One of the common features of an epic is the "fabulous loci" for the hero to visit. Fantasy novels can have some loci that are quite pretty or terrifying, but science fiction has some that will make your jaw hit the floor. Try comparing the land of Fairie with a ring around a sun with a radius of an entire astronomical unit and a livable surface area of three million times Terra.

Some of them are even from reality, e.g., Saturn's Rings.

This entire page counts as backgrounds and plot ideas for science fiction authors.

The Lost Spaceship

A nice standard location is a famous mysterious lost spaceship, especially if it is full of treasure or something. This is commonly part of a treasure hunt story, with the protagonists searching for the ship in order to discover the Dread Secret of its disappearance. In many stories the lost spaceship also has the answer to some old mystery, typically something that the political powers that be would prefer to remain secret because it would shake things up. Examples include The Ghost Line: The Titanic of the Stars by Andrew Neil Gray, J.S. Herbison, All Cats Are Gray by Andre Norton, and A Talent for War by Jack McDevitt.

And in others it turns out that there is a blasted good reason the ship is lost, because there is Something Awful lurking inside. The protagonists who discover the ship are quick to regret it. Examples include Alien, Event Horizon, The Dark Side of the Moon, and ST:TOS Space Seed; which contain respectively the Xenomorph, a Gate To Hell, The Devil and Khan Noonien Singh.

If there are a huge number of lost spaceship, this turns into a Sargasso of Space.

If this is more a Mary Celeste situation (protagonists are not looking for a ship but unexpectedly encounter a recently deserted ship with hot food still on plates), it is called a Ghost Ship. Examples include Polaris by Jack McDevitt, ST:TOS The Tholian Web, The Black Hole, and 2010: Odyssey Two. In the movie Sunshine the Icarus I initially appears to be a Ghost Ship but it is actually a ship with Something Awful lurking inside.

If the ship has been traveling for centuries (sometimes containing a miserable crew that cannot escape), it is called a Flying Dutchman. Examples include Firebird by Jack McDevitt and Andromeda "The Mathematics of Tears".


For I was there, right in the Rigel Royal, when it all began on the night that Cliff Moran blew in, looking lower than an antman’s belly and twice as nasty. He’d had a spell of luck foul enough to twist a man into a slug-snake and we all knew that there was an attachment out for his ship. Cliff had fought his way up from the back courts of Venaport. Lose his ship and he’d slip back there—to rot. He was at the snarling stage that night when he picked out a table for himself and set out to drink away his troubles.

However, just as the first bottle arrived, so did a visitor. Steena came out of her corner, Bat (the cat) curled around her shoulders stole-wise, his favorite mode of travel. She crossed over and dropped down without invitation at Cliff’s side. That shook him out of his sulks. Because Steena never chose company when she could be alone. If one of the man-stones on Ganymede had come stumping in, it wouldn’t have made more of us look out of the corners of our eyes.

She stretched out one long-fingered hand and set aside the bottle he had ordered and said only one thing, “It’s about time for the Empress of Mars to appear again.”

Cliff scowled and bit his lip. He was tough, tough as jet lining—you have to be granite inside and out to struggle up from Venaport to a ship command. But we could guess what was running through his mind at that moment. The Empress of Mars was just about the biggest prize a spacer could aim for. But in the fifty years she had been following her queer derelict orbit through space many men had tried to bring her in—and none had succeeded.

A pleasure-ship carrying untold wealth, she had been mysteriously abandoned in space by passengers and crew, none of whom had ever been seen or heard of again. At intervals thereafter she had been sighted, even boarded. Those who ventured into her either vanished or returned swiftly without any believable explanation of what they had seen—wanting only to get away from her as quickly as possible. But the man who could bring her in—or even strip her clean in space—that man would win the jackpot.

“All right!” Cliff slammed his fist down on the table. “I’ll try even that!”

Steena looked at him, much as she must have looked at Bat the day Bub Nelson brought him to her, and nodded. That was all I saw. The rest of the story came to me in pieces, months later and in another port half the System away.

Cliff took off that night. He was afraid to risk waiting—with a writ out that could pull the ship from under him. And it wasn’t until he was in space that he discovered his passengers—Steena and Bat. We’ll never know what happened then. I’m betting that Steena made no explanation at all. She wouldn’t.

It was the first time she had decided to cash in on her own tip and she was there—that was all. Maybe that point weighed with Cliff, maybe he just didn’t care. Anyway the three were together when they sighted the Empress riding, her dead-lights gleaming, a ghost ship in night space (dead-lights signal "danger, stay out!").

She must have been an eerie sight because her other lights were on too, in addition to the red warnings at her nose. She seemed alive, a Flying Dutchman of space.

(ed note: and yes, there is Something Awful on board)

From ALL CATS ARE GRAY by Andre Norton (1953)

But Van Rycke was not just a machine of facts and figures, he was also a superb raconteur, a collector of legends who could keep the whole mess spellbound as he spun one of his tales. No one but he could pay such perfect tribute to the small details of the eerie story of the New Hope, the ship which had blasted off with refugees from the Martian rebellion, never to be sighted until a century later — the New Hope wandering forever in free fall, its dead lights glowing evilly red at its nose, its escape ports ominously sealed — the New Hope never boarded, never salvaged because it was only sighted by ships which were themselves in dire trouble, so that "to sight the New Hope" had become a synonym for the worst of luck.

Then there were the "Whisperers", whose siren voices were heard by those men who had been too long in space, and about whom a whole mythology had developed.

Van Rycke could list the human demi-gods of the star lanes, too. Sanford Jones, the first man who had dared Galactic flight, whose lost ship had suddenly flashed out of Hyperspace, over a Sirius world three centuries after it had lifted from Terra, the mummified body of the pilot still at the frozen controls, Sanford Jones who now welcomed on board that misty "Comet" all spacemen who died with their magnetic boots on. Yes, in his way, Van Rycke made his new assistant free of more than one kind of space knowledge.

From SARGASSO OF SPACE by Andre Norton (1955)

Sargasso of Space

In old pulp science fiction there is a long history of taking a dramatic and comfortable metaphor and transporting it intact into the outer space environment. Generally the author has to savagely pound a square peg into a round hole, with regrettable results. The classic horrible example is deep space fighter aircraft.

Most pulp falls for the old Space Is An Ocean fallacy along with the related misconceptions.

Many pulp writers figured they were the first to have the bright idea of transplating the colorful legend of the dreaded Sargasso Sea into science fiction. A deadly area of space that somehow traps spaceships who venture too close, only to join the deadly graveyard of lost ships. And not just human ships, a couple stories mention humans discovering wrecks of unknown alien spacecraft mixed in with the conventional ships. The graveyard typically contains everything from recent ships all the way back to historical ships dating to the dawn of space flight.

Some stories populate the graveyard of dead ships with castaways. Who will probably be interested in looting your ship of any supplies it contains.

The original legend dates back to when line-of-sight was limited to the horizon, so a sailing vessel poking at the edge of the sargasso could not see the interior. Not without being caught, that is.

With the invention of radar and the realization that there ain't no horizon in space, writers realized they'd have to make the space sargasso sea more invisible. Usually they'd add on the legend of the Bermuda Triangle in the form of an intermittent "hole in space" leading to a pocket universe. Some kind of wormhole or stargate that would transport the hapless spacecraft to a graveyard of lost ships safely out of sight.

Obviously this is highly unlikely to happen in the real world. But it sure is romantic, in a sci-fi pulp fiction sort of way.

THE SARGASSO OF SPACE by Edmond Hamilton (1931)
The sargasso here is apparently the Neptune-Sol L5 point. Disabled spacecraft who drift into the point will be trapped, which is sort of true. The author does not explain why this is not true of the L4 and L5 points of every single planet in the solar system. He calls the graveyard of lost ships the "wreck-pack", and the gravitational attraction of the wrecks keep ships from drifting out.
CALLING CAPTAIN FUTURE by Edmond Hamilton (1940)
In this novel, the sargasso of space is created by ether-currents in the luminiferous aether. The latter is a concept that was disproved by Michelson and Morley in 1887, but most of the readers didn't know that. The ether-currents form sort of a one-way whirlpool which sucks hapless spacecraft into the graveyard of lost ships trapped in the eye of the storm. Captain Future escapes by cannibalizing engine and atomic fuel from the other derelict ships, an idea that apparently didn't occur to any of the prior castaways. He has a side adventure when he stumbles over an alien spacecraft full of aliens in suspended animation. The "adventure" part comes in when Captain Future discovers the octopoid creatures are space vampires and they start to wake up.
SARGASSO OF LOST STARSHIPS by Poul Anderson (1952)
Superstition says that the Black Nebula is haunted. Certainly strange things happen to hyperdrive starships who venture too close. Things like hallucinations, ghostly whispering voices ("Spaceman, go home. Turn back, adventurer. It is death."), electrical gear malfunctioning. Many dissappear, so prudent ship captains give the Nebula a wide berth. The cause of all this is an ancient race of Elf-like psionic aliens living on a planet near the Nebula's center.
SARGASSO OF LOST CITIES by James Blish (1953)
The spacegoing cities of CITIES IN FLIGHT gather in the sargasso for reasons that have less to do with physics and more with economics. The antigravity Okie cities are sort of the migrant laborers of the galaxy. The stellar currency is based on germanium, some idiot figure out how to synthesize it and inadvertenly obliterated the economy of the entire galaxy. Since everybody is now broke, the flying cities cluster in what is basically an interstellar hobo jungle.
SARGASSO OF SPACE by Andre Norton (1955)
The valiant free traders of the good ship Solar Queen obtain the trading rights to the dead planet with the cheery name "Limbo". When they visit they learn the planet has a still-working alien installation created by forerunners which can grab passing spacecraft and crash them onto the graveyard of lost ships. As it turns out a crime syndicate wants to utilize the installation for fun and profit, so hilarity ensues.
THE GRAVEYARD OF SPACE by Milton Lesser (1956)
The graveyard of space is a ball of dead spacecraft orbiting in the asteroid belt. Apparently it started as a small sphere of neutronium or other dense material. As derelict ships stuck to it by gravitational attraction the total gravity grew. It is only a menace to ships with broken engines or no fuel. The planetary governments keep talking about blasting it and salvaging the metal but can never agree on the details. Our heroes accidentally crash into it, breaking their Gormann series eighty radarscope. They cannot escape without one. So they start investigating the ships of the graveyard hoping to scavange a replacement. That's when they discover the hard way that anybody trapped in the graveyard will have to resort to cannibalism in order to survive, and who will treat them like the unexpected arrival of fresh meat on the hoof.
THE STARS MY DESTINATION by Alfred Bester (1956)
The protagonist Gulliver Foyle encounter the Sargasso Asteroid, a body in the main asteroid belt built entirely from the hulks of abandonned spaceships.
TIME TRAP episode of Star Trek Animated (1973)
The Starship Enterprise and a Klingon battle cruiser become trapped in the "Delta Triangle", an almost not disguised reference to the Bermuda Triangle. A hole in space drops them in to a pocket universe answering to a sargasso sea, and packed with the graveyard of lost starships. They find the centuries-old Starship Bonaventure, first starship with warp drive. But all the crew of all the ships are still alive, since people age slowly inside the sargasso, and antimatter lasts a long time. The Enterprise and the Klingon escape by hot-wiring their engines together, though true to form the dastardly Klingons try last minute treachery.
DRAGON'S DOMAIN epsiode of Space 1999 (1975)
In a flashback, Tony Cellini remembers when he was on the Ultra Probe to the newly discovered planet Ultra. Nearby they encounter a cluster of drifting abandoned alien ships. They discover why the ships are abandoned when an unconvincing octopoid monster with one eye and a firey maw materializes and starts to eat the crew.
THE METAMORPH epsiode of Space 1999 (1976)
Mentor of the planet Psychon needs to abduct sentient beings so he can drain their mental energy into his diabolical biological computer. He uses magnetic force to drag down to the planet any spacecraft that pass by, creating a large graveyard of lost ships nearby his operation.
DEADLY REUNION (Star Wars Comic) by Archie Goodwin (1981)
The Graveyard of Lost Ships was a collection of starships which were drawn into orbit around a collapsed dwarf star by Doctor Arakkus. The Graveyard consisted of five interconnected rings of ships all of which had been lured to the Graveyard with distress calls, in an attempt to make others suffer as he had suffered. The ships were trapped in the Graveyard by the gravitational pull of the dwarf star. Incapable of escaping its grasp, the ships slowly began to plunge into the star, while most of the crews went insane and committed suicide. But Han Solo, Luke Skywalker, and Chewbakka put a stop to this.
MÖBIUS DICK episode of Futurama (2011)
The Planet Express makes the mistake of taking a short-cut through the Bermuda Tetrahedron (an almost not disguised reference to the Bermuda Triangle) and land in a graveyard of lost spacecraft. The graveyard includes many media science fiction ships as joke references, including Discovery One from 2001 A Space Odyssey, Oceanic Airlines Flight 815 from Lost, the Satellite of Love from Mystery Science Theater 3000, the Jupiter II from Lost In Space, the ship from Josie and the Pussycats in Outer Space, the ship from the album covers of Electric Light Orchestra and Boston, an Apollo Lunar Module, an Apollo Command and Service Module, and Skylab.

