air of amused detachment had not changed, though. "Tougher than bullets, are you, or didn't the humans think you were worth killing?"
     "The latter, I suspect. With their firepower, why should they worry about one soldier more or less?" Togram said bitterly. "I didn't know you were still alive, either."
     "Through no fault of my own, I assure you," Ransisc said. "Olgren, next to me—" His voice broke off. It was not possible to be detached about everything.
     "What are you doing here?" the captain asked. "Not that I'm not glad to see you, but you're the first Roxolan face I've set eyes on since—" It was his turn to hesitate.
     "Since we landed." Togram nodded in relief at the steerer's circumlocution. Ransisc went on, "I've seen several others before you. I suspect we're being allowed to get together so the humans can listen to us talking with each other."
     "How could they do that?" Togram asked, then answered his own question: "Oh, the recorders, of course." He perforce used the English word: "Well, we'll fix that."
     He dropped into Oyag, the most widely spoken language on a planet the Roxolani had conquered fifty years before. "What's going to happen to us, Ransisc?"
     "Back on Roxolan, they'll have realized something's gone wrong by now," the steerer answered in the same tongue.
     That did nothing to cheer Togram. "There are so many ways to lose ships," he said gloomily. "And even if the High Warmaster does send another fleet after us, it won't have any more luck than we did. These gods-accursed humans have too many war-machines." He paused and took a long, moody pull at a bottle of vodka. The flavored liquors the locals brewed made him sick, but vodka he liked. "How is it they have all these machines and we don't, or any race we know of? They must be wizards, selling their souls to the demons for knowledge."
     Ransisc's nose twitched in disagreement. "I asked one of their savants the same question. He gave me back a poem by a human named Hail or Snow or something of that sort. It was about someone who stood at a fork in the road and ended up taking the less-used track. That's what the humans did. Most races find the hyperdrive and go traveling. The humans never did, and so their search for knowledge went in a different direction."
     "Didn't it!" Togram shuddered at the recollection of that brief, terrible combat. "Guns that spit dozens of bullets without reloading, cannon mounted on armored platforms that move by themselves, rockets that follow their targets by themselves. And there are the things we didn't see, the ones the humans only talk about—the bombs that can blow up a whole city, each one by itself."
     "I don't know if I believe that," Ransisc said.
     "I do. They sound afraid when they speak of them."
     "Well, maybe. But it's not just the weapons they have. It's the machines that let them see and talk to one another from far away; the machines that do their reckoning for them; their recorders and everything that has to do with them. From what they say of their medicine, I'm almost tempted to believe you and think they are wizards—they actually know what causes their diseases, and how to cure or even prevent them. And their farming: this planet is far more crowded than any I've seen or heard of, but it grows enough for all these humans."
     Togram sadly waggled his ears. "It seems so unfair. All that they got, just by not stumbling onto the hyperdrive."
     "They have it now," Ransisc reminded him. "Thanks to us."
     The Roxolani looked at each other, appalled. They spoke together: "What have we done?"

From THE ROAD NOT TAKEN by Harry Turtledove (1985)

"Back then, on Terra, they knew FTL travel was impossible forever. It was a rude shock when they found that a couple of simple experiments could have given them the key to contragrav and the hyperdrive three, four, even five centuries earlier." (ed note: in the 1500's.)

"How did they miss them?" Chang asked.

"No idea — in hindsight they're obvious enough. What's that race that flew bronze ships because they couldn't smelt iron? And every species we know that reached what the old Terrans would have called a seventeenth-century technological level did what was needed — except us."

"But trying to explain contragrav and the hyperdrive skews an unsophisticated, developing physics out of shape. With attention focused on them, too, work on other things, like electricity and atomics, never gets started. And those have much broader applications — the others are only really good for moving things from here to there in a hurry."

With a chuckle, Chang said, "We must have seemed like angry gods when we finally got the hyperdrive and burst off Terra. Radar, radio, computers, fission and fusion — no wonder we spent the next two hundred years conquering."

From HERBIG-HARO by Harry Turtledove (sequel to "The Road Not Taken") (1984)
They Don't Make 'em Like They Used To

After the fall of the first galactic empire, after the dark ages, comes the re-birth of the galactic empire. But it will take some time before the reborn empire's tech level reaches that of the old empire.

During that period, any first empire technology that survives will be highly prized, since it is more advanced than current technology. In the MechWarrior video games they call this "Lostech" (lost-tech).

For our purposes, starships might have a limited built-in self-repair capability. But guns probably will not. So if the civilization forgets how to repair both starships and guns, the number of useable starships will stay constant while the usable guns will gradually vanish.


Blaine was searching for something to say when Whitbread gave him his opportunity. At first Blaine saw only that the junior midshipman was doing something under the edge of the table - but what? Tugging at the tablecloth, testing its tensile strength. And earlier he'd been looking at the crystal. "Yes, Mr. Whitbread," Rod said. "It's very strong."

Whitbread looked up, flushing, but Blaine didn't intend to embarrass the boy. "Tablecloth, silverware, plates, platters, crystal, all have to be fairly durable," he told the company at large. "Mere glassware wouldn't last the first battle. Our crystal is something else. It was cut from the windscreen of a wrecked First Empire reentry vehicle. Or so I was told. It's certain we can't make such materials any longer. The linen isn't really linen, either; it's an artificial fiber, also First Empire.

From THE MOTE IN GOD'S EYE by Larry Niven and Jerry Pournelle
"To be fair, we don't invent them. We find them. They're gifts, Mr. Miles, from Those Who Came Before."
Warren Vidic, Assassin's Creed I

Beyond Schizo Tech, beyond Scavenger World, there's Lost Technology.

The Ancients had some pretty neat gear. Robots, weapons, even the answer to The Ultimate Question of Life, The Universe, and Everything. Easy to use, little or no maintenance required, and after thousands of years of neglect often still in perfect working order!

...oh yeah, and this technology completely and utterly destroyed the Ancients and most of the world with it. But that doesn't stop the villains (or the heroes) from wanting to get some for themselves by pillaging an Advanced Ancient Acropolis. Usually, said Lost Technology then tries to destroy the world again. Some, but not all, heroes are smart enough to try to keep people away from the stuff.

Occasionally the good guys need Lost Technology to combat ancient evils that have arisen again (or villains who have acquired Lost Technology of their own). They usually use it as best they can, despite Black Boxes. Still, they suffer from Low Culture, High Tech.

It is similar to Imported Alien Phlebotinum, with the catch that the current population comprises the survivors or replacements of an age that fell due to its arrogance, war, or some other catastrophe.

May also show up in the guise of Lost Magic in fantasy settings. Often a consequence of No Plans, No Prototype, No Backup. Also see Sufficiently Advanced and Pointless Doomsday Device. Compare Bamboo Technology. A subtrope of Older Is Better. Frequently overlaps with Sufficiently Advanced Bamboo Technology. May lead to an Archaeological Arms Race.

(ed note: see TV Trope page for list of examples)

Technology and Society


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Technological Disruption

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Technological Unemployment

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Future Shock

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You Are Not Ready

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They Are Not Ready

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Man Was Not Meant To Know

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End of Natural Selection

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Decadent Population

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Intelligence Amplification

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The Singularity

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Revolt of the AIs

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Remember the difference between Unobtainium and Handwavium:

UNOBTANIUM: We can't build a physical example of it, but insofar as we can postulate that it can be built at all, the laws of physics say it would behave like thus and so. While Handwavium and Technobabble tell you what you CAN do, Unobtainium usually tells you what is NOT possible. Examples: gigawatt laser, antimatter weapons, ladderdown reactors.

HANDWAVIUM: It flat out violates laws of physics. We're waving our hands and saying pay no attention to the man behind the curtain. Examples: faster-than-light drive, time travel, reactionless drives.

Science fiction authors can make up handwavium on their own with no help from this website, it ain't that hard. As long as you are not scared of RocketCat and his dreaded Atomic Wedgie. The main problem is keeping it internally consistent within its own made-up rules, and dealing with unintended consequences. It is a big help if during the design phase the author focuses on effects not causes.

Black Holes

The popular conception of a black hole is that it sucks everything in, and nothing gets out. However, it is theoretically possible to extract energy from a black hole, for certain values of "from."

Due to their extreme conditions, black holes have a thousand and one uses. A pity there doesn't seem to be any closer that a few light-centuries.

And by the way, there appears to be no truth to the rumor that Russian astrophysicists use a different term, since "black hole" in the Russian language has a scatological meaning. It's an urban legend, I don't care what you read in Dragon's Egg.



With the release of the Disney catastrophe, general interest in black holes has peaked. The release of this film also signals a critical overdose of misinfor- mation to which the public has been exposed. We read statements like: “The pull of a black hole’s gravity is so strong . . . time is stopped and space does not exist. . . [A black hole’s dis- covery] would unravel the mystery of both the universe’s creation and even- tual destruction.”

Such blatant idiocy induces the public conception of black holes as monsters which gobble up all the matter in the universe, as miracle workers which can solve all our energy problems, as gate- ways to other universes, and as time machines. This conception is pro- foundly misplaced. The same theory which predicts the black hole’s exist- ence also predicts that each of the pre- ceeding properties has severe limitations or does not occur at all. The very ex- istence of black holes is itself debatable; within our own galaxy only one not-yet- conclusive candidate for a black hole has been found to this date, the x-ray source, Cygnus X-1.

Thus, it strikes us as bordering on the ridiculous to use black holes as an ex- planation for every property of known space. Of course, there are mistakes and there are mistakes. Some involve subtle points, and physicists advance their own field only by making lots of them. The layman cannot be faulted for doing the same. Nonetheless, most of the non- sense written about black holes stems from an ignorant exploitation of a sub- lime idea, and a lack of interest in the pursuit of knowledge. As we will see, the theoretical properties of black holes are in themselves so remarkable that there is no need to exaggerate them in an attempt to capture the public’s atten- tion. Bearing this in mind, we now ex- amine some properties of black holes-—-without exaggeration.


Visualize a black hole. Most of us, encumbered by the limits of imagina- tion, will visualize a small, black sphere floating in space among the stars. We probably think of this ball as a highly compressed solid, somethng like cold iron but unimaginably more dense. Un- imaginably high density, we assure our- selves, produces an unimaginably great gravitational field. We further imagine the field to be so strong that all sur- rounding matter is pulled into this tiny sphere, never to escape again. Light it- self cannot avoid the same fate; fleeting, ephemeral, yet once light enters this strange object it is trapped forever by gravity. Thus, the “black hole”; ab- solutely black since light cannot be re- flected from it to show its existence.

The question is, is this picture a de- scription of anything? The answer is not straightforward but requires more pre- cise concepts, caveats, and “yes buts.” In attempting an answer, one should first keep in mind that relativists, ped- dlers of gravitational theories, distin- guish between several types of black holes. There is the basic, Schwarzschild black hole which is spherical, electri- cally uncharged, and does not rotate; there is the Kerr black hole, which ro- tates and is not spherical; and there is the Reissner-Nordstrom black hole, which is spherical and non-rotating, but contains an electric charge. (The holes are named in honor of the mathemati- cians who worked out their theoretical existence.)

These three types, without additional complications, are lumped under the heading “classical black holes” to dis- tinguish them from “quantum black holes.” A quantum black hole is any black hole, including one of the above types, in which it is necessary to take into account the fact that light, for in- stance, consists of indivisible units called quanta. For light the quanta are photons; for the gravitational field itself the quanta are gravitons. Thus, we can have quantum Kerr black holes, quan- tum Reissner-Nordstrom black holes, and quantum Schwarschild black holes. But for now limit ourselves to classical black holes.

Evidently, the above mental picture corresponds—-more or less--to the basic Schwarschild black hole. However, the emphasis in the previous sentence is on the “more or less,” specifically on the “less.” We will now begin to give a more accurate description of a classical black hole, keeping in mind that spe- cific details may vary from one category of hole to the next.

The classical, astronomical picture of a blackihole is one of a remnant left over by the collapse of a massive star; the examples typically used have about ten solar masses. The escape velocity from the surface of the black hole ex- ceeds that of light; indeed, this is the definition of both a “black hole” and its “surface.” The surface of a black hole is called the event horizon. Now, we know that no physical object can move faster than light, so nothing what- soever, having fallen across the event horizon of a black hole, can come back out through that horizon.

A ten-solar-mass black hole has a ra- dius of about 30 kilometers, roughly the size of New York City. It is this typical example of a small, collapsed object with a gravitational field so strong that not even light can escape, which has conjured up the vision of black holes as extremely dense objects which grab anything in the vicinity. In fact, the density of the ten-solar-mass hole (den- sity is the mass of the hole divided by the volume enclosed within the. event horizon) is of order l015 grams per cubic centimeter. This seems a very high den- sity by everyday standards (the density of iron is only about 8 grams per cubic centimeter) until we realize it is com- parable to the density in the nuclei of atoms. Each one of us is composed of particles of this sort of density.

In any case, a black hole does not have to be so dense. The basic black hole equations show a very simple re- lationship between the size and mass of a black hole and the density. As the radius of the hole or its mass is in- creased, the density goes down. Thus, by making a black hole large enough or massive enough, we can make the density as low as we want. Actually, there is no reason we could not make a black hole out of air. Such a hole would have a radius of about 30 billion kilometers, roughly ten times the size of our solar system. If one entered this black hole, one would hardly feel a thing, but after a few days life would become uncomfortable—as one ap- proached the singularity.

While we will not talk much about singularities in this article, we should mention that the singularity in the center of the black hole is the place where all the matter eventually ends up. The den- sity at this point is infinite, which in- troduces a “yes but” into the above remarks. The density we have been dis- cussing is the average density of the hole and, strictly speaking, one can only talk about the average density from out- side the horizon.

At the surface of the air-bag black hole, the gravitational acceleration would be about 100 times the acceleration we feel on the surface of the earth, or roughly the same as the gravitational acceleration on the surface of the sun. A larger black hole, made out of hy- drogen, would have an even lower sur- face acceleration. We see then, the gravitational acceleration of a black hole is not always overwhelmingly large.

If the gravitational field is so weak, the question immediately arises, why can’t one escape by firing a rocket en- gine. The answer is somewhat tricky. We know that by accelerating even at very low accelerations, say 0.l gee, we can eventually reach huge velocities. Similarly, even the weak acceleration produced by our air bag will eventually accelerate objects to high velocity. In fact, by the time an object has fallen to the event horizon of any black hole, it is moving at the speed of light, inward. If the falling object wants to remain even stationary at the horizon, it must then move with the speed of light, out- ward. The principle of relativity says that nothing can move faster than the speed of light. Therefore, there is no escape. Acceleration is somewhat irrel- evant to the problem; the speed of light simply cannot be exceeded.


Related to the idea that a black hole possesses a strong gravitational field is the misconception that nothing can get remotely near the hole without being gobbled up. A good illustration of this nonsense is in the Disney film where the ship, the Cygnus, seems to require an antigravity field to prevent it from falling into the black hole. The film- makers ignore the fact that, at distances greater than about 10 times the radius of the black hole, ordinary orbital me- chanics—known since the time of New- ton--is applicable. For example, if the sun were suddenly replaced by a black hole of equal mass, the orbits of the planets would not change by the width of an ant’s eyebrow. Admittedly, it would get dark, but that is another story.

This brings us to the first important rule of black hole orbital mechanics: At large distances, the fact that we are in orbit around a black hole is irrel- evant. We may consider the black hole to be a spherical mass concentration producing an ordinary, Newtonian gravitational field, like that of the earth or the sun.

As the orbital radius approaches 10 black hole radii (300 kilometers for the 10 solar mass case), general relativistic effects become very important. The proverbial curvature of space and slow- ing of time come into play. Such dis- tortions of space and time manifest themselves in such effects as perihelion shifts in non-circular orbits. To under- stand perihelion shifts, we recall that Newtonian orbits are steady ellipses around the central body. The satellite’s point of closest approach, the perihe- lion, remains at a fixed point in space. We say, in this instance, space time is flat or Newtonian. (See Figure la.) When curvature of spacetime is more significant, the point of closest ap- proach pivots around the central body with each orbit of the satellite. (See Figure lb.) This pivoting is called a “perihelion shift” when speaking of orbits around the sun, a “periastron shift” when speaking of orbits around stars in general, and a “peribarythron shift” when speaking of orbits around black holes. (“Balythron" is the Greek name for a a deep pit in Athens into which condemned criminals were thrown.)

Because the shift is a cumulative, continuous effect, it can be detected even in satellites far from the central body, if a sufficiently long time is spent on the observation. For instance, Mer- cury’s perihelion shift is about 42 sec- onds of arc per century, a very small effect indeed. We can say that, as far as Mercury is concerned, the spacetime curvature caused by the sun is hardly noticeable. Spacetime is very nearly flat. Close to a black hole, on the other hand, the peribarythron shift becomes very important. At ten black-hole radii, it amounts to about 70 degrees per orbit!

Even closer to the black hole, circular orbits become unstable. A small devia- tion inward leads to a continuing spiral into the hole. For a Schwarzschild black hole, the point of instability comes at 3 black-hole radii (i.e., at 2 radii from the surface). This does not mean any- thing which falls within 3 radii of the black hole is irretrievably sucked in. One may still swoop down from a very large distance, down to 2 radii, and re- tum to infinity, just as a comet ap- proaches and then recedes from the sun. And this approach can be made without engines, again, like a comet. If rockets are employed, one can come almost all the way down to the Schwarzschild ra- dius, i.e., the horizon, and out again. Alternatively, one can continue to orbit around the hole‘ below 3 radii; but, in this instance, rockets must be fired to maintain position. What is not allowed in this region are free, uncorrected or- bits like those of satellites and skylabs around the Earth.

In the Disney film, the featured hole was not Schwarzschild, but a rotating or Kerr hole (even though the computer graphics shown during the credits were mistakenly those for Schwarzschild). For a Kerr hole, the point of the last stable orbit depends on how fast the hole is spinning, but the results are compa- rable to the Schwarzschild case; insta- bilities set in between l and 9 radii. Thus, the Cygnus should not need “an- tigravity devices" until very close to the hole indeed. On the other hand, as far as 1000 radii from the black hole, the Cygnus would be orbiting with a period of about one second. Admittedly, this may be why the antigravity device was posited in the first place——to dispense with orbits altogether. On the third hand, we doubt the filmmakers thought this far.

Since we have been speaking of or- bits, it is appropriate at this time to in- troduce the second important rule of black hole orbital mechanics: The prin- ciple of equivalence still applies. This fact seems to have escaped the attention of almost all moviemakers and writers. The principle of equivalence states that any body in a free orbit or in free fall does not experience the force of gravity. We might say, “Falling free or orbiting ’round, equivalence says gravity not found.” Examples of this are encoun- tered in everyday life: When we dive off a diving board we feel weightless. When an airplane drops suddenly, those in it feel momentarily weightless. As- tronauts in orbit around the Earth are not weightless because gravity has been tumed off above the atmosphere; rather, they are falling around the Earth, con- tinually diving off the board, if you will. Under these circumstances, the principle of equivalence says that grav- ity is not felt.

This is a very important point which applies to any situation near a black hole when rockets are not being fired: orbit- ing on a stable orbit; orbiting on an unstable orbit (when not correcting for instabilities); spiraling in; swooping down like a comet; or just falling in. In these cases, one does not suddenly feel heavy near the hole. On the contrary, one feels weightless, as if he were or- biting the Earth or diving into a swim- ming pool.

There is a complication to be intro- duced here. When an object comes close to a black hole, tidal forces can become extreme. As their name im- plies, tidal forces are those forces which raise tides on the surface of the Eaith. Because one side of the Earth is slightly closer to the moon than the other side, the near side feels a slightly greater gravitational attraction to the moon than does the far side. Thus, we get a “tidal bulge”; the Earth is stretched out in the direction of the moon. (Some readers may know there are actually two tidal bulges. We do not pause to discuss why this occurs.) We might say, with fair accuracy, that tidal forces are those which arise from the difference in the gravitational field between two points. The greater the difference, the greater the tidal forces.

Consider a man in a spaccsuit orbit- ing a black hole. He is in free fall, so by the previous discussion, feels per- fectly weightless. However, the feet of the astronaut are slightly closer to the black hole than is his head. Therefore he experiences tidal forces: his feet are being pulled toward the hole more strongly than his head. As a result, the astronaut is stretched. One might think, because a man is so small, that the dif- ference in the gravitational force be- tween his head and his feet cannot be very large. After all, gravity does not decrease so fast over a couple of meters. This is not true. Near a white dwarf, neutron star, or black hole, tidal forces can be immense. If he is orbiting a one- solar-mass body at a height of 10 kil- ometers, the tidal forces on our astro- naut are approximately ten million times the force the Earth is, at this moment, exerting on us. That is, while the Earth is pulling us to its surface with a force which, by definition, is equal to our weight, the astronaut is being ripped apart by forces about ten million times stronger. This particular example has roughly the conditions presented in Larry Niven’s story, “Neutron Star.” It is, alas, ludicrous to think the hero could save himself by curling up into a ball at the ship’s center. More likely, he would end up spread over the walls, the consistency of pink applesauce. Per- haps, we have estimated, if he initially started out as a piano wire for triple high C, he might have survived.

