## Antimatter

Any Star Trek fan can tell you that when it comes to the most bang for your buck, you can't beat antimatter (sometimes called "Contra-terrene" or "Seetee"). How much bang? Well, in theory if you mix one gram of matter with one gram of antimatter you should get 1.8e14 joules of energy or about 43 kilotons.

Why 1.8e14 joules? Surely you remember Einstein's famous E = Mc2. c is the speed of light which is 299,792,458 meters per second. Squared it is 89,875,517,900,000,000 or about 9.0e16. M is mass in kilograms and E is energy in joules. So 0.002 kilograms (2 grams) times 9.0e16 equals 1.8e14 joules. QED.

Once more, to get some idea of the amount of damage represented by a given amount of Joules, refer to the Boom Table.

And remember from the discussion about nuclear weapons that there are 4.184e12 joules in a kiloton and 4.184e15 joules in a megaton. So simply:

Ekt = M * 42961.6

Emt = M * 43.0

where:

• Ekt = total annihilation energy (kilotons)
• Emt = total annihilation energy (megatons)
• M = mass of antimatter (kilograms) Please note that M is the mass of antimatter, NOT the mass of the matter + the antimatter.

If you are interested, 42961.6 is from (9.0e16 * 2) / 4.184e12 where 9.0e16 = c2, 4.184e12 = joules in a kiloton, 2 = 1 unit of matter + 1 unit of antimatter.

### Efficiency

But in practice it ain't gonna be anywhere near that much. The trouble is trying to use this as a bomb. It is much easier to extract all the energy from a matter-antimatter reaction if you do it in a slow controlled fashion, say in a power plant or a propulsion system. An antimatter particle beam is more difficult. Making an explosion (in vacuum) is downright hard.

Consider two bricks, one of matter and one of antimatter. Watch as they hit each other. The atoms and antiatoms just on the surface will come into contact and annihilate each other. This creates an explosion. Which is perfectly placed to push the two bricks apart with incredible force, preventing the rest of the atoms and antiatoms from coming into contact. (Actually it will probably vaporize the bricks and blow the vapor away, which amounts to the same thing.)

You may get close to 100% of the antimatter reacting if you, say, drop the antimatter chunk onto a planet, but getting that efficiency with a warhead exploding in the matter-less depths of deep space is much more difficult. You may be lucky to get 10%. Naturally as the state-of-the-art of antimatter warhead design advances, this percentage will rise.

The second problem is that not all the energy from the blast is dangerous. Some of it is in the form of neutrinos, which are utterly harmless (you know, those slippery little customers who can fly through one light year of solid lead like nothing is there).

First off, a particle will only annihilate with the corresponding anti-particle. This means if an electron hits an anti-proton, they will just bounce off each other (actually, protons and antineutrons sometime annihilate, and vice versa).

The good news for antimatter bomb makers is that electron-positron annihilations create flaming death in the form of a pair of deadly gamma rays. However, this is tempered by the unfortunate fact that electrons and positrons are approximately 1/1836 the mass of protons and other nucleons, and there are about 2.5 times as many nucleons as electrons. This means we can more or less ignore the energy contribution from electron-positron annihilation. Unless you want to just use pure positrons instead of anti-atoms of actual anti-hydrogen. Which means you'll need about 1836 times as many positrons as you would anti-hydrogen atoms to get the same boom.

The trouble is with proton-antiproton annihilations. This produces (on average) two neutral and three charged pions. The neutral pions cooperate by almost instantly decaying into gamma rays.

The charged pions though, are a pain in the posterior, er, ah, behave most inconveniently. Assuming that they are zipping along at about 0.94c, they will on average only make it to about 21 meters from ground zero before decaying into mostly harmless muons and neutrinos. If the intended target is farther away than that, the blast energy that is composed of charged pions is totally wasted. Accurate figures are hard to come by, but from what I've managed to dig up, something like 30% of the energy from proton-antiproton annihilation is going to be wasted as harmless muons and neutrinos. At worst, 4/9ths of the energy (44.4%) will be deadly (3/9ths are the helpful neutral pions decaying into gamma rays, 1/9th are muons decaying into electrons). At best, 100% of the energy will be deadly. My expert said that the deadly energy percent will normally be over 70%. So conservatively one can take 70% as the deadly percent, or optimistically take 85% (the average of 70% and 100%) as the percent. You can read all the gory details here.

Putting it all together, our new (conservative) formulae will be:

EktB = M * 42961.6 * 0.7 * Rf

or

EktB = M * 30073.1 * Rf

EmtB = M * 43.0 * 0.7 * Rf

or

EmtB = M * 30.1 * Rf

where:

• EktB = deadly blast energy (kilotons)
• EmtB = deadly blast energy (megatons)
• M = mass of antimatter (kilograms)
• Rf = reaction factor, percentage of the matter and antimatter that manages to annihilate before the rest is blown apart. 1.0 if you are an optimist, 0.1 if you are a pessimist, or a point in between that varies according to the technological level of the bomb-maker.

Also note that, for the most part, antimatter particle beam weapons are a waste of good antimatter.

As a side note, SF Author Colin Kapp often had ships armed with "Diffract Meson" warheads (what splendid technobabble!), presumably based on an as-yet undiscovered scientific principle. I always thought that there was some room for a warhead type in between the 10% efficient thermonuclear warhead and the 100% efficient antimatter warhead. Say Diffract Meson warheads are 50% efficient.

### Annihilation Notes

The gamma-ray flux from an antimatter annihilation can be strong enough to transmute some elements into radioactive isotopes. This happens by the phototransmutation process. The cross-section of this is quite low, but the gamma-ray flux can be quite high. And I am also informed that the charged pions may be short-lived, but they have a high cross-section and will do all sorts of interesting things to atomic nuclei. Apparently the higher the mass of the element transmuted, the longer lived it is as a radioisotope. I will get back to you when I manage to find some hard numbers.

As a side note, electron-positron annihilation produces two gamma rays with precisely an energy of 511 keV. Which means this is a dead giveaway for antimatter use. As you zip along in your antimatter powered rocket, everybody within a couple of light-years will be able to see a fool broadcasting the fact that their rocket contains militarily significant amounts of antimatter. If you head towards an alien race's home planet, you may inadvertently frighten them into giving you a very hot reception.

### Containment

Unsurprisingly, it is very difficult to safely contain antimatter. Earnshaw's theorem proves that no set of static charges can be used to create a stable trap. The best you can do is metastable, and the vast majority of configurations are actively unstable. You need to cheat with nonstationary fields, as in a Penning Trap.

Dr. Robert Forward spoke of storing antimatter in the form of a frozen snowball of anti-hydrogen at temperatures below two Kelvin, levitated in a magnetic field to avoid contact with the chamber wall. In a vacuum, of course. The cold temperature is to keep the blasted stuff from sublimating any anti-atoms from the surface and starting an annihilation reaction with the chamber. There will be some infrequent annihilation events caused by stray cosmic rays, but these should not be a problem.

If you are using your ball of antimatter as a fuel source instead of a bomb, Dr. Forward suggests extracting antimatter fuel from the chamber by using ultraviolet lasers. The lasers ionize a bit of anti-hydrogen from the snowball, which is captured by tailored electrostatic fields and piped to the engine. To insure the snowball's mass is not removed asymmetrically (which would destabilize the magnetic levitation), it is spun on its axis while under the laser.

Current particle accelerators are horribly inefficient at generating antimatter, but Dr. Forward says this is because they were designed by physicists, not industrial engineers. He is of the opinion that a dedicated antimatter factory built with current technology could approach 0.01% efficiency (which isn't good but is still about 6000 times better than Fermilab). The theoretical maximum is 50% efficiency due to the pesky Law of Baryon Number Conservation (which demands that when turning energy into matter, equal amounts of matter and antimatter must be created).