      "The dead area," Crain told them, "is a region of space ninety thousand miles across within Neptune's orbit, in which the ordinary gravitational attractions of the solar system are dead. This is because in that region the pulls of the sun and the outer planets exactly balance each other. Because of that, anything in the dead-area, will stay in there until time ends, unless it has power of its own. Many wrecked space-ships have drifted into it at one time or another, none ever emerging; and it's believed that there is a great mass of wrecks somewhere in the area, drawn and held together by mutual attraction."
     "Wreck-pack in sight ahead!"
     "We've arrived, anyway!" Kent cried, as he and Crain hastened up into the pilot house. The crew was running to the deck-windows.
     "Right ahead there, about fifteen degrees left," Liggett told Kent and Crain, pointing. "Do you see it?"
     Kent stared; nodded. The wreck-pack was a distant, disk-like mass against the star-flecked heavens, a mass that glinted here and there in the feeble sunlight of space. It did not seem large, but, as they drifted steadily closer in the next hours, they saw that in reality the wreck-pack was tremendous, measuring at least fifty miles across.
     Its huge mass was a heterogeneous heap, composed mostly of countless cigar-like space-ships in all stages of wreckage. Some appeared smashed almost out of all recognizable shape, while others were, to all appearances unharmed. They floated together in this dense mass in space, crowded against one another by their mutual attraction.
     There seemed to be among them every type of ship known in the solar system, from small, swift mail-boats to big freighters. And, as they drifted nearer, the three in the pilot-house could see that around and between the ships of the wreck-pack floated much other matter—fragments of wreckage, meteors, small and large, and space-debris of every sort.
     "Lord, who'd have thought there were so many wrecks here!" Kent marvelled. "There must be thousands of them!"
     "They've been collecting here ever since the first interplanetary rocket-ships went forth," Crain reminded him. "Not only meteor-wrecked ships, but ships whose mechanisms went wrong—or that ran out of fuel like ours—or that were captured and sacked, and then set adrift by space-pirates."
     In those hours Kent and Crain and all in the ship watched with a fascinated interest that even knowledge of their own peril could not kill. They could see swift-lined passenger-ships of the Pluto and Neptune runs shouldering against small space-yachts with the insignia of Mars or Venus on their bows. Wrecked freighters from Saturn or Earth floated beside rotund grain-boats from Jupiter.
     The debris among the pack's wrecks was just as varied, holding fragments of metal, dark meteors of differing size—and many human bodies. Among these were some clad in the insulated space-suits, with their transparent glassite helmets. Kent wondered what wreck they had abandoned hastily in those suits, only to be swept with it into the dead-area, to die in their suits.

From THE SARGASSO OF SPACE by Edmond Hamilton (1931)

      Captain Future fought to break clear of this strong, invisible current, but the rocket-tubes seemed utterly powerless. At appalling speed, the space-boat was whirled through the void.
     He realized the terrible peril into which they had fled. Its nearness had been haunting him during all this time.
     "The cruiser has given up the pursuit!" Joan cried joyfully. "They're turning back – leaving us!"
     Captain Future's tanned face was grim. "They're doing so because they don't want to be trapped as we're trapped."
     "Trapped?" cried Kansu Kane. "What do you mean?"
     "We can't get out of this ether-current," Curt gritted. "It's too strong. And its whirling us on into the most dangerous spot in space, one from which no interplanetary ship has ever escaped."
     Joan's hand went to her throat. "You mean –" Captain Future nodded grimly.
     "Yes. We're being carried into the Sargasso Sea of Space."
     The Sargasso Sea of Space! The legendary, mysterious peril to navigation that was dreaded by every spacesailor in the System!
     Joan Randall's pretty face was pale and stricken, and little Kansu Kane stared bewilderedly, as Captain Future told them that their space-boat was being drawn into that deadly trap.
     The space-boat was still being carried at frightful speed through the void by the ether-current gripping it. The Legion of Doom cruiser, recoiling from the danger, had vanished.
     "It's my fault," Curt Newton said, his tanned face self-accusing. "I knew from the currents that we were getting near the Sargasso. But I thought I could escape it and shake off pursuit."
     "You were wonderful to get us out of that ship!" Joan cried loyally to the red-haired scientific wizard. "And you'll get us out of the Sargasso – I know you will."
     "What is this Sargasso of Space you're talking about?" Kansu Kane demanded. "I'm no space-sailor – I never heard of it."
     "You know what an ether-current is, don't you?" Captain Future asked him. "Well, there are many strong ether-currents, strange running tides in the luminiferous ether itself, out in this part of the System. They all flow into a central vortex, and anything that is carried into the vortex can't get out again, against the currents. That central vortex is the Sargasso Sea of Space."
     Curt reached for the throttles. "I'll try once more to break out of the current," he muttered. "But I'm afraid –"
     He opened the throttles to the limits. It was futile. The power was not enough to get them out of the remorseless grip of the ether-current that was sweeping them fatally on into a dreaded, unknown region of space.
     Captain Future shut off the rockets. "No go," be said, shaking his red head. "Might as well save our power, until we get into the central vortex. Then we'll see what we'll see."
     Clinging for support, they felt their craft batted about by titanic, unseen tides. Everything was topsy- turvy.
     Then, after terrifying minutes of chaotic movement, the space-boat seemed to enter smooth. undisturbed space. It floated now as placidly as though on a millpond.
     "Why, we're out of the currents now." Kansu Kane faltered, peering out with myopic eyes.
     "We've escaped from the Sargasso?" Joan cried joyfully to Captain Future.
     Curt shook his bead. "I'm sorry to disillusion you. We've reached the dead-center of the whirlpool of currents, an area of undisturbed space at the heart of this space-maelstrom."
     He opened the throttles, starting up the rockets. "We'll try to buck our way back out, but I'm pretty sure it's useless."
     Rockets flaming, the little boat shot back in the direction from which it had come. In a half-minute it plunged again into the titanic, invisible ether-currents. The currents grasped the craft once more and flung it like a toy back into the dead-center.
     "Thought so," Curt muttered. "We're in here to stay, unless we can devise enough new power to carry us out."
     "Where do you expect to find any additional source of power in this empty hole in space?" Kansu asked hopelessly.
     "There," said Captain Future quietly, pointing ahead.
     They stared. Far ahead, avast jumbled metal mass floated motionless in space. The mass was lenticular in shape, and hung at the very center of the dead-area here in the maelstrom.
     As their craft hummed closer, they saw that this farflung, jumbled mass was a great aggregation of space ships and debris of all descriptions. All this flotsam was held together by its own slight mutual gravitation.
     "What is it?" Joan Randall whispered awedly.
     "It is the graveyard of space ships," Curt said. "The last resting-place of every ship that has been sucked into the Sargasso Sea of Space since interplanetary travel began. No ship has ever escaped here – all that blundered in are still here."
     In the pack were space ships of every kind that had ever sailed the System. Great Jovian grain-boats, dumpy Martian freighters, streamlined liners from the Neptune and Uranus routes, black cruisers of the Planet Police, ominously armed pirate ships, even small spaceyachts. These dead ships floated, rubbing slowly against each other's sides. And between and among them floated all kinds of interplanetary debris that had been swept into the maelstrom – meteors large and small, fragments of splintered asteroids, bits of metal wreckage, and stiff, space-suited bodies of dead men who perhaps had floated in the void for years before drifting into this last resting place.
     Unutterably awe-inspiring was the sight, here in the thin, pale sunlight of outer space. Here was the end of many a brave-hearted voyage. Here many a good ship that had once throbbed from world to world had come to peace and quiet at last. Here was a Valhalla of space ships and space-men. whose eternal tranquility and silence would not be disturbed until the System ended.
     "Do you think there are any living people in those ships, Captain Future?" asked Joan Randall in a low voice.
     "I'm afraid there's no chance of that. The air-supply of any ship that drifted in here would soon be exhausted, and then any living people aboard would die."
     "Then we will perish when our boat's air-tanks are empty?' the girl cried. "Only two days from now?"
     "We're going to try to get out of here before then"' Curt said grimly. "There's just a chance that if we fitted up this space-boat with additional cyclotrons taken from some of these wrecks, it would give us enough power to fight out through the currents. We'll have to go through the wrecks first and see if we can find enough cyclotrons in good condition," he added.

     Curt stared. She was pointing at a strange object several ships away. It was a cylinder of blank gray metal several hundred feet long, without the lines of a ship at all.
     "I don't know – it's certainly no space ship of our System," Curt declared. "It may be from outside the System – a queer wreck out of interstellar space that drifted into the System and was caught here in the Sargasso." His gray eyes kindled with scientific interest. "We'll take a look. Come on, Joan."
     They started toward the enigmatic cylinder. But they stopped again, before they reached it. stricken with wonder by the appearance of the craft that floated next to it.
     This was a space ship of ridiculously small size and flimsy appearance. It was crudely designed, with projecting rocket-tubes of an ancient, inefficient type. The little vessel was the most antiquated and obsolete of any they had seen yet.
     "Why, it looks like one of the first space ships that was ever built!" Joan cried. "Could men ever have sailed space in a craft like that?"
     Curt's tanned face was suddenly tense and strange. "I've an idea I know what craft this is," he said. "Yes, I'm right-look at the name on its bows!" The name was Pioneer III.
     "Pioneer III?" cried Joan. "Why, that was the ship of Mark Carew, the first man ever to –"
     "The first man ever to sail beyond Jupiter," Captain Future finished softly, staring almost in reverence at the clumsy little craft. "Mark Carew, the second great trailblazer of space – the man who first visited Saturn and Uranus and Neptune, and who was lost in space in a later voyage. And this is where he was lost, here in the Sargasso."