Still, a caveat is in order here. Near black holes which are large enough, like our air bag, tidal forces become totally insignificant, much less than even those tidal forces we feel on Earth. Thus, no shredding at all will take place near these holes until one falls close to the singularity. At the singularity, in all black holes, the tidal forces are infinite.

To sum up this section, we reiterate that it is the tidal forces which wreck spaceships near black holes, not the simple fact of strong gravity. And, as just mentioned, for very large holes, over about 105 solar masses, even this does not happen. As an astronaut orbits a black hole, he feels as weightless as if he were floating amid the clouds on a fine spring day. Near a typical black hole, though, his head is being wrenched from his feet by forces which make the bed of Procrustes amateurish by com- parison.


Two astronauts are orbiting a ten-so- lar-mass black hole. Richard, having seen one too many bad science fiction films, decides to end it all by taking the fateful plunge. He jumps. Tony, curi- ous to see the demise of his dissertation advisor, decides to clock Richard’s fall to the‘ event horizon. “Time is on my side,” Tony chuckles to himself, but he has a surprise waiting for him. As Richard approaches the event horizon, he seems to fall more and more slowly. Tony knows this because Richard is carrying a green, flashing beacon. The time interval Tony measures between each flash of the beacon is becoming longer and longer. In addition, he is startled to find that the flashes are grow- ing much redder and dimmer “as time goes by.” Tony grows impatient, but to no avail. The fall seems to take for- ever. Tony dies of old age muttering, “Veritam dies aperit,” but Richard has still not reached the event horizon. Tsvi arrives in his space shuttle to take over the observations but suffers Tony’s fate. He too grows old watching Richard’s beacon flash ever more slowly and redly. With his dying breath, he en- treats, “Stand still you ever-moving spheres of heaven/That time may cease and midnight never come.” Tsvi’s des- cendents have no better luck. Richard fades away completely just as he reaches the horizon, after a truly infinite amount of time. The clock has stopped.

Richard, on the other hand, realizes, i “Time and tide wait for no man.” He does not notice his beacon flashing any more slowly than normal, nor does he notice it growing redder and dimmer. He reaches the event horizon after a perfectly finite number of flashes. From that point, he crosses the event horizon, although he does not realize he has done so, and continues his plunge to the sin- gularity at the center of the black hole. Of course, Richard is ripped apart by tidal forces long before he gets there, but his dispersed atoms reach the dreaded singularity in a rather short amount of time—about 10-4 seconds as measured by his flashing beacon.

As well as a mild discrepancy be- tween two clocks, there is a moral to this fable: Relativity is called relativity because relativity is truly relative. The question, “Does time stop at a black hole?” is meaningless as it stands. We can say, “To an observer in a space- ship, an object falling into a black hole takes an infinite amount of time to reach the event horizon.” But we can also say, without contradiction, “To an ob- server falling into a black hole, the time required to reach the event horizon is quite finite.” When posing relativistic questions, one must be careful to spec- ify about whom one is talking, or else one runs the risk of lapsing into gib- berish.

The slowing down of Richard’s bea- con-clock (as measured by Tony and Tsvi on the ship) and the reddening of the light are two aspects of the same effect. The curvature of spacetime as- sociated with the gravitational field around the black hole actually causes time to flow at different rates. Just as the flashing of the beacon can be thought of as a clock, so can the oscil- lations in a light beam, or the move- ments of atoms in the beacon motor. Everything is slowed down from the point of view of Tony or Tsvi on the ship. The slower oscillations of the light are interpreted by Tony’s eye as a red- dening of the light, and since light is being emitted from the beacon at longer intervals, fewer photons (light particles) reach the eye per unit time. The com- bination of these effects causes the ex- cessive dimming of the beacon.

Richard, however, falling into the hole, is subject to the principle of equiv- alence. (Falling free or orbiting ’round, equivalence says gravity not found.) He does not feel any gravity on him or on his beacon. As far as he is concerned there is no gravity to slow down his flashes and everything proceeds as nor- mal, with the exception of tidal effects.

It is important to keep in mind that all these effects occur around any grav- itating body, the sun for instance. The only difference is in the magnitude of the effects, which will be much greater around a typical black hole than near the sun or the Earth.

To conclude this brief discussion of space and time near a black hole, we would have wished to comment at length on the quotation found at the beginning of this article, to the effect that, a black hole is a place where “space does not exist.” This, unfor- tunately, has proven to be impossible because we have entirely failed to dis- cover in that statement any meaning whatsoever.


Present energy dilemmas have made popular the idea of extracting large amounts of energy from black holes. The attraction of this idea is not hard to see. We are all familiar with the large flywheels used by electric companies in their power plants. These huge fly- wheels store rotational energy. By cou- pling the flywheel to a generator, we are transforming the rotational energy into electricity for use in home and in- dustry. In doing so, we have extracted the rotational energy from the flywheel and, as a consequence, it slows down.

Now, we have mentioned that Ken black holes rotate, much like the above flywheels. The rotational energy of a rapidly rotating solar mass Kerr hole is about 1054 ergs. At the Earth’s present rate of energy consumption, 1054 ergs would last approximately 1027 years, or about 1017 times the present age of the universe. This is a long time.

The question naturally arises, can the rotational energy of a Kerr hole be ex- tracted. If it could, we would expect the black hole to slow down like the fly- wheel. When no further energy could be extracted, the black hole would no longer be a spinning Kerr hole; it would be a non-rotating Schwarzschild hole. In 1969, the British relativist, Roger Penrose, showed that extraction of the rotational energy of a Kerr hole is pos- sible. Immediately after his suggestion appeared, others further proposed that the Penrose process might be used by an advanced civilization to tap the en- ergy of black holes. From there, science fiction took over. The basic idea was used in Gateway by Fred Pohl. Indeed one of us (T.R.) succumbed to the temp- tation to use the idea in his novel, The World Is Round. Unbeknownst to T.R. , T.P. and others were at the same time proving how difficult the Penrose pro- cess was to implement.

To understand the Penrose process further, we must first talk in more detail about Kerr holes. The rotation of a Kerr hole causes a “whirlpool in space.” This whirlpool is actually quite similar to an ordinary ocean whirlpool except that, instead of water whirling around, it is spacetime itself swirling around the black hole. If a space traveller is caught in this whirlpool, he is dragged around the black hole exactly as he would be dragged around the eye of the vortex if caught in an ocean whirlpool. If the space traveller wanted to remain sta- tionary, he would have to fire his rocket engines to overcome the spacetime dragging. Again, this has a marine analogy. A swimmer must swim against the current in the vortex if he wishes to remain in the same place.

We should note that this dragging is not unique to black holes but, according to relativity, occurs around any rotating body. In fact, a team of experimentalists at Stanford, led by Francis Everitt, is planning to measure the dragging force caused by the Earth's rotation. This measurement will be carried out by a satellite to be launched by the space shuttle. The dragging caused by a tiny body like the Earth is really very small. While the Stanford satellite orbits the Earth, the gyroscopes on board will be tilted a slight amount by the drag. After a full year, the cumulative angle of tilt will be less than a second of arc, about the angle subtended by a penny as seen from a distance of a kilometer.

Although the effect due to the Earth is small, around a black hole the drag- ging can become enormous. In fact, beneath a certain distance from the hole which is termed the “stationary limit,” no matter how hard one fires his rocket engines against the current, the drag- ging cannot be overcome and one is inevitably swept around the hole. This notion can be made more precise. Con- sider an observer on a “space buoy” being dragged passively around the hole; To him, someone in a rocket trying to overcome the dragging will appear to be moving in the opposite direction. At the stationary limit, this rocket will appear to the observer on the buoy to be moving at the speed of light. From a space station far above, how- ever, the rocket is just managing to fight the current and remain stationary, hence the name “stationary limit.”

We recall the famous words of the Red Queen: “ . . . it takes all the run- ning you can do to keep in the same place. If you want to get anywhere else, you must run at least twice as fast as that.” Unfortunately, one cannot run any faster than the speed of light. If she is unlucky enough to fall beneath the stationary limit, even the Red Queen will never be able to stay put and will be dragged around the hole along with space buoys, rockets, and everyone else. (See Figure 2.)

The region between the stationary limit and the event horizon is called the “ergosphere.” “Ergosphere” was coined by Wheeler and Ruffini from the Greek word “ergo” meaning “work.” It is in the ergosphere that the Penrose process takes place. (See Figure 3, for the relationship between the horizon, ergosphere, and stationary limit.)

Consider a rocket orbiting in the er- gosphere. It ejects a load of garbage against the current (like the Red Queen). Although this garbage is swept around the hole——since it is beneath the sta- tionary limit—-—it is “struggling against the current.” One can imagine that an object moving on such a “counterm- tating” orbit would exert a braking force on the hole and therefore slow it down in the same manner as we slow a flywheel. Thus, some of the rotational energy is lost and is, in fact, transferred to the ship as a recoil effect. (Think of a gun shooting a bullet. The recoil is greater than normal due to the presence of the rotating black hole.) This energy would be manifested as a greater kinetic energy of the ship, that is, a higher ve- locity. The ship could then leave the ergosphere with more energy than it had to start with, to be used elsewhere.

However, the matter is not so simple. The ejected garbage will be captured by the black hole, adding its own mass to the original mass of the hole. Since E = mc2, by losing the garbage we are losing energy to the hole. If the amount of energy lost to the hole is greater than the amount of energy gained by braking the hole, we have a net loss of energy. No extraction has taken place.

Nonetheless, if certain conditions are met, the energy balance will be favor- able. That is, if the garbage is ejected at sufficiently high velocity onto a coun- terrotating orbit within the ergosphere, the net result will be an energy gain. Any orbit which meets these require- ments is termed an “energy extraction orbit.” We emphasize that they only exist within the ergosphere. Note also that it is the orbit which is important, not what we eject. T herefore. it makes sense to use garbage, since this elimi- nates waste disposal problems as well.

The Penrose process is best illustrated by the machine in Figure 4. adapted from the text Gravitation, by Misner, Thorne and Wheeler. An advanced civ- ilization builds a huge shell around a Kerr black hole. Space shuttles loaded with garbage enter the ergosphere. They eject their payloads in the manner al- ready described. receive a giant dose of energy which boosts them to huge ve- locities. and return to the surface. They are caught in the arms of a giant gen- erator which converts this kinetic en- ergy into electricity for use over the shell.

Even if our supply of garbage is lim- ited to one Earth mass, this is enough to power the Penrose process for about 1021 years, or 1011 ages of the universe, not an insignificant amount of time.

Two technical details make this ex- traordinary picture somewhat less op- timistic. The first difflculty is jettisoning the garbage onto an energy extraction orbit. The second difficulty is getting the boosted shuttle out of the ergosphere without being captured by the black hole. We can better understand these problems if we pretend we are on a shut- tle, the Penrosia, whose mission is to go into the ergosphere, dump garbage, and return to the shell with as much energy as possible. The crew is fresh out of Starfleet Academy and so learns by the dangerous method of trial and error.

We have entered the ergosphere. Be- cause fuel supplies are limited, the Cap- tain has turned our engines off. The Penrosia is now being passively dragged around the black hole’s whirlpool like a space buoy. Since we are in orbit, we feel weightless. An inexperienced space cadet attempts to eject a load of garbage onto an energy extraction orbit simply by throwing it out by hand. To our dis- may, we find that the garbage only fol- lows the shuttle along, very gradpally drifting away (exactly like what hap- pens with garbage jettisoned from a space capsule in Earth orbit). The bun- dle is certainly moving too slowly to be on an energy extraction orbit; this gar- bage would hardly brake a snail, let alone a black hole. Determined, the crew tries again, this time firing the garbage out of a cannon. Now the gar- bage vanishes into the distance, but when our sensors plot the trajectory, we find that the garbage is still not moving fast enough to be on an energy extrac- tion orbit. Many such attempts are made, each using increasing amounts of power. They all fail. Finally, the frustrated crew of the Penrosia succeeds in shooting a thimblefull of garbage onto an energy extraction orbit. They calculate the velocity of the thimble and find it to be nearly the speed of light. This has been accomplished only by momentarily diverting the full power of the shuttle’s reactor engine, just for the purpose of launching the thimble. When the energy balance is computed, the crew discovers that the energy gener- ated by the reactor on board was almost equal to that gained by ejecting the gar- bage. However, they have gained some energy and tired but happy, prepare to leave the ergosphere.

At this moment, the Captain realizes he has made a fatal mistake: He has forgotten Newton’s Third Law. When a rocket ejects fuel from its engines, the rocket is propelled in the opposite di- rection. By ejecting garbage from the Penrosia, the crew has inadvertently boosted the shuttle onto a new orbit. The ship’s computer makes a quick cal- culation. To the Captain’s horror, he realizes that the new orbit will lead the Penrosia—-and us—-directly into the black hole. The Captain guns his en- gines. After expending all the energy gained by launching the thimble, we barely escape to the surface, tired but unscathed.

What happened?

Recall our previous discussion. The “sufficiently high velocity?’ mentioned earlier for,an energy extraction orbit, turns out to be nearly the speed of light. That is, the garbage must be like the Red Queen, moving at nearly the speed of light with respect to other objects in the whirlpool. To accelerate an object to the speed of light requires stupendous amoupts of energy which, in this case, must be generated on board. It tums out that we must convert a large part of the garbage into energy in order to boost what little remains to the velocity of light.

The second problem was to get the energy out. Most orbits within the er- gosphere intersect the black hole. The Penrosia boosted herself onto one of these orbits and to escape it required also a stupendous amount of energy. In most cases, anything gained by the ejec- tion is lost in trying to escape. This sec- ond problem, as it turns out, can be overcome only by jettisoning the gar- bage exactly at the peribarythron of the orbit. Then one escapes to the surface with what little energy was initially gained by the ejection.

We have just seen that to get an ap- preciable amount of energy out of the hole requires that matter be converted on board the shuttle with essentially 100% efficiency. Then by ejecting this “energy beam” (photons), we get an additional 20% boost from the hole, for a grand total of l20% efficiency. Not bad; but since this requires almost 100% conversion efficiency to begin with, the Penrose process might not be worth all the trouble. It can, however, be used for a more efficient energy conversion process than is available on Eanh. That is, it tums out we can use a modified Penrose process to extract energy from matter with up to 10 times efficiency of the 1/2% of hydrogen bombs, the most efficient process known at present. Unfortunately, we do not have space in this article to discuss such modifica- tions, and a more detailed discussion will have to wait for another.opportu- nity.


Any interstellar empire or commer- cial consortium need a means of rapid communication and transport. The smuggler Han Solo made the “jump into hyperspace” and emerged at his destination some time (l2 parsecs!?) later. Space warps and star gates are a staple of science fiction.

Relativity, as already mentioned, de- scribes gravity as a warping of space and time, and a black hole is the result of the strongest possible curvature. It is not surprising, then, that science fic- tion has latched onto black holes in an attempt to make space warps sound more plausible. To some extent, it is our own fault; in idealized situations, relativists have discovered the tantaliz- ing possibility of a “star gate” lurking in black holes. Unfortunately, the sit- uation has gotten out of hand and almost everyone has chosen to ignore work started as far back as a decade by Pen- rose and Floyd, which shows that “star gates” cannot be realized in practice.

To discuss this problem, we will need to back up and fetch some concepts not yet introduced in this article. Relativity is, in a sense, a study of geometry, but not simply the ordinary Euclidean kind which we all learn in high school. For one thing, space and time have been combined into a 4-dimensional space- time. To pursue this point briefly, let us refer to Figure 5. Here, only two spatial directions are shown, x and y (east-west and north-south if you like) and the time direction, labeled by ct. Time increases upward. From the ex- planations accompanying Figure 5, we distill four rules for understanding these diagrams: l) An object stationary in space still moves through time. Its path through spacetime, or worldline, is therefore a vertical line; 2) An ordinary, moving object, like a rocket, has a world line which is tilted at less than 45 degrees from the vertical; 3) Light travels along 45 degree lines; 4) Trav- eling on a worldline tilted greater than 45 degrees from the vertical is prohib- ited because this is motion faster than the speed of light.

This type of spacetime diagram has its defects. The most serious one is the difficulty of showing things which are very far apart——it is especially difficult to map an infinite universe onto a finite piece of paper. Nonetheless, with suf- ficiently vigorous squeezing, one can actually distort the outer edges of the universe in such a way that we can fit the entire infinite universe onto a finite piece of paper. We can even retain cer- tain features of the real universe. The one feature which is usually kept is the 45 degree angle which represents the trajectory of a light beam. A diagram like Figure 6 results.

All this is in preparation for a dis- cussion of star gates and time machines based on black holes. Recall our dis- cussion of tidal forces. We mentioned that in a simple Schwarzschild black hole, tidal forces on an infalling object (remember Richard’s plunge) become greater and greater until they become infinite at the singularity. Well, inside a rotating Kerr hole, or a charged Re- issner-Nordstrom black hole, this is not necessarily true. In fact, the theory states the following: Unless the black hale" has exactly zero charge and zero rotation, it will allow an object, say a spaceship, whose own gravitational ef- fects are negligible, to enter the black hole at a speed slower than light, avoid the singularity, and leave again by an exit diflerent from the surface through which it entered. The different exit sur- face gets around the immediate objec- tion that nothing which falls into a black hole can escape again; it can, but not through the same surface through which it entered.

If the exit surface is not the same as the event horizon by which we entered, then where does the spaceship end up? Figure 7, a spacetime diagram drawn for a Reissner-Nordstrom black hole, attempts to explain the situation. The two diamond shaped regions are like Figure 6 and thus both represent infinite universes. The diagram therefore shows two universes connected by a black hole tunnel. (Again, we are plotting space horizontally and time vertically.) The curve shows the history of the infalling- spaceship-cum-observer as it travels through the hole.

A complicated figure indeed. The in- trepid traveller falls inward. The first 45 degree line he crosses is the event horizon of the black hole; nothing can re-exit via this surface once having crossed it. The jagged lines represent the singularities, where tidal forces are infinite. (Remember, singularities are moving forward through time; therefore on this diagram they appear as vertical lines.)But the traveller can avoid these reefs; just by coasting he passes at a safe distance. When he emerges from the black hole,’ he finds himself in a normal universe like the one he just left. In fact, it may be precisely the one he left, but the black hole exit need not be near the entrance, and there is reason to think it would not be near that entrance.

We might at first worry whether the second universe is the same as ours. According to the theory, there is no rea- son it should not be, but equally no rea- son it should be either. (Parallel worlds!) If many charged or rotating black holes inhabited our universe, the possibility would exist that their exits would emerge in our own universe, or all in the same second universe, or in any number of alternate worlds (see Figure 8). More bizarrely, these various universes might be connected in such a way that, after traveling through several black holes, one returns to our own universe, but at a previous time. The theory does allow for this possibility, suggesting the use of black holes as time machines. In any case, the first pioneer to determine which of this possibilities exists, will be a very brave man, and exceedingly dedicated to the progress of science.

Unfortunately, at this point, hard sci- ence drags us back from such interesting speculation. The crucial flaw in the above discussion was the assumption that the spaceship had a negligible grav- itational effect on the hole. Can a real spaceship travel through the hole with- out disturbing its structure? In short, the answer is no.

To see this, just consider the energy content of solid space garbage, laser photons, radio and other waves, all of which a well-equipped interstellar space traveller would likely spread around during his trip. The central problem is that some of this stuff falls into the black hole too. As it falls into the hole, gar- bage, for instance, has picked up a ve- locity very close to the speed of light. We know that mass increases to infinity at these velocities. By E=mc2, this means that the energy of even the small- est amount of garbage has also become infinite. The same occurs with the en- ergy content of infalling radio waves and light signals emitted by the ship; their energy goes up to infinity also. But what has infinite matter and energy den- sities in a black hole? The singularity, of course. Where the clean black hole provided clear sailing, by allowing for garbage or radio waves we have created a singularity of infinitely destructive tidal forces, as in the Schwarzschild case.

A moment’s thought leads to the con- clusion that the black hole star gate is a one-time affair at best. If just the radio signals transmitted by the space trav- eller can be so disruptive, the mass of the spaceship itself must certainly dis- rupt the black hole and close the gate behind him.

Assuming he makes it through in the first place. What if he is extremely care- ful not to sully theblack hole before his joumey? He maintains radio silence and stows his garbage bags. Could he make it through the tunnel?

Surely, his spaceship must have sub- stantial mass. A mass falling toward a black hole is accelerating and, conse- quently, generates gravitational waves, analogous to the generation of electro- magnetic waves by accelerating electric charges. These waves are oscillations in the gravitational field which travel at the speed of light. Again, this is in analogy to radio waves which travel at the speed of light and are oscillations in the electromagnetic field. Some of these waves travel ahead of the infalling spacecraft, are amplified to infinite en- ergy in the same way as already dis- cussed for radio waves; and the gate to the other side of the galaxy slams shut in his face. The star gate cannot even be used once.