## Space Hackers

Spacecraft in a war zone had better have military-grade firewalls on their internal computer networks. Space hackers can try to crack the network through a radio link and issue a variety of computer commands. Such as vent the atmosphere, scram the reactor, or induce the warheads in the magazine to detonate. Not to mention uploading all the classified information in the data banks. This is an old trick, seen in such movies as The Wrath of Khan (where Admiral Kirk uses the "prefix code" to turn off the deflectors on Khan's ship), Independence Day, TV shows like the latest incarnation of Battlestar Galactica (where the Galactica's computers are NOT networked since the Cylons are just a little too good at hacking), and in novels such as Vernor Vinge's A Fire Upon The Deep, Ken MacLeod's The Cassini Division and James P. Hogan's Giant's Star.

The technical term for defending a computer by cutting off its access to the local internet is called air-gapping. Then security experts had to surround the computer's room with a Faraday cage to prevent rogue wifi signals and remote viewing of the computer monitors via van Eck Phreaking. Still later they had to worry about acoustical signaling and other weird channels. The standard used by most top security organizations is called TEMPEST, and yes most of the details are classified.

In Joel Shepherd's science fiction series The Spiral Wars, air-gapped computers are called Autistic Computers, since one of the symptoms of autism is persistent deficits in social communication and interaction across multiple contexts.

Paul Zimmerle points out that Battlestar Galactica does get the threat slightly wrong. It is not networked computers per se that are at risk, it is computers with some kind of data connection to the outside world that is the threat. Removing the network connection just slows the rate of contagion.

In some science fiction novel whose name escapes me at the moment, huge corporations and organized crime bosses keep their records on paper. The theory is that if you can put information into a computer, some hacker will eventually figure out how to spy on and copy the information. Regardless of how many firewalls you defend the information with.

## EMP Weapons

These are designed to create strong electro-magnetic pulses designed to fry electronics and electrical equipment. Many e-bomb designs are not nuclear, they use a conventional high-explosive charge in an armature to generate the pulse. These tend to be short range, on the order of hundreds of meters, and they do obey the inverse square law. The defense is enclosing all electrical devices in Faraday cages. It is amusing to note that vacuum tube technology is much less vulnerable to EMP than are transistors.

Fiber optic cables are immune to EMP, unfortunately they are not shock tolerant. Specifically they have poor shear tolerance. Fiber can withstand a certain amount of flex, but it's resistance to "instantaneous flex" (like you'd see with a conventional missile hit) is not good. Ordinary twisted pair wires will stretch with the displacement from the explosion (assuming a hit close enough to warp the local supports but far enough not to directly break the cables) but are vulnerable to EMP. A sharp strike, bend or flex to fiber optic cable will shatter the individual strands across the grain, and destroy the cable.

Conventional nuclear weapons will also produce an EMP under certain circumstances.

## Propulsion Systems

If your torchship's exhaust is pumping out a few terawatts, it might occur to you that your enemy would be real unhappy if you hosed them with your tail flame.

This is called "The Kzinti Lesson", from a Larry Niven short story called "The Warriors". Most science fiction fans have the mistaken belief that Niven first came up with the idea, even though John W. Campbell Jr. used it in his short story Solarite in 1930 (collected in The Black Star Passes).

The Kzinti Lesson states:

The warlike Kzinti invaded the solar system, figuring that humanity would be a pushover since the pacifist humans of the time had no weapons. Humans showed the Kzin the error of their ways by annihilating Kzinti warships with laser arrays used for solar sails, multi-million degree fusion exhausts, and photon drives that were basically titanic lasers. The humans did indeed have no weapons, technically. But any machine with that much energy at its disposal can be re-purposed.

So keep in mind that the higher the exhaust velocities of the rocket engine, the more damage it will do to anything unfortunate enough to be in the path of the exhaust.

Having said that, realize that as a general rule propulsion exhaust is poorly collimated, which means after a very short range it will have expanded and dissipated into harmlessness. This is because there are different criteria for optimising a device for a propulsion system and optimising it for a weapon. On the other tentacle, certain propulsion systems are virtually identical to weapons, I'm looking at YOU, mass drive propulsion.

Also note that using one's exhaust as a weapon has the same drawback of a spinal mount weapon. To wit: since you have to rotate the entire ship to aim the weapon, a long and skinny ship will rotate painfully slowly because of its large moment of inertia. Speaking of spinal mount weapons, the Space Battleship Yamato is technically an example of the Kzinti Lesson. If the ravening energy exits through the exhaust it is the Wave Motion Engine. If the energy is vectored to exit through the weapon port it is the Wave Motion Gun.

For examples of this in science fiction, consult the ever informative TV Tropes under Weaponized Exhaust.

Please note that if civilian ships are equipped with torch drives, they could do a Kzinti by accident. There may be a branch of the quasi-military Spaceguard that will remotely trigger a civilian's self-destruct device if there is danger of them blasting some innocent bystander with their exhaust.

Any army man can tell you it is an extraordinarily bad idea to stand directly behind an MLRS or any other rocket-propelled weapon. The backblast will cook you. And a soldier firing a man portable rocket weapon had better not have a wall close behind, or the wall will reflect the flaming backblast all over the stupid soldier.

Sometimes it works the other way. If you are attacking an Orion drive spacecraft with nuclear warheads, they will just point their pusher plate at the missiles and laugh at you. Though come to think, any propulsion system that uses a stream of detonating nuclear warheads should be easy to weaponize. In Larry Niven and Jerry Pournelle's Footfall they use the x-ray bursts from nuclear propulsion charges to pump x-ray lasers.

In the Space 1999 episode "Voyager's Return" the hapless inhabitants of Moonbase Alpha are alarmed to see the infamous Voyager One space probe approaching. The probe's propulsion system is the dreaded "Queller Drive", which uses a deadly radioactive stream of fast neutrons. The first test of the Queller drive accidentally killed everyone at a lunar colony. Lucky for the Alphans the inventor of the drive is actually hiding in Moonbase Alpha in a version of the witness protection program, since everybody who had relatives at the dead colony wants to kill him. Dr. Queller manages to turn Voyager off before it can fry everybody in Alpha.

But things go from bad to worse when they notice three alien warships following Voyager. As it turns out the aliens are seeking vengeance for millions of their citizens who were killed when the incompetently programmed Voyager One came blundering through their empire. Voyager One was programmed to turn off the Queller drive so as to avoid torching any inhabited planets, but Dr. Queller's software had a few bugs.

In The Outcasts of Heaven's Belt by Joan Vinge, warships attacking a visiting Bussard Ramjet starship get a rude surprise when the starship shows them its tail. The starship's fusion drive is quite deadly at close range. Things are more extreme in the anime Space Battleship Yamato (later watered down and made politically correct for viewers in the US under the name Star Blazers). The battleship's propulsion system is the incredibly powerful "wave-motion engine". But if attacked, the thrust is vectored out the nose of the ship to create the equally incredibly powerful "wave-motion cannon".

### Anti-Kzinti Lesson

Jonathan Cunningham notes that sometimes the opposite is true as well.

The effect is strongest with kinetic kill weapons of course, but will still be noticeable with particle beam weapons or even lasers. It will be less of an issue for missile launchers, assuming the missile don't begin full thrust until after they've left the tubes.

Any force acting through the center of a body affects the movement of that body. Any force acting anywhere else on a body will affect its rotation. The more powerful the beam, the stronger the thruster effect. The further away from the center of mass, the greater the lever arm, and the greater the rotational effect.

So when the Space Cruiser Virtuous has X turret cuts lose with a high energy broadside against the flagship of the Insidious Empire, the ship starts spinning until it comically slices its own escorts in half. The Despicable Lord cackles and returns fire from one of several fixed mounted emplacements, each one aligned through the center of mass, likes quills on a porcupine. Foolish humans...

TV Tropes calls this concept "Exhaustized Weapons".

Of course, if the weapon has low power compared to the mass, or fires in a short enough burst the effect is minimized. But not removed. During the Apollo 13 mission, NASA was mystified as to why the powerless craft kept drifting off course. It turns out that normal, periodic venting of water was enough to strike panic in the hearts of distant controllers who gasped, "Now what?"