(ed note: in other words a historical ship dating to the dawn of space flight)

     Next moment, he stiffened inside his space suit and heard a sharp cry from Joan. A door was opening in the cylinder.
     It opened like the iris shutter of a camera, expanding from a tiny aperture into a circular opening ten feet across.
     "What opened that door?" cried the girl, panic-stricken. "We weren't even near it."
     Curt's gray eyes flashed. "That door must be telepathically operated—when I wished a door would open, it opened!"

From CALLING CAPTAIN FUTURE by Edmond Hamilton (1940)

      Five years. Five years ago Barbara Jean Ramsey and their son Harold were due back from Meiji. Superstitiously, Bart had waited for them before accepting his promotion... Barbara Jean had never come home from Meiji. Her ship had taken a new direct route along an Alderson path just discovered. It never came out into normal space. A scoutcraft was sent to search for the liner, and Senator Grant (Barbara's father) had enough influence to send a frigate after that. Both vanished, and there weren’t any more ships to send.

     “You got five forces in this universe we know about, ja? Only one of them maybe really isn’t in this universe; we do not quibble about that, let the cosmologists worry. Now we look at two of those forces, we can forget the atomics and electromagnetics. Gravity and the Alderson force, these we look at. Now you think about the universe as flat like this table, eh?” He swept a pudgy hand across the roseteak surface. “And wherever you got a star, you got a hill that rises slowly, gets all the time steeper until you get near the star when it’s so steep you got a cliff. And you think of your ships like roller coasters. You get up on the hill, aim where you want to go, and pop on the hyperspace drivers. Bang, you are in a universe where the Alderson effect acts like gravity. You are rolling downhill, across the table, and up the side of the next hill, not using up much potential energy, so you are ready to go again somewhere else if you can get lined up right, O.K.?”
     Ramsey frowned. “It’s not quite what we learned as middies—you’ve got ships repelled from a star rather than—”
     “Ja, ja, plenty of quibble we can make if we want to. Now, Captain, how is it you get out of hyperspace when you want to?”
     “We don’t,” Ramsey said. “When we get close enough to a gravity source, the ship comes out into normal space whether we want it to or not.”
     Stirner nodded. “Ja. And you use your photon drivers to tun around in normal space where the stars are like wells, not hills, at least thinking about gravities. Now, suppose you try to shoot past one star to another, all in one jump?”
     “It doesn’t work,” Ramsey said. “You’d get caught in the gravity field of the in-between star. Besides, the Alderson paths don’t cross each other. They’re generated by stellar nuclear activities, and you can only travel along lines of equal flux. In practice that means almost line of sight with range limits, but they aren’t really straight lines. . . .”
     “Ja. O.K. That’s what I think is happening to them. I think there is a star between A-7820 and 82 Eridani, which is the improbable name Meiji’s sun is stuck with.”
     “Now wait a minute,” Admiral Torrin protested. “There can’t be a star there, Professor. There’s no question of missing it, not with our observations. Man, do you think the Navy didn’t look for it? A liner and an explorer class frigate vanished on that route. We looked, first thing we thought of.”
     “Suppose there is a star there but you are not seeing it?”
     “How could that be?” Torrin asked.
     “A Black Hole, Admiral. Ja,” Stirner continued triumphantly. “I think Senator Grant fell into a Black Hole.”

     “Then how would Black Holes interact with—oh,” Rap Torrin said, “gravity. It still has that.”
     Stirner’s round face bobbed in agreement. “Ja, ja, which is how we know is no black galaxy out there. Would be too much gravity. But there is plenty of room for a star. Now one thing I do not understand though, why the survey ship gets through, others do not. Maybe gravity changes for one of those things, ja?”
     “No, look, the Alderson path really isn’t a line of sight, it can shift slightly—maybe just enough!” Torrin spoke rapidly. “If the geometry were just right, then sometimes the Hole wouldn’t be in the way. . . .”
     “O.K.,” Stirner said. “I leave that up to you Navy boys. But you see what happens, the ship is taking sights or whatever you do when you are making a jump, the captain pushes the button, and maybe you come out in normal space near this Black Hole. Nothing to see anywhere around you. And no way to gets back home.”
     “Of course.” Ramsey stood, twisted his fingers excitedly. “The Alderson effect is generated by nuclear reactions. And the dark holes—”
     “Either got none of those, or the Alderson force stuff is caught inside the Black Hole like light and everything else. So you are coming home in normal space or you don’t come home at all.”

(ed note: in other words the ships fell into the interstellar Bermuda Triangle and are currently caught in the Sargasso Sea of Space)

     “Which is light-years. You’d never make it.” Ramsey found himself near the bar. Absently he poured a drink. “But in that case—the ships can sustain themselves a long time on their fuel!”
     “Yes.” Lermontov said it carefully. “It is at least possible that Senator Grant is alive. If his frigate dropped into normal space at a sufficient distance from the Black Hole so that it did not vanish down.”
     “Not only Martin,” Bart Ramsey said wonderingly. His heart pounded. “Barbara Jean. And Harold. They were on a Norden Lines luxury cruiser, only half the passenger berths taken. There should have been enough supplies and hydrogen to keep them going five years, Sergei. More than enough!”

(ed note: Spoiler: a rescue mission is sent. The only way to get back is to somehow generate a large nuclear reaction to create the Alderson effect. Crashing one of the trapped starships on the Black Hole will work. Unfortunately this is even more difficult that crashing a ship onto the Sun: the intense gravity will make the ship miss if you are a fraction of a degree off. Which means some brave volunteer will have to sacrifice themself to save the others, manually piloting the ship into a collision while the rescue ship is poised to jump. The rescue ship waits with their Alderson drive turned on, when the crashing ship creates the Alderson effect the drive will have something to make the ship jump.)

From HE FELL INTO A DARK HOLE by Jerry Pournelle (1973)

Space Trees

I knew about Dyson Trees but I had no idea that there were enough instances of space-going trees in science fiction that they were considering making it into a TV Tropes entry. They certainly are in Orion's Arm.

The idea is to make a space habitat or spacecraft out of a tree. Not out of wood, but out of a living tree. Now, of course you'll have to genetically engineer the tree so it can live in the vacuum of space, but there is certainly is plenty of sunlight in space to make a plant very happy. Add a comet or other source of volatile gases and the tree will have all it needs. Then all you have to do is tinker with its genes so it naturally grows a habitat module suitable for humans to live in, and you are all set.

Now, a tree might not be a durable as a habitat made out of titanium or something, but it does have all the advantages of an organic object. Self-healing, does not need repair technicians or imported spare parts, self-reproducing, that sort of thing. But from a science fiction author's point of view they are a very romantic and fabulous location. Perfect for space elves or other mythological creatures that traditionally live in trees.


A Dyson tree is a hypothetical genetically-engineered plant (perhaps resembling a tree) capable of growing in a comet, suggested by the physicist Freeman Dyson. Plants could produce a breathable atmosphere within hollow spaces in the comet (or even within the plants themselves), utilising solar energy for photosynthesis and cometary materials for nutrients, thus providing self-sustaining habitats for humanity in the outer solar system analogous to a greenhouse in space or a shell grown by a mollusc.

A Dyson tree might consist of a few main trunk structures growing out from a comet nucleus, branching into limbs and foliage that intertwine, forming a spherical structure possibly dozens of kilometers across.

From the Wikipedia entry for DYSON TREE

Examples of space trees in science fiction include:

  • Manifold: Space by Stephen Baxter (the protagonist finds himself in a dyson tree at one point)
  • The Dirty Pair (in the episode "Run From the Future" there is an outlaw habitat called Nimkasi which is a dyson tree)
  • The Fountain movie (the "space traveler" sections are set in a space-going tree)
  • The Genesis Quest series by Donald Moffitt (he calls them "Space Poplars", the spacecraft version have silver leaves used as organic solar sails)
  • Orion's Arm (dyson trees and dyson tree "forests" are called orwoods)
  • Tree House by Rachel Pollack
  • Comet by Carl Sagan and Ann Druyan (not science fiction, science fact)
  • Absolution Gap by Alastair Reynolds (the "Greenfly" infestation that is depicted taking over the galaxy in Absolution Gap is shown to be billions of self-contained biospheres containing trees and tree-like plants.)
  • Hyperion by Dan Simmons (the Ousters fly around in "Treeships". The main one is of course named Yggdrasil)
  • Vacuum Flowers by Michael Swanwick (in the story "dysonsworlders" have established tree settlements in the Oort Cloud)
  • Tenchi Muyo (the Jurai utilize trees that can live in space as ships)
  • Transhuman Space roleplaying game (includes a dyson tree endeavour on Yggdrasil Station)

Vaguely related tree concepts include: Larry Niven's Stage Trees and Integral Trees, and Marshall Savage's The Millennial Project section Avalon.


An arcology is a titanic multi-level building containing a population of around one hundred thousand people who live, work, and play without ever leaving the building. These were popular in science fiction in the latter half of last century, back in the days when people were frightened that our civilization would be destroyed by runaway overpopulation. Nowadays in industrialized nations, people have started worrying about the opposite. Apparently this has caused science fiction stories about arcologies to become unfashionable.


Arcology, a portmanteau of "architecture" and "ecology", is a field of creating architectural design principles for very densely populated, ecologically low-impact human habitats.

The term was coined by architect Paolo Soleri, who posited that a completed arcology would provide space for a variety of residential, commercial, and agricultural facilities while minimizing individual human environmental impact. These structures have been largely hypothetical insofar as no arcology, even one envisioned by Soleri himself, has yet been built.

The concept has been popularized by various science fiction writers. Authors such as Peter Hamilton in Neutronium Alchemist and Paolo Bacigalupi in The Water Knife explicitly used arcologies as part of their scenarios. They are often portrayed as self-contained or economically self-sufficient.


An arcology is distinguished from a merely large building in that it is designed to lessen the impact of human habitation on any given ecosystem. It could be self-sustainable, employing all or most of its own available resources for a comfortable life: power; climate control; food production; air and water conservation and purification; sewage treatment; etc. An arcology is designed to make it possible to supply those items for a large population. An arcology would supply and maintain its own municipal or urban infrastructures in order to operate and connect with other urban environments apart from its own.

Arcology was proposed to reduce human impact on natural resources. Arcology designs might apply conventional building and civil engineering techniques in very large, but practical projects in order to achieve pedestrian economies of scale that have proven, post-automobile, to be difficult to achieve in other ways.

Frank Lloyd Wright proposed an early version called Broadacre City although, in contrast to an arcology, Wright's idea is comparatively two-dimensional and depends on a road network. Wright's plan described transportation, agriculture, and commerce systems that would support an economy. Critics said that Wright's solution failed to account for population growth, and assumed a more rigid democracy than the U.S.A. actually has.

Buckminster Fuller proposed the Old Man River's City project, a domed city with a capacity of 125,000, as a solution to the housing problems in East St. Louis, Illinois.