The simple argument just given shows that the inner structure of black holes is unstable to small disturbances from the outside. Any amount of energy or debris falling in from the outside will develop an infinite energy density and destroy the inner structure of the hole. In a perfectly clean universe, we could not know a priori whether a given Kerr or Reissner-Nordstrom black hole con- tains a tunnel to another part of the universe. But we do know that, if we probe the black hole by trying to reflect radiation off it, we automatically de- stroy the star gate, because some ab- sorption of radiation is inevitable. In the real uniyerse, of course, the situation is even worse because radiation and matter are everywhere present to some degree and must be falling into any ex- isting black holes.

So it seems, for instance, the collap- sar transpon system used in Joe Halde- man’s Forever War will not work; nor does the physics at the end of the Disney film hold water (not to mention the metaphysics); and, in fact, the syphon- ing of extra matter from another uni- verse mentioned at the conclusion of T.R.’s own novel will not go through either. At least these works were re- leased as science fiction. Books such as Adrian Berry's The Iron Sun, which purport to be science are either flagrant rip-offs or bad science fiction. As either rip-offs or science fiction, they deserve no further serious consideration.


Until now, we have concentrated our attention on large black holes, from l0 solar masses to over 1010 solar masses. In this section, we turn our attention to the other end of the spectrum: mini black holes. At the very beginning of the universe, at times much less than one second after the Big Bang, the den- sity of matter was comparable to what is found in typical black holes. It is con- ceivable, then-—but by no means proven—that a slight fluctuation in den- sity would “snap” the matter into black holes. Such “primordial” black holes would range in size from the very large, about 100,000 solar masses, to the very small, about 10-5 grams. The small holes would be formed first, when the density was highest, followed by suc- cesively large holes, until the density was too low to form any at all.

Large primordial black holes would behave in exactly the same way as the other large holes which we have already discussed. There is nothing to be added here. At the other extreme, holes of 1015 grams and below are remarkable ob- jects. The density of 1015 gram black holes is so high that one cubic centi- meter of them would contain the known mass of the universe! Holes smaller than this mass would exhibit extraordinary quantum properties, specifically the fa- mous Hawking radiation named after its discoverer. Space does not permit us to discuss these amazing properties. Suf- fice to say, there is no observational evidence to indicate that holes smaller than 1015 grams exist or existed. More- over, theoretical upper limits placed on such holes by Page, Hawking, Novikov et al., and two of us (R.M. and T.R.), indicate that, if they ever existed, they were few and far between. For instance, there cannot now be more than about 10 black holes of 1015 grams per cubic parsec, each with the mass of a moun- tain but the size of a proton.

Primordial black holes with masses greater than 1015 grams have negligible quantum properties and can be treated classically. Such black holes have also received attention in science fiction and popular folklore and therefore their share of misrepresentation. Perhaps the most famous—or notorious—suggestion was put forth by Al Jackson and Mike Ryan, then at the University of Texas, that the 1908 Tunguska blast in Siberia was caused by the collision of a 1021 gram black hole with the Earth.

We may first ask, “What are the odds of such a collision taking place?” Not bloody likely. Assuming all the observ- able mass in the universe to be concen- trated into 1021 gram black holes, one can calculate that one collision should occur about every ten ages of the Uni- verse, or 1011 years. Marauding black holes do not seem an overwhelming threat to U.S. security. Nonetheless, it is possible that Tunguska was the col- lision. Although a 1021 gram black hole is small in radius, about 10-7 centi- meters, its mass is large, about one million small mountains. Jackson and Ryan proposed that the gravitational attraction of this hole caused the sur- rounding air to be yanked inward, re- sulting in a compact ball of air whose shock effects produced the destruction seen in well-known photographs. There was, however, substantial debate on whether a black hole of this mass would have the Claimed effect when interacting with the solid earth. Most physicists believe the ground shock would have been tremendous, much more so than what actually occurred. So in scientific circles the matter is considered dead and buried. In any case, Al Jackson and Mike Ryan have on occasion confided that the suggestion was not entirely se- rious in the first place.*

(*We have recently learned that a report in Sotsialisticheskaya Industriya, 1/24/80, in- dicates that ordinary meteoric debris was re- cently found at the Tunguska site.)

Detailed statements about the inter- action of smaller black holes (about 1015 grams) with matter are difficult to make. Nonetheless, simple calculations give the following general picture, which should not be too far wrong: Recall, a 1015 gram black hole has the diameter of a proton. This is too small a size to rapidly accrete (gobble up) surrounding matter. Even if one considers that any nearby particle in random motion falls in when nearing the hole, one finds an accretion rate such that the black hole will not even double its mass in the life- time of the universe. Talk of eating a planet becomes absurd. Thus, the black hole posited by Larry Niven in “The Hole Man” would certainly never gob- ble up Mars in less than extreme cos- mological times, meaning millions or billions of ages of the universe.


We have talked about many types of black holes and many properties but have omitted discussion of many other interesting properties as well. We have not spoken about Hawking radiation, nor about black hole collisions, nor about superradiance, nor about astro- physical accretion, nor about photon trajectories and imaging properties, nor about the influence of primordial black holes on nucleosynthesis after the Big Bang. We have also shied away from direct discussion of the famous singu- larity which occurs within all black holes. The singularity, as already men- tioned, is the center of the black hole where all the matter has fallen. It is a place where the density of matter is in- finite, as well as gravitational and tidal forces. When people speak of space and time ending at black holes, they are perhaps thinking of the singularity. But it may be a mistake to say space and time end at the singularity; what ends is our present knowledge of physics.

Much work is currently underway to remedy the situation. Many physicists believe that true singularities do not ex- ist, that at such small distances the quantum properties of spacetime itself come into play. They suggest that mat- ter cannot be compressed to a smaller size than the so-called Planck length, about l0-33 centimeters, where the quantum effects become dominant. Ac- cording to this view, the singularities of classical black holes are nonexistent in reality and are only the temporary nuisances of defective mathematics.

At least two Russian physicists, Fro- lov and Vilkovisky, have recently claimed to have proven that black holes, in some sense, do not exist at all. Proper use of quantum field theory, they argue, shows that as matter collapses to form a black hole, it misses the singularity, “rebounds," and eventually re-expands beyond the event horizon. This process, for even Tunguska-sized black holes, will take longer than the age of the universe. Nonetheless, in a strictly»log- ical sense, a black hole is no longer a black hole, but only temporarily out of sight. We are not yet sure whether Fro- lov and Vilkovisky are correct, but we are certain that the full merger of rela- tivity and quantum theory will reveal many answers and even more ques- tions.

From DEMYTHOLOGIZING THE BLACK HOLE by Richard Matzner, Tsvi Piran, and Tony Rothman (1980)

First, let me establish something. When I go to Cal Tech I do not expect an experience out of H. P. Lovecraft. Horror may be interesting at the proper time and place, but it's not very pleasant as a total surprise.

It started peacefully enough. Dr. Robert Forward, the Hughes Research gravity expert you've heard of here and other places, called to ask if I would be interested in meeting Stephen Hawking. Since Hawking is thought by important physicists possibly to rank alongside Newton and Einstein, it took perhaps five milliseconds to think over the proposition. I didn't even need to look at my calendar; nothing I had planned could be that important.

A week later Larry Niven and I drove over to the California Institute of Technology. It was a bright spring afternoon. . .

The lecture was in a small modern slant-floored room of the type sometimes called lecture theaters; the sort of classroom lecturers like. The tiered seats let everyone have a good view of the speaker and his demonstration materials, and give the speaker a good view of the audience.

It was only partly filled: graduate students, several undergraduates, a sprinkling of faculty, one or two of the top names in theoretical physics. It was a room of serious women and men, mostly younger than I, all expectantly quiet. At the bottom of the well, the focus of attention on the stage, was an incredibly thin, very young-appearing man seated in a high-backed motorized chair of Victorian design; the chair had no flavor of the hospital about it. He wore a light suit, dark shirt, and flowered tie, and he kept his hands folded carefully in his lap as he was introduced.

The chairman gave his credits and spoke wonderingly of how privileged we were to hear a man of this stature. No one disagreed. Not, of course, that anyone would have said anything no matter what he thought, but the total silence in the room was an obvious sign of unanimous assent.

Hawking began to speak Everyone leaned slightly forward, straining to hear. Except for the heavily slurred voice there was absolutely no sound; you could quite literally hear a pen drop, for I dropped mine and it clattered loudly on the cement floor.

This is the scene, then: a lecture room partly filled with very bright people, a few extremely well known in theoretical physics, others students at one of the world's most prestigious institutions. They all strain to hear a wizened young man who makes awkward gestures and speaks with a thick slur that keeps his words just at the edge of intelligibility.

He grins like a thief. He's obviously not in pain, and he doesn't feel sorry for himself. And he tells that room of bright people that everything they thought they knew is nonsense. And he chuckles.

He tells us that the pudding that ate Chicago may someday exist; that duplicates of each one of us may one day wander the universe; that anything can, and probably will, happen. He tells us that the universe isn't lawful, never will be lawful, never can be lawful; that we cannot ever know enough to predict the totality of events in this universe; that at best we study local phenomena that may be predictable for an unspecifiable time.

And he laughs.

He tells us that Cthulthu may exist after all.

As I said, it was an afternoon of Lovecraftian horror.

Larry and I escaped with our sanity, after first, in the question period, making certain that Hawking really did say what we thought he'd said.

He had.

Stephen Hawking's lecture had originally been entitled "The Breakdown of Physics in the Region of Space-Time Singularities." The title was flashed on the screen; then another slide took its place, and Hawking chuckled. The new slide said:



He began simply enough. The principle of equivalence, he said, is well established. This is the principle that states that inertial mass, that is, the resistance of objects to being moved by an outside force, is exactly equivalent to gravitational mass, that is, the gravitational force a given mass will exert. There are not two kinds of mass.

This was Galileo's principle, and there's the famous apocryphal story of his dropping a cannon-ball and a musket-ball from the Leaning Tower of Pisa and observing their striking the ground at the same time. Obviously if gravitational and inertial mass were different, heavy objects would not fall at the same speed as light ones.

So far so good. Next, gravity affects light. It can bend light rays, as predicted by Einstein and observed several times in solar eclipses.

Now in short order: the energy-momentum tensor of gravity is positive; gravity is universally attractive, not repellent. Therefore, enough mass will create a field from which no light can escape.

The Special Theory of Relativity says that nothing can travel faster than light.

And therefore sufficient mass must create a space-time singularity, a place which cannot be observed.

A singularity is therefore inevitable; that is, at least one singularity must exist, provided only. (1) that Einstein's general relativity is correct; (2) gravity is truly attractive and never repellent; and (3) enough mass has ever been collected together.

And therefore at least one singularity exists in our universe, since at the time of the Big Bang all the conditions certainly prevailed; and also, it's very likely that other singularities have been created by collapse of stars, since many stars have more than enough matter and don't have enough energy to throw that matter away as they die.

OKAY so far? Nothing startling here. Bit dry, but all we've shown is that singularities must exist, and nearly everyone accepts the idea now. They're hidden away inside black holes, of course, and observers are now very nearly certain that we can observe a black hole.

Well, not observe the hole itself; but Cygnus X-l, an x-ray emitting star in the constellation Cygnus, has an invisible companion and the pair of stars, the one we can see and the one we can't, together act very like what Gal Tech's Kip Thorne predicted such a pair would act like if one were a black hole.

So what else is new? We've proved black holes can exist, and lo, the observers think they've found one. What's scary about that?

Nothing, so far. Holes aren't scary unless you're about to fall into one. We even understand them. We know they "have no hair," that is, that they can be completely described given their mass, M; angular momentum, J; and electric charge, Q, Given these data we can describe their shape, and predict what effect they'll have on nearby objects, and play all kinds of fascinating scientific-theory games.

We can talk about black hole bombs, and toy with ideas on how to extract energy from them: take one rotating black hole, throw garbage into it, and you not only get rid of the garbage, but can get useful energy back out. There are speculations (not SF; just plain science) about extremely advanced civilizations using black holes for precisely that purpose.

There's just no end to the nice things you could do with black holes, and although not many years ago they were no more than toys for theoreticians to play mental games with, black holes have become household-word objects now.

Black holes don't make us nervous.

Ah, but inside each black hole there lurks a singularity. This is the little beastie that breaks down physics in the nearby regions. By definition they do things we can't predict. They behave in strange ways. Up close to them time reversals can happen. How, then, can we avoid this breakdown of our nice predictable universe?

Hawking discussed several theoretical alternatives, and dismissed each. A couple of the cases seemed to startle one of the big-name theoreticians listening to the lecture. When Hawking was finished, though, the singularities were back and inevitable. I won't pretend to have understood all of this part of the lecture; and I wouldn't bore my readers with it if I had. If you appreciate that sort of thing you'll read Hawking's paper when it comes out.

For the rest of us I sum up by saying that he found no good alternatives; eliminating General Relativity doesn't eliminate the singularities, or else lands you in an even worse theoretical soup.

Therefore, let us look at General Relativity; but let us add quantum theory to it. Hawking recently published that work, and I described it here.

The important fact is that the quantum effects violate cosmic censorship. The Law of Cosmic Censorship, you may recall, states that there shall be no naked singularities; every singularity shall be decently clothed with an event horizon that prevents us from ever being able to observe it directly, and thus prevents us from observing the region in which physics breaks down.

Thus we needn't fear the singularity. It can't affect our lives, because nothing it does can get out of that black hole "around" it.

But adding quantum effects to General Relativity repeals cosmic censorship. Black holes evaporate. Big ones slowly, small ones rapidly, all inevitably. And what of the singularity that MUST have been created by the Big Bang of creation?

Evaporation of black holes produces naked singularities. We may play about with the concept of quantizing relativity, and Hawking did; but the conclusion was inescapable. Again I don't pretend to have followed every step, nor did most of the rest of us in that room; but several did, and they weren't pleased.

Because now comes the punchline. The singularities emit matter and energy. And "they emit all possible configurations with equal probability. Thus, perhaps, this is why the early universe from the Big Bang singularity was in thermal equilibrium and was very nearly homogeneous and isotropic. Thermal equilibrium would represent the largest number of configurations."

But since that time the universe has changed, and we have stars and planets and nematodes and comets and people; but the singularity must still be around. It emits. And what comes out is completely random, absolutely un-correlated. This fundamental breakdown in prediction—Hawking is saying not only that we can't predict now, but that in principle we can never predict, no matter how much we know or how smart we get or how large a computer we build—is a "consequence of the fact that General Relativity allows fundamental changes in the topology of space-time; that is, allows holes.

"Matter and information can fall into these holes—or can come out. And what comes out is completely random and uncorrelated."

The hole can emit anything. Anything at all.

"No," I thought. I looked to Niven. "No," he was thinking. Surely we misunderstood.

And the thin chap grinned ever more broadly. "Of course we might have to wait quite a while for it to emit one of the people here this afternoon, or myself, but eventually it must—"

Hawking chuckled and waited expectantly, and after a long and very silent pause first one, then another joined him in laughter; but it had a rather hollow sound, or so I thought. Larry agreed when we could talk about it later.

So far as we can tell, we've just heard one of the top people in theoretical physics tell us that we don't know anything and can't know anything; that causality is a local phenomenon of purely temporary nature; that time travel is possible; that Cthulthu might emerge from a singularity, and indeed is as probable as, say, H. P. Lovecraft.

Hawking concluded by reminding us that Albert Einstein once said "God does not play dice with the universe."

"On the contrary," Hawking said, "it appears that not only does God play dice, but also that he sometimes throws the dice where they cannot be seen!"

Lovecraftian horror indeed. Our rational universe is crumbling. Western civilization assumes reason; that some things are impossible, that's all, and we can know that; that werewolves don't exist, and there never was, never could be, a god Poseidon, or an Oracle that spoke truly; that the universe is at least in principle discoverable by human reason, is knowable.

That, says one of the men we believe best understands this universe, is not true. It's not very probable that Cthulthu will emerge from the primeval singularity created in the Big Bang, or that Poseidon will suddenly appear on Mount Olympus, but neither is impossible; and for that matter, this world we think we understand, which seems to obey rational laws we can discover, isn't very probable either—isn't, in fact, in the long run any more probable than a world that includes Cthulthu, or the pudding that ate Chicago.

From IN THE BEGINNING by Jerry Pournelle (1975)

Broadcast Power

This was a totally silly sci-fi idea when I was a young man. The idea was since a pocket transistor radio could pick up music broadcasts from radio stations with no wires invovled (wirelessly), perhaps it would be possible for an engine to pick up electricity broadcast from a power station with no wires involved. The technical term is Inductive Charging or Wireless power transfer.

Nikola Tesla found out the hard way the drawback to this little scheme. The lions share of the power radiates into the wild blue yonder and is wasted, since Tesla's attempt to channel the energy into standing waves around the entire globe was an utter failure. This means the inverse square law is your enemy.

True, there was lots of work done in the 1960s on transmitting power with beams of microwaves aimed at rectennas. However, while this was wireless, it was not a "broadcast." It was a narrowcast beam, if the rectenna wandered outside the beam the power would be cut off.

Broadcast power was officially confirmed to be a handwavium idea.

Until everything changed in 2006 when some geniuses at M.I.T. figured out how to use resonant coupling to transfer large amounts of power over a distance of a few times the resonator size. You sometimes see this used to charge smartphones, by laying the phone on a "charging mat".

For now, broadcast power seems to have made the jump from pure handwavium into fringe unobtanium.

The main practical problem is how does the power company determine who tapped some power, so the company knows where to send the bill?


(ed note: instead of conventional electrical power lines, the planet uses broadcast power technology. A row of broadcast power pylons is built, with each pylon being in line-of-sight of its neighbors. Any truck or other electrical power using equipment with an installed power receptor which is in line-of-sight of a pylon can tap the pylon for power. So roads tend to follow a broadcast pylon row. Of course the pylon row has to be attached to some kind of power generator in order to be energized, just like electrical power lines.)

      The lower curve of the freighter’s hull rested a meter and a half deep in the ground. Normally the Karyn Forest would have docked at a proper spaceport like the one at Praha. Copper would he carried from the smelter to the port on ground-effect trucks which hissed down the line of broadcast power pylons. Increased pressure on the Front thirty kilometers to the east had brought a modification. A starship would be landed directly at the mine and refinery complex (Smiricky #4) to eliminate the slow process of transferring the cargo and to free scarce transport to carry materials to the Front.
     From what the crew had seen when the Katyn Forest popped out of hyperspace on her landing run, the Federal side of the Front needed more help than it was likely to get.

(ed note: Katyn Forest's main fusion reactor is destroyed by a carefully placed enemy missile. All it has now is the one-lung Auxiliary Power Unit {APU}. The ship does not have enough power to lift and run away)

     "I apologize," Ortschugin (captain of the Katyn Forest) said. "I know you must be busy, but—" he took a leather-covered flask out of his breast pocket and uncapped it—"we know now what we must have, and it is crucial that we leam as soon as possible who we must see to get it." He handed the flask to Waldstejn, shifting his cud of tobacco to his right cheek in preparation for the liquor’s return. "We must have a truck power receptor so that we can fly to Praha on broadcast power."
     Waldstejn choked on his sip of what seemed to be industrial-strength ethanol. “What?” he said through his coughing. It was not that the request was wholly impossible, but it certainly had not been anything the local man had expected.
     The Spacer drank deeply from his own flask and belched. He stared gloomily upward before he resumed speaking. Several of the brighter stars were tremblingly visible through the plastic sheets. "Our powerplant is gone, kaput," the bearded man said at last. Replacement and patching the hull, those are dockyard jobs. We can fly, using the APU to drive the landing thrusters—but minutes, you see, ten, twenty at most before the little bottle ruptures also under load and we make fireworks as pretty as those this morning, yes?” (when a lucky shot from the artillery piece blew up the ship that was bombing them) He swigged again, then remembered and offered the flask to Waldstejn—who waved it away. "So we are still sitting when your Republicans take over, yes?" Ortschugin concluded with a wave of his hand.

(ed note: The Republican army over-runs the mine/refinery complex Smiricky #4, and the Federalists soldiers surrender. The starship Katyn Forest has installed a broadcast power receptor, but it is also captured by the Republican army. Captain Ortschugin is hauled in to face the army unit leader, Chaplain Bittman.)