In The Expanse, small ships use their point-defense systems as ship-killing machine guns. Since they fire hundreds of rounds a second they have a bigger kick than the ship's reaction control system. So the guns have a compensating thruster mounted on the rear of the guns to neutralize the recoil.

### Jon's Law

This is a more general concern. As propulsion systems get more powerful, the more energy they contain, and the worse the damage if an accident occurs. This is known as Jon's Law for science fiction authors.

As an example, a spacecraft with an ion drive capable of doing a meager 0.0001g of acceleration may be scientifically realistic and the exhaust is relatively harmless. However, to most of the audience it will not be interesting. "Nine months just to travel to Mars? How boring!"

The author, not wanting his book sales to go flat, hastily re-fits the hero's spacecraft with a fusion drive and makes it into a torchship. The good news is that the ship can make it to Mars in twelve days flat. The bad news is that the ship's exhaust is putting out enough terawatts of energy to cut another ship in two, or make the spaceport look like it was hit by a tactical nuclear weapon.

The author can still use the drive, but must consider the logical ramifications of the wide-spread civilian availability of the equivalent of thermonuclear weapons. How would you like to have the captain of the Exxon Valdez skippering a tramp freighter with an antimatter drive? That brilliant mushroom cloud you see marks the former location of Clinton-Sherman spaceport. The more devastation a propulsion system can wreck, the shorter the leash the captains will be on.

Having said that, trying to use a high-powered rocket exhaust like a giant blow-torch to deliberaly destroy a city is more likely to destroy the rocket. Depending upon the type of propulsion system.

So one of the logical ramification is that if drives are too powerful, there won't be any colorful tramp freighters or similar vessels. One can imagine a branch of Spaceguard who act as range safety officers. If any civilian ship starts behaving erratically or suspiciously, Spaceguard will take notice. If the ship looks like it is going to incinerate a city with its torch drive, Spaceguard will have to neutralize the ship with extreme prejudice. As a matter of fact, civilian spacecraft will probably by law be required to have a remote control self-destruct device to make Spaceguard's job easier.

Or even more severe: logically torchships would be strictly forbidden for civilian ownership, they would be reserved for the military. Which is also boring.

Another consideration is that if a propulsion system can impart over a certain amount of kinetic energy to a spacecraft, the ship becomes a giant kinetic energy weapon. Even if the drive is no torchdrive and the exhaust is as harmless as cream-pie to the face, the ship can obliterate a large city. This is why Friends Don't Let Friends Use Reactionless Drives In Their Scifi Universes.

## Ramming Speed

In science fiction books, movies and TV the crew knows that even if all your weapons are impotent against your opponent, ramming always works.

Understand that technically ramming requires that the ship is crewed. If it is uncrewed and programmed or remotely controlled, it is basically a missile.

Several thousand years ago naval combat was mostly a matter of getting close enough to the enemy ship to enable the soldiers to hop on board and start close quarters combat. This is because the state-of-the-art was not advanced enough allow ship-killing weapons that could be carried on a ship.

But soon the ancient Greeks and Romans managed to build oar-driven galleys big enough to mount a metal ram. These are huge metal beaks of bronze weighing about half a metric ton, which could really do some severe damage to anything it rammed. The target would at a minimum be disabled, shearing off all the oars on that side. If punctured it was on a one-way trip to Davy Jone's locker, straight down that-a-way. One of the more famous battles featuring rams was the Battle of Salamis in 480 BCE.

The age of sail made the ram worthless, because they do as much damage to you as they do to your target. The shock of impact would snap off all your masts and turn your rigging into something resembling the tangled mess of marionette puppet strings in your child's toy box. Ship cannons were ineffective as well, so boarding with hand-to-hand combat came back into favor.

The age of steam brought rams back into favor because there were no masts or rigging to worry about and the cannons were still pretty ineffective. Especially ineffective because steam powered warships could carry anti-cannon armor. But the advent of the breech-loading cannon meant that enemy ships could be sunk several thousand meters before they got into ramming contact, so rams once again became obsolete. Except for weird Rube Goldberg warships like torpedo rams, which were never particularly popular.

Ramming more or less died out as a tactic, except for oddities like ships in World War I ramming and cutting in twain German submarines, and Japanese Kamikaze in World War II. In Jules Verne's Twenty Thousand Leagues Under The Sea the main weapon of the submarine Nautilus was a huge steel ramming spike, used to puncture ships below the waterline. This is because Verne never came up with the idea of a submarine launched torpedo. But what did you expect for a novel written in 1870?

## Relativistic Weapons

For relativistic combat between Bussard Ramjet starships, go here.

Relativistic weapons are kinetic-kill weapons where the projectile moves faster than 14% the speed of light (42,000 kilometers per second or so) although the real fun doesn't start until about 90% the speed of light. Refer to the gamma chart. They are sometimes called "R-bombs." Such weapons do incredible amounts of damage, but by the same token they require absurd amounts of energy (refer to second equation below). They are very likely to remain science-fictional for centuries to come.

Even more so than kinetic-kill weapons, an actual warhead adds very little to the total damage inflicted. Note that at 86.6% the speed of light the amount of kinetic energy is equal to the rest mass, which means that the projectile will inflict upon the target the same energy as if it was composed of pure antimatter. Well, actually it will just contain that much energy, as Ken Burnside mentions about kinetic penetrator effects, in many cases the projectile will penetrate the target and exit the back of the ship while still containing joules of damage it failed to inflict on the target.

At such speeds, the kinetic kill equation is no longer accurate. Instead, the following equation is used. Remember that this not only tells how much kinetic damage the projectile will do to the target, it is also the minimum amount of energy the weapon will consume when it fires a round.

Again, to get some idea of the amount of damage represented by a given amount of Joules, refer to the Boom Table.

Ker = ((1/sqrt(1 - (V2/C2))) - 1) * M * C2

Ker = ((1/sqrt(1 - (V2/9e16))) - 1) * M * 9e16

Ker = ((1/sqrt(1 - P2)) - 1) * M * 9e16

where:

• Ker = relativistic kinetic energy (Joules)
• M = mass of projectile (kg)
• V = velocity of projectile relative to target (m/s)
• P = velocity of projectile relative to target (percentage of c, e.g., three quarters lightspeed = 0.75)
• C = speed of light in m/s = 3e8

And as before

Wp = Ker * (1 / We)

where:

• Wp = power required by weapon to fire one projectile (Joules)
• Ker = kinetic energy of one weapon projectile (Joules)
• We = efficiency of the weapon (0.0 = 0%, 1.0 = 100%)

But a civilization that does gain the ability to create relativistic kinetic-kill weapons becomes a deadly threat to any and all alien civilizations in range.

### Poor Man's R-Bomb

Iain Paterson did some calculations which produced some surprising results.

### The Killing Star

From The Killing Star by Charles Pelligrino and George Zebrowski (you really should read this book):

## Space Fighters

This section has been moved here

### Culture

This section has been moved here

### Efficacy

This section has been moved here

### Role

This section has been moved here

### In Fiction

This section has been moved here

## Alien Technology

This section has been moved here.

## Plasma Weapons

Silly as they are, plasma weapons are a popular SF concept that just won't go away. They are encountered in such diverse places as the original Star Trek TV series, the Traveler role playing game, and the Babylon 5 TV series. They play the role of a futuristic flame-thrower.

Their main draw-back is that they won't work.

Plasma is the so-called "fourth state of matter", and is basically hot air. That is, it is a gas heated to temperatures comparable to the interior of a star or the center of a thermonuclear explosion so that all the atoms are ionized. Unfortunately, according to the virial theorem, the plasma wants to equalize its internal pressure with the external, i.e., it wants to expand into a diffuse cloud of nothing.

Dr. Rodolphe D'Inca is a physicist and researcher of fusion energy at the Max Planck Institute for Plasma Physics. He was kind enough to answer a few questions on the topic for me. Looking at the concept, it was his understanding that a plasma weapon is a gun that ejects a ball of plasma, a plasmoid, at high velocity to destroy the target through kinetic impact.