Paolo Soleri proposed later solutions, and coined the term 'arcology'. Soleri describes ways of compacting city structures in three dimensions to combat two-dimensional urban sprawl, to economize on transportation and other energy uses. Like Wright, Soleri proposed changes in transportation, agriculture, and commerce. Soleri explored reductions in resource consumption and duplication, land reclamation; he also proposed to eliminate most private transportation. He advocated for greater "frugality" and favored greater use of shared social resources, including public transit (and public libraries).

In popular culture

Most proposals to build real arcologies have failed due to financial, structural or conceptual shortcomings. Arcologies are therefore found primarily in fictional works.

  • One of the earliest examples in literature is William Hope Hodgson's 1912 horror/fantasy novel The Night Land, where the last remnants of humanity survive in two enormous self-contained metal pyramids.
  • Another significant example is the 1981 novel Oath of Fealty by Larry Niven and Jerry Pournelle, in which a segment of the population of Los Angeles has moved into an arcology. The plot examines the social changes that result, both inside and outside the arcology. Thus the arcology is not just a plot device but a subject of critique.
  • In Robert Silverberg's The World Inside, most of the global population of 750 billion lives inside giant skyscrapers, called "urbmons", each of which contains hundreds of thousands of people. The urbmons are arranged in "constellations". Each urbmon is divided into "neighborhoods" of 40 or so floors. All the needs of the inhabitants are provided inside the building – food is grown outside and brought into the building – so the idea of going outside is heretical and can be a sign of madness. The book examines human life when the population density is extremely high.
  • The Maxis computer game SimCity 2000 allows the construction of four different types of arcologies in the future, introducing a wider audience to the concept.
From the Wikipedia entry for ARCOLOGY
Arcology , n.: a concept in which the ideal city is a massive vertical structure, which preserves more of the natural environment, a concept combining architecture and ecology as envisioned by Paolo Soleri
Etymology: arc(hitecture) + (ec)ology definition

Arcology is the architectural discipline described in the page quote. An arcology is the result of said discipline, and is a thing with the following three attributes:
  1. High population density.
  2. Constructed as a single building.
  3. Self-contained in regards to energy, amenities and waste reclamation.

Imagine a skyscraper. Every five or so floors, there is an entire floor dedicated to the inner workings of the floors above it. This is called a deck. The deck level houses all power lines, plumbing mains and anything else that needs to work properly for life to be livable with all the modern conveniences. Now make the skyscraper cover the ground area of a small city or a large town and realize that the decks number in the triple digits. There's the ideal description in a nutshell.

The name of the game here is self-sufficiency. The second attribute above links to the Closed Circle page because the materials required to keep the systems of the building going cannot leave. These processes include food production, waste recycling and environmental refinement (air conditioning and such). People can, in theory, come and go as they please, but the idea is that they don't need to leave. It's worth mentioning that some of the truly huge mega cities in fiction are made up of "arcoplexes," or residentially, commercially, or industrially specialized arcologies that link to each other to create a unified, futuristic ecosystem. After some application of Fridge Logic, City Planet settings almost have to qualify as arcoplexes; otherwise they wouldn't function.

This trope tends towards either extreme hard or soft sci-fi, since the full explanation is pretty complex. It's either going to be explained in detail, or it's going to be handwaved. Depending on who we ask, we may or may not currently have the technology required to make an arcology work in the real world. What is certain is that we don't yet have the political pressure and economy of scale to build one with any reasonable payoff; with current population densities, such a project would be Awesome, but Impractical, thus a fully functional arcology in fiction often requires some Applied Phlebotinum until Technology Marches On comes into effect.

Arcologies appear most often in speculative fiction that tend toward the cynical end of the spectrum, since they are essentially futuristic paradises with a bit of science to back up their justified existence and functionality, and Utopia never holds up under scrutiny. They often appear in video games set After the End or 20 Minutes into the Future, Cyber Punk stories, and most often feature heavily in stories that rely on an environmental or class warfare aesop.

Because they are so insular and answer all of humanity's material needs, arcologies are a great setting for a Wretched Hive masquerading as a Shining City, if not just playing the Layered Metropolis disgustingly straight. If the arcology is actually a Shining City, and a sympathetic character hails from it, expect it to look like a Doomed Hometown eventually. Broken arcologies tend to be the breeding ground for all sorts of nasties, too, since they are no longer fit for human habitation, there's a chance at least some of the sustenance systems still work, and there are at least millions of hiding places. In some Cyber Punk settings, an arcology may be a Shining City in the middle of a Wretched Hive, the arcology's walls forming a neat divide for Urban Segregation.

If the arcology has space engines, it's a Generation Ship. Shares blurred lines with the Mega City, which need only be huge, but sometimes an example of one is an example of both, especially the arcoplex variation. Contrast Hub City, which offers everything you need but a place to call home. Citadel Cities that also qualify as arcologies function extremely well under siege conditions, since dwindling supplies are no longer an issue. Compare and contrast with Layered Metropolis, City on the Water, City in a Bottle, Underground City, Skyscraper City, and Domed Hometown. Even though most of the tropes above are sub-tropes of the Mega City, technically the Arcology is not, since one can exist inside a city without actually being one, itself, even though it usually works out that way. Lastly, see Shining City, which is what an arcology is trying to be from an ecological standpoint, whether it succeeds or not.

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

Dome Cities

Floating Cities

When the ultra-rich upper crust wants to really look down on the lower classes, nothing can beat living in a floating city. Or even if there are no miserable peons living in slums below, the view will still be spectactular. If there are slums, the combination of floating city above and ghetto below is called a Stratified City.


Retreating to the net, she scanned for free feelie casts, finding a 3V ad for a resort and retirement aerostat in Typhon’s upper atmosphere (Typhon is a gas giant). Floating like a huge transparent bubble several klicks across, the aerostat hung from a giant balloon of heated hydrogen, suspended amid brown clouds of ammonium hydrosulfide hundreds of klicks above a grey-white sea of water ice clouds. Within the aerostat’s protective bubble was a free-form world, where beautiful people flitted between aerial hamlets on gossamer wings and skycycles. Fairyland to a child raised in cubicals and corridors, breathtakingly wonderful no matter how often she felt it. She blended with the ad, riding a skycycle with wind streaming in a cool rush of feeling over her face, weirdly refreshing. She peddled along, dodging skyships, pleasure barges, and colorful homes floating like open flowers complete with hanging gardens and rooftop landing pads. Aerostat technology was used by the first settlers to terraform Oceania and the inner worlds, then introduced to Typhon to provide living space in the outer system. Ice mining and terraforming left colonies scattered about Typhon living off local resources and gravity advantage—not everyone could pick up and move to the wonderful new inner worlds. Kay was having her troubles just getting to The Hub.

Shooting through waterfall rainbows, she skimmed the surface of the warm ballast lake at the bottom of the bubble, feeling the splash of spray on her feet, all without fear of crashing—this was just a commercial. To prove it she pulled back on the skycycle and did a perfect inside loop right into the lake.

Soon as she hit the water she was swimming, no longer aboard a skycycle, but nude, wearing only swim fins, goggles, and a rebreather. Warm oxygenated water turned her into an aquatic creature, gliding at will over sunlit sand through schools of tiny silver fish, swimming effortlessly despite never having been in water deeper than a sponge bath—all thanks to the power of advertising.

From RING RATS by R. Garcia y Robertson (2002)

Undersea Cities

Come to inner space! Undersea cities are a time-honored trope in science fiction. And cinematically dramatic to boot. A domed city on the ocean floor with zillions of fish, squids, and other sea life swimming by; how cool is that?

In older science fiction, a common trope is for oceanic explorers on Terra to stumble over the lost continent of Atlantis. Which is typically inhabited by humans descended from the original inhabitants, who either have learned how to breath water or who quickly became good at building air-tight underwater cities. In Lester del Rey's Attack from Atlantis the Atlanteans accidentally discover how to make unreasonably strong force fields, which is a good trick since at the time they hadn't discovered electricity yet.

Most science fiction movies featuring underwater cities are pretty abysmal (sorry). These include City Beneath The Sea, City Under the Sea, Captain Nemo and the Underwater City, and The Underwater City. Oh, and in Star Wars there is Otoh Gunga, but I didn't want to dredge up any unpleasant memories.

"City Beneath The Sea" was obviously a poorly disguised pilot for a proposed TV series. Sank without a trace. The TV show seaQuest DSV lasted two and one-half seasons before they pulled the plug. A few episodes featured underwater colonies. And there was that old animated series Sealab 2020.

Don't forget the underwater city of Rapture in the video game BioShock.

The hapless protagonists in the novel Dome have to learn real quick how to convert their temporary underwater lab off the coast of Hawaii into an underwater colony. It seems that the political situation on the surface deteriorated rapidly, and a global war using biological weapons had rendered life above water impossible for the foreseeable future.

The people in Frederik Pohl and Jack Williamson's Undersea Trilogy live in underwater cities with magic force fields. The novel series is sort of like Robert Heinlein's Space Cadet set underwater. In Kenneth Bulmer's City Under the Sea the protagonist discovers what a cut-throat industry underwater food production is.

For a more scientifically accurate underwater colony there is Hal Clement's Ocean On Top. Predictably, since Hal Clement has a reputation for writing hard science fiction. The colonists use geothermal power, and live in a special oxygenated liquid to cope with the ocean pressure.

Back in the day there were a few underwater cities set on the planet Venus, because back in the day one of the leading astronomical theories was that Venus was totally covered in oceans (a "pelagic planet"). Of course back then astronomers thought Mars had canals. The classic was the Keeps series by Henry Kuttner and C. L. Moore. Others include Isaac Asimov's Lucky Starr and the Oceans Of Venus and Roger Zelazny's The Doors of His Face, the Lamps of His Mouth.

There have been a few novels with extensive underwater research labs in the oceans of Europa or other Jovian moons, ever since scientist figured out the Galilean satellites had sub-ice oceans and might even have black-smoker type ecosystems.


      Aphrodite is the largest city on Venus, with a population of over a quarter of a million.
     With the Venus Marvel still a mile away, the sea about it was lit into green translucence by Aphrodite’s lights. In the eerie luminosity the. dark, sleek shapes of the rescue vessels, which had been sent out to meet them after radio contact had been established, could be plainly made out. They slipped along, silent companions.
     As for Lucky and Bigman, it was their first sight of one of Venus’s underwater domed cities. They almost forgot the unpleasantness they had just passed through, in their amazement at the wonderful object before them.
     From a distance it seemed an emerald-green, fairyland bubble, shimmering and quivering because of the water between them. Dimly they could make out buildings and the structural webbing of the beams that held up the city dome against the weight of water overhead.
     It grew larger and glowed more brightly as they approached. The green grew lighter as the distance of water between them grew less. Aphrodite became less unreal, less fairylandish, but even more magnificent.
     Finally they slid into a huge air lock, capable of holding a small fleet of freighters or a large battle cruiser, and waited while the water was pumped out. And when that was done, the Venus Marvel was floated out of the lock and into the city on a lift field.