     “You mean that your whole huge starship can run on broadcast power in good truth?" the Chaplain (Bittman) demanded.
     "We, ah, thought perhaps so," the Swobodan (Captain Ortschugin) agreed. "We didn't test it before the Complex, ah—”
     " Yes, was liberated," Chaplain Bittman finished for Ortschugin. He added, in a voice which had no more expression or mercy than the clack of a trap closing, "I advise you not to ‘test’ the system now, either, Captain. The idolators are attempting to make a stand along the line between here and Praha— they know how important it will be. Elements of the three armored regiments are pushing them back. Major elements.” Bittman permitted himself a smile at something he probably thought was funny. "What do you suppose the concentrated fire of, say, four Terra-built tanks would do to the hull even of your starship, Captain?"
     " We're at your service, E-Chaplain Bittman," the spacer said through dry lips, " but the pylons do lead only west from here.”
     "For the moment! " the Chaplain retorted with a zeal that shone across his slim, swarthy face. "Do you know why this line is crucial to the Lord's work, Captain?" he demanded rhetorically. "Because the fusion plant here, for the mining and smelting operations, was more than big enough to energize a broadcast system as well. That means that when we complete a temporary link from our own system east of Bradova, we have a channel for the heaviest, bulkiest supplies straight to the idolators' capital! Our armor is the head of the spear plunging into the heart of schism and idolatryl "
     For the moment, Ortschugin‘s mind made of him an engineer again and not merely a victim. He understood the situation perfectly. Pylons were easy enough to raise and align. They were, after all, little more than lattices with two pairs of antennas. The lower alignments beamed power to whatever vehicle was equipped to receive it, while the upper alignments charged the system itself. Cutting a pylon would prevent vehicles from proceeding until the gap was repaired, but the other parts of the system would continue to function.

     If it were energized from both sides of the gap.

     Republicans and Federalists both had crisscrossed their sides of the Front with branch lines to supply their troops. The power and load capacity of the branches was limited, however. The working, full-scale fusion plant of Smiricky #4 could very well tip the scales. The next Republican thrust would not outrun its supplies and so be contained, the way previous victories had been.

(ed note: The protagonist mercenary unit sneaks back into the captured refinery and makes common cause with Captain Ortschugin. The Katyn Forest lifts under broadcast power and heads for friendly territory down the line of broadcast power pylons. It can only manage an altitude of a few tens of meters but that is enough. The reason it did not do this earlier is because it was surrounded by Republican troops who would shoot the starship down. The reason it can do this now is because it is full of mercenary soldiers along with their artillery piece, who proceed to shoot the living snot out of the Republican troops and the base.

The surviving Republican troops are not amused, especially Chaplain Bittman. He angrily sends an order to Colonel Kadar, located further down the pylon row.)

     Kadar did not need a repetition. The orders were as simple as their accomplishment should be.
     A ripple of interest was running through the troops who a moment before had been waiting in bored lethargy. They knew a signal had been received, but only Colonel Kadar knew what the message was. Exulting in the power of secret knowledge, Kadar himself swung the turret of his tank. His gunner peered up at him, as much at a loss as were the infantrymen outside.
     The laser had been in ready position, zero deflection (yaw), zero elevation (pitch). Instead of aiming, Kadar kept his foot down on the traversing pedal as he squeezed the hand switch. The weapon drew a pale line across the daylight. The beam merely hissed until the turret rotated it through the nearest broadcast pylon. Steel latticework vaporized with a roar and a coruscant white glare. Larger, fluid gobbets spit from the supports and sparkled as they rained into the dust and stunted vegetation below.
     The Republican soldiers were on their feet now. Heads twisted even from the commo van to watch the fireworks. The power-broadcasting antennas waved madly as their support toppled, taking them out of the circuit. Kadar continued to traverse his blade of pure energy. A pylon of the east-bound roadway collapsed as the beam slashed it also. There was now a one-kilometer gap in the Praha-Smiricky truck route. Both halves of the lines were still energized, but the receptor antenna of a vehicle could not align across the gap and leap it.


(ed note: The Katyn Forest travels the gap by straining its APU. Kadar and his unit rips into the Katyn Forest with their laser tanks, only to discover that the ship is using its high pressure hoses to spray a protecting cloud of mercury, from the ship's ore cargo. The cloud severely attenuates the weapon laser beams. At least enough so the ship is not sliced like a giant salami. Meanwhile the mercenaries on the ship use their artillery gun as a direct-fire weapon and manage to mission-kill all the hostile laser tanks. The lighter hostile vehicles are converted into metal confetti.)

From THE FORLORN HOPE by David Drake (1984)

      The landing system was from what Gallagher called their solar tap. They were tapping the electrical potential that exists between a planet and its orbiting proton and electron belts—the belts of ionized particles caught in the planet's magnetic field.
     The landing system was part of a power system that produced, from this one site, enough electricity to power the entire continent on a broadcast basis.
     Broadcast power. It had been known on Earth since the days of Nicola Tesla—the system for putting power on the airwaves the way radio and TV are broadcast. Electric power that you could tune into, the way you tune in a radio.
     With broadcast power, you didn't have to have wires strung around the continent to plug in motors and appliances and furnaces and the like. You didn't have to carry your own fuel in! your ground car. You tuned in your motor to the power frequency, the way you tune in a radio to the frequency of the station you want to hear.
     Earth hadn't had broadcast power, though she'd known how to broadcast it, because the production of power was geared to installations that didn't have sufficient potential that you could waste it on the airwaves. But the power potential in the solar tap was so great you could throw it away on an inverse-square: basis and still be able to tune in at the coast lines, two thousand miles distant, and run anything you wanted to run, from a manufacturing complex to a skimmer.
     The power that exists between the ground potential on any planet and the orbiting proton and electron belts trapped in the magnetic field of any planet, is fed by the solar wind of the sun around which the planet orbits, and it is a practically limitless potential. Electrons from the solar wind make their way in through the magnetic poles of the planet, distribute themselves at its crust, and seep through the insulating atmosphere towards the strong positive potential of the inner proton belt.
     If you make a "short circuit" through the atmosphere by creating an ionized pathway with a laser beam that reaches to the ionosphere, the top of the insulating atmospheric layers, the electrons will jump across the short circuit, changing the groundside potential. When the groundside potential lowers, it makes it possible for more electrons to pour in from the solar wind to equalize the potential. The planet is effectively recharged, and you can short-circuit again.
     It's done in milliseconds, and it's done on a pulse-basis. You turn the laser-beam short circuit off and on in an alternating-current effect, and it's most efficient at a low sonic frequency, although it has radio-frequency overtones.
     There was a group of huge pyramidal structures that were the bases for the solar tap and landing system. A huge, central pyramid was the tap itself; built of granite with a marble overlay, and of sufficient size to insulate the tremendous bursts of power flow from the ground. The laser installation was on a small platform at the peak of the pyramid, and the control systems were centered well inside where the X rays and other radiation from the flow would not harm the technicians.
     From this, central pyramid, the pulsed power was broadcast across the continent, and even from inside the canteen and at this distance you could hear the deep-throated roar of that power, pulsing through at a frequency within the audible range. Chee-ops, chee-ops, chee-ops, it seemed to say as it shorted in, was cut off, and pulsed in again.

From GALLAGHER'S GLACIER by Walt and Leigh Richmond (1970)

(ed note: Seetee is antimatter (from the work Contraterrene or C.T.) In the story it can be found in antimatter meteor drifts in the asteroid belt. The Brand Transmitter is a species of power broadcast. Naturally the powers that be are angry at this threat to their monopoly on fission power because no empire has ever survived an energy-related phase shift with its full power intact.)

      A dull, hopeless anger took hold of Jenkins. He hated the stubborn stupidity of old Bruce O’Banion, and raged against the anonymous leaders of the, Free Space Party. He detested the complacent aristocracy of the Interplanet directors, despised the sordid greed of the Mandate bureaucrats, and bitterly scorned the cynical schemes of his uncle.
     All humanity, it seemed to him, impelled by its confusion of ignorant fears and blind desires, was somehow involved in a monstrous conspiracy against the bright dream of the Fifth Freedom. The engineering problems of the Brand transmitter were solved long ago, but the human difficulties loomed gigantic, complex beyond solution. The great barrier to human progress stood revealed as the nature of man himself.
     Urgently, he tugged at O’Banion’s arm.
     “Listen!” he whispered. “Your revolt has failed—but the Brand transmitter hasn’t. It can still bring peace and freedom to the people of the rocks—and all the planets.”

     “Physical power is the basis of political power,” he went on grimly. “The Mandate is able to oppress you because the governments of its member planets bave joined to establish a monopoly of the fissionable elements and fission energy. Your rebellion has failed to break that monopoly of power. But there is another way to do it, with a new power-source—the seetee drift!”
     They still listened, their lean, battle-soiled faces bleakly mistrustful.
     “Free power!” he whispered huskily. “Just look at the actual meaning of that. The Brand transmitter, that we’re trying to build on Freedonia, can supply free seetee energy to all men everywhere. That will mean economic freedom, and economic freedom will create political freedom. Our Freedonia plant can set you free of the Mandate and also from the rule of your own Party leaders.”

(ed note: The protagonist is dying from Seetee Shock: radiation sickness caused by being too close to a matter-antimatter explosion)
     But he towed them into place. He aligned them, with painful care. Groggily, swaying at the task, he tightened the connections and brazed them with condulloy metal. He inspected the assembly, tested all the circuits, and straightened triumphantly in the chafing confinement of his armor.
     The Brand transmitter was finished!

     Awkward now in the powered suit, he missed the high control platform. He plunged on past it, fumbling feebly at the control studs, toward the untouchable metal of the upper hemisphere and the red signs that warned: SEETEE—KEEP OFF!
     The steel rails of the terrene barrier caught him. His trembling fingers found the studs again, and he alighted at last on the platform. Abruptly ill, he vomited again. Darkness came down upon him, and he thought he was blind.
     He lay a long time, merely clinging to the platform rail, until he found that he could see again. Nearly too weak to move the stiff armor, he drew himself erect. He waited for his head to clear, and make meaning come back to the gauges and controls before him. He pressed buttons and pulled switches.
     The generator ran.
     A green indicator light told him that the Levin-Dahlberg field was functioning. The fuel-milling machines ran silently in that airless space, grinding terrene and seetee rock to dust. Separator coils refined the fuel, and paragravity injectors metered it into the reaction field.
     Matter was annihilated there, but Jenkins saw no frightful fire. He heard no ultimate crash. He was not destroyed. For the reaction field contained that raving energy, and converted it into a silent tide of power flowing in the condulloy coils.
     Meter needles crept over, as that river of tamed energy flooded higher. They steadied, as full output of the generator built up the power field extending beyond the far sun to the limits of the solar system. They dropped back suddenly, as the full potential was established and automatic relays shut off the flow of fuel.
     Swaying over the board, Jenkins pressed one final button. Fever was burning his body. Unquenchable thirst consumed him. He felt the drip of unstaunchable blood from his nose. Illness crushed him down, until only the cruel stiffness of the armor supported him. Yet he clung to consciousness, and tried to listen.
     “People of all the planets—”
     Those triumphant words came faintly from the speaker in his helmet, spoken in the deep voice of old Jim Drake. A red photophone light was flickering on the board, and his mind could see the powerful automatic photophone and ultra-wave beam transmitters above, sweeping every rock and planet in the ecliptic with that recorded announcement, as Freedonia turned.
     “The Fifth Freedom has arrived!” Drake’s canned voice proclaimed—for he had planned and toiled against this crucial hour. “Free power is flowing out from our contraterrene plant, and all you who hear can tap the power field with simple tri-polar receptors.
     “Receptor voltage is set by the dimensions of the elements, current output limited only by circuit resistance. Specifications are—”
     Jenkins vomited again, into the rubber bag beneath his chin. Sweat was clammy on his body, and the vast, untouchable machines beyond the barriers blurred and dimmed. But he tried to listen, and he heard Drake’s recorded voice again.
     “… benefit all men. But there are men too blind to see the good. There are a few selfish men and women, anxious to preserve their cruel old monopoly of power, who will attempt to stop the Brand transmitter. We beg all common men, everywhere, not to let that happen.”
     A pause, and then the tape repeated:
     “People of all the planets—

     “Open this.” Smiling mysteriously, she gave him a little package. “Ann wanted me to bring flowers, but Rick said you’d like this better. Even if it’s just a toy.”
     Eagerly, he opened the box. He found a small light bulb and another tiny gadget made of insulating plastic, sheet copper, and a few turns of wire. Peering at it, he caught his breath.
     “A Brand receptor !” he whispered. “Does it work?”
     “Try it.”
     Anxiously, he twisted the bulb into the gadget. It lit—and its tiny glow was enough to show him the illimitable might of the Brand power field, pervading all the planets of man. It was a searchlight, probing feebly into the misty splendor of a new human era.

From SEETEE SHOCK by Jack Williamson (1949)

(ed note: Director Rickman and his wife Gelda have to escape out of the city since the government has put out an order for them to be assasinated. They use their flying car, powered by broadcast power.)

      He said brusquely, "Come, we've got to get out of here."
     "Of course." She rose, pale and unsteady but obviously clear-headed. "We'd better take my flyer. It's out at the front."
     "Yes." He nodded quickly. "I'll pre-set my own flyer to take off in an hour. No one will worry about Trudy and Valance for some time. They like to enjoy their fun." He hurried from the house and was back in less than a minute. "Let's go." He gripped her hand and almost pulled her from the house.
     The parked vehicle which belonged to his wife was a luxury craft but fortunately discreet in appearance. He was glad he had insisted on a four-contact receptor. If they wanted to bring him down by cutting the beam they would have to bring down about a third of the normal air traffic as well.

(ed note: I guess that means there are 12 power channels total.)

From THE PRODIGAL SUN by Philip E. High (1964)

"Forgive me for being obtuse but where is the outline?"

"You're not being obtuse, my friend, merely looking in the same damn direction I was looking. Now look at it this way: suppose this alleged telepathic broadcast affects different kinds of minds in different ways. To give a rather broad example, take a power broadcast. A ground car will pick up that power and translate it into energy for propulsion, a radiant unit will convert that same power into heat, and so on. Suppose this telepathic broadcast reacts on different types of brains in different ways. Let us assume, therefore, that it doesn't touch the Norms but plays hell with what we call a Delink-type brain. In short, again drawing a parallel with a power broadcast, the Delink-type brain converts that broadcast into lawlessness… ."

From INVADER ON MY BACK by Philip E. High (1968)

"There is an old story in our folklore," he continued, "about a boy who bought himself an animal somewhat like your terrestrial calf. He thought that if he lifted it above his head ten times a day while it was little, he would build up his strength gradually until he would still be able to lift it over his head when it was a full-grown animal. He soon discovered the existence of a natural limiting factor. Do you see what I mean? When those people down there reached their natural limits, there was no place for them to go but backward. We had the machine, though, and the machine can always be made smaller and better, so we had no stopping point."

He reached inside his vest and pulled out a small shining object about the size of a cigarette case. "This is hooked by a tight beam to the great generators on Altair. Of course I wouldn't, but I could move planets with it if I wanted to. It's simply a matter of applying a long enough lever, and the lever, if you'll remember, is a simple machine."

From LIMITING FACTOR by Theodore R. Cogswell (1954)

      While his friend complied, Grimes shucked himself out of the outlandish anachronistic greatcoat he was wearing and threw it more or less in the direction of the robing alcove. It hit the floor heavily, much more heavily than its appearance justified, despite its unwieldy bulk. It clunked.
     Stooping, he peeled off thick overtrousers as massive as the coat.
     He was dressed underneath in conventional business tights in blue and sable. It was not a style that suited him. To an eye unsophisticated in matters of civilized dress, let us say the mythical Man-from-Antares — he might have seemed uncouth, even unsightly. He looked a good bit like an elderly fat beetle.
     James Stevens’s eye made no note of the tights, but he looked with disapproval on the garments which had just been discarded.
     ‘Still wearing that fool armour,’ he commented.
     ‘Damn it, Doc — you’ll make yourself sick, carrying that junk around. It’s unhealthy.’
     ‘Danged sight sicker if I don’t.’
     ‘Rats! I don’t get sick, and I don’t wear armour — outside the lab.’
     ‘You should.’ Grimes walked over to where Stevens had reseated himself. ‘Cross your knees.’ Stevens complied; Grimes struck him smartly below the kneecap with the edge of his palm. The reflex jerk was barely perceptible. ‘Lousy,’ he remarked, then peeled back his friend’s right eyelid.
     ‘You’re in poor shape,’ he added after a moment. Stevens drew away impatiently. ‘I’m all right. It’s you we’re talking about.’
     ‘What about me?’
     ‘Well—Damnation, Doc, you’re throwing away your reputation. They talk about you.’
     Grimes nodded. ‘I know. “Poor old Gus Grimes — a slight touch of cerebral termites.” Don’t worry about my reputation; I’ve always been out of step. What’s your fatigue index?’
     ‘I don’t know. It’s all right.’
     ‘It is, eh? I’ll wrestle you, two falls out of three.’ Stevens rubbed his eyes. ‘Don’t needle me, Doc. I’m rundown. I know that, but it isn’t anything but overwork.’
     ‘Humph! James, you are a fair-to-middlin’ radiation physicist —
     ‘—engineer. But you’re no medical man. You can’t expect to pour every sort of radiant energy through the human system year after year and not pay for it. It wasn’t designed to stand it.’
     ‘But I wear armour in the lab. You know that.’
     ‘Surely. And how about outside the lab?’
     ‘But—Look, Doc — I hate to say it, but your whole thesis is ridiculous. Sure there is radiant energy in the air these days, but nothing harmful. All the colloidal chemists agree—‘
     ‘Colloidal, fiddlesticks!’
     ‘But you’ve got to admit that biological economy is a matter of colloidal chemistry.’
     ‘I’ve got to admit nothing. I’m not contending that colloids are not the fabric of living tissue—They are. But I’ve maintained for forty years that it was dangerous to expose living tissue to assorted radiation without being sure of the effect. From an evolutionary standpoint the human animal is habituated to and adapted to only the natural radiation of the sun, and he can’t stand that any too well, even under a thick blanket of ionization. Without that blanket—Did you ever see a solar-X type cancer?’
     ‘Of course not.’
     ‘No, you’re too young. I have. Assisted at the autopsy of one, when I was an intern. Chap was on the Second Venus Expedition. Four hundred and thirty-eight cancers we counted in him, then gave up.’
     ‘Solar-X is whipped.’
     ‘Sure it is. But it ought to be a warning. You bright young squirts can cook up things in your labs that we medicos can’t begin to cope with. We’re behind — bound to be. We usually don’t know what’s happened until the damage is done. This time you’ve torn it.’

     Even though the thesis be too broad and much oversimplified, it is nonetheless true that much which characterized the long peace which followed the constitutional establishrnent of the United Nations grew out of the technologies which were hot-house-forced by the needs of the belligerents in the war of the forties. Up to that time broadcast and beamcast were used only for commercial radio, with rare exceptions.
     Even telephony was done almost entirely by actual metallic connexion from one instrument to another. If a man in Monterey wished to speak to his wife or partner in Boston, a physical, copper neuron stretched bodily across the continent from one to the other.
     Radiant power was then a hop dream, found in Sunday supplements and comic books.
     A concatenation, no, a meshwork of new developments was necessary before the web of copper covering the continent could be dispensed with.
     Power could not be broadcast economically; it was necessary to wait for the co-axial beam, a direct result of the imperative military shortages of the Great War. Radio telephony could not replace wired telephony until ultra micro-wave techniques made room in the ether, so to speak, for the traffic load. Even then it was necessary to invent a tuning device which could be used by a nontechnical person, a ten-year-old child, let us say, as easily as the dial selector which was characteristic of the commercial wired telephone of the era then terminating.
     Bell Laboratories cracked that problem; the solution led directly to the radiant power receptor, domestic type, keyed, sealed, and metered.
     The way was open for commercial radio power transmission, except in one respect: efficiency. Aviation waited on the development of the Otto-cycle engine; the Industrial Revolution waited on the steam engine; radiant power waited on a really cheap, plentiful power source. Since radiation of power is inherently wasteful, it was necessary to have power cheap and plentiful enough to waste.
     The same war brought atomic energy. The physicists working for the United States Army, the United States of North America had its own army then, produced a superexplosive; the notebooks recording their tests contained, when properly correlated, everything necessary to produce almost any other sort of nuclear reaction, even the so-called Solar Phoenix, the hydrogen-helium cycle, which is the source of the sun’s power.
     The reaction whereby copper is broken down into phosphorus, silicon-29, and helium-8, plus degenerating chain reactions, was one of the several cheap and convenient means developed for producing unlimited and practically free power.
     Radiant power became economically feasible, and inevitable.
     Of course Stevens included none of this in his explanation to Grimes.
     Grimes was absent-mindedly aware of the whole dynamic process; he had seen radiant power grow up, just as his grandfather had seen the development of aviation. He had seen the great transmission lines removed from the sky — ‘mined’ for their copper; he had seen the heavy cables being torn from the dug-up streets of Manhattan.