I asked him if the plasma would expand and dissipate its energy due to Coulomb repulsion, the same problem suffered by charged particle beams. Rodolphe explained:

The Debye length is about 10-4 meters for a Tokamak fusion container (0.1 millimeters) down to about 10-11 meters for solar core plasma (0.01 nanometers). Which means if your plasmoid is larger than a speck of dust you do not have to worry about Coulomb repulsion.

I asked him about Ideal gas laws. Since the plasmoid was basically a hot gas in a vacuum, would it expand and dissipate its energy like, well, a hot gas in a vacuum. Rodolphe explained that yes indeed, due to the virial theorem a plasmoid with no external forces would expand at the Alfven velocity or the ion acoustic velocity due to internal plasma (fluid) and magnetic (electromagnetic) pressures. The Alfven velocity depends upon things like magnetic field strength and total mass density of the charged plasma particles, it is typically something like 500 km/s to 5000 km/s.. This means that after the plasmoid travels for one second, its diameter will be approximately five thousand kilometers, i.e., it has dissipated into nothing.

Well, you might ask, what about adding some external forces to prevent this? Sorry. If you use matter, you are basically trying to make an armored shell capable of containing a thermonuclear explosion in its interior, and having it somehow break apart when it hits its target. This is more or less impossible. And if it was somehow possible using some kind of handwavium, there is nothing preventing your opponents from armoring their combat spacecraft with the exact same thing. It would be much simpler to just use a missile with a thermonuclear warhead.

And if you try to use energy, in the form of a magnetic field or something, you have the same problems. Plus the new problem of somehow making a self-sustaining magnetic ball powerful enough to contain a thermonuclear explosion.

Rodolphe did note that things were different if you were shooting plasmoids inside an atmosphere. In the lab next to his office they are trying to create ball-lightning (page is in German, use Google Translate).

Finally I asked him if the thermal glare from the hot, brightly energetic gas would interfere with tracking your target. Rodolphe explained:

He went on to say:

So there you have it.

For further analysis of the worthlessness of plasma weapons with a focus on Star Wars and Star Trek, I refer you to Stardestroyer.net.

And please note that the jet from a Casaba Howitzer, while it is a plasma, it is not a plasmoid. In any event, it is a very short-ranged weapon.

## Nanotechnology

Nanotechnology (and it's extension nanorobotics) is the concept of molecule sized machine. The idea is attributed to Richard Feynman and it was popularized by K. Eric Drexler. It didn't take long before military researchers and science fiction writers started to speculate about weaponizing the stuff. A good science fiction novel on the subject is Wil McCarthy's Bloom.

There are many ways nanotechnology could do awful things to a military target. One of the first hypothetical applications of nanotechnology was in the manufacturing field. Molecular robots would break down chunks of various raw materials and assemble something (like, say, an aircraft), atom by atom. Naturally this could be dangerous if the nanobots landed on something besides raw materials (like, say, an enemy aircraft). However, since they are doing this atom by atom, it would take thousands of years for some nanobots to construct something (and the same thousands of years to deconstruct the source of raw materials).

But using nanobots for manufacturing suddenly becomes scary indeed if you make the little monsters into self-replicating machines (AKA a "Von Neumann universal constructor") in an attempt to reduce the thousands of years to something more reasonable. Suddenly you are facing the horror of wildfire plague spreading with the power of exponential growth. This could happen by accident, with a mutation in the nanobots causing them to devour everything in sight. Drexler called this the dreaded "gray goo" scenario. Or it could happen on purpose, weaponizing the nanobots.

Drexler is now of the opinion that nanobots for manufacturing can be done without risking gray goo. And Robert A. Freitas Jr. did some analysis that suggest that even if some nanotech started creating gray goo, it would be detectable early enough for countermeasures to deal with the problem.

What about nanobot gray goo weapons? Anthony Jackson thinks that free nanotech that operates on a time frame that's tactically relevant is in the realm of cinema, not science. And in any event, nanobots will likely be shattered by impacting the target at relative velocities higher than 3 km/s, which makes delivery very difficult. Rick Robinson is of the opinion that once you take into account the slow rate of gray goo production and the fragility of the nanobots, it would be more cost effective to just smash the target with an inert projectile. Jason Patten agrees that nanobots will be slow, due to the fact that they will not be very heat tolerant (a robot made out of only a few molecules will be shaken into bits by mild amounts of heat), and dissipating the heat energy of tearing down and rebuilding on the atomic level will be quite difficult if the heat is generated too fast.

Other weaponized applications of nanotechnology will probably be antipersonnel, not antispacecraft. They will probably take the form of incredibly deadly chemical weapons, or artificial diseases.

Some terminology: according to Chris Phoenix, "paste" is non-replicating nano-assemblers while "goo" is replicating nano-assemblers. Paste is safe, but is slow acting and limited to the number of nano-assemblers present. Goo is dangerous, but is fast acting and potentially unlimited in numbers.

"Gray or Grey goo" is accidentally created destructive nano-assemblers. "Red goo" is deliberately created destructive nano-assemblers. "Khaki goo" is military weaponized red goo. "Blue goo" is composed of "police" nanobots, it combats destructive type goos. "Green goo" is a type of red goo which controls human population growth, generally by sterilizing people. "LOR goo" (Lake Ocean River) nano-assemblers designed to remove pollution and harvest valuable elements from water, it could mutate into golden goo. "Golden goo" are out-of-control nanobots which were designed to extract gold from seawater but won't stop (the "Sorcerer's Apprentice" scenario). "Pink goo" is a humorous reference to human beings.

ACE Paste (Atmospheric Carbon Extractor) designed to absorb excess greenhouse gasses and covert them into diamonds or something useful. Garden Paste is a "utility fog" of various nanobots which helps your garden grow (manages soil density and composition for each plant type, controls insects, creates shade, store sunlight for overcast days, etc.) LOR paste: paste version of LOR goo. Medic Paste is a paste of nanobots that heals wounds, assists in diagnosis, and does medical telemetry to monitor the patient's health.

## X-Ray Bomb

Mid 2018 this interesting article turned up:

Do note that Terra's atmosphere is pretty opaque to X-rays (so much for Superman's X-ray vision). So on the one hand this would limit collateral damage, but on the other hand such a weapon would have to produce vast amounts of X-ray energy or it will not damage the target at all.

A pity that the main article is behind a paywall. However, an expert of my acquaintance who goes by the handle of Kerr opined:

## Neutrino Gun

Ian Mitchell is an acquaintance of Rob Davidoff (the gentleman who I brainstormed with to develop Cape Dread). He was reading an interesting paper entitled Potential Hazards from Neutrino Radiation at Muon Colliders and got an idea. I agree with him that his idea is unobtainium not handwavium. Meaning it is not forbidden by the laws of physics, it is just a bit beyond our technological capabilities. As yet.

It is also interesting that Hirotaka Sugawara et al have calculated that ultra-high energy neutrino beam (about 1000 TeV) can detect and destroy the nuclear warheads.

As a humorous aside, Randall Munroe did a "What If" analysis on the topic of deadly neutrino flux from supernovae.

## Hafnium Bomb

Consider an electron buzzing around an atomic nucleus. If it is as close as it can get to the nucleus (i.e., it is in the lowest unoccupied energy band structure) it is in its base energy state. This means it is "at rest", or at least as close as an electron gets to being at rest.

Anyway, if the electron absorbs some energy, from a photon or something, it can no longer occupy the base energy state. It has to rise to a higher energy state. In scientific terms, the electron has become "excited." This is not a stable situation, eventually the electron spits out the extra energy (generally in the form of a photon) and falls back into its base energy state.

Nuclear physicists immediately wondered if the protons and neutrons in the atomic nucleus could also become excited. As it turns out, indeed they could. When a nucleon becomes excited, the nucleus becomes a nuclear isomer.