     The Green Room of the Hotel Bellevue-Aphrodite was just that. The quality of the lighting and the shimmer of it gave the tables and guests the appearance of being suspended beneath the sea. The ceiling was an inverted bowl, below which there turned slowly a large aquarium globe, supported by cunningly placed lift beams. The water in it was laced with strands of Venusian seaweed and in among it writhed colorful “sea ribbons,” one of the most beautiful forms of animal life on the planet.
     Then the music started, the domed ceiling gradually came to glowing life, and the aquarium globe began its gentle spinning. The sea ribbons were of different lengths, varying from tiny threads two inches long to broad and sinuous belts that stretched a yard or more from end to end. They were all thin, thin as a sheet of paper. They moved by wriggling their bodies into a series of waves that rippled down their full length.
     And each one fluoresced; each one sparkled with colored light. It was a tremendous display. Down the sides of each sea ribbon were little glowing spirals of light: crimson, pink, and orange; a few blues and violets scattered through; and one or two striking whites among the larger specimens. All were overcast with the light-green wash of the external light. As they swam, the lines of color snapped and interlaced. To the dazzled eye they seemed to be leaving rainbow trails that washed and sparkled in the water, fading out only to be renewed in still brighter tints.

     Lucky handled the trim subsea craft with growing expertness as he learned the touch of the controls and began to get the feel of the sea about them.
     For the first hour Bigman had been scarcely aware of the microwaves and the object of their search. He had been lost in the spectacle to be seen from the portholes.
     Venusian subsea life is phosphorescent, and the black ocean depths were dotted with colored lights thicker than the stars in space, larger, brighter, and most of all, moving. Bigman squashed his nose against the thick glass and stared, fascinated.
     Some of the life forms were little round splotches, whose movement was a slow ripple. Others were darting lines. Still others were sea ribbons of the type Lucky and Bigman had seen in the Green Room.
     Lucky joined him after a while. He said, “If I remember my xenozoology “
     “Your what?”
     “That’s the study of extraterrestrial animals, Bigman. I’ve just been looking through a book on Venusian life. I left it on your bunk in case you want to look at it.”
     “Never mind. I’ll take it second hand from you.”
     “All right. We can start with those little objects. I think that represents a school of buttons.”
     “Buttons?” said Bigman. Then, “Sure, I see what you mean.”
     There were a whole series of yellow ovals of light moving across the black field visible through the porthole. Each had black markings on it in the form of two short parallel lines. They moved in brief spurts, settled down for a few moments, then moved again. The dozens in view all moved and rested simultaneously, so that Bigman had the queerly swimming sensation that the buttons weren’t moving at all, but that every half minute or so the ship itself lurched.
     Lucky said, “They’re laying eggs, I think.” He was silent for a long moment, then said, “Most of these things I can’t make out. Wait! That must be a scarlet patch there. See it? The dark red thing with the irregular outline? It feeds on buttons. Watch it.”
     There was a scurrying among the yellow blotches of light as they became aware of the swooping predator, but a dozen buttons were blotted out by the angry red of the scarlet patch. Then the patch was the only source of light in the porthole’s field of vision. On all sides of it, buttons had scattered away.
     Pre-eminent among them were arrow fish of all sizes. Each had a straight white line of phosphorescence that marked its backbone (it wasn’t a backbone really, but merely an unjointed rod of horny substance). At one end of that white line was a pale yellow V that marked the head. To Bigman it looked indeed as though a countless swarm of animated arrows were swarming past the ship, but in imagination he could see their needle-rimmed jaws, cavernous and ravenous.


Cyclopean Installations

Cyclopean installations always make the readers sit up and take notice. Even more so in TV or movies, since the show cannot resist displaying dizzying scenes of bottomless drops with no guard rails. Something to make acrophobics close their eyes and tremble. These scenes commonly use one-point perspective with the vanishing point set to "down".

Such installations can usually perform some cosmically powerful function:

  • The Krell Machine: allows any Krell citizen to desire something to be so, then use the power of 9,200 thermonuclear reactors to make it happen

  • Project Tic-Toc: a time machine, how cool is that?

  • Tractor Beam Controls On The Death Star: all it does is demonstrate that OSHA does not exist in the Star Wars galaxy

  • The Living Computers of Xandar: holds the still living brains of every Xandarian who has lived for the past ten million years. Contains all of Xandar's history, science, and other knowledge

  • The Great Machine: this does several things; such as controlling and widening temporal rifts, projecting the operator's mind into deep space, boost a tachyon signal over dozens of light years, and scan and project images. And it also has a defensive system capable of obliterating any warship in orbit which has less than First One technology

Spectacular Planets

When you are trying your hand at worldbuilding, please try to avoid ice planets, desert planets, swamp planets, farm planets, volcano planets, and other single-biome planets. The pejorative term for this mistake is Monocosm (term invented by Roz Kaveney). Jerry Pournelle parodied this trope with the phrase "It was raining on Mongo that morning"

Back in the 1950s nothing said "scifi" better than the ringed planet Saturn. One amusing variation is the planet Moth from The Tar Aiym Krang by Alan Dean Foster. Instead of having a full ring, it has two cresents on each side. This makes it look like the planet has wings.
The ultimate urban planet, with cities covering every square centimeter of land area (except for a few acres of Imperial Pleasure Gardens) including kilometer-high skyscrapers and kilometers of underground levels for the morlocks.

The most famous is the planet Trantor from Isaac Asimov's Foundation trilogy (but given a much more detailed description in Donald Kingsbury's pastiche Psychohistorical Crisis). Trantor is famous among those literate in science fiction, the SF illiterates are familiar with the concept mostly from the planet Coruscant from the Star Wars series of movies.
This is a famous bit of worldbuilding from the novel Mission Of Gravity by Hal Clement. The only planet in the 61 Cygni system, Mesklin's surface gravity varies from 3 gees at the equator to an outrageous 700 gees at the poles. The variation is due to the ultra-high rotation rate, it spins at twenty degrees a minute making the day some seventeen and three quarter minutes long.
This is a dumbbell-shaped double planet which are so close together that they share a common atmosphere. It is possible to fly from one planet to another with an aircraft.
These planets were the result of some worldbuilding for the ill fated "Twayne Triplet" series of science fiction novels. Uller is a planet containing silicon life while Niflheim's atmosphere contained dangerous amounts of the hideously corrosive gas fluorine.
In this allegorical story, the main planet of Alpha Virginis has a gynecomorphous mountain range called the Virgin. It is a plateau about ten thousand feet above sea level, and it looks exactly like a titanic sculpture of a nude woman in repose with lakes for eyes. (Goddess in Granite by Robert Young)
The planet has a Venus-like uninhabitable atmospheric pressure. Except for the unreasonably tall (40 kilometers) plateau Mount Lookitthat. It has habitable atmospheric pressure, a pity the surface area is only half that of California. (A Gift From Earth by Larry Niven)
Sort of the opposite of Plateau, the atmosphere is too thin for humans. A weapon called the "Wunderland Treatymaker" gouged out a long kilometer deep canyon with a size about equal to the Baja California peninsula. Air pressure at the bottom of the canyon is suitable for humans. (The Ringworld Engineers by Larry Niven)
The planet is not spherical, it is a prolate spheroid. The poles actually rise out of the amosphere in to vacuum, the atmospheric pressure at the equator is too high for human habitation, the intermediate regions are suitable for humans. (World of Ptavvs, Borderland of Sol by Larry Niven)
This is a torus (donut shape) composed of breathable gases with a jaw-dropping radius of 26,000 kilometers, about four times the radius of Terra. The smoke ring is created by a gas giant called Goldblatt's World which apparently is mostly oxygen instead of hydrogen as is usual. Goldblatt is orbiting a neutron star named Voy, just outside the Roche limit. Which means Goldblatt is constantly shedding its atmosphere to replenish the smoke ring.

There is a wide variety of life living in the free fall environment of the smoke ring, including a colony of humans. There are even aquatic creatures living in huge spherical floating ponds. (The Integral Trees, The Smoke Ring by Larry Niven)

It is theoretically possible that habitable planets exist around pulsars. Such planets must have an enormous atmosphere that convert the deadly X-rays and high energy particles of the pulsar into heat. That is stated in a scientific paper by astronomers Alessandro Patruno and Mihkel Kama, working in the Netherlands and the United Kingdom. The paper appears today in the journal Astronomy & Astrophysics.

Pulsars are known for their extreme conditions. They are neutron stars of only 10 to 30 kilometers in diameter. They have enormous magnetic fields, they accrete matter and they regularly burst out large amounts of X-rays and other energetic particles. Nevertheless, Alessandro Patruno (Leiden University and ASTRON) and Mihkel Kama (Leiden University and Cambridge University) suggest that there could be life in the vicinity of these stars.

It is the first time that astronomers try to calculate so-called habitable zones near neutron stars. The calculations show that the habitable zone around a neutron star can be as large as the distance from our Earth to our Sun. An important premise is that the planet must be a super-Earth with a mass between one and ten times of our Earth. A smaller planet will lose its atmosphere within a few thousand years. Furthermore, the atmosphere must be a million times as thick as that of the Earth. The conditions on the pulsar planet surface might resemble those of the deep sea at Earth.

The astronomers studied the pulsar PSR B1257+12 about 2300 light-years away in the constellation Virgo. They used the Chandra space telescope that is specially made to observe X-rays. Three planets orbit the pulsar. Two of them are super-Earths with a mass of four to five times our Earth. The planets orbit close enough around the pulsar to warm up. Patruno: "According to our calculations, the temperature of the planets might be suitable for the presence of liquid water on their surface. Though, we don't know yet if the two super-Earths have the right, extremely dense atmosphere."

In the future, the astronomers would love to observe the pulsar in more detail and compare it with other pulsars. The ALMA telescope of the European Southern Observatory would be able to show dust discs around neutron stars. Such disks are good predictors of planets.

Probably our Milky Way contains about 1 billion neutron stars of which about 200,000 pulsars. So far, 3000 pulsars have been studied and only 5 pulsar planets have been found. PSR B1257+12 is a much-studied pulsar. In 1992, the first exoplanets ever were discovered around this object.

Article: Neutron Star Planets: Atmospheric processes and irradiation. By: A. Patruno & M. Kama. In Astronomy & Astrophysics (free preprint)

from Netherlands Institute for Radio Astronomy (2017)

It is possible that there could be planets where terrestrial-type life could survive orbiting a neutron star, but they are likely extremely rare and transient.

The habitable zone where liquid water can persist around a star has a range ≈ 0.7√L* to 1.4√L* AU, where L* is the luminosity of the star measured in solar luminosities. The exact limits are debatable and depends somewhat on the planet's properties, but this is close enough for this answer. A typical neutron star has a low luminosity, so the habitable zone will be very close and narrow.

Neutron stars cool down very rapidly at first. A young, million-Kelvin neutron star has luminosity around 0.18 solar luminosities, but a 10 million year old neutron star is down to 0.000026, and after a billion years it will be down to a millionth of the sun. This rapid cooling means that the life zone moves inwards from around 0.3-0.6 AU for the young star to 0.003-0.007 for the 10 million year star to 0.0007-0.0014 AU for the old star.

This means that a planet orbiting inside the zone at some time will become too cold before too long unless it is very close to the star since the zone drift slows down over time. It is hence unlikely that life would naturally be able to emerge on a planet like this, since planets that are in the habitable zone early only get a few million years before they freeze. The close planets that get a long period with decent temperature also have a period of extremely hot temperature before that, when most likely all volatiles are boiled away.

(Given that such a system has experienced a supernova in its past, volatiles will have been reduced even further).