     ‘I don’t think you appreciate the importance of this problem, Doc. Have you any idea of the amount of horsepower involved in transportation? Counting both private and commercial vehicles and common carriers, North American Power-Air supplies more than half the energy used in this continent. We have to be right.
     You can add to that our city-power affiliate. No trouble there, yet. But we don’t dare think what a city-power breakdown would mean.’
     ‘I’ll give you a solution.’
     ‘Yeah? Well, give.’
     ‘Junk it. Go back to oil-powered and steam-powered vehicles. Get rid of these damned radiant-powered deathtraps.’
     ‘Utterly impossible. You don’t know what you’re saying. It took more than fifteen years to make the change-over. Now we’re geared to it. Gus, if NAPA closed up shop, half the population of the northwest seaboard would starve, to say nothing of the lake states and the Philly-Boston axis.’
     ‘Hrrmph—Well, all I’ve got to say is that that might be better than the slow poisoning that is going on now.’
     Stevens brushed it away impatiently. ‘Look, Doc, nurse a bee in your bonnet if you like, but don’t ask me to figure it into my calculations. Nobody else sees any danger in radiant power.’
     Grimes answered mildly. ‘Point is, son, they aren’t looking in the right place. Do you know what the high-jump record was last year?’
     ‘I never listen to the sports news.’
     ‘Might try it sometime. The record levelled off at seven foot two, ‘bout twenty years back. Been dropping ever since. You might try graphing athletic records against radiation in the air — artificial radiation. Might find some results that would surprise you.’
     ‘Shucks, everybody knows there has been a swing away from heavy sports. The sweat-and-muscles fad died out, that’s all. We’ve simply advanced into a more intellectual culture.’
     ‘Intellectual, hogwash! People quit playing tennis and such because they are tired all the time. Look at you. You’re a mess.’
     ‘Don’t needle me, Doc.’
     ‘Sorry. But there has been a clear deterioration in the performance of the human animal. If we had decent records on such things I could prove it, but any physician who’s worth his salt can see it, if he’s got eyes in him and isn’t wedded to a lot of fancy instruments. I can’t prove what causes it, not yet, but I’ve a damned good hunch that it’s caused by the stuff you peddle.’
     ‘Impossible. There isn’t a radiation put on the air that hasn’t been tested very carefully in the bio labs. We’re neither fools nor knaves.
     ‘Maybe you don’t test ‘em long enough. I’m not talking about a few hours, or a few weeks; I’m talking about the cumulative effects of years of radiant frequencies pouring through the tissues. What does that do?’
     ‘Why, nothing—I believe.’
     ‘You believe, but you don’t know. Nobody has ever tried to find out. F’rinstance — what effect does sunlight have on silicate glass? Ordinarily you would say “none”, but you’ve seen desert glass?’
     ‘That bluish-lavender stuff? Of course.’
     ‘Yes. A bottle turns coloured in a few months in the Mojave Desert. But have you ever seen the windowpanes in the old houses on Beacon Hill?’
     ‘I’ve never been on Beacon Hill.’
     ‘OK, then I’ll tell you. Same phenomena, only it takes a century more, in Boston. Now tell me, you savvy physics — could you measure the change taking place in those Beacon Hill windows?’
     ‘Mm-rn-in — probably not.’
     ‘But it’s going on just the same. Has anyone ever tried to measure the changes produced in human tissue by thirty years of exposure to ultra short-wave radiation?’
     ‘No, but—‘
     ‘No “buts”. I see an effect. I’ve made a wild guess at a cause. Maybe I’m wrong. But I’ve felt a lot more spry since I’ve taken to invariably wearing my lead overcoat whenever I go out.’

From WALDO by Robert Heinlein (1942)

      "Hello, boss!" said a deep voice immediately above and behind his left ear. "Won't you come in?"
     Spencer rose six inches from his chair in a spasmodic jump and turned on Aarn with a sour face. "You misplaced decimal point, if it weren't for my memories and loyalty to dear old Mass Tech, I'd amputate you from the pay roll."
     "Would you?" asked Aarn, with a pensive air. When pensive, Aarn's broad face and huge body succeeded in looking like a cow of subnormal intelligence, ruminating on the possible source of its next meal. He did now. "I'd hate that, Russ. But I think you'd hate it worst. I got my super-permeable space condition. That's about the poorest name imaginable, so I've decided to invent a name. Be it herein after referred to by the party of the first part as the 'transpon' condition. Anyway, come on in."

     Aarn's workship was large and divided into two parts, the apparatus room, inhabited by four technical assistants who made up the apparatus Aarn called for, and Munro's own sanctum.
     In Aarn's inner lab were a series of benches and cabinets and tables. These were all loaded with junked apparatus, unused parts, spare voltmeters, and coils of wire. The floor was reserved for the heavier junk that would have crushed the tables.
     Spencer was quite surprised to see that one of the largest benches had actually been entirely cleared, and two sets of apparatus set up on it. Aarn smiled his blank grin again. Spencer knew from sad experience that that smile meant something completely revolutionary that would upset all his calculations and probably cost him, temporarily at least, several million dollars.
     "Look," said Aarn.
     He waved his hands toward the new apparatus he had set up on the bench. The apparatus consisted of two main groups. At one end of the bench was a squat control panel, backed by a complex assortment of tubes and a device that closely resembled the magnetic atmosphere apparatus connected with a curious wire cone. There was a standard a foot tall surmounted by a cone of copper bars running lengthwise to form the sides and around, binding the longitudinal bars in position.
     The tip of the cone was a block of copper, the size of a golf ball. The mouth of the device was some four inches across and the length over all about ten inches. But the copper bars that formed the sides of the cone were care fully insulated from the block that was at the tip. From this block, a single straight bar of copper projected along the axis of the cone.
     Aarn smiled and turned on the apparatus. A low, musical hum rose from the tubes and coils, and slowly a faint blue glow centered about the copper block at the tip of the cone and the pencil of metal that extended up the axis. For five seconds this held steady while a similar blue glow began to build up about the outer system of copper conductors. Presently, as this reached a maximum, the inner glow began to fade, then swiftly a pulsing rhythm was set up, first the inner, then the outer conductor system glowing more intensely. The light settled down to a steady flickering that the eye could barely perceive, and Aarn smiled at it thoughtfully.
     "The apparatus takes a few minutes to warm up. That's the first half. That was the hardest part, too, curiously, though this projector here is a far more important discovery."
     Aarn pushed a second standard into view, which was surmounted by a metal bowl that closely resembled a deep soup dish. The inner surface was evidently a parabolic one, made up of a maze of tiny coils, each oriented carefully toward some definite aim, while the entire rim of the "soup dish" was a single larger coil.
     Carefully Aarn adjusted it so that it pointed toward the flickering cage of copper wires, and beyond it to the apparatus at the other end of the bench. This apparatus seemed fairly simple, merely a number of standards with various arrangements of wires. Two parallel copper bars, a double spiral made of two insulated wires, two metal disks.
     "Those," said Aarn softly, "are simply connected with the normal power supply. It is alternating current of sixty cycles at two hundred and twenty volts. The device I have is a pickup. It will collect the power from those wires. The projector here is the real secret—it makes space itself become a perfect conductor of electric-space-strain. Not electricity. Electric-space-strain. But the result is the same. It makes the space along its axis capable of carrying power along the axis—and along the axis only. When I start this, the space between here and that interrupter coil back there will be come a perfect conductor. The interrupter coil is necessary to prevent the thing reaching on, out indefinitely.
     "The pick-up there, will be in that path of conduction, and so will the first of those lead-offs there. That pair of straight wires. The wires will not be mutually short circuited because this will conduct current only along the axis. But the pick-up there keeps sending out flashes of a somewhat similar energy at an angle so that it covers the entire column, and so can pick up the power in it.
     "I can't make that pick-up work continuously, because the energies would then interfere and simply short-circuit things. But I can make it work at any frequency from one cycle a second to about fifty megacycles. Now I'm going to adjust it to sixty cycles, and it will get in step with the power on the two leads—and run that series of lights and that motor."
     Aarn pushed a switch. Instantly three tumblers snapped over automatically, a powerful surge of power seemed to draw at the men themselves momentarily, and then the little flickering pick-up was sending out searchlight beams of brilliant ionization. They started out along the shape of the cone, spread rapidly, till they filled the tight, round column of power coming from the transpon condition projector, then the ionization stretched along like a luminous liquid flower in a pipe.
     "The thing isn't in phase—wasting a lot of power," said Aarn.
     He began adjusting a dial, and the slight visible flickering vanished as the frequency rose. Suddenly the ionization all but vanished, leaving only a slight glow about the pick up itself. Then an instant later it was back, but vanished again. Each time the ionization stopped, the lights glowed, and the motor Aarn had pointed out hummed into speed.

     Presently he had it exactly adjusted, and the lights burned steadily, the five horse-power motor continuing smoothly.
     "The efficiency is about seventy-five per cent, which is not very good, I'll admit—but good enough for what I have in mind."
     Spencer was looking at the device intently. At last he asked: "But why doesn't the pick-up short-circuit the thing when it has thrown out its pick-up force? It throws a conducting band or disk completely across the tube of the transpon beam, as you said you called it. That will carry current at right angles to the axis, so it lies completely across the two terminals of the wires."
     Aarn smiled grimly. "That, Russ, Is why I took nearly nine months to do this. I had to prevent that. The answer is that the lock and the grid don't project the same force. The grid projects a force which will accept only a negative electric force, while the block will accept only positive. Therefore it can't short-circuit."
     "Then it rectifies, too? Some little device! It's a thing we've sought for a century, Aarn —power broadcast along a beam."
     "No," said Aarn sharply. "That's the point—it isn't broadcast along a beam. A beam reaches out and picks it up. The difference is as great and as vital as the difference between being hit and stopping something going by. If a man's fist connects with the button, your jaw absorbs kinetic energy. He has broadcast it along the beam of his arm.
     "But if you reach out and grab hold of a man running by you, you have reached out for and taken hold of a source of kinetic energy and momentum. Right?"
     "Hm—hum! Distinct difference. But why does it count here? What difference does it maker'
     "Nuts—a system of difference. No beam any man ever made could hold an absolute beam—a fixed diameter from here to infinity. Any power beam you make has to carry so much power per square-inch cross section at the point where the power is picked up. Suppose I'm sending power to a ship going to the Moon. On Earth the beam is ten feet across. Fine, the ship has an absorber or pick-up twenty feet in diameter, let's say. When the ship is fifty miles up, the beam and the pick-up are the same size. At one hundred miles the beam is wasting seventy-five per cent of its power because it has to maintain a certain power at the ship, and only twenty-five per cent of the beam is impinging on the target.
     "Now—take it the other way. If the ship projects the beam, the earth power station is simply pouring power into a funnel. The energy can go only one way, and no matter how widespread it is at Earth, it has to get out on the pick up in the beam. It's bound to be infinitely more efficient after you get more than ten miles away."
     "Slightly," agreed Spencer with a smile. "So hereafter, ships won't carry accumulators, eh? Just send back a beam and pick up power from Earth. But say—how are they going to be —made to pay for it? They could tap any power source or any line on Earth?"
     Aarn smiled and replied: "In the first place, they won't get their power from Earth, and in the second place, just suppose you sent back one of the beams to tap any sixty cycle line on Earth. What would happen? First, you'd have to get in phase with some one of the big power-line net works. Then, bingo, you have everything from one hundred and ten to one hundred and ten thousand and above volts coming smashing along. It would blow you to kingdom come and wreck the apparatus. Might do some damage back on Earth, but I doubt it."
     "Not get the power from Earth? Where then? Not from one of the other planets surely, because they have power troubles of their own."
     "From the mightiest machine!"
     "Good Heaven! The Sun! Do you mean that thing could tap the awful power of the Sun?"
     Spencer's face was suddenly pale. He could visualize that beam as though a visible thing reaching from some tiny dust mote out across space to impinge on the Sun, and drink of the power in that million-mile electric furnace, where matter was smashed beyond atoms, ground to radiation.
     "The Sun," Aarn nodded. "It's hard to think of all at once. Tapping the mightiest machine—the most inconceivably huge engine in the universe really—for any star would do. Making a star supply your power. A furnace that consumes nearly four million tons of matter a second.
     "It's simple really. You need a power stack, of course— a huge supply of power storage to operate your machine when you were not in position to tap the Sun. It would require only a modification of this device—one I have worked out completely—and we could draw a billion billion horse power in direct current at any voltage you wished, up to a maximum of about five hundred million, which would make insulation impossible in any circumstances."
     "Then—unlimited power—and I thought it was just a new power-transmission device. Atomic energy! Man could never build—of course he couldn't make one as big—a sun—two million million million tons of engine—three hundred thousand worlds like this—"
     He laughed suddenly. "Car, you wanted to know why physics didn't give you the atomic energy they promised. Here's physics' answer! Atomic energy would be too expensive—require too elaborate a control—so physics taps a sun!"

From THE MIGHTIEST MACHINE by John W. Campbell Jr. (1947)

Gravity train

This is an ancient idea that is hard-core unobtanium. The idea is if you pick a spot on Terra, somehow dig from that spot to the core of the planet and continue until you emerge at the antipode, in some manner (left as an excercise for the reader) prevent the tunnel from imploding, you will have a gravitationally powered subway. Unobtanium, we can calculate exactly how it would operate, but there is no way we could make one.

The technical term is Gravity Train.

You can get a more precise view of a given tunnel's antipodes locations by using the online Antipodes Map. Though a cursor glance at the map above shows that most tunnels have both ends located in the ocean (white areas), and of the ones that involve dry land most have an oceanic end (gold and blue areas). Very frew location have both ends on dry land (orange areas).

Actually, the tunnel does not require the ends to be at the antipodes, it does not have to pass through the center of the planet. All straight-line tunnels (using only gravity as the propulsive force) take the same amount of time to transit, regardless of where the end points are. Transit time is faster if the tunnel is a hypocycloid curve between the points. Sadly if the two points are antipodes, the hypocycloid curve becomes a straight line. For the equations to calculate the transit time, go here.


A gravity train is a theoretical means of transportation intended to go between two points on the surface of a sphere, following a straight tunnel that goes directly from one point to the other through the interior of the sphere.

In a large body such as a planet, this train could be left to accelerate using just the force of gravity, since during the first half of the trip (from the point of departure until the middle), the downward pull towards the center of gravity would pull it towards the destination. During the second half of the trip, the acceleration would be in the opposite direction relative to the trajectory, but (ignoring the effects of friction) the speed acquired before would be enough to cancel this deceleration exactly (so that the train would reach its destination with speed equal to zero).


In reality, there are two reasons gravity trains do not exist. First, a lengthy transit distance would pierce the Earth's mantle and traverse a region where rock is more fluid than solid. No materials are known that would withstand the tremendous heat and pressure in the inner core. Temperature is estimated as 5,700 K (5,430 °C; 9,800 °F), and pressure as high as about 330 to 360 gigapascals (3,300,000 to 3,600,000 atm). Secondly, frictional losses would be significant. Rolling friction losses could be reduced by using a magnetically levitated train. However, unless all air is evacuated from the tunnel, frictional losses due to air resistance would render the gravity train unusable. Evacuating the atmosphere to make it a vactrain would eliminate this drag but would require additional power. Such objections would not apply for solid planets and moons that do not have an atmosphere.

Origin of the concept

In the 17th century, British scientist Robert Hooke presented the idea of an object accelerating inside a planet in a letter to Isaac Newton. A gravity train project was seriously presented to the Paris Academy of Sciences in the 19th century. The same idea was proposed, without calculation, by Lewis Carroll in 1893 in Sylvie and Bruno Concluded. The idea was rediscovered in the 1960s when physicist Paul Cooper published a paper in the American Journal of Physics suggesting that gravity trains be considered for a future transportation project.

Mathematical considerations

Under the assumption of a spherical planet with uniform density, and ignoring relativistic effects as well as friction, a gravity train has the following properties:

  • The duration of a trip depends only on the density of the planet and the gravitational constant, but not on the diameter of the planet.
  • The maximum speed is reached at the middle point of the trajectory.

For gravity trains between points which are not the antipodes of each other, the following hold:

  • The shortest time tunnel through a homogeneous earth is a hypocycloid; in the special case of two antipodal points, the hypocycloid degenerates to a straight line.
  • All straight-line gravity trains on a given planet take exactly the same amount of time to complete a journey (that is, no matter where on the surface the two endpoints of its trajectory are located).

On the planet Earth specifically, a gravity train has the following parameters:

  • The travel time equals 2530.30 seconds (nearly 42.2 minutes), assuming Earth were a perfect sphere of uniform density.
  • By taking into account the realistic density distribution inside the Earth, as known from the Preliminary Reference Earth Model, the expected fall-through time is reduced from 42 to 38 minutes.
  • For a train that goes directly through the center of the Earth, the maximum speed is about 7,900 meters per second (28440 km/h) (Mach 23.2).

To put some numbers in perspective, the deepest current bore hole is the Kola Superdeep Borehole with a true depth of 12,262 meters. While to cover a distance between London and Paris (350 km) via a hypocycloidical path would need the creation of a 55,704-metre-deep hole. This depth isn't only 4.5 times as deep; it will also already need a tunnel that passes inside the Earth's mantle.

In fiction

The 1914 book Tik-Tok of Oz has a tube, that passed from Oz, through the center of the earth, emerging in the country of the Great Jinjin, Tittiti-Hoochoo.

In the 2012 movie Total Recall, a gravity train called "The Fall" goes through the center of the Earth to commute between Western Europe and Australia.

In the video game Super Mario Galaxy, there are various planets with holes that Mario can jump through to illustrate the gravity train effect.

From the Wikipedia entry for GRAVITY TRAIN

This is a continuation of Travel on Airless Worlds where I looked at suborbital hops.

The surface of airless worlds will be exposed to radiation so it's likely the inhabitants would live underground.

Moreover, it is not as hard to burrow. The deepest gold mine on earth goes down about 4 kilometers. The heat and immense pressure make it hard to dig deeper. In contrast, the entire volume of a small body can be reached.

Courtney Seligman shows how to compute the pressure of a body with uniform density. The bodies we look at don't have uniform density but we'll use his method as a first order approximation.

Central pressure of a spherical body with uniform density is 3 g2/(8 π G)

Where G is universal gravitation constant, g is body's surface gravity and R is body's radius.

At distance r from center, pressure is (1 - (r/R)^2) * central pressure.

What is the pressure 4 kilometers below earth's surface?
Earths's radius R is 6378000 meters. r is that number minus 4000 meters. g is about 9.8 meters/sec^2.
Plugging those numbers into
(1 - (r/R)^2) * 3 g2/(8 π G)
gives 2120 atmospheres.

Besides pressure, heat also discourages us from burrowing deeper. So it might be possible to dig deeper on cooler worlds but for now we'll use 2120 atmospheres as the limit beyond which we can't dig.

3/(8 π G) * g * R2 gives different central pressures for various worlds:

Ceres center is 1430 atmospheres, well below our 2120 atmosphere limit. And Ceres is a cooler world than earth. We would be able to tunnel clear through the largest asteroid in the main belt. Since smaller asteroids would have smaller central pressure, we would be able to tunnel through the centers of every asteroid in the main belt.

Imagine a mohole going from a body's north pole to south pole:

The diagram above breaks the acceleration vector into vertical and horizontal components. The mohole payload has the same vertical acceleration components as an object in a circular orbit with orbital radius R, R being body radius.

Somone jumping into this mohole could travel to the opposite pole for zero energy. Trip time would be the orbital period: 2 π sqrt(R3/μ).

Other chords besides a diameter could be burrowed. I like to imagine 12 subway stations corresponding to the vertices of an icosahedron:

The red subway lines to nearest neighbors would correspond to the 30 edges of an icosahedron .

Green subway lines to the next nearest neighbors would correspond to the 30 edges of a small stellated dodecahedron.

And there could be 6 diameter subway lines linking a station to stations to their antipodes.

The energy free travel time of all these lines would be the same as the diameter trip time: 2 π sqrt(R3/μ).

It would be possible have a faster trip time than 2 π sqrt(R3/μ). A train could be accelerated during the first half of the trip and decelerated the second half. During the second half, energy could be recovered using regenerative braking.

(ed note: Mr. David also mentioned to me that if you omitted the regenerative braking and had the destination end of the tunnel open to the sky, you could use this to launch spacecraft)

Most of small bodies in our solar system have internal pressures that don't prohibit access. But in some cases central pressure exceeds 2120 atmospheres. We'd be able to burrow only so deep. Here's my guesstimate of the maximum depth for various bodies:

Luna 40 kilometers
Mars 15 kilometers
Ganymede 77 kilometers
Callisto 97 kilometers
Europa 55 kilometers
Titania 318 kilometers
Oberon 61 kilometers
Pluto 200 kilometers
Haumea 82 kilometers
Eris 108 kilometers

Here is the spreadsheet I used to look at internal pressures.

The top four kilometers of earth's surface is only a tiny fraction of the accessible mass in our solar system.

Standup Maths did a nice look at moholes going through a body.