Most nuclear isomers decay back into the base state in a fraction of a second. However, one or two can stay excited for years. Tantalum's isomer Ta-180m has a half-life of 1015 years, which is much longer than the age of the universe. But then there is Hafnium's isomer hafnium-178m2, which has a half-life of 31 years.

### Storing Energy

By now you are thinking "So what?"

Well consider this. Excited electrons contain the energy of chemical reactions. For example: a stick of dynamite. Excited nucleons contain the energy of nuclear reactions. For example: a nuclear weapon. Not so boring now, are they?

So converting ordinary hafnium into hafnium-178m2 would be the equivalent of revving up a rechargeable battery with nuclear energy.

One gram of pure hafnium-178m2 (the same mass as a paperclip) contains about 1330 megajoules of energy. This is the equivalent of 317 kilograms of TNT, about the same as the warhead on a Tomahawk cruise missile (TLAM-C). Now you know why people started to talk about a "nuclear hand grenade." (as Alan Bellows puts it: "the most appealing aspect of isomer triggering was its potential to shoehorn yet more death and destruction into convenient 'fun size' packages")

There was also speculation about using hafnium-178m2 as a power source. A suggested application was a nuclear isomer powered airplane. The popular term was "quantum nucleonic reactor".

What was even better is the fact that the energy emerges not as visible light photons, not as ultraviolet photons, not even as x-ray photons. This stuff spits out freaking gamma rays! In other words, it just might be the key to constructing a gamma-ray laser.

The US military was also interested in the fact that hafnium-178m2 could be used to circumvent the Nuclear Non-Proliferation Treaty. Tremendous energy release, intense gamma rays, but it ain't a nuke.

### The Problem

The trouble is that it is a worthless weapon if it takes thirty one years for half of the energy to slowly leak out. For a weapon you want it all to burst forth instantly. Therein lies the rub, nobody knew how.

That is where the controversy started.

Enter Dr. Carl B. Collins of the university of Texas. He figured that hafnium-178m2 could be triggered to release its energy by irradiating it with carefully tuned x-rays. The process is called induced gamma emission.

In January of 1999, Dr. Collins lead a team to explore this possibility. They put a tiny smear of hafnium-178m2 on the top of a styrofoam coffee cup, and used a scavenged dental x-ray machine to bombard the sample. After several weeks, the team studied the results. They concluded that there was a teeny-tiny increase in gamma rays measured in the data, which they interpreted as proof positive that they had succeeded. Or at least opened the possibility that there might be some magic frequency which would make the hafnium-178m2 create the desired explosion.

As always in science, if one has extraordinary claims, one had better have extraordinary evidence. And the sad fact of the matter is that Dr. Collins' evidence was pretty pathetic. Many scientists were uncomfortable with his outlandish claims and his experiment's large margin for error. Indeed, his findings were somewhat at odds with the laws of physics given that nuclei are thought to be practically unaffected by electromagnetic radiation.

The US military didn't want to provide funding to a crack-pot, but didn't want to miss out on nuclear hand grenades either. So they asked the Jason Defense Advisory Group (a panel established in 1960 to advise the government in matters of scientific controversy) to make an assessment. The Jasons concluded that the results fell into the former category: the data did not prove that induced gamma emission had occured, and even if it had a successful triggering event would not start the necessary chain reaction due to energy dissipation.

Meanwhile the Argonne National Laboratory used their own powerful x-ray machine in an attempt to reproduce Dr. Collins results. They failed: no induced gamma emission was recorded. Dr. Collins said it must be because your machine is too powerful. The skeptical Argonne scientists tried again using Dr. Collins' specifications. Still nothing was seen. Collins again ascribed the problem to experimental minutia, but by now the Argonne scientists had better things to do with their time.

Dr. Collins' work is more or less totally discounted nowadays, but there is a small group of true believers that still dreams of nuclear hand grenades.

## Subnuclear Bomb

The old-fashioned "atomic" bomb or "A-bomb" uses the awesome might of nuclear fission. When a uranium 235 atom is split, about 0.1% of the rest mass is converted into energy (202.5 MeV per fission). The new and improved "hydrogen" bomb or "H-bomb" uses the even more awesome might of thermonuclear fusion. When a deuterium nucleus fuses with a tritium nucleus, about 0.7% of the rest mass is converted into energy (17.6 MeV per fusion).

In 2017 physicists Marek Karliner and Jonathan Rosner were aghast to discover than if two bottom quarks "melted" together, the blasted things would convert a colossal 4.0% of the rest mass into energy (138 MeV per melt). It was 5.7 times as efficient as fusion and 40 times as efficient as fission.

With visions of an Armageddon full of subnuclear bombs that would make mere thermonuclear bombs look like wet firecrackers, Karliner and Rosner were ready to suppress the discovery. After some calculation they reassured themselves that the reaction had no practical applications and certainly no military ones.

Personally I think the physicists were being somewhat optimistic that suppressing their discovery would have any effect, since when it is Steam Engine Time lots of independent researchers are going to make steam engines. By the same token their assessment that the reaction is impractical for power generation depends upon some assumptions. These are very good assumptions, and very unlikely to change. But if any of them do, things are going to get tense.

From the standpoint of a science fiction writer, they can change an assumption by virtue of Author Fiat to get things started.

What's the problem with subatomic power? Well, the fuel. Specifically the availability and stability of the fuel.

Fission typically uses uranium-235. You can go to uranium mines to dig the stuff up, you do not have to make it. So it is available. And when you have some, it is not going to evaporate before your eyes because it has a half life of 703.8 million freaking years. As long as you do not pile enough together to make a critical mass it will be stable.

Fusion typically uses deuterium and tritium. Deuterium is usually extracted from seawater, you do not have to make it. True, tritium has to be manufactured but this is relatively easy to do by neutron activation of lithium-6 and it does not use much energy. So it is available. Deuterium is totally stable, while tritium has a half life of about 12 years. So they are reasonably stable.

Quark melting uses Lambda Baryons. This is the problem.

There ain't no lambda baryon mines. They do not occur in nature, short of a supernova or something. They must be manufactured. The particle accelerators used to make the little monsters have efficiencies measured in microscopic fractions of one percent (meaning you need gigawatts of power to make a miserable few lambda particles). So they are NOT available. The tiny manufacturing efficiency makes the quark melting worthless as a power supply, you'd be better off disconnecting the particle accelerator from its power supply and using the power directly. Meaning that the particle accelerator would gobble gigawatts of electricity while producing only enough lambda particles to generate a fraction of a watt plus gigawatts of worthless waste heat. The only reasonable use is for propulsion which needs incredibly concentrated fuel … or as a bomb warhead.

Which is where the second problem makes the stuff worthless. Lambda baryons containing a "bottom" quark have a lifespan of (1.429±0.024)×10-12 sec or one-and-a-half picoseconds. You can't make a chunk of the stuff, put it in a bomb, let the bomb sit in a weapon stockpile for a few months, move it to a bomber spacecraft, and drop it on an enemy city. A particle decays into something worthless one pico-jiffy after the particle accelerator makes it, you have 0.0000000000015 second to use it or lose it. So it is NOT stable.

With respect to science fiction, off the top of my head the "easiest" solution is to handwave some item that can freeze time for the lambda baryons or otherwise prevent them from decaying. The trouble with such a solution is anything operating on something so fundamental is going to have tons of unintended consequences. Larry Niven had that problem with his time-stopping "stasis fields." Every new technical problem he put in his stories had to be examined to see if it would be trivially solved by using a stasis field.

HOW DOES IT WORK?

If you could care less about the nitty-gritty details, you'd best skip this section.

An example of nuclear fission is when a uranium-235 nucleus is split by an incoming neutron. The end result is two fission fragments (e.g., a nuclei of barium-141 and a nuclei of krypton-92) plus two neutrons (141+92+2 = 235). If you weigh all the particles before the split and then after the split, you'll see that the total mass after is less than the total before. The discrepancy is the "mass deficit" or "binding energy", this creates the "boom" of the atom bomb by the magic of e=mc2. The mass deficit is 0.1% of the total "before" particles.