That said, I don't see a fundamental reason a close planet might not be terraformed with volatiles added from elsewhere. If we consider a planet orbiting a L*=10-6L neutron star 10-3 AU away (that is, 149,597 km from the star) it could maintain water. It would have a period of 16 minutes. There would be some relativistic corrections to the orbit, but they are minor (we are 105 Schwarzschild-radii away). It would be tidally locked (since tidal locking happens on a timescale a6), but currently there are a fair number of atmosphere models suggesting such worlds could remain stable/ Living on the shady side would also prevent the damaging UV and X-rays, which would likely strip away the atmosphere over time. The main problem is that there would not be any geodynamic dynamo to power a protective magnetic field; this is a planet that really needs it.

It is worth noting that there is a very different system around a neutron star that in principle (but likely not in practice) may be habitable, and that would be far away from an accretion disk. A quiescent accretion disk may have a luminosity about 1/3 of the sun, but when going active this increases by a factor of 1,000-10,000. So here one could imagine a planet orbiting at distance, getting powered by the accretion disk light. This will likely be too unstable to actually work over long periods and have the same hard radiation problem as the close one, but on paper (or in a suitable work of fiction) it is not impossible.

Killer Planet

Ah, the good old Planet Of No Return! Where the environment is slow death, the geology is full of earthquakes and volcanoes, the plants are poisonous and carnivorous, and there are more animals that can kill you than Australia.

But do try to have a bit of internal self consistency when you create your death world. In the old Lost In Space episode "A Day at the Zoo" they become trapped on a planet along with a native teenage alien named Oggo. Another alien notes that the life expectancy on the planet is about fifteen minutes, which leaves the puzzle of how the alien teenager got so old.

People who call a Killer Planet "Home" tend to be called "The Most Deadly Warriors In The Entire Galaxy." If you can survive there, you can survive anywhere. Naturally such warriors are in high demand and get top dollar.

Examples include:

DEATHWORLD by Harry Harrison
     The heavy-gravity constant-earthquake tsunami-prone planet Pyrrus is home to plants and animals that evolved telepatic communication and cooperation in order to survive. The high background radiation ensures that it does all its evolution very quickly. Basically the entire ecosystem is a hive mind.
     Regrettibly, the first human colonists inadvertenly made the ecosystem very very angry.
     Since then it has been an arms race between the ecosystem evolving new and more deadly flora and fauna and the colonists training themselves and future generations how to be more efficient killing machines out of simple survival. Which means they are super-soldiers.
DUNE Frank Herbert
     The planet Salusa Secundus is so horrible it became the Corrino prison planet. It became the planet where the "worst riff-raff in the galaxy are sent."
     Naturally it bred super-soldiers. The most deadly are recruited into the dreaded Imperial Sardaukar.
     Unfortunatly for them the planet Dune is even more deadly. A total desert planet with practically no water and infested with giant sand worms makes Salusa Secundus look like a resort island. The native Fremen are so ferocious that a Fremen child is more than a match for a Sardaukar.
GALACTIC PATROL by E. E. "Doc" Smith
     Like everything else Doc Smith did, he not only invented the science fictional concept, but he simultaneously turned it up to 11.
     The planet Trenco takes the cake.
     The atmosphere is not air, the oceans are not water. The seas are of a chemical of low latent heat of vaporization, with a boiling-point such that during the daytime it is a vapor and at night a liquid. The air has feeble stopping power, so the nights are icy cold and the days are blazing hot. Which means during the 13 hour night it doesn't rain a few inches of precipitation, it rains forty-seven feet and five inches every night.
     There is lightning as well. Not a bolt or to, it is continuous. So much that it warps space. If you shoot a blaster at somebody it is possible for the beam to be bent such that it strikes you in the back.
     Did I mention that the wind blows at 800 miles per hour?
     And then there are the animals and plants. Who constantly eat each other while they are themselves being eaten.
     The protagonist is with an alien called an "Ezwal" in a space ship. The ship is shot down and crash lands on a planet. An Ezwal has a mass of almost three metric tons, six limbs each with claws that can slap the head off an elephant, is smarter than Einstein, and telepathic to boot.
     The planet is Eristan II, which is a killer planet. The protagonists knows all about it, the Ezwal had never heard of it.
     The protagonist offers to team up with the Ezwal, saying that together we have a chance of survival.
     The Ezwal looks down its nose at the protagonist, says "What do you mean we, white man? How tough could this planet possibly be?", and trots into the forest.
     About an hour later the Ezwal come galloping back to the protagonist and pleads for help...
MIDWORLD by Alan Dean Foster
The entire planet is covered by a rain forest. However the trees are about 0.75 kilometers tall. The base of the trees are swamps in mindless darkness infested by monsters that can eat an elephant like an after dinner mint. The tree tops are infested by eternally hungry pteranodon-like flying reptiles. The only part of the world that is not swift death is the middle area between the swamp and the sky. And that is only relative. There are deadly plants like the grenade fruit, which kills you with an explosion that simultaneously sends seeds deep into your fresh corpse to grow. And the false cubble-vines, which look just like the roadway type vines but which will literally bite your foot off. But the worse is the army ants, devouring all in their path. Except these ants are the size of a hippo.

"We've run into scorpions the size of battle tanks, three men died from Eyerot last week, I've sweated enough to fill a lake, my boots just got sucked into a sink-swamp and the trees are so thick in places, you can't squeeze between them. Emperor help me, I love this place! It's just like home!"

Captain Rock of Catachan, Warhammer 40,000

A Death World is a highly dangerous place, where simply going there is considered taking your life into your own hands. It could be from hazardous environmental conditions, such as an acidic swamp or poisonous fog, or from powerful native predators (Here there be Dragons, or worse, something that eats them), dangerous flora, or even all of the above. It's like the entire place is deliberately hostile to human life. (Of course, if it's also a Genius Loci, it just might be!)

Very few people would ever choose to live there, but since anyone who does is almost always a badass, expect any populated Death World to be a World of Badass by default. Sometimes, The Mentor may hide out here. Alternately, it may be Mordor, and/or home for an exceptionally tough and ferocious race. Some actually take advantage of this as a way of training their Super Soldiers on a planetary scale. Sure, half of the population might not survive through adolescence, but those who do should make good soldiers. Sometimes they are genetically engineered. Those who live on such a world may be an example of Had To Be Sharp.

In real life, every planet outside Earth that we know of to a reasonable degree, is dangerous, because we have yet to verify that any other planet out there can support human life. In fiction, Death worlds generally have relatively breathable atmospheres (for native life, at least), have compelling reasons for characters to get out and walk around, and have varieties of dangerous flora and fauna. A planet that cannot host life for any amount of time is just "uninhabitable", not this.

For more details, the various Videogame Settings actually do a decent job of describing the various kinds of dangers you might find in different ecosystems, as a result of Everything Trying to Kill You. The Dark World is often a magical variant. Don't be too surprised if there are More Predators Than Prey.

The Trope Namer is Harry Harrison's novel from 1960, Deathworld, in which the entire flora and fauna of a planet treat the human colonizers as enemies and do their best to kill them.

Compare to Gaia's Vengeance where a world can become like this as a response to some threat. For examples of entire Death Universes, see Crapsack World.

Truth in Television: There are plenty of environments here on our own planet that can and will kill those who fail to prepare for them or take the appropriate precautions around their hazards. Even the most fantastic fictional examples are often extrapolations of dangers present here on Earth — and that's before we get into the fact that we still haven't found any worlds outside our own that are particularly inviting for human life.

Not to be confused with a Place Worse Than Death, which refers to Real Life locations with bad publicity.

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


(ed note: Our heroes, traveling in the spaceship Skylark, land on a jungle planet. When the monsters appear, Seaton only has a clip of x-plosive atomic bullets in his gun. If one goes off too near the spaceship, the blast will wreck it.)

As they reached the broken projections, Margaret glanced back over her shoulder and screamed. The others saw that her face was white and her eyes wide with horror, and Seaton instinctively drew his pistol as he whirled about, only to check his finger on the trigger and lower his hand.

"Nothing but X-plosive bullets," he growled in disgust, and in helpless silence the four watched an unspeakably hideous monster slowly appear from behind the Skylark. Its four huge, squat legs supported a body at least a hundred feet long, pursy and ungainly; at the extremity of a long and sinuous neck a comparatively small head seemed composed entirely of a cavernous mouth armed with row upon row of carnivorous teeth. Dorothy gasped with terror and both girls shrank closer to the two men, who maintained a baffled silence as the huge beast passed his revolting head along the hull of the vessel.

"I dare not shoot, Martin," Seaton whispered, "it would wreck the bus. Have you got any solid bullets?"

"No. We must hide behind these small ledges until it goes away," answered Crane, his eyes upon Margaret's colorless face. "You two hide behind that one, we will take this one."

"Oh, well, it's nothing to worry about, anyway. We can kill him as soon as he gets far enough away from the boat," said Seaton as, with Dorothy clinging to him, he dropped behind one of the ledges. Margaret, her staring eyes fixed upon the monster, remained standing until Crane touched her gently and drew her down beside him.

There came the crack of a rifle from the Skylark. There was an awful roar from the dinosaur, which was quickly silenced by a stream of machine-gun bullets.

"Blackie's on the job—let's go!" cried Seaton, and they raced up the slope. Making a detour to avoid the writhing and mutilated mass they plunged through the opening door. DuQuesne shut it behind them and in overwhelming relief, the adventurers huddled together as from the wilderness without there arose an appalling tumult.

The scene, so quiet a few moments before, was instantly changed. The trees, the swamp, and the air seemed filled with monsters so hideous as to stagger the imagination. Winged lizards of prodigious size hurtled through the air, plunging to death against the armored hull. Indescribable flying monsters, with feathers like birds, but with the fangs of tigers, attacked viciously. Dorothy screamed and started back as a scorpion-like thing with a body ten feet in length leaped at the window in front of her, its terrible sting spraying the glass with venom. As it fell to the ground, a huge spider—if an eight-legged creature with spines instead of hair, many-faceted eyes, and a bloated, globular body weighing hundreds of pounds, may be called a spider—leaped upon it and, mighty mandibles against poisonous sting, the furious battle raged. Several twelve-foot cockroaches climbed nimbly across the fallen timber of the morass and began feeding voraciously upon the body of the dead dinosaur, only to be driven away by another animal, which all three men recognized instantly as that king of all prehistoric creatures, the saber-toothed tiger. This newcomer, a tawny beast towering fifteen feet high at the shoulder, had a mouth disproportionate even to his great size—a mouth armed with four great tiger-teeth more than three feet in length. He had barely begun his meal, however, when he was challenged by another nightmare, a something apparently half-way between a dinosaur and a crocodile. At the first note the tiger charged. Clawing, striking, rending each other with their terrible teeth, a veritable avalanche of bloodthirsty rage, the combatants stormed up and down the little island. But the fighters were rudely interrupted, and the earthly visitors discovered that in this primitive world it was not only animal life that was dangerous.

The great tree standing on the farther edge of the island suddenly bent over, lashing out like a snake and grasping both. It transfixed them with the terrible thorns, which were now seen to be armed with needlepoints and to possess barbs like fish-hooks. It ripped at them with the long branches, which were veritable spears. The broad leaves, armed with revolting sucking disks, closed about the two animals, while the long, slender twigs, each of which was now seen to have an eye at its extremity, waved about, watching each movement of the captives from a safe distance.