From TRAVEL ON AIRLESS WORLDS PART II by Hollister David (2014)

      The car raced through broad boulevards to a huge marble structure on the other side of the city.
     Over its wide entrance were the carved letters:



     They made their way through a wide concourse, noisy and crowded; but everyone gave them plenty of room. Ryeland grinned sourly to himself. No side trips! Of course not — and for the same reason. It wasn't healthy for a man who wore the collar to step out of line. And it wasn't healthy for anyone else to be in his immediate neighborhood if he did (Ryeland is a prisoner being transported, as a security measure he is wearing a remotely detonated exploding collar).
     "Track Six, was it?"
     "Train 667, Compartment 93.
     "There's Track Six." Ryeland led the way. Track Six was a freight platform. They went down a flight of motionless moving stairs and emerged beside the cradle track of the subtrains.
     Since the subtrains spanned the world, there was no clue as to where they were going. From Iceland they could be going to Canada, to Brazil, even to South Africa; the monstrous atomic drills of the Plan had burrowed perfectly straight shafts from everywhere to everywhere. The subtrains rocketed through air-exhausted tunnels, swung between hoops of electrostatic force. Without friction, their speed compared with the velocity of interplanetary travel.
     "Where is it?" Oporto grumbled, looking around. A harsh light flooded the grimy platforms, glittering on the huge aluminum llalloons that lay in their cradles outside the vacuum locks. Men with trucks and cranes were loading a long row of freightspheres in the platform next to theirs; a little cluster of passengers began to appear down the moving stairs of a platform a hundred yards away.
     Red signals flickered from the enormous gates of the vacuum lock on Track Six. Air valves gasped. The gates swung slowly open and a tractor emerged towing a cradle with the special car they were waiting for.
     The car stopped. Equalizer valves snorted again, and then its tall door flopped out from the top, forming a ramp to the platform. Escalators began to crawl along it.
     Ryeland shook his head. "No, you're not lightheaded. We're moving." The hand at the controls of the subtrain knew whose private car he was driving down the electrostatic tubes. The giant sphere was being given a featherbed ride. They had felt no jar at all on starting, but now they began to feel curiously light.
     That was intrinsic to the way of travel. The subtrain was arrowing along a chord from point to point; on long hauls the tunnels dipped nearly a thousand miles below the earth's surface at the halfway mark. Once the initial acceleration was over, the first half of a trip by subtrain was like dropping in a superspeed express elevator.
     Absently Ryeland reached out an arm to brace Oporto as the little man weaved and shuddered. He frowned. The helical fields which walled the tunnels of the subtrains owed part of their stability to himself. On that Friday night, three years before, when the Plan Police burst in upon him, he had just finished dictating the specifications for a new helical unit that halved hysteresis losses, had a service life at least double the old ones.

From THE REEFS OF SPACE by Jack Williamson and Frederik Pohl (1963)

High-Tech Materials

Dating back to the Orichalcum that was all the rage in Atlantis, to modern-day Wolverine's indestructable Adamantium bones, fiction is full of marvelous materials that would be oh so useful if we could only lay our hands on some.


Material composed of nothing but closely packed neutrons. Found in the core of neutron stars. The best figure I can find for the density of neutronium is 4×1017 kilograms per cubic meter, and dwarf star matter 1×109 kilograms per cubic meter.

No, you can't us it as the ultimate armor because if you somehow take a chunk out of the neutron star's core, the accurséd chunk explodes.

Outside of the core the neutrons undergo beta-decay with a half-life of 10 minutes and 11 seconds (611 seconds) with each cubic centimeter emitting energy at a rate of 19 megawatts average over the first half life.

Translation: sitting next to a cube of neutronium will be like having four and a half sticks of TNT blow up in your lap every second for 611 seconds.

As with all half-life decays, the second half-life will only have half the energy (two and a quarter sticks TNT per second) but by that point there won't be much left of your miserable carcass anyway.

Physicist Luke Campbell points out to me that my understanding is imperfect. Beta-decay is the least of your worries. He told me "An additional thing I didn't see mentioned in the section on neutronium is that all the neutrons are unbound. That means, there is nothing sticking them together. Once removed from the crushing gravity of a neutron star, all the individual neutrons fly off on their own independent happy trajectories. In an instant, you no longer have any kind of -ium any more, but rather a flash of highly penetrating energetic ionizing radiation."

In atomic nuclei, neutrons and protons stick together due to the strong nuclear force. Since the neutrons in a neutron star are not in a nucleus, there ain't no strong nuclear force gluing them. They are unbound.

The only thing keeping them together is the neutron star's outrageous gravity field. Once you take a chunk of neutronium away from the neutron star's gravity, the unbound neutrons composing the chunk instantly go flying in all direction at relativistic speeds. In other words it becomes a blast of neutron radiation with a flux strong enough to shred you into subatomic particles.


Neutronium (sometimes shortened to neutrium) is a proposed name for a substance composed purely of neutrons. The word was coined by scientist Andreas von Antropoff in 1926 (before the discovery of the neutron) for the conjectured "element of atomic number zero" that he placed at the head of the periodic table. However, the meaning of the term has changed over time, and from the last half of the 20th century onward it has been also used legitimately to refer to extremely dense substances resembling the neutron-degenerate matter theorized to exist in the cores of neutron stars; hereinafter "degenerate neutronium" will refer to this. Science fiction and popular literature frequently use the term "neutronium" to refer to a highly dense phase of matter composed primarily of neutrons.

Neutronium and neutron stars

Neutronium is used in popular literature to refer to the material present in the cores of neutron stars (stars which are too massive to be supported by electron degeneracy pressure and which collapse into a denser phase of matter). This term is very rarely used in scientific literature, for three reasons: there are multiple definitions for the term "neutronium"; there is considerable uncertainty over the composition of the material in the cores of neutron stars (it could be neutron-degenerate matter, strange matter, quark matter, or a variant or combination of the above); the properties of neutron star material should depend on depth due to changing pressure (see below), and no sharp boundary between the crust (consisting primarily of atomic nuclei) and almost protonless inner layer is expected to exist.

When neutron star core material is presumed to consist mostly of free neutrons, it is typically referred to as neutron-degenerate matter in scientific literature.


Due to beta (β) decay of mononeutron and extreme instability of aforementioned heavier "isotopes", degenerate neutronium is not expected to be stable under ordinary pressures. Free neutrons decay with a half-life of 10 minutes, 11 seconds. A teaspoon of degenerate neutronium gas would have a mass of two billion tonnes, and if moved to standard temperature and pressure, would emit 57 billion joules of β decay energy in the first half-life (average of 95 MW of power). This energy may be absorbed as the neutronium gas expands. Though, in the presence of atomic matter compressed to the state of electron degeneracy, the β decay may be inhibited due to Pauli exclusion principle, thus making free neutrons stable. Also, elevated pressures should make neutrons degenerate themselves. Compared to ordinary elements, neutronium should be more compressible due to the absence of electrically charged protons and electrons. This makes neutronium more energetically favorable than (positive-Z) atomic nuclei and leads to their conversion to (degenerate) neutronium through electron capture, a process which is believed to occur in stellar cores in the final seconds of the lifetime of massive stars, where it is facilitated by cooling via νe emission. As a result, degenerate neutronium can have a density of 4×1017 kg/m3, roughly 13 magnitudes denser than the densest known ordinary substances. It was theorized that extreme pressures of order 100 MeV/Fermi3 may deform the neutrons into a cubic symmetry, allowing tighter packing of neutrons, or cause a strange matter formation.

In fiction

The term "neutronium" has been popular in science fiction since at least the middle of the 20th century. It typically refers to an extremely dense, incredibly strong form of matter. While presumably inspired by the concept of neutron-degenerate matter in the cores of neutron stars, the material used in fiction bears at most only a superficial resemblance, usually depicted as an extremely strong solid under Earth-like conditions, or possessing exotic properties such as the ability to manipulate time and space. In contrast, all proposed forms of neutron star core material are fluids and are extremely unstable at pressures lower than that found in stellar cores. According to one analysis, a neutron star with a mass below about 0.2 solar masses will explode.

From the Wikipedia entry for NEUTRONIUM

Higgsinium and Monopolium

Higgsinium may or may not be handwavium. It depends upon a subatomic particle called the negative Higgsino predicted by supersymmetry theory. So far there is no evidence for supersymmetry from any physics experiment, and obviously no proof the negative Higgsino exists.

Monopolium may or may not be handwavium. It depends upon a subatomic particle called a magnetic monopole. There have been a couple of experiments which produced candidate events that were initially interpreted as monopoles, but are now regarded as inconclusive. On the other hand, pretty much all of the various theories of subatomic physics predict the existence of monopoles.



The theoretical physicists make some tentative promises. Supersymmetry is a class of theories that predicts "spin-reflected" analogs of all of the known (and some merely predicted) particles. The theories are not well enough along to assign exact masses to these new particles, but, constrained by already performed experiments, do set bounds. Accelerators being completed now may produce some of these before 1990. One possibility is that the peculiarly named negative Higgsino particle is stable, and has a mass about 75 times that of a proton (or 150,000 electrons).

Suppose we start with a mass of Hydrogen, the simplest atom. In it one electron orbits one proton. Since Higgsinos are heavier than protons, substituting one for the electron will turn the atom inside out: the massive Higgsino will become the nucleus, and the proton will do most of the orbiting, and will set the size of the atom, about 2000 times smaller in diameter than a normal one. The force between adjacent atoms would be 20002 or four million times as great — only astronomical temperatures would break those bonds — the material would remain a solid under any earthly conditions, and there would be 20003 or eight billion times as many atoms per cubic centimeter. Because Higgsinos are heavy, each atom will weigh 75 times as much, so the density would be about 1012 times that of normal matter. But there's a surprise. Each Higgsino added will itself generate about 20,000 electron volts of energy as it captures a proton — enough to radiate gamma rays. That's minor. But then the exposed orbiting protons of adjacent resulting "Higgsino Hydrogen" atoms will be in an optimum position to combine with one another in fours to form Helium nuclei in a fusion reaction. Each fusion liberates a whopping 10 million electron volts, and frees the Higgsinos to catalyse more fusions. This will continue until the resulting nuclear explosion blows the material apart. The Higgsinos may cause fusion of heavier elements as well, and perhaps fission of very heavy nuclei. Great opportunities here, but not quite what we had in mind!

Iron nuclei are prone neither to fusion nor fission — it takes energy to both break them down or to build them up — and so can (perhaps) be combined safely with Higgsinos. Each iron nucleus contains 26 protons, and must be neutralized by 26 negative Higgsinos. But it's unlikely that the Higgsinos can overcome their mutual repulsion to neatly form the right sized nuclei. A different, more condensed, arrangement is probable. Suppose we mix small amounts of hydrogen and Higgsinos very slowly and carefully, taking away waste energy (perhaps to help power the Higgsino manufacturing accelerator). The resulting mass will settle down to some lowest energy configuration, probably a crystal of Higgsinos and protons, electrically neutralizing each other, and some neutrons, bound by both electromagnetism and the strong nuclear force. If there are too many neutrons, some will decay radioactively until a stable mix is reached. The protons and neutrons, being the lighter and fuzzier of the particles, will determine the spacing: about that found in neutron stars. The millionfold speedups possible there will apply here also.

The final material (let's call it Higgsinium) would be 1018 times as dense as water; a thimbleful has the weight of a mountain. It'll be a while before that much of it is manufactured. A cubical speck a micron on a side weighs a gram, and should be enough to make thousands of very complex integrated circuits — analogous to a cubic centimeter of silicon. Their speed would be a millionfold greater, as would their power consumption and operating temperature. It may be possible to build the circuits with high energy versions of the optical and particle beam methods used to construct today's ICs, though the engineering challenges are huge! And in the long run tiny machines of Higgsinium might be dropped onto neutron stars to seed the construction of immense Neutronium minds.

Magnetic Monopoles

Higgsinos, and the rest of the supersymmetric stable, were "invented" only recently. An equally plausible, and even more interesting, kind of particle was theorized in 1930, by Paul Dirac. In a calculation that combined Quantum Mechanics with Special Relativity, Dirac deduced the existence of the positrons, mirror images of the electrons. This was the first indication of antimatter, and positrons were actually observed in 1932. The same calculation predicted the existence of a magnetic monopole, a stable particle carrying a charge like an isolated north or south pole of a magnet. Dirac's calculation did not give the monopole's mass, but it did specify the magnitude of its "charge". Recent "gauge" theories, in which the forces of nature are treated as distortions in higher dimensional spaces, also predict monopoles (as knots in spacetime), and even assign masses. Unfortunately there are competing versions with different mass predictions ranging from 1000 to 1016 times that of a proton. These masses are beyond the energy of existing and planned particle accelerators. Some cosmic rays are energetic enough.

For over forty years searches for monopoles all came up empty handed, and there was great skepticism about their existence. But they may have been fleetingly observed three times in the last decade, though none has yet been caught for extended observation. In 1973 a Berkeley cosmic ray expirement was lofted above most of the scattering atmosphere in a high altitude balloon. In 1975, after two years of study, a very heavy track bearing the stigmata of a monopole was noted in the lexan sheets that served as three dimensional detecting film. Calculations suggested it had twice Dirac's predicted charge, and a mass over 600 times that of a proton. Since monopoles had never been observed before, there was much skepticism. Other, more elaborate but more conventional possibilities were devised, and the incident was shelved.

On Valentine's day in 1982, a modest experiment in Blas Cabrera's Stanford physics lab registered a clean, persistent, steplike jump in the current in a superconducting loop. The size of the step was just what a monopole with Dirac's quantum of magnetic charge would have caused had it passed through the loop. The only alternative explanation was mechanical failure in the experimental apparatus. Subsequent prodding and banging produced no effect — everything seemed shipshape. The result was so exciting many groups around the world, including Cabrera's, built larger detectors, hoping to confirm the observation. For four years there was silence. By then the cumulative experience of the new detectors (collecting area multiplied by time) was over a thousand times that of Cabrera's original experiment. Once again the possibility of monopoles faded. Then, on May 22, 1986, a detector at Imperial College, London, whose experience was over four hundred times as large as Cabrera's original, registered another event. Until a monopole is caught and held, its existence will be in question. Yet, each additional detection greatly increases the odds that the others were not mistakes.

Magnetism and electricity are right angle versions of the same thing. A monopole waved up and down will cause a nearby electric charge to move side to side (and vice versa). A current of monopoles flowing in one wire will induce an electric current at right angles to itself. An electric current in a loop of conductor will flow in lockstep with a current of monopoles in a monopole-conducting loop chain linked with it. Two coils of wire wrapped around a monopole loop make a DC transformer — a current started in one coil will induce a monopole current in the loop, which will produce an electric current in the other coil's circuit. If good DC transformers had existed in the late nineteenth century, Thomas Edison and George Westinghouse would have had less to fight about, and all our electrical outlets would produce direct current. With monopoles we might refrain from making electrical connections at the plug at all, and draw power simply by passing the two ends of our power cords through a partially exposed monopole loop.

But let's get serious. If there are monopoles, they're not very common, and few will be simply picked out of the air. If they're very heavy, they will be hard to stop. Perhaps a few can be found already trapped here and there, and can be coaxed out (such a search was conducted worldwide by Kenneth Ford of Brandeis University, armed with a portable electromagnetic solenoid, in the early 1960s). Many things are possible given a few monopoles. Physicists routinely build superconducting solenoids with powerful magnetic fields several hundred thousand times as strong as Earth's. A monopole accelerates along magnetic field lines (for instance, a "North" monopole is strongly attracted to the south pole of a magnet). A monopole riding the field lines down the center of a powerful solenoid will gain an energy equivalent to the mass of several protons for every centimeter of travel. Ten meters of solenoid will impart an energy matching that of the most powerful existing accelerators. A few kilometers of solenoids will produce energies equal to millions of proton masses. The fireball resulting from a head on collision of two monopoles moving thusly is intense enough to produce some number of additional monopoles, in North/South matching pairs. These can be sorted out magnetically, and so monopoles can be harnessed to breed more monopoles.

Detectors of the Cabrera type do not measure the mass of passing monopoles, and the theories are little help. Monopoles can't be too light or they would have been created in existing accelerators. As mentioned above, the theoretical range of uncertainty is enormous. Things are especially interesting if there are at least two kinds of non mutually annihilating stable monopole, analogous to the proton and electron in normal matter (the North/South pairs mentioned above don't count — the two are antiparticles of each other, and annihilate when brought in contact). Here's a real leap of ignorance: let's suppose there are two kinds and that they are near the low end of the possible mass range. Let's suppose the lighter variety weighs 1000 protons, and the the heavier 1,000,000 protons. If two kinds don't exist, or if monopoles turn out to be much heavier many of the following proposals will become more extreme, or impossible. Others may open in their place.

An atom of Monopolium has a light monopole of one polarity (let's say North) bound to a heavy monopole of the opposite pole. Its size is set by the fuzzier light monopole. We assumed this has a mass of 1000 protons (or two million electrons), making the monopole atom about two million times smaller than a normal one. The particle spacing in Monopolium is thus comparable to that in Neutronium or Higgsinium. Its density, however, will be a million times beyond those because of the great mass of the central heavy monopole. This makes it 1025 times as heavy as normal matter. A thimbleful weighs as much as the Moon. Dirac's calculation found the magnetic quantum of charge to be 68.5 times as intense as the electric quantum. Two monopoles a certain distance apart would attract or repel each other 68.52 or 4,692 times as strongly as two equally separated electric particles. Combining this with the (inverse square) effects of much closer spacing and the increased density, makes Monopolium ten thousand times as strong for its weight as normal matter, though this number changes radically with changes in the assumed masses of the two kinds of monopole. The limiting switching speeds may be a thousand times higher than those we found for Higgsinium.

Other Applications

If Higgsinium or Monopolium can be made they may have applications beyond circuitry. Both materials are very tightly held together, and have no mechanism for absorbing small amounts of energy such as those found in photons, even soft gamma rays. This should make the materials very transparent. Yet the internal electromagnetic fields are huge, making for a tremendous index of refraction. Submicroscopic gamma ray microscopes, telescopes and lasers merely hint at the possibilities. In larger optics, gravitational effects will become important. If the materials can host loose electric or magnetic charges, they would be almost certainly be superconductors up to very high temperatures. because the tremendous binding forces would limit the number of states that the conducting particles can assume. To them the surface of the sun would is still very close to absolute zero in temperature. Superconducting versions of the materials should be nearly perfect mirrors, again up to gamma ray energies.

(ed note: amusingly enough, in his story THE BLACK STAR PASSES and in INVADERS FROM THE INFINITE the legendary John W. Campbell jr. postulates an absurdly strong transparent metal called "Lux" (density 103,500 kg/m3) which is a perfect insulator, and an absurdly strong mirror metal called "Relux" which is a conductor. Though in Campbell's stories these materials were composed out of solidified photons, i.e., Bose–Einstein condensates. )

Macroscopic extents of these substances are possible in very thin fibers or sheets. An (utterly invisible) Higgsinium strand one conventional atom (= 106 particles) in diameter masses 100 grams per centimeter of length. It may be able to support a 100 million tonnes, being about ten thousand times stronger for its weight than normal materials. Although it would slice through conventional matter as through a cloud (but sometimes the extremely thin cut would heal itself immediately), properly mounted it would make gargantuan engineering projects such as orbital elevators trivial. A single particle thick layer of Higgsinium would weigh about ten kilograms per square centimeter. Overlayed on structures of conventional matter the superconducting version especially would make powerful armor that would shield against essentially all normal matter projectiles, temperatures into the nuclear range, and all but the highest energy radiation. (But it could be penetrated by even denser Monopolium tipped bullets. Arms races are relentless!)

The same armor could be used to line the combustion chamber and expansion bell of a matter-antimatter rocket. Normal matter is instantly disintegrated by the violence of the reaction, but Higgsinium would easily bounce the pions, gamma rays and X rays produced when hydrogen meets antihydrogen. Single particle thick Monopolium, at a hundred tonnes per square centimeter, may be too heavy to use as a veneer at macroscopic scales. But it might be just the thing for constructing microscopic interstellar ships. A ship with two tiny tanks crammed with ultra compressed hydrogen and antihydrogen could rapidly propel itself at high acceleration to a few percent of the speed of light. Unaffected by either protons or antiprotons, Monopolium it would be better for building the engine and tanks than Higgsinium. The ship's front end might house a superfast mind, and tiny robot arms. It could probably land on a neutron star and start raising Neutronium crops and children.

Combining electrically conducting matter and Monopolium is interesting. Our Monopolium is about 10,000 times as strong for its weight as normal matter. Properly exploited, it can store $10,000$ as much energy in mechanical or electromagnetic form. Monopolium superconductor plated in a ring around a copper rod should make a lovely storage battery. To charge it, pass a current through the rod, thus setting up a monopole supercurrent in the ring. The magnetic current remains when you break the electrical connection, and causes the ends of the rod keep the voltage you had applied. When you connect a load to the rod ends, a current flows, and the voltage gradually drops towards zero as the monopole current slowly converts to electrical power. A kilogram of Monopolium should be able to store a fantastic one million watt hours. Caution: Do Not Overcharge! If the monopole current becomes too large, the electric field it generates will burst the ring, and all of the stored energy will be released at once in an explosion equal to a ton of TNT. There are other possibilities, especially involving intimate mixtures of monopoles and electrically charged matter (intertwined, like links of a chain), but we're out far enough on this limb for now.