An example of nuclear fusion is when a deuterium nucleus and a tritium nucleus merge or fuse. The result is a helium-4 nucleus and a neutron. The mass deficit in this case is 0.7% of the total "before" particles.

In both fission and fusion the starting particles are atomic nuclei, which are balls composed of protons and neutrons. The end result may be two nuclear balls of protons/neutrons, or one ball; but the point is that the protons and neutrons do not change. The only thing that changes is which nuclear ball they are considered to be part of. For instance, a proton that was in a uranium-235 nuclear ball might end up in the barium-141 nuclear ball. But it is still a proton.

With quark melting, the nuclear particles do change. The reaction is not happening the nuclear level, it is happening at the sub-nuclear level.

Let's take a closer look at the nuclear particles. Protons and neutrons are what we call baryons. All baryons inside are composed of three quarks. Since protons and neutrons are dull, boring, commonplace baryons they are composed of the dull, boring, commonplace quarks. These are the so-called "up quark" and "down quark." A proton has two "up" quarks and one "down" quark. The neutron is the opposite, with one "up" quark and two "down quarks."

As you probably have suspected there exists more exciting, interesting, and rare quarks. These are the "top", "bottom", "charmed", and "strange" quarks (named by whimsical physicists). Which can be used to compose more exciting, interesting, and rare baryons. The important point here is that the "top", "bottom", and "charmed" quarks ("heavy quarks") are much more massive than the commonplace quarks (by one to three orders of magnitude). The "strange" quark is about the same mass as the commonplace quarks ("light quarks").

For reasons I am not even going to try and explain it is impossible to split a baryon into its component quarks. But it is possible for two baryons to briefly splat together into a virtual 6-quark cluster, quickly swap quarks, and separate into two new types of baryons. If heavy quarks are involved, there will be a mass deficit, and energy will be released.

Baryons containing only up and down quarks are called "nucleons", or "dull, boring, commonplace baryons". Baryons that contain two commonplace quarks (ups and downs) plus an exotic quark are called "Lambda" (Λ). And baryons with a single commonplace quark plus two exotic quarks are called "Xi" (Ξ).

Dr's. Karliner and Rosner examined the charmed Lambda (Λc) and the bottom Lambda (Λb). Λc has up, down, and charmed quarks. Λb has up, down, and bottom quarks.

If two Λc slammed together into a virtual 6-quark cluster, lambda 1 could give lambda 2 a down quark and receive in trade a charmed quark. Lambda 1 would then become a charmed Xi (Ξc, one up quark and two charmed quarks) while lambda 2 would become a neutron (one up and two down quarks). This releases 12 MeV of energy from the mass deficit.

In the same way two Λb can slam together and transform into a Ξb, a neutron, and 138 MeV.

## Collapsing Rounds

Fission warheads (old-school A-bombs) are an old favorite. Basically the warhead creates a nuclear explosion by rapidly assembling a critical mass of weapons-grade uranium or plutonium.

It is a pity that the smallest warhead will be about 20 kilograms, with a yield of about a kiloton. Not exactly bullet-sized.

A simplistic mechanism is inefficient at converting uranium into bang, so you need lots of uranium. A fancy mechanism with explosive lenses and everything can get the same amount of bang with less uranium. Alas, all the fancy mechanism adds more mass to warhead.

So mad scientists figured that the key was to find some isotope with a far lower critical mass than U235. The rumors from the conspiracy theories was that the element Californium would do nicely.

This report says that Californium-251 has a very small calculated critical mass of about 5 kg. That's where things become murky, since 5 kg is not exactly bullet-sized either. If my slide-rule isn't lying to me, that would be a sphere 4.3 cm in radius. Of course you'd want a geometry that was more dispersed, since a sphere is critical mass. 251Cf has a half life of 898 years.

The idea was to make each Californium round in the shape of a dumb-bell. That is, two sub-critical hemispheric masses connected by a tab, and surrounded by an explosive charge designed to crush the Californium into a sphere. Even better if the explosive charge can be omitted, but that probably means it could only be used in a hypervelocity weapon, and only targeting hard objects such as tanks or buildings.

Things get even more murky. The various sources can't even agree on which isotope to use. Some say 252Cf has a critical mass of only 2.6 kg, that has a much shorter half-life of 2.645 years. A russian publication said 252Cf critical mass was only 0.0018 kg, but that sounds too good to be true.

In the Traveller role-playing game, they suggest that collapsing rounds be stored inside a handwavium nuclear damper boxes. Otherwise the Californium will decay into uselessness too quickly. I dunno, that does not seem to be a problem with a half-life of 2.645 years, and certainly not with 898 years.

## Meson Accelerator

In the science fiction role-playing game Traveller, the most potent starship weapon of all is the dreaded Meson Accelerator (MA). Before MA technology is developed, warship designs have lots of armor to protect them from hostile missile, laser, and particle beam weapon fire. After MA, warship designs omit armor in favor of more weapons, because armor is utterly worthless against MA fire. There is also a tendency to make lots of small warships instead a few large ones, in the pious hope this will prolong the life of your fleet. Or at least prolong it longer than the life of the enemy fleet.

As with all powerful Traveller starship weapons, MA are typically installed as a "spinal mount". MA are also marvelous as a planetary defense weapon. You can put MAs several kilometers below the planetary surface and still shoot at hostile orbiting spacecraft. The spacecraft will not be able to shoot through several kilometers of solid rock (unless they too are armed with MAs).

Later a star nation can develop the technology for the meson screen, which renders MA powerless (much like Kryptonite's all-or-nothing effect on Superman). Then warship design goes back to normal, except all designs must include a meson screen.

Why are meson accelerators so deadly? Because their method of action is so sneaky.

Some background. Nuclear physicists love to play with atom-smashers, particle accelerators, cyclotrons, and the like. These create subatomic particles (i.e., the component particles that atoms are made out of) and make them move really really fast in beam form. Yes, if you weaponize this, you have a particle beam weapon. Anyway, some kinds of particles are unstable, they have a short life-span. After a few nanoseconds they decay into other particles, radiation, or both.

Einstein's relativity, besides forbidding faster-than-light starships, also says that at speeds close to that of light, time will slow down. At about 90% the speed of light (0.9 c), the slowdown is about 2 (called the "gamma factor"). So if a particle has a life-span of 10 nanoseconds when sitting still (relative to you), when the particle is travelling at 0.9 c (relative to you) you will time it as having a life span of 20 nanoseconds or twice what it should be. At 0.95 c the life span will be 30 nanoseconds, at 0.98 c it will be 50 nanoseconds, and so on (see table here). This is yet another bit of weirdness from the screwy world of Einstein's relativity. Thanks, Albert.

Now in physics 101, you'll learn that distance equals rate times time. Our particle moving at 0.9 c has a rate of 269,813,212 meters per second. It has a time (life-span) of 20 nanoseconds or 0.00000002 seconds. Multiplying will show you that the particle will move a distance of about 5.396 meters before it decays. At 0.95 c, it will move 8.544 meters. At 0.98 c it will move 14.690 meters.

Your eyes are probably glazing over by now. The point is by altering the speed of the particle you alter the point in space where it decays.

So how do we weaponize this? Say we have a particle that easily passes through most matter in general (and starship armor in particular) but will eventually decay into a spray of deadly radiation. You aim your particle accelerator at the enemy starship, calculate the range between the accelerator and the enemy, then adjust the speed of the particles such that the point where they decay into deadly radiation is inside the center of the enemy starship. It is like teleporting a burst of radiation into the enemy ship's guts.

Now you see why the meson accelerator is so deadly.

Why the "meson" in "meson accelerator"? Because the people who wrote the Traveller RPG figured that the particle called the neutral pi-meson (pions) would work. They have a mean lifetime of 0.000000084 nanoseconds, and decay into a splendidly nasty spray of gamma rays, electrons and antimatter electrons.