If the struggle between the two animals had been awful, this was Titanic. The air was torn by the roars of the reptile, the screams of the great cat, and the shrieks of the tree. The very ground rocked with the ferocity of the conflict. There could be but one result—soon the tree, having absorbed the two gladiators, resumed its upright position in all its beauty.

From THE SKYLARK OF SPACE by E. E. "Doc" Smith (1920)

It looked sinister and dark: no sun, no moon illumined this celestial body; only a bloody gleam, not unlike the Northern Light, oozed down out of the atmosphere, apparently proceeding from phosphorescent matter or bacteria in the air.

For all this illumination, little could be seen; but what they did see left a revolting impression.

The land seemed to be fairly level, mostly swampy in character.

At certain spots, luminous fumes or vapor rose from the swamps, which shed a cadaverous, sulphuric light; in between, bluish and greenish tongues of flame shot up, so that the immediate surroundings were lit by a dull gleam which was more gruesome than the most infernal torches would have been, in a world of horrors.

Yes, a world of horrors! What kind of trees and plants were these! All of them seemed alive and at the same time repulsive: grasses which wound, twisted, and squirmed about on the ground in convulsive jerks like loathsome vermin, as if striving in vain to be free from the putrid soil in which they were rooted! Many-limbed trees, whose bleak, leafless branches curled like monster serpents or octopi, in constant motion, stretching out and drawing back, forming waves, arches, rings, and knots, as if the living branches of every tree were engaged in murderous combat.

And down below, the swamps teemed with ghastly creatures: whitish maggots, larger than elephants, bared their teeth in snarls; monster spiders, whose fat, spherical bodies were covered above, below, and at the sides with long, thin, hairy legs, so that they could revolve around themselves and always crawl with a number of feet while the others quivered in the air; greenish toads as large as buffaloes, with hideous eyes popping out of their wormlike heads; thin-legged mosquitoes as tall as giraffes, which sucked the life out of other animals with their long, transparent fangs or else were bitten and crushed to death by them.

Everything crawled and fought against everything else; not only animal against animal, but also plant and animal, were engaged in incessant, deadly warfare.

There a gigantic worm with crocodile’s jaws bit off the branch of a tree and the branch twitched and jerked and squirmed convulsively on the ground, while a thick, greenish-black juice gushed from the stump, distorted as if in the ghastliest pain.

Here was one of the monster beasts with countless arms, seized by a tree and seeking in vain with desperate contortions to free itself from the fatal embrace: it was squeezed, strangled, and crushed into a shapeless mass.

And then slender vermin shot up out of the morass, sailed through the air, and bored through the body of a no less repulsive beast, finally to vanish completely into its bulk, there to commence on its entrails its ghastly work of destruction.

It was blood-curdling to watch such a monster-beast, itself gruesome in appearance, leaping about in terrific pain, to see it writhe madly and finally collapse in the throes of death, while its shapelessly swollen bulk suddenly burst open and revealed a mass of serpentine vermin which had devoured its still living body from within.

Then the livid flames shot up again through these teeming masses, singeing and devouring the bodies which vainly sought to escape: even these infernal fire-serpents seemed to be alive and to pursue their victims with bloodthirstiness.

Heliastra was deathly pale and filled with horror: “Is this what the Earth looks like?” she asked uneasily.

“No,” Hank consoled her. “This ghastly spectacle fills us also with a horror we have never known before!”

“Yes,” the Professor reassured her. “Even scientific investigation revolts here and turns away in disgust. This is a realm of darkness in the fullest sense of the word, and I propose to give it the name ‘Sheol.’”

“It is enough,” said Flitmore. “Rather into the eternal night of solitary space than watch such a spectacle any longer !” And he switched the centrifugal power on at full force.

From WUNDERWELTEN (DISTANT WORLDS) by Friedrich Mader (1911)

Judged by any earthly standards the planet Trenco was—and is—a peculiar one indeed. Its atmosphere, which is not air, and its liquid, which is not water, are its two outstanding peculiarities and the sources of most of its others. Almost half of that atmosphere and by far the greater part of the liquid phase of the planet is a substance of extremely low latent heat of vaporization, with a boiling point such that during the daytime it is a vapor and at night a liquid. To make matters worse, the other constituents of Trenco’s gaseous envelope are of very feeble blanketing power, low specific heat, and of high permeability, so that its days are intensely hot and its nights are bitterly cold.

At night, therefore, it rains. Words are entirely inadequate to describe to anyone who has never been there just how it does rain during Trenco’s nights. Upon Earth one inch of rainfall in an hour is a terrific downpour. Upon Trenco that amount of precipitation would scarcely be considered a mist, for along the equatorial belt, in less than thirteen Tellurian hours, it rains exactly forty-seven feet and five inches every night—no more no less, each and every night of every year.

Also there is lightning. Not in Terra’s occasional flashes, but in one continuous, blinding glare which makes night as we know it unknown there; in nerve-wracking, battering, sense-destroying discharges which make ether and sub-ether alike impenetrable to any ray or signal short of a full driven power beam. The days are practically as bad. The lightning is not violent then, but the bombardment of Trenco’s monstrous sun, through that outlandishly peculiar atmosphere, produces almost the same effect.

Because of the difference in pressure set up by the enormous precipitation always and everywhere upon Trenco there is wind—and what a wind! Except at the very poles, where it is too cold for even Trenconian life to exist, there is hardly a spot in which or a time at which an Earthly gale would not be considered a dead calm, and along the equator, at every sunrise and at every sunset, the wind blows from the day side to the night side at the rate of well over eight hundred miles an hour!

Through countless thousands of years wind and wave have planed and scoured the planet Trenco to a geometrically perfect oblate spheroid. It has no elevations and no depressions. Nothing fixed in an Earthly sense grows or exists upon its surface, no structure has ever been built there able to stay in one place through one whole day of the cataclysmic meteorological phenomena which constitute the natural Trenconian environment.

There live upon Trenco two types of vegetation, each type having innumerable sub-divisions. One type sprouts in the mud of morning, flourishes flatly, by dint of deeply sent and powerful roots, during the wind and the heat of the day, comes to full fruit in later afternoon, and at sunset dies and is swept away by the flood. The other type is freefloating. Some of its genera are remotely like footballs, others resemble tumbleweeds, still others thistledown, hundreds of others have not their remotest counterparts upon Earth. Essentially, however, they are alike in habits of life. They can sink in the “water” of Trenco, then can burrow in its mud, from which they derive part of their sustenance, they can emerge therefrom into the sunlight, they can, undamaged float in or roll along before the ever-present Trenconian wind, and they can enwrap, entangle, or otherwise seize and hold anything with which they come in contact which by any chance may prove edible.

Animal life, too, while abundant and diverse, is characterized by three qualities. From lowest to very highest it is amphibious, it is streamlined, and it is omnivorous. Life upon Trenco is hard, and any form of life to evolve there must of stern necessity be willing yes, even anxious, to eat literally anything available. And for that reason all surviving forms of life, vegetable and animal, have a voracity and a fecundity almost unknown anywhere else in the galaxy.

Thionite, the noxious drug referred to earlier in this narrative, is the sole reason for Trenco’s galactic importance. As chlorophyll is to Earthly vegetation, so is thionite to that of Trenco. Trenco is the only planet thus far known upon which this substance occurs, nor have our scientists even yet been able either to analyze or to synthesize it.

Thionite is capable of affecting only the races who breathe oxygen and possess warm blood, red with hemoglobin. However, the planets peopled by such races are legion, and very shortly after the drug’s discovery hordes of addicts smugglers, peddlers, and out-and-out pirates were rushing toward the new Bonanza. Thousands of these adventurers died, either from each other’s ray-guns or under an avalanche of hungry Trenconian life; but, thionite being what it is, thousands more kept coming. Also came the Patrol, to curb the evil traffic at its source by beaming down ruthlessly any being attempting to gather any Trenconian vegetation.

Thus between the Patrol and the drug syndicate there rages a bitterly continuous battle to the death. Arrayed against both factions is the massed life of the noisome planet, omnivorous as it is, eternally ravenous, and of an individual power and ferocity and a collective aggregate of numbers by no means to be despised. And eternally raging against all these contending parties are the wind, the lightning, the rain, the flood, and the hellish vibratory output of Trenco’ s enormous, malignant, blue-white sun.

Kinnison obeyed; and, released from all duty, the visitors stared in fascinated incredulity into the visiplate. For that at which they stared was and must forever remain impossible of duplication upon Earth, and only in imagination can it be even faintly pictured. Imagine all the fantastic and monstrous creatures of a delirium-tremens vision incarnate and actual. Imagine them being hurled through the air, borne by a dust-laden gale more severe than any the great American dust-bowl or Africa’s Sahara Desert ever endured. Imagine this scene as being viewed, not in an ordinary, solid distorting mirror, but in one whose falsely reflecting contours were changing constantly, with no logical or intelligible rhythm, into new and ever more grotesque warps. If imagination has been equal to the task, the resultant is what the visitors tried to see.

As the end of the third hour neared, Kinnison watched with a spy-ray—there were no windows in Trenco spaceport—the leeward groundway of the structure. In spite of the weird antics of Trenco’s sun—gyrating, jumping, appearing and disappearing—he knew that it was going down. Soon he saw the ground-car coming in, scuttling crabwise, nose into the wind but actually moving backward and sidewise. Although the “seeing” was very poor, at this close range the distortion was minimized and he could see that, like its parent craft, the ground-car was a blister. Its edges actually touched the ground all around, sloping upward and over the top in such a smooth reverse curve that the harder the wind blew the more firmly was the vehicle pressed downward.

The ground-flap came up just enough to clear the car’s top and the tiny craft crept up. But before the landing bars could seize her the ground-car struck an eddy from the flap—an eddy in a medium which, although gaseous, was at that velocity practically solid. Earth blasted away in torrents from the leading edge, the car leaped bodily into the air and was flung away, end over end. But Tregonsee, with consummate craftsmanship, forced her flat again, and again she crawled up toward the flap. This time the landing-bars took hold and, although the little vessel fluttered like a leaf in a gale, she was drawn inside the port and the flap went down behind her. She was then sprayed, and Tregonsee came out.

     “Why the spray?” thought Kinnison, as the Rigellian entered his control-room.
     “Trencos. Much of the life of this planet starts from almost imperceptible spores. It develops rapidly, attains considerable size, and consumes anything organic it touches. This port was depopulated time after time before the lethal spray was developed. Now turn your spy-ray again to the lee of the port.”

During the few minutes that had elapsed the wind had increased in fury to such an extent that the very ground was boiling away from the trailing edge in the tumultuous eddy formed there, ultra-streamlined though the space-port was. And that eddy, far surpassing in violence any storm known to Earth, was to the denizens of Trenco a miraculously appearing quiet spot in which they could stop and rest, eat and be eaten.

A globular monstrosity had thrust pseudopodia deep into the boiling dirt. Other limbs now shot out, grasping a tumble-weed-like growth. The latter fought back viciously, but could make no impression upon the rubbery integument of the former. Then a smaller creature, slipping down the polished curve of the shield, was enmeshed by the tumbleweed. There ensued the amazing spectacle of one-half of the tumbleweed devouring the newcomer, even while its other half was being devoured by the globe!