The largest of the probes was really an automated factory, but its single output was very unusual—monopoles. It had some monopoles on board already, both positive and negative types. These were not for output, but the seed material needed to run the monopole factory. The factory probe headed for the first of the large nickel-iron planetoids that the strong magnetic fields of the neutron star had slowed and captured during its travels. It started preparing the site while the other probes proceeded with the job of building the power supply necessary to operate the monopole factory, for the power that would be needed was so great that there was no way the factory probe could have carried the fuel. In fact, the power levels needed would exceed the total power-plant capability of the human race on Earth, Colonies, Luna, Mars, asteroids, and scientific outposts combined.

Although the electrical power required was beyond the capability of those in the Solar System, this was only because they didn't have the right energy source. The Sun had been—and still was—very generous with its outpouring of energy; but so far the best available ways to convert that radiant energy into electricity, either with solar cells or by burning some fossilized sun energy and using it to rotate a magnetic field past some wires in a generator, were still limited.

Here at Dragon's Egg (neutron star), there was no need for solar cells or heat engines, for the rapidly spinning, highly magnetized neutron star was at one time the energy source and the rotor of a dynamo. All that was needed were some wires to convert the energy of that rotating magnetic field into electrical current.

The job of the smaller probes was to lay cable. They started at the factory and laid a long thin cable in a big loop that passed completely around the star, but out at a safe distance, where it would be stable for the few months that the power would be needed. Since a billion kilometers of cable was needed to reach from the positions of the asteroidal material down around the star and back out again, it had to be very unusual cable—and it was. The cables being laid were bundles of superconducting polymer threads. Although it was hot near the neutron star, there was no need of refrigeration to maintain the superconductivity, for the polymers stayed superconducting almost to their melting point—900 degrees.

The cables became longer and longer and started to react to the magnetic field lines of the star, which were whipping by them ten times a second—five sweeps of a positive magnetic field emanating from the east pole of the neutron star, interspersed with five sweeps of the negative magnetic field from the west pole. Each time the field went by, the current would surge through the cable and build up as excess charge on the probes. Before they were through, the probes were pulsating with displays of blue and pink corona discharge—positive, then negative. The last connection of the cable to complete the circuit was tricky, since it had to be made at a time when the current pulsating back and forth through the wire was passing through zero. But for semi-intelligent probes with fractional-relativistic fusion-rocket drives, one-hundredth of a second is plenty of time.

With the power source hooked up to the factory, production started. Strong alternating magnetic fields whipped the seed monopoles back and forth at high energies through a chunk of dense matter. The collisions of the monopoles with the dense nuclei took place at such high energies that elementary particle pairs were formed in profusion, including magnetic monopole pairs. These were skimmed out of the debris emanating from the target and piped outside the factory by tailored electric and magnetic fields, where they were injected into the nearby asteroid. The monopoles entered the asteroid and in their passage through the atoms interacted with the nuclei, displacing the outer electrons. A monopole didn't orbit the nucleus like an electron. Instead, it whirled in a ring, making an electric field that held the charged nucleus, while the nucleus whirled in a linked ring to make a magnetic field that held onto the magnetically charged monopole.

With the loss of the outer electrons that determined their size, the atoms became smaller, and the rock they made up became denser. As more and more monopoles were poured in the center of the asteroid, the material there changed from normal matter, which is bloated with light electrons, into dense monopolium. The original atomic nuclei were still there; but, now with monopoles in linked orbits around them, the density increased to nearly that of a neutron star. As the total amount of converted matter in the asteroid increased, the gravitational field from the condensed matter became higher and soon began to assist in the process, crushing the electron orbits about the atoms into nuclear dimensions after they had only been partially converted into monopolium. After the month-long process was complete, the 250-kilometer-diameter asteroid had been converted into a 100-meter-diameter sphere with a core of monopolium, a mantle of degenerate matter of white dwarf density, and a glowing crust of partially collapsed normal matter.

From DRAGON'S EGG by Robert L. Forward (1980)

Programmable Matter

What is a Programmable Matter™ smart material?
A Programmable Matter™ smart material is any bulk substance whose physical properties can be adjusted in real time through the application of light, voltage, electric or magnetic fields, etc. Primitive forms may allow only limited adjustment of one or two traits (e.g., the "photodarkening" or "photochromic" materials found in light-sensitive sunglasses), but there are theoretical forms which, using known principles of electronics, should be capable of emulating a broad range of naturally occurring materials, or of exhibiting unnatural properties which cannot be produced by other means.
What is Wellstone™ smart material?
Wellstone™ was a hypothetical form of smart material first proposed by Wil McCarthy in his novella "Once Upon a Matter Crushed" (Science Fiction Age, May 1999), consisting of nanoscopic semiconductor threads covered with quantum dots. These threads can be woven together to form a bulk solid with real-time adjustable properties. The terms "Wellstone™" and "Programmable Matter™" are occasionally incorrectly used interchangeably, although many other forms of smart materials exist.
Is this science fiction?
No. Various forms of smart material have appeared in fiction, but are in many cases based on technologies which exist today, or on reasonable extrapolations from them.
Where is smart material research being conducted?
Various aspects of smart materials (including quantum dots, electrochromic materials, magnetoreheologic materials, and various kinds of fiber-based circuitry) are under investigation in labs all over the world. Major players include (but are by no means limited to) IBM, Nippon Telehone and Telegraph, Fujitsu, Delft University, MIT, Harvard, Stanford, Princeton, Cornell, CalTech, and The University of California at Santa Barbara. Wellstone™, Wafflestone™, and Gridwell™, using quantum dots incorporated into fibers, ribbons, and plates are under explicit investigation at the Programmable Matter™ Corporation.
Are smart materials the same thing as nanotechnology?
Yes and no. The word "nanotechnology" simply means "technology on the scale of nanometers," or billionths of a meter, i.e. technology on the molecular scale. Most forms of Programmable Matter™ smart materials rely on nano-circuitry, designer molecules, or both, so in this literal sense they are nanotechnology. However, as originally coined by K. Eric Drexler in the 1980s and as commonly used by lay persons today, the word nanotechnology implies nanoscale machinery, more properly known as molecular nanotechnology or MNT. While bulk materials incorporating MNT may have programmable properties, they also have moving parts. Our smart materials do not rule out such materials, but more typically refers to substances whose properties can be adjusted in the solid state, with no moving parts other than photons and electrons.
Are Programmable Matter™ smart materials the same thing as MEMS?
No. Micro Electromechanical Systems, or MEMS, are microscopic machines crafted using standard methods for the manufacture of microchips. MEMS have many useful applications in the real world, but are far too large to exhibit the quantum effects necessary to affect the bulk properties of matter. However, the "Utility Fog" substance proposed by J. Storrs Hall in the early 1990s, consisting of millions or billions of MEMS micromachines — each with with 12 retractable, linkable arms -- has numerous adjustable bulk properties and can thus be considered a crude, mechanical form of smart materials. Also, The Programmable Matter™ Corporation is exploring the possible uses of Wellstone™ smart materials to enhance the properties of MEMS.
Is a cellular automaton computer simulation a smart material?
Yes, although technically speaking, a cellular automaton can only contain virtual smart material, whereas physical examples which meet the definition are available in the real world.
Does an LCD screen qualify as a smart material ? Does a transistor?
An LCD screen's optical properties can be dramatically altered by the application of electrical signals. Thus, it is clearly a form of smart material, albeit a simple one. A transistor can switch between an electrically conductive state and an electrically insulative one, but is properly a "device" rather than a substance or material. However, a bulk material fashioned from transistors (transistronium?) would be electrically switchable between these two states, and possibly numerous intermediate states. This meets (trivially) the definition for smart material stated above. In general, the more capable forms of Programmable Matter™ smart materials rely on the doping effects of "artificial atoms" or "quantum dots" inside a bulk material.
What is doping?
Doping is the addition of impurities (dopants) to a bulk material (the substrate) in order to adjust its electrical, thermal, optical, or magnetic properties. The addition of one dopant atom per million atoms of substrate is often sufficient to cause major changes in the material's behavior, and impurities in the parts-per-billion can disrupt the expected behavior of a pure crystal.
What is quantum confinement?
Quantum confinement is the trapping of electrons or electron "holes" (charge carriers) in a space small enough that their quantum (wavelike) behavior dominates over their classical (particle-like) behavior. In quantum mechanical terms, for quantum confinement to occur the dimension of the confining device or particle must be comparable to, or smaller than, the de Broglie wavelength of the carriers, and also the carrier inelastic mean free path IMFP and electron-hole Bohr radius of the material it's made from. Under cryogenic conditions, this typically occurs with dimensions of 1000 nm (0.001 mm) or less. At room temperature, depending on the materials, confinement dimensions of 20 nm or smaller are typically required.
What are quantum dots and artificial atoms? Are they the same thing?
A quantum dot is any device capable of the quantum confinement of electrons (for holes, it becomes an "antidot"). Once the electrons are confined, they repel one another and also obey the Pauli Exclusion Principle, which forbids any two electrons from having the same quantum state. Thus, the electrons in a quantum dot will form shells and orbitals highly reminiscent of (though larger than) the ones in an atom, and will in fact exhibit many of the optical, electrical, thermal, and (to some extent) chemical properties of an atom. This electron cloud is therefore referred to as an artificial atom. In their various forms, quantum dots may be referred to as single-electron transistors, controlled potential barriers, Coulomb islands, zero dimensional electron gases, colloidal nanoparticles or semiconductor nanocrystals.
What is a quantum well?
A quantum well is a device for confining electrons in one dimension, such that their quantum (wavelike) behavior dominates over their classical (particle-like) behavior along the confined axis, while classical behavior dominates along the other two axes, permitting the electrons to flow two-dimensionally through the material like billiard balls on a table. A typical quantum well may be fashioned from an N-type semiconductor, doped with electron donor atoms, trapped between two layers of P-type semiconductor, doped with electron borrower atoms. Other arrangements, such as a metal layer sandwiched between two insulators, are also possible. A quantum well is the primary component of miniature laser pointers.
What are Programmable Matter™ smart materials made of?
Programmable Matter™ smart materials are composed of manmade objects too small to perceive directly with the human senses. This may include microscopic or nanoscopic machines, but more typically refers to fixed arrangements of conductors, semiconductors, and insulators designed to trap electrons in artificial atoms.
How are Programmable Matter™ smart materials made?
Current forms of quantom dot smart materials fall into three types: colloidal films, bulk crystals, and quantum dot chips which confine electrons electrostatically. Quantum dots can be grown chemically as nanoparticles of semiconductor surrounded by an insulating layer. These particles can then be deposited onto a substrate, such as a semiconductor wafer patterned with metal electrodes, or they can be crystalized into bulk solids by a variety of methods. Either substance can be stimulated with electricity or light (e.g., lasers) in order to change its properties.

Electrostatic quantum dots are patterns of conductor (usually a metal such as gold) laid down on top of a quantum well, such that varying the electrical voltage on the conductors can drive electrons into and out of a confinement region in the well — the quantum dot. This method offers numerous advantages over nanoparticle ("colloidal") films, including a greater control over the artificial atom's size, composition, and shape. Numerous quantum dots can be placed on the same chip, forming a semiconductor material with a programmable dopant layer near its surface. A number of fabrication technologies exist whose resolution is sufficient to produce room-temperature quantum dot devices. Rolling such quantum dot chips into cylindrical fibers produces Wellstone™ smart material, a hypothetical woven solid whose bulk properties are broadly programmable.
Can Programmable Matter™ smart materials mimic the substances on the periodic table?
Yes. Artificial atoms can easily be constructed which mimic the properties of any natural atom, except that they are larger and their electrons are bound more loosely. However, these artificial atoms have negligible mass, and can exist only inside the quantum-dot substrate which generates them, usually a semiconductor. Thus, the final properties of the material are a blend of the simulated element and the underlying substrate. Note that the color of an artificial element made of oversized atoms would be redshifted as compared with the equivalent natural element.
Is this alchemy? Can it convert lead into gold?
Yes and no. An artificial atom of pseudo-lead (atomic number 82), trapped permanently inside a semiconductor material, can be converted to an artificial atom of pseudo-gold (atomic number 79) by the subtraction of three electrons. Sufficient numbers of these pseudoatoms may overwhelm the natural behavior of the semiconductor to produce a metal-like material similar to lead or gold, except for its mass, ductility, and probably color. Artificial atoms designed to mimic the colors of lead or gold might have other properties (e.g., electrical or thermal conductivity) which do not match the original metal.
Can Programmable Matter™ smart materials mimic transuranic elements?
Yes. An artificial atom can contain any number of electrons, from 1 to over 1000. The form and properties of highly transuranic atoms (atomic number >> 92) are dramatically different from those of natural atoms.
Aren't these transuranic elements highly unstable? Can you create nuclear reactions with them?
Electrons in an atom are confined by their attraction to the nucleus, and the nuclei of highly transuranic elements are unstable. However, an artificial atom does not have a nucleus of its own, relying instead on geometry, insulative barriers, and/or electrostatic repulsion to confine its electrons inside a semiconductor substrate. Thus, transuranic artificial atoms are stable as long as the device containing the electrons continues operating. The only atomic nuclei present are those of the metal and/or semiconductor atoms which make up the quantum dot. Because the confined electrons cannot affect the properties of these nuclei, they cannot be used to trigger or modify nuclear reactions. An artificial atom with 92 electrons in it is not "real" uranium, and will not be radioactive.
Can Programmable Matter™ smart materials be used to create superstrong materials?
Probably not. The binding energy of artificial atoms cannot exceed the binding energy of the semiconductor substrate. However, using diamond fibers or fullerenes as a substrate should allow for some very tough smart materials. Also, changes in the magnetic behavior of a material can affect its stiffness and tensile/compressive strength in useful ways.
What does "unnatural properties" mean?
Unlike natural atoms, artificial atoms can be square, pyramidal, two-dimensional, highly transuranic, composed of charged particles other than electrons (e.g., "holes"), and can even be asymmetrical. Their size, energy, and shape are variable quantities. Thus, artificial atoms exhibit optical, electrical, thermal, magnetic, mechanical, and (to some extent) chemical behaviors which do not occur in natural materials. This variety is bounded but infinite, in sharp contrast to the 92 stable atoms of the periodic table.
What does matter made of artificial atoms feel like? Is is solid?
Artificial atoms can exist only inside a semiconductor substrate. They are charge discontinuities rather than physical objects, so they don't "feel" like anything. However, their doping effects can dramatically alter the properties of the substrate, causing it to feel different. For example, a dramatic increase in thermal and electrical conductivity would make the semiconductor feel (in terms of thermal response) like a metal.
What are Programmablse Matter™ smart materials good for?
Almost anything. They can improve the efficient collection, storage, distribution, and use of energy from environmental sources. They can be used to create novel sensors and computing devices, probably including quantum computers. They can create materials which are not available by other means, and which change their apparent composition on demand. Currently, the design of new materials is a time- and labor-intensive process; with Programmable Matter™ smart materials, it becomes a real-time issue, similar to the design and debugging of software.
Who is Wil McCarthy?
Wil McCarthy, an aerospace engineer, is a contributing editor for WIRED magazine, the science columnist for the SciFi channel web site, and an author of numerous book-length works of science fact and science fiction. He has written extensively about quantum dots and smart materials, and faces a consistent set of questions, objections, and misconceptions when presenting this material. This FAQ is intended to promote intelligent discussion of smart materials and quantum dots by increasing awareness of their underlying issues and principles.
Who invented this?
Single-electron transistors, a form of quantum dot, were first proposed by A.A. Likharev in 1984 and constructed by Gerald Dolan and Theodore Fulton at Bell Laboratories in 1987. The first semiconductor SET, a type of quantum dot sometimes referred to as a designer atom, was invented by Marc Kastner and John Scott-Thomas at MIT in 1989. The term "artificial atom" was coined by Kastner in 1993. However, Wil McCarthy was the first to use the term "Programmable Matter™" in connection with quantum dots, and to propose a mechanism for the precise, 3D control of large numbers of quantum dots inside a bulk material. The most interesting forms of this device or substance -- known as "quantum dot fiber", "programmable dopant fiber", or "Wellstone™" — are under development at The Programmable Matter™ Corporation. The term "Wellstone™" was coined by McCarthy's business associate, Gary E. Snyder.
Are there unresolved issues regarding Programmable Matter™ smart materials?
Quantum dots are a new field with much basic research still remaining, so the ultimate properties of bulk quantum-dot materials cannot be known with precision at this time. However, the principles underlying quantum confinement are fairly well understood, and the experimental evidence overwhelmingly indicates that programmable quantum-dot smart materials are feasible, and will play an important role in future technology. Many issues have been considered, and many more are under investigation.
Is the technology patented?
Wil McCarthy and Gary E. Snyder hold pending U.S. patents on the concept, one entitled "Fiber Incorporating Quantum Dots as Programmable Dopants", filed 13 August 2001.
Where can I learn more?
The best online reference for lay readers is "Ultimate Alchemy," a 7,000-word article from WIRED magazine available (minus the pictures) at:

Offline lay-references include Richard Turton's THE QUANTUM DOT: A Journey into the Future of Microelectronics (Oxford University Press, 1996, ISBN 0-195-10959-7).

and Wil McCarthy's HACKING MATTER: Levitating Chairs, Quantum Mirages, and the Infinite Weirdness of Programmable Atoms (Basic Books, 2003, ISBN 0-465-04429-8).

For serious theoreticians, Paul Harrison's Quantum Wells, Wires, and Dots (Wiley, 2000, ISBN 0-471-98495-7) provides equations and computer code for estimating the behavior of confined electrons.
From The Programmable Matter Corporation


Computronium is a material hypothesized by Norman Margolus and Tommaso Toffoli of the Massachusetts Institute of Technology to be used as "programmable matter," a substrate for computer modeling of virtually any real object. It also refers to a theoretical arrangement of matter that is the best possible form of computing device for that amount of matter.

Matter that has been transformed from its natural state into an optimized, maximally efficient computer. (A true Extropian would argue that this is matter's "natural state".)

What constitutes "computronium" varies with the level of postulated technology. A rod logic nanocomputer is probably too primitive to qualify as computronium, since large molecular aggregates (hundreds or thousands of atoms) are used as computing elements. A more archetypal computronium would be a three-dimensional cellular automaton which attached computational significance to each individual atom, perhaps with quantum-computing elements included.

More exotic forms of computronium include neutronium, Higgsium, monopolium, or — my personal invention — an interlaced structure of positive-matter and negative-matter monopolium wrapped up in a fractal Van Den Broeck warp. (The total mass is zero, so the whole doesn't undergo gravitational collapse. If paired negative and positive matter can be manufactured in unlimited quantities, the fractal Van Den Broeck warp can continue extending indefinitely and exponentially. Threading the system with wormholes keeps latency down. And the whole thing fits in your pocket.)
From CREATING FRIENDLY AI by Singularity Institute for Artificial Intelligence, Inc. (2001)

Room Temperature Superconductor

Superconductors are nifty wires that have exactly zero resistance to the flow of electricity. They are vital to the construction of ultra-powerful magnets (for coilguns, particle beam weapons, and some propulsion systems) and for hyperfast computers.

The first superconductors had to be cooled with expensive and troublesome liquid helium. They became practical when new superconductors were discovered which could work with cheap and easy liquid nitrogen.

But the holy grail is a superconductor that doesn't need to be cooled at all. These are high-temperature superconductors, colloquially called "room-temperature superconductors."

Larry Niven used superconductors a lot in his Known Space series, especially Ringworld. His electrical superconductors are also superconductors of heat, which I have so far failed to find a reference on that topic.


High-temperature superconductors (abbreviated high-Tc or HTS) are materials that behave as superconductors at unusually high temperatures. The first high-Tc superconductor was discovered in 1986 by IBM researchers Georg Bednorz and K. Alex Müller, who were awarded the 1987 Nobel Prize in Physics "for their important break-through in the discovery of superconductivity in ceramic materials".

Whereas "ordinary" or metallic superconductors usually have transition temperatures (temperatures below which they are superconductive) below 30 K (−243.2 °C), and must be cooled using liquid helium in order to achieve superconductivity, HTS have been observed with transition temperatures as high as 138 K (−135 °C), and can be cooled to superconductivity using liquid nitrogen. Until 2008, only certain compounds of copper and oxygen (so-called "cuprates") were believed to have HTS properties, and the term high-temperature superconductor was used interchangeably with cuprate superconductor for compounds such as bismuth strontium calcium copper oxide (BSCCO) and yttrium barium copper oxide (YBCO). Several iron-based compounds (the iron pnictides) are now known to be superconducting at high temperatures.

In 2015, hydrogen sulfide (H2S) under extremely high pressure (around 150 gigapascals) was found to undergo superconducting transition near 203 K (-70 °C), the highest temperature superconductor known to date.

For an explanation about Tc (the critical temperature for superconductivity), see Superconductivity § Superconducting phase transition and the second bullet item of BCS theory § Successes of the BCS theory.