Unfortunately, the meson accelerator shares the same problem with plasma weapons: they won't work. Anthony Jackson points out:

• Pions are stopped by armor (because they are affected by the strong nuclear force)
• Pions do not have a life span of exactly 0.000000084 nanoseconds. That is the half life. This means along the entire beam pions are decaying, by the time you reach 0.000000084 nanoseconds half of the pions in the beam have decayed. So there is not a pin-point dot where the pions decay, it is a gradual decay along the whole beam.
• If you can accelerate pions to such high velocities that the "decay point" is in a ship several million meters away, the particles will have so much energy that you don't have to use pions. At that energy, a beam of garden variety electrons will instantly vaporize any armor that is made out of matter. The gamma factor will be about 1016. This means every single one of the zillions of subatomic pions will have a blast energy of 2.16 × 105 joules. That's right, each single subatomic particle will have the energy of an antipersonnel land mine.

In defense of the authors of Traveller, much of this nuclear science had not been discovered at the time Traveller was written. Later version of the Traveller game try to retcon this by saying the meson accelerator was invented by George Meson, and it actually works by some hand-waving way, and has nothing to do with pions at all.

## Strangelet Bomb

Subatomic particles such as protons and neutrons are classified as hadrons. Unlike leptons, hadrons are composed of smaller particles called quarks, you may have heard of them.

Quarks come in six varieties, though pretty much all the matter you have ever come into contact with contained only "up" quarks and "down" quarks. The other varieties are charm, top, bottom, and strange. The other varieties all have more mass than the basic up and down quarks, so other quarks tend to decay into basic quarks.

Strange quarks are only a little bit more massive than up and down quarks. In all known strange-quark containing hadrons, the strange quark quickly decays as expected. But physicists Bodmer and Witten have formulated the Strange Matter Hypothesis, which implies that the decay may not happen if one has a large collection of quarks (a "Strangelet"). The theory predicts that the stable state would be an equal number of up, down, and strange quarks; instead of just up and down quarks. This is due to the Pauli exclusion principle, which I won't bore you with. Whether the Strange Matter Hypothesis is true or not depends upon the surface tension of strange matter. If it is large enough, the hypothesis is true. So far physicists have been unable to determine the value of its surface tension.

"So what?" I hear you grumble irritably. Well, this what:

Strangelets can infect ordinary matter, transforming it into more strangelets.

Does anybody remember the fictional Ice-nine from Kurt Vonnegut's novel Cat's Cradle? Drop a piece of the stuff into the Atlantic and soon all the water on Terra becomes solid and everybody dies. The word you are looking for is "chain-reaction."

If strange matter has a large enough surface tension, a larger collection is more stable than a smaller. In contact with ordinary matter, that matter will move to the more stable energy state, i.e., it will transform into more strange matter. And when matter moves to a more stable state, the excess energy is released (which is basically what powers a nuclear warhead).

Dr. Luke Campbell points out that for a chain reaction, the strangelets have to be negatively charged or neutral. If they are positively charged they will be repelled by positively charged atomic nuclei, and therefore cannot get close enough for infection.

So a speck of strange matter dropped on Terra will gradually consume it, converting it (and everybody living on it) into a hot lump of strange matter.

This is the reason why everybody was screaming about the the Relativistic Heavy Ion Collider (RHIC) experiment at Brookhaven and the Large Hadron Collider (LHC) at CERN. They were afraid one of the experiments would spit out a strangelet with results indistinguishable from a visit by Galactus. Most scientists think the possibility is far fetched, and the fact that you are alive to read these words shows that nothing has happened. So far.

Until the value of strangelet surface tension can be determined, we will not know if strangelet bombs are possible or not. But the idea has already been used in several science fiction stories, so the idea at least is close to being mainstream.

## Absorbic Bomb

This little nasty weapon is from The Killing Star by Charles Pellegrino and George Zebrowski. It isn't quite forbidden by the laws of physics, but it sure looks questionable.

When you get right down to it, the basis of most bombs is Einstein's good ol' E = mc2. A little bit of matter is convereted into lots and lots of energy, which causes an explosion and inflicts damage on the target. This applies equally well to a bomb based on dynamite, nuclear fission, nuclear fusion, or antimatter.

Pellegrino and Zebrowski wondered what would happen if you ran the equation in reverse? BOOM! and lots of energy is sucked up from the blast radius and converted into a bit of matter. Ground zero would suddenly be at zero Kelvin, with a bit of extra dust floating in the air. Behold the power of m = E / c2

They called it an "absorbic bomb."

## Ridiculous Handwavium

### Tractor Beams

Attractor beams are laser-like beams of energy that pull the target closer to your ship, while pressor beams push the target away. Pressors are also called "repulsors", "repellors", or "deflectors". Often a unit that can emit both attractor beams and pressor beams is called a "tractor" beam (though sometimes that term is just an abbreviation for attractor beam). Some authors call tractor beams "Traction Beams", which doesn't look right to me. Sounds like a ray you'd use on a patch of black ice to prevent your car from skidding.

These more or less totally science fictional (if you disregard things like using microscopic laser beams as optical tweezers to move microbes around) (maybe I spoke too soon. See articles below). Tractor Beams are like super-duper electromagnets, but much better. Electromagnets can only attract ferrous objects, while tractor beams can both attract and repel objects made of any material.

Magnets broadcast their attractive effect in all directions, all ferrous objects in the vicinity are drawn in. Tractor and pressor beams are beams, any object not actually struck by the beam is unaffected. Tractor beams can pluck one object out of a group and leave the others undisturbed.

Electromagnets attraction strength falls off as the 1/r4 inverse square law, while tractor beams tend to have absurdly long ranges (with the exception of the Geegee fields in Poul Anderson's TALES OF THE FLYING MOUNTAINS. They had a range of a few centimeters, so ships had to touch hulls in order to grapple each other).

Young readers may believe that tractor beams were invented by the writers of the original Star Trek (1966). Even younger readers may believe it made its first appearance in the movie Star Wars: A New Hope (1977). I've got news for you, the first example I found was the "Attractive Ray" featured in Edmund Hamilton's Crashing Suns, published in 1928!. "Attractor" and "Pressor" beams appear in E. E. "Doc" Smith's The Skylark of Space (1929). The term "tractor beam" appears to originate in E. E. "Doc" Smith's Spacehounds of IPC (1931).

In James White's novel Star Surgeon (1963) we find a weaponized version of the tractor-pressor beam, the so-called "Rattler." These weapons attract then repel the target at 80 gravities, several times a minute. When used on an entire ship, the hapless crewmembers are shaken like the dried beans in a baby's rattle. If focused down to just affect a small spot on the target's hull, the shear forces can rip the hull like it was wet cardboard. This was also used on C.C. MacApp's nearly forgotten and definitely underrated novel Recall Not Earth.

In the Exordium series by Sherwood Smith and Dave Trowbridge, "ruptors" fire unpolarized gravitons to shake their target to pieces. If you polarize the gravitons you have a tractor beam.

In E. E. "Doc" Smith's Lensman series, tractor beams are used to anchor the inertialess target so it can be damaged by weapon beams (otherwise the weapon beam pushes the intertialess ship away at lightspeed but does not harm it). In response, the enemy developed "tractor beam shears", which were planes of energy capable of "cutting" a tractor beam. Of course if your ship had more tractor beam projector than the target had tractor shears, the target was out of luck.

Doc Smith also implies that if you hit a ship with a attractor and a pressor beam, you can pin the ship at the distance where the force of the two beams balance. He also thinks that you can move the pinned ship laterally left and right by swinging the beam projectors, but that doesn't make sense to me.

Also in Doc Smith's Skylark series, the Osnomian hand guns are very silent, since bullets are propelled not with gunpowder, but by "force-field projection." So logically if one has tractor beams, one also has the equivalent of a railgun or coilgun. In MacApp's Recall Not Earth, tractor beams are used to launch torpedoes out of their tubes.

If you want some nice technobabble, a tractor beam can be hand-waved as a sort of laser using gravitons instead of photons.

#### Newton's Laws

In any event, pretty much all of the depictions of tractor beams totally ignore the fact that they must obey Newton's Third Law (i.e., the law of action and reaction). There are only two exceptions I am aware of. One exception is in TOM SWIFT AND THE RACE TO THE MOON, where the intrepid teenage inventor Tom uses his repelatrons for the propulsion system of his amazing spacecraft Challenger. Another is in the wargame Vector 3. In that game, your ship can use tractor beams to impose x, y, and z acceleration vectors on the enemy ship. However, due to Newton, your ship receives the same vectors in the opposite direction (e.g., if you give the enemy a +4 z acceleration, your ship receives a -4 z acceleration). Note that this only works if the two ships are of equal mass.

Anyway, Newtons says that if the starship Enterprise uses a tractor beam to reel in a Klingon battle cruiser, the Enterprise will also move towards the Klingon. Both will move towards the point called the Barycenter of the two ship system. In the same way if the Enterprise pushes away the Klingon, the Enterprise will also be pushed away from the barycenter.

The acceleration each ship will experience towards or away from the barycenter depends upon each ship's mass. Simply put: if ship Alfa has twice the mass of ship Bravo, it will be accelerated half as fast as ship Bravo. If an Imperial Star Destroyer tractors the Tantive IV, it will be accelerated about 1/110th as fast as the Tauntive. And if the Death Star tractors the Millenium Falcon, its acceleration will be so tiny as to be difficult to detect.

The actual equation is from Newton's Second Law:

a = F / m

where:

• a = ship's acceleration (m/sec)
• F = tractor beam energy (Newtons)
• m = ship's mass (kg)

If you want relative acceleration, use 1 for F and measure m in terms of the other ship's mass.

#### Calculating Movement

If you want to open up a real can of worms, you can try calculating what happens if the two ships are moving when the tractor beam is turned on. I am not going to try and calculate the minute to minute effects (because it is way above my pay grade) but the final results after the two ships come into contact can be approximated by the mathematics of a completely inelastic collision. This is the equivalent of figuring the trajectory of two balls of clay that collide and stick together. I will show the equations for figuring this in two dimensions, since I am unsure of my ability to expand it to three dimensions.

Given two spacecraft with masss of M1 and M2, velocities of V1 and V2, and vector directions angles of θ1 and θ2; when they are tractor beamed and drawn together into contact, calculate the combined ships velocity Vf and vector angle θf.

#### Tensegrity

E. E. "Doc" Smith was a big fan of attractor and pressor beams, using them in many of his space operas. For reasons that he did not go into, but which I think had to do with Newton's Laws, he sometimes had fleets use attractors and pressors to turn the entire fleet into one rigid object. I figure this gives the fleet immunity to hostile attractor beams. A solitary enemy ship trying to use an attractor on a rigid multi-ship fleet will be like you having a tug-of-war contest with a caterpillar tractor, with the cable looped through your nose-ring. The mass difference between the rigid fleet and the single enemy ship will see to that.

Anyway, in my long and misspent youth I was a fan of Doc Smith and a fan of a weird concept called Tensegrity. Tensegrity is where you have compression members (girders) held with tension members (cables) attached to the girder ends. The girders float in the air while not touching each other, held rigidly by the tension of the cables. I realized the two concepts could be combined.

In a tensegrity structure, you replace the girders with pressor beams, and the cables with attractor beams. The ships of the fleet occuply the girder ends. Instant Doc-Smithian rigid fleet! I mentioned this to Sean Barrett and he added it to GURPS: Lensman. It was only a single sentence, but I was tickled pink that it made the cut.

Now actually a tensegrity struture is not absolutely rigid. Under pressure the entire structure regularly contracts then expands. This is called "jitterbugging." This is probably a good thing, since structures that are too rigid tend to shatter instead of flexing a bit.

It is possible to make a minimal tensegrity structure, but this is not a good idea for something going into a combat situation. With a minimal structure, if one single attractor or pressor fails, the entire structure collapses. Best to have some redundant attractors and pressors to allow for combat damage.

Of course in a world without attractors and pressors there is no practical reason to want to make a rigid fleet in the first place. But after all this segment is in the "Ridiculous Handwavium" section.

### Protean Weapons

Protean weapons are ones that can transform from one weapon into another.

### Electromag Catalysis Poison

This one is total technobabble nonsense, but it is entertaining.

In James Blish's The Triumph of Time (fourth novel in the Cities in Flight series) the alien empire The Web of Hercules has spread from the Great Globular Cluster in Hercules to conquer the galaxy. They use the Web to destroy planets: beams of heavy nuclei of antimatter send from about one light-year distant. As they hit the planet's atmosphere, they make weird yellow-green glowing patches as they undergo matter-antimatter annihilation and bath the planet in a lethal bombardment of gamma radiation.

They attack the planet He, but the Hevians have a counter weapon.

### Medusa Weapons

This is totally utterly science fictional with no basis in reality, but it is too amusing not to mention. Remember the Greek myth about the Medusa? Anyone unfortunate enough to look at the Medusa was turned into stone, such was her extreme ugliness. The science fictional version is an image on a monitor or a sound over a headphone that can kill.

The general idea is a person suffering physical or mental damage merely by experiencing what should normally be a benign sensation.

The closest thing to this in the real world are the flashing lights that can trigger a seizure in a person suffering from photosensitive epilepsy. But that is not quite the same thing as a medusa weapon. You may have read about the Denno-Senshi Porygon episode of the TV show Pokémon, where the cartoon flashed the TV screen in such a manner that several viewers had seizures. Mention of such a seizure-inducing flash can be found in the novel and movie of The Andromeda Strain. In 2008 there was a photosensitive epilepsy attack on the on-line forum for the nonprofit Epilepsy Foundation.

#### Examples

Blit

In the story "Blit" and others by David Langford, some scientist, who should know better, invents a graphic pattern called a "basilisk" that will cause the viewer's brain to lock-up, killing the viewer instantly. It works much like a computer virus, crashing the brain's operating system.

As the FAQ puts it:

The Cassini Division

In the novel by Ken MacLeod, one of the weapons is the so-called "Langford Visual Hack" (an obvious tip-of-the-hat to David Langford). As a defense, all computer monitors on the ship are designed to contain enough visual static to prevent the visual hack from working.

ST:TNG "I, Borg"

In this episode the valiant crew of the Starship Enterprise plan to kill all the Borg by introducing a lethal computer virus, an invasive program called the topological anomaly. This is a a paradoxical geometric form designed to overwhelm a computer's processing functions by spawning an infinite number of interlocking anomalous solutions.

War Against The Rull

In the novel by A.E. van Vogt, the alien Rull can draw the "lines-that-could-seize-the-minds-of-men". Any human who looks at such a diagram is instantly hypnotized, and will just stand there in a trance.

The Black Cloud

In the novel by Fred Hoyle, a helpful intelligent interstellar nebula attempts to teach a human being its native language with remote controlled audio-visual equipment. This proved to be fatal the the person. The trouble is that humans know to be true too many things that actually are not true. They have to un-learn too much in order to learn the alien language, and the cognitive dissonance is fatal (it causes an inflammation of brain tissue).

Macroscope

In the novel by Piers Anthony scientists discover an alien interstellar broadcast that is sort of a galactic library. Unfortunately for the scientists, the broadcast is overlayed with the "Destroyer Sequence." This is a visual sequence that forces the brain to think certain thoughts it is not able to think, which burns out the brain leaving the hapless victim mentally a vegetable.

Kaleidoscope Century

In the novel by John Barnes, a rogue artificial intelligence can call a person up on a telephone, then use rapidly changing audio signals to reprogram the person's brain, turning them into a brainwashed zombie.

Battlefleet Mars

In the wargame by Redmond Simonsen, a top executive of the Ares corporation is assassinated by a sonic pulse over the telephone.

## Atomic Rockets notices

This week's featured addition is SPIN POLARIZATION FOR FUSION PROPULSION

This week's featured addition is INsTAR

This week's featured addition is NTR ALTERNATIVES TO LIQUID HYDROGEN