The phenomenon of superconductivity was discovered by Kamerlingh Onnes in 1911, in metallic mercury below 4 K (−269.15 °C). Ever since, researchers have attempted to observe superconductivity at increasing temperatures with the goal of finding a room-temperature superconductor. In the late 1970s, superconductivity was observed in certain metal oxides at temperatures as high as 13 K (−260.1 °C), which were much higher than those for elemental metals. In 1986, J. Georg Bednorz and K. Alex Müller, working at the IBM research lab near Zurich, Switzerland were exploring a new class of ceramics for superconductivity. Bednorz encountered a barium-doped compound of lanthanum and copper oxide whose resistance dropped down to zero at a temperature around 35 K (−238.2 °C). Their results were soon confirmed by many groups, notably Paul Chu at the University of Houston and Shoji Tanaka at the University of Tokyo.

Shortly after, P. W. Anderson, at Princeton University came up with the first theoretical description of these materials, using the resonating valence bond theory, but a full understanding of these materials is still developing today. These superconductors are now known to possess a d-wave pair symmetry. The first proposal that high-temperature cuprate superconductivity involves d-wave pairing was made in 1987 by Bickers, Scalapino and Scalettar, followed by three subsequent theories in 1988 by Inui, Doniach, Hirschfeld and Ruckenstein, using spin-fluctuation theory, and by Gros, Poilblanc, Rice and Zhang, and by Kotliar and Liu identifying d-wave pairing as a natural consequence of the RVB theory. The confirmation of the d-wave nature of the cuprate superconductors was made by a variety of experiments, including the direct observation of the d-wave nodes in the excitation spectrum through Angle Resolved Photoemission Spectroscopy, the observation of a half-integer flux in tunneling experiments, and indirectly from the temperature dependence of the penetration depth, specific heat and thermal conductivity.

Until 2015 the superconductor with the highest transition temperature that had been confirmed by multiple independent research groups (a prerequisite to be called a discovery, verified by peer review) was mercury barium calcium copper oxide (HgBa2Ca2Cu3O8) at around 133 K.

After more than twenty years of intensive research, the origin of high-temperature superconductivity is still not clear, but it seems that instead of electron-phonon attraction mechanisms, as in conventional superconductivity, one is dealing with genuine electronic mechanisms (e.g. by antiferromagnetic correlations), and instead of conventional, purely s-wave pairing, more exotic pairing symmetries are thought to be involved (d-wave in the case of the cuprates; primarily extended s-wave, but occasionally d-wave, in the case of the iron-based superconductors). In 2014, evidence showing that fractional particles can happen in quasi two-dimensional magnetic materials, was found by EPFL scientists lending support for Anderson's theory of high-temperature superconductivity.


"High-temperature" has two common definitions in the context of superconductivity:

  1. Above the temperature of 30 K that had historically been taken as the upper limit allowed by BCS theory(1957). This is also above the 1973 record of 23 K that had lasted until copper-oxide materials were discovered in 1986.
  2. Having a transition temperature that is a larger fraction of the Fermi temperature than for conventional superconductors such as elemental mercury or lead. This definition encompasses a wider variety of unconventional superconductors and is used in the context of theoretical models.

The label high-Tc may be reserved by some authors for materials with critical temperature greater than the boiling point of liquid nitrogen (77 K or −196 °C). However, a number of materials – including the original discovery and recently discovered pnictide superconductors – had critical temperatures below 77 K but are commonly referred to in publication as being in the high-Tc class.

Technological applications could benefit from both the higher critical temperature being above the boiling point of liquid nitrogen and also the higher critical magnetic field (and critical current density) at which superconductivity is destroyed. In magnet applications, the high critical magnetic field may prove more valuable than the high Tc itself. Some cuprates have an upper critical field of about 100 tesla. However, cuprate materials are brittle ceramics which are expensive to manufacture and not easily turned into wires or other useful shapes. Also, high-temperature superconductors do not form large, continuous superconducting domains, but only clusters of microdomains within which superconductivity occurs. They are therefore unsuitable for applications requiring actual superconducted currents, such as magnets for magnetic resonance spectrometers.

After two decades of intense experimental and theoretical research, with over 100,000 published papers on the subject, several common features in the properties of high-temperature superconductors have been identified. As of 2011, no widely accepted theory explains their properties. Relative to conventional superconductors, such as elemental mercury or lead that are adequately explained by the BCS theory, cuprate superconductors (and other unconventional superconductors) remain distinctive. There also has been much debate as to high-temperature superconductivity coexisting with magnetic ordering in YBCO, iron-based superconductors, several ruthenocuprates and other exotic superconductors, and the search continues for other families of materials. HTS are Type-II superconductors, which allow magnetic fields to penetrate their interior in quantized units of flux, meaning that much higher magnetic fields are required to suppress superconductivity. The layered structure also gives a directional dependence to the magnetic field response.


Molecule Chain

This is an unnaturally strong thread one molecule thick. This means it has remarkably low mass per towing capacity, which makes it popular for moving asteroids and for waterskiing spacecraft and starships.

It will basically cut through anything except another molecule chain. Naturally it is also used to make edged weapons.


In fiction

Monomolecular wire is often used as a weapon in fiction. It has applications in cutting objects and severing adjacent molecules. A similar or identical concept may be called a microfilament wire or, as a weapon, a microfilament whip.

Among the first references in fiction to a monofilament is in John Brunner's Stand on Zanzibar (1968), where hobby terrorists deploy this over-the-shelf General Technics product across roads to kill or injure the people passing there. According to Brunner, the monofilament will easily cut through glass, metal and flesh, but in any non-strained structure the molecules will immediately rebond. No harm is done if the cut object is not under mechanical stress.

An early example of a substance similar to monomolecular wire is 'borazon-tungsten filament' from G. Randall Garrett's "Thin Edge." (Analog, Dec 1963) The main character uses a strand from an asteroid towing-cable to cut jail bars and to booby-trap the door of his room. Frank Herbert later described shigawire in his Dune novels. First making its appearance in Dune (1965), shigawire is a metallic extrusion produced naturally from a ground vine found on the planets Salusa Secundus and III Delta Kaising. It varies in diameter from approximately 1.5 cm down to monomolecular (micronic) diameters, and is notable for its incredible tensile and mechanical strength. Shigawire is able to cut through almost any material cleanly, possessing edges that are incredibly sharp. It is a weapon of choice for assassins.

Monomolecular wire is a plot element in the short story "Johnny Mnemonic" by William Gibson. The assassin following the protagonist has a diamond spindle of monomolecular wire (or filament) implanted in his thumb, the idea being that diamond is also made of a single molecule and thus hard enough to not be cut by a monomolecular wire. The top of a prosthesis, attached to the other side of the wire, was used as a weight and the wire could be used as a whip-like weapon or a garotte.

Monomolecular wire (in the form of wide 'tapes' of a "pseudo-one-dimensional modified diamond crystal") is used as the basic building material of the space elevator in Arthur C. Clarke's novel The Fountains of Paradise.

Monomolecular wires are seen in the Star Wars expanded universe, Cyber City Oedo 808, Hyperion Cantos, Robert J. Sawyer's Illegal Alien, Battle Angel Alita, Naruto, Akame ga Kill, Hellsing, Trinity Blood, My-Hime, Vampire Knight, Simon R. Green's Deathstalker series, Alastair Reynolds's Revelation Space universe, as well as the roleplaying games Shadowrun, One Piece as Doflamingo's string-string devil fruit and Cyberpunk 2020. Monomolecular wires are also seen in Larry Niven's "Known Space" universe as human-produced "Sinclair Molecule Chain".

In the One Piece manga, the character Donquixote Doflamingo ate the Ito Ito no Mi, a devil fruit that grants the user the ability to create and manipulate strings. He is capable of creating strings so thin that they cannot be seen, and he can use this ability to ensnare people and control them like a puppet. His strings are also incredibly strong, being able to cut through stone with ease.

Various Imperial and alien technologies in the Warhammer 40,000 universe use monomolecular blades or wire offensively. Possibly the most notable example are Eldar Warp Spiders, whose Deathspinner weaponry traps targets in a mesh of such filaments or the Dark Eldar Shredder weapon which shoots meshes of it.

The game Chaos Overlords featured a weapon 'monom rod' which used this technology.

Sion Eltnam Atlasia wields a monofilament whip called the Etherlite in Melty Blood.

In the 2000 film XChange, the main character acquires an Urban survival Kit which includes a monomolecular wire.

Monomolecular swords are used by some Kzin in Larry Niven's Known Space series.

Monomolecular wire ranks 14th on IGN's list of the "25 Coolest Sci-Fi weapons".

From the Wikipedia entry for MONOMOLECULAR WIRE

      The instrument man opened the outer door and saw the surface of the gigantic rock a couple of yards in front of him. And projecting from that surface was the eye of an eyebolt that had been firmly anchored in the depths of the asteroid, a nickel-steel shaft thirty feet long and eight inches in diameter, of which only the eye at the end showed.
     The instrument man checked to make sure that his safety line was firmly anchored and then pushed himself across the intervening space to grasp the eye with a space-gloved hand.
     This was the anchor.
     Moving a nickel-iron asteroid across space to nearest processing plant is a relatively simple job. You slap a powerful electromagnet on her, pour on the juice, and off you go.
     The stony asteroids are a different matter. You have to have something to latch on to, and that’s where the anchor-setter comes in. His job is to put that anchor in there. That’s the first space job a man can get in the Belt, the only way to get space experience. Working by himself, a man learns to preserve his own life out there.
     Operating a space tug, on the other hand, is a two-man job because a man cannot both be on the surface of the asteroid and in his ship at the same time. But every space tug man has had long experience as an anchor setter before he’s allowed to be in a position where he is capable of killing someone besides himself if he makes a stupid mistake in that deadly vacuum.
     “On contact, Jack,” the instrument man said as soon as he had a firm grip on the anchor. “Release safety line.”
     “Safety line released, Harry,” Jack’s voice said in his earphones.
     Jack had pressed a switch that released the ship’s end of the safety line so that it now floated free. Harry pulled it towards himself and attached the free end to the eye of the anchor bolt, on a loop of nickel-steel that had been placed there for that purpose. “Safety line secured,” he reported. “Ready for tug line.”
     In the pilot’s compartment, Jack manipulated the controls again. The ship moved away from the asteroid and yawed around so that the “tail” was pointed toward the anchor bolt. Protruding from a special port was a heavy-duty universal joint with special attachments. Harry reached out, grasped it with one hand, and pulled it toward him, guiding it toward the eyebolt. A cable attached to its other end snaked out of the tug.
     Harry worked hard for some ten or fifteen minutes to get the universal joint firmly bolted to the eye of the anchor. When he was through, he said: “O.K., Jack. Try ’er.”
     The tug moved gently away from the asteroid, and the cable that bound the two together became taut. Harry carefully inspected his handiwork to make sure that everything had been done properly and that the mechanism would stand the stress.
     “So far so good,” he muttered, more to himself than to Jack.
     Then he carefully set two compact little strain gauges on the anchor itself, at ninety degrees from each other on the circumference of the huge anchor bolt. Two others were already in position in the universal joint itself. When everything was ready, he said: “Give ’er a try at length.”
     The tug moved away from the asteroid, paying out the cable as it went.
     Hauling around an asteroid that had a mass on the order of one hundred seventy-four million metric tons required adequate preparation.
     This particular asteroid presented problems. Not highly unusual problems, but problems nonetheless. It was massive and had a high rate of spin. In addition, its axis of spin was at an angle of eighty-one degrees to the direction in which the tug would have to tow it to get it to the processing plant. The asteroid was, in effect, a huge gyroscope, and it would take quite a bit of push to get that axis tilted in the direction that Harry Morgan and Jack Latrobe wanted it to go. In theory, they could just have latched on, pulled, and let the thing precess in any way it wanted to. The trouble is that that would not have been too good for the anchor bolt. A steady pull on the anchor bolt was one thing: a nickel-steel bolt like that could take a pull of close to twelve million pounds as long as that pull was along the axis. Flexing it—which would happen if they let the asteroid precess at will—would soon fatigue even that heavy bolt.
     The cable they didn’t have to worry about. Each strand was a fine wire of two-phase material—the harder phase being borazon, the softer being tungsten carbide. Winding these fine wires into a cable made a flexible rope that was essentially a three-phase material—with the vacuum of space acting as the third phase. With a tensile strength above a hundred million pounds per square inch, a half inch cable could easily apply more pressure to that anchor than it could take. There was a need for that strong cable: a snapping cable that is suddenly released from a tension of many millions of pounds can be dangerous in the extreme, forming a writhing whip that can lash through a spacesuit as though it did not exist. What damage it did to flesh and bone after that was of minor importance; a man who loses all his air in explosive decompression certainly has very little use for flesh and bone thereafter.

     “What…what do you want?” Fergus asked.
     “I want to give you the information you want. The information that you killed Jack for.” There was cold hatred in his voice. “I am going to tell you something that you have thought you wanted, but which you really will wish you had never heard. I’m going to tell you about that cable.”
     Neither Fergus nor Tarnhorst said a word.
     “You want a cable. You’ve heard that we use a cable that has a tensile strength of better than a hundred million pounds per square inch, and you want to know how it’s made. You tried to get the secret out of Jack because he was sent here as a commercial dealer. And he wouldn’t talk, so one of your goons blackjacked him too hard and then you had to drop him off a bridge to make it look like an accident.
     “Then you got your hands on me. You were going to wring it out of me. Well, there is no necessity of that.” His grin became wolfish. “I’ll give you everything.” He paused. “If you want it.”
     Fergus found his voice. “I want it. I’ll pay a million—”
     “You’ll pay nothing,” Morgan said flatly. “You’ll listen.”
     Fergus nodded wordlessly.
     “The composition is simple. Basically, it is a two-phase material-like fiberglass. It consists of a strong, hard material imbedded in a matrix of softer material. The difference is that, in this case, the stronger fibers are borazon—boron nitride formed under tremendous pressure—while the softer matrix is composed of tungsten carbide. If the fibers are only a thousandth or two thousandths of an inch in diameter—the thickness of a human hair or less—then the cable from which they are made has tremendous strength and flexibility.
     “Do you want the details of the process now?” His teeth were showing in his wolfish grin.
     Fergus swallowed. “Yes, of course. But…but why do you—”
     “Why do I give it to you? Because it will kill you. You have seen what the stuff will do. A strand a thousandth of an inch thick, encased in silon for lubrication purposes, got me out of that filthy hole you call a prison. You’ve heard about that?”
     Fergus blinked. “You cut yourself out of there with the cable you’re talking about?
     “Not with the cable. With a thin fiber. With one of the hairlike fibers that makes up the cable. Did you ever cut cheese with a wire? In effect, that wire is a knife—a knife that consists only of an edge.
     “Or, another experiment you may have heard of. Take a block of ice. Connect a couple of ten-pound weights together with a few feet of piano wire and loop it across the ice block to that the weights hang free on either side, with the wire over the top of the block. The wire will cut right through the ice in a short time. The trouble is that the ice block remains whole—because the ice melts under the pressure of the wire and then flows around it and freezes again on the other side. But if you lubricate the wire with ordinary glycerine, it prevents the re-freezing and the ice block will be cut in two.”
     Tarnhorst nodded. “I remember. In school. They—” He let his voice trail off.
     “Yeah. Exactly. It’s a common experiment in basic science. Borazon fiber works the same way. Because it is so fine and has such tremendous tensile strength, it is possible to apply a pressure of hundreds of millions of pounds per square inch over a very small area. Under pressures like that, steel cuts easily. With silon covering to lubricate the cut, there’s nothing to it. As you have heard from the guards in your little hell-hole.
     “Hell-hole?” Tarnhorst’s eyes narrowed and he flicked a quick glance at Fergus. Morgan realized that Tarnhorst had known nothing of the extent of Fergus’ machinations.
     “That lovely little political prison up in Fort Tryon Park that the World Welfare State, with its usual solicitousness for the common man, keeps for its favorite guests,” Morgan said. His wolfish smile returned. “I’d’ve cut the whole thing down if I’d had had the time. Not the stone—just the steel. In order to apply that kind of pressure you have to have the filament fastened to something considerably harder than the stuff you’re trying to cut, you see. Don’t try it with your fingers or you’ll lose fingers.”
     Fergus’ eyes widened again and he looked both ill and frightened. “The man we sent…uh…who was found in your room. You—” He stopped and seemed to have trouble swallowing.
     “Me? I didn’t do anything.” Morgan did a good imitation of a shark trying to look innocent. “I’ll admit that I looped a very fine filament of the stuff across the doorway a few times, so that if anyone tried to enter my room illegally I would be warned.” He didn’t bother to add that a pressure-sensitive device had released and reeled in the filament after it had done its work. “It doesn’t need to be nearly as tough and heavy to cut through soft stuff like…er…say, a beefsteak, as it does to cut through steel. It’s as fine as cobweb almost invisible. Won’t the World Welfare State have fun when that stuff gets into the hands of its happy, crime-free populace?”
     Edway Tarnhorst became suddenly alert. “What?”
     “Yes. Think of the fun they’ll have, all those lovely slobs who get their basic subsistence and their dignity and their honor as a free gift from the State. The kids, especially. They’ll love it. It’s so fine it can be hidden inside an ordinary thread—or woven into the hair—or…” He spread his hands. “A million places.”
     Fergus was gaping. Tarnhorst was concentrating on Morgan’s words.
     “And there’s no possible way to leave fingerprints on anything that fine,” Morgan continued. “You just hook it around a couple of nails or screws, across an open doorway or an alleyway—and wait.”
     “We wouldn’t let it get into the people’s hands,” Tarnhorst said.
     “You couldn’t stop it,” Morgan said flatly. “Manufacture the stuff and eventually one of the workers in the plant will figure out a way to steal some of it.”
     “Guards—” Fergus said faintly.
     “Pfui. But even you had a perfect guard system, I think I can guarantee that some of it would get into the hands of the—common people. Unless you want to cut off all imports from the Belt.”
     Tarnhorst’s voice hardened. “You mean you’d deliberately—”
     “I mean exactly what I said,” Morgan cut in sharply. “Make of it what you want.”
     “I suppose you have that kind of trouble out in the Belt?” Tarnhorst asked.
     “No. We don’t have your kind of people out in the Belt, Mr. Tarnhorst. We have men who kill, yes. But we don’t have the kind of juvenile and grown-up delinquents who will kill senselessly, just for kicks. That kind is too stupid to live long out there. We are in no danger from borazon-tungsten filaments. You are.” He paused just for a moment, then said: “I’m ready to give you the details of the process now, Mr. Fergus.”
     “I don’t think I—” Fergus began with a sickly sound in his voice. But Tarnhorst interrupted him.
     “We don’t want it, commodore. Forget it.”
     “Forget it?” Morgan’s voice was as cutting as the filament he had been discussing. “Forget that Jack Latrobe was murdered?”
     “We will pay indemnities, of course,” Tarnhorst said, feeling that it was futile.
     “Fergus will pay indemnities,” Morgan said. “In money, the indemnities will come to the precise amount he was willing to pay for the cable secret. I suggest that your Government confiscate that amount from him and send it to us. That may be necessary in view of the second indemnity.”
     “Second indemnity?”
     “Mr. Fergus’ life.”
     Tarnhorst shook his head briskly. “No. We can’t execute Fergus. Impossible.”
     “Of course not,” Morgan said soothingly. “I don’t suggest that you should. But I do suggest that Mr. Fergus be very careful about going through doorways—or any other kind of opening—from now on. I suggest that he refrain from passing between any pair of reasonably solid, well-anchored objects. I suggest that he stay away from bathtubs. I suggest that he be very careful about putting his legs under a table or desk. I suggest that he not look out of windows. I could make several suggestions. And he shouldn’t go around feeling in front of him, either. He might lose something.”
     “I understand,” said Edway Tarnhorst.
     So did Sam Fergus. Morgan could tell by his face.

From THIN EDGE by Randall Garrett (1963)

Interstellar Ramscoop Robot #143 left Juno at the end of a linear accelerator. Coasting toward interstellar space, she looked like a huge metal insect, makeshift and hastily built. Yet, except for the contents of her cargo pod, she was identical to the last forty of her predecessors. Her nose was the ramscoop generator, a massive, heavily armored cylinder with a large orifice in the center. Along the sides were two big fusion motors, aimed ten degrees outward, mounted on oddly jointed metal structures like the folded legs of a praying mantis. The hull was small, containing only a computer and an insystem fuel tank.

Juno was invisible behind her when the fusion motors fired. Immediately the cable at her tail began to unroll. The cable was thirty miles long and was made of braided Sinclair molecule chain. Trailing at the end was a lead capsule as heavy as the ramrobot itself.

(ed note: "Sinclair molecule chain" is an unobtanium wire that is only one molecule thick and absurdly strong. The theoretical ultimate of low mass cable.)

From A GIFT FROM EARTH by Larry Niven (1968)

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