     “Now look out farther… still farther,” directed Tregonsee.
     “I can’t. Things take on impossible motions and become so distorted as to be unrecognizable.”
     “Exactly. If you saw a zwilnik out there, where would you shoot?”
     “At him, I suppose—why?”
     “Because if you shot at where you think you see him, not only would you miss him, but the beam might very well swing around and enter your own back. Many men have been killed by their own weapons in precisely that fashion. Since we know, not only what the object is, but exactly where it is, we can correct our lines of aim for the then existing values of distortion. This is of course the reason why we Rigellians and other races possessing the sense of perception are the only ones who can efficiently police this planet.”
     “Reason enough, I’d say, from what I’ve seen,” and silence fell.

For minutes the two Lensmen watched, while creatures of a hundred kinds streamed into the lee of the space-port and killed and ate each other. Finally something came crawling up wind, against that unimaginable gale, a flatly streamlined creature resembling somewhat a turtle, but shaped as was the ground-car. Thrusting down long, hooked flippers into the dirt it inched along, paying no attention. to the scores of lesser creatures who hurled themselves upon its armored back, until it was close beside the largest football-shaped creature in the eddy. Then, lightning-like, it drove a needle-sharp organ at least eight inches into the leathery mass of its victim. Struggling convulsively, the stricken thing lifted the turtle a fraction of an inch—and both were hurled instantly out of sight, the living ball still eating a luscious bit of prey despite the fact that it was impaled upon the poniard of the turtle and was certainly doomed.

The rain came—forty-four inches per hour of rain—and the incessant lightning. The dirt became first mud, then muddy water being driven in fiercely flying gouts and masses. Now, in the lee of the space-port, the outlandish denizens of Trenco were burrowing down into the mud—still eating each other and anything else that came within reach.

The water grew deeper and deeper, its upper surface now whipped into frantic sheets of spray. The structure was now afloat, and Kinnison saw with astonishment that, small as was the exposed surface and flatly curved, yet it was pulling through the water at frightful speed the wide-spreading steel sea-anchors which were holding its head to the gale.

     “With no reference points how do you know where you’re going?” he demanded.
     “We neither know nor care,” responded Tregonsee, with a mental shrug. “We are like the natives in that. Since one spot is like every other spot, why choose between them?”
     “What a world—what a world! However, I am beginning to understand why thionite is so expensive,” and, overwhelmed by the ever-increasing fury raging outside, Kinnison sought his bunk.

Morning came, a reversal of the previous evening. The liquid evaporated, the mud dried, the flat-growing vegetation sprang up with shocking speed, the animals emerged and again ate and were eaten.

From GALACTIC PATROL by E. E. "Doc" Smith (1937)
      “It has meaning enough,” Kerk told him. “But only on one planet in the universe. Just how much do you know about Pyrrus?”
     “Absolutely nothing.”
     For a moment Kerk sat wrapped in memory, scowling distantly. Then he went on.
     “Mankind doesn’t belong on Pyrrus—yet has been there for almost three hundred years now. The age expectancy of my people is sixteen years. Of course most adults live beyond that, but the high child mortality brings the average down.
     “It is everything that a humanoid world should not be. The gravity is nearly twice earth normal. The temperature can vary daily from arctic to tropic. The climate—well you have to experience it to believe it. Like nothing you’ve seen anywhere else in the galaxy.”
     “I’m frightened,” Jason said dryly. ‘What do you have, methane or chlorine reactions? I’ve been down on planets like that—”
     Kerk slammed his hand down hard on the table. The dishes bounced and the tablelegs creaked. “Laboratory reactions!” he growled. “They look great on a bench—but what happens when you have a world filled with those compounds? In an eye-wink of galactic time all the violence is locked up in nice, stable compounds. The atmosphere may be poisonous for an oxygen breather, but taken by itself it’s as harmless as weak beer.
     “There is only one setup that is pure poison as a planetary atmosphere. Plenty of H2O, the most universal solvent you can find, plus free oxygen to work on—”

     “Water and oxygen!” Jason broke in. “You mean Earth—or a planet like Cassylia here? That’s preposterous.”
     “Not at all. Because you were born in this kind of environment, you accept it as right and natural. You take it for granted that metals corrode, coastlines change, and storms interfere with communication. These are normal occurrences on oxygen-water worlds. On Pyrrus these conditions are carried to the nth degree.
     “The planet has an axial tilt of almost 42 degrees, so there is a tremendous range of temperature from season to season. This is one of the prime causes of a constantly changing icecap. The weather generated by this is spectacular to say the least.”

     “If that’s all,” Jason said, “I don’t see why…”
     “That’s not all—it’s barely the beginning. The open seas perform the dual destructive function of supplying water vapor to keep the weather going, and building up gigantic tides. Pyrrus’ two satellites, Samas and Bessos, combine at times to pull the oceans up into thirty meter tides. And until you’ve seen one of these tides lap over into an active volcano you’ve seen nothing.
     “Heavy elements are what brought us to Pyrrus—and these same elements keep the planet at a volcanic boil. There have been at least thirteen supernovas in the immediate stellar neighborhood. Heavy elements can be found on most of their planets of course—as well as completely unbreathable atmospheres. Long-term mining and exploitation can’t be done by anything but a self-sustaining colony. Which meant Pyrrus, where the radioactive elements are locked in the planetary core, surrounded by a shell of lighter ones. While this allows for the atmosphere men need, it also provides unceasing vulcanic activity as the molten plasma forces its way to the surface.”
     For the first time, Jason was silent. Trying to imagine what life could be like on a planet constantly at war with itself.

     “I’ve saved the best for last,” Kerk said with grim humor. “Now that you have an idea of what the environment is like—think of the kind of life forms that would populate it. I doubt if there is one offworld specie that would live a minute. Plants and animals on Pyrrus are tough. They fight the world and they fight each other. Hundreds of thousands of years of genetic weeding-out have produced things that would give even an electronic brain nightmares. Armor-plated, poisonous, claw-tipped and fanged-mouthed. That describes everything that walks, flaps or just sits and grows. Ever see a plant with teeth—that bite? I don’t think you want to. You’d have to be on Pyrrus and that means you would be dead within seconds of leaving the ship. Even I’ll have to take a refresher course before I’ll be able to go outside the landing buildings. The unending war for survival keeps the life forms competing and changing. Death is simple, but the ways of dealing it too numerous to list.”
     “I suppose there is no logical reason why we should stay and fight this endless war. Except that Pyrrus is our home.” The last piece of gravy-soaked bread vanished and he waved the empty fork at Jason. “Be happy you’re an offworlder and will never have to see it.”

     They were all there ahead of him, two of the men rolling transparent cylinders from a nearby room. From their obvious weight and the way they clanged when they bumped, Jason knew they were made of transparent metal. He couldn’t conceive any possible use for them. Empty cylinders a meter in diameter, longer than a man. One end solid, the other hinged and sealed. It wasn’t until Kerk spun the sealing wheel and opened one of them that their use became apparent.
     “Get in,” Kerk said. “When you’re locked inside, you’ll be carried out of the ship.”
     “Thank you, no,” Jason told him. “I have no particular desire to make a spectacular landing on your planet sealed up like a packaged sausage.”
     “Don’t be a fool,” was Kerk’s snapped answer. “We’re all going out in these tubes. We’ve been away too long to risk the surface without reorientation.”

     Jason did feel a little foolish as he saw the others getting into tubes. He picked the nearest one, slid into it feet first, and pulled the lid dosed. When he tightened the wheel in the center, it squeezed down against a flexible seal. Within a minute the CO2 content in the closed cylinder went up and an air regenerator at the bottom hummed into life.
     Kerk was the last one in. He checked the seals on all the other tubes first, then jabbed the airlock override release. As it started cycling, he quickly sealed himself in the remaining cylinder. Both inner and outer locks ground slowly open and dim light filtered in through sheets of falling rain.
     For Jason, the whole thing seemed an anticlimax. All this preparation for absolutely nothing. Long, impatient minutes passed before a lift truck appeared driven by a Pyrran. He loaded the cylinders onto his truck like so much dead cargo. Jason had the misfortune to be buried at the bottom of the pile so could see absolutely nothing when they drove outside.

     It wasn’t until the man-carrying cylinders had been dumped in a metal-walled room, that Jason saw his first native Pyrran life.
     The lift truck driver was swinging a thick outer door shut when something flew in through the entrance and struck against the far wall. Jason’s eye was caught by the motion; he looked to see what it was when it dropped straight down toward his face.
     Forgetful of the metal cylinder wall, he flinched away. The creature struck the transparent metal and clung to it. Jason had the perfect opportunity to examine it in every detail.
     It was almost too horrible to be believable. As though it were a bearer of death stripped to the very essentials. A mouth that split the head in two, rows of teeth, serrated and pointed. Leathery, claw-tipped wings, longer claws on the limbs that tore at the metal wall. Terror rose up in Jason as he saw that the claws were tearing gouges in the transparent metal. Wherever the creature’s saliva touched, the metal clouded and chipped under the assault of the teeth.
     Logic said these were just scratches on the thick tube. They couldn’t matter. But blind, unreasoning fear sent Jason curling away as far as he could. Shrinking inside himself, seeking escape.
     Only when the flying creature began dissolving did he realize the nature of the room outside. Sprays of steaming liquid came from all sides, raining down until the cylinders were covered. After one last dash of its jaws, the Pyrran animal was washed off and carried away. The liquid drained away through the floor and a second and third shower followed.

From DEATHWORLD by Harry Harrison (1960)

Cemetery Planets

RocketCat sez

If you're a writer, the point of fabulous planets is to be fabulous. If you novel is set on a planet about as exciting as the town of Resume Speed Flyover-State (population 230, 170, 78 and still growing!) you are starting out on the wrong foot. Grab your reader's attention with every trick you've got or get used to seeing your work on the clearance shelf.

And the old reliable attention-getter is Death. Tends to make people sit up and take notice, it does.

Sterile planets that never had life in the first place are a milli-credit a kilo-pack. And there really isn't any "death" when there was no "life" in the first place. So setting your novel on sterile planet is just as boring as setting it on any of the interchangeable faceless outer moons of the solar system. Astronomers may find them fascinating but to the great unwashed it is the big Ho-Hum. Same-old, same-old.

To play the Death card and perk up the reader's interest there has to have been something previously living. Say a planet with ruins belonging to an alien interstellar empire which went extinct before Terran fish decided to evolve into land creatures. This will take a bit of the glaze out of the reader's eye even if the empire and the alien species quietly died of old age after a long boring decadence. This is an "extinct" planet.

But if you want to kick it up a notch, have the species die abruptly and violently. A "murdered" planet. That will wake up the readers. Have their planets suffer the scars of cosmic civil war, with craters where cities used to be and lots of collateral damage. Some still glowing faintly blue with Cherenkov radiation. Even if the last bomb dropped a billion years ago, this will look like an allegory for our current times. Well, at least an allegory for readers who grew up during the Cold War and can remember Bert the Turtle advising them to "Duck and Cover." That film should have been about bending over to kiss your buns good-bye, but I digress.

You the writer can just imagine all the purple prose you can write about the arid lifeless landscape with skeletal wrecked buildings, skeletal burnt forests, and skeletal skeletons of alien unburied bodies.

To turn it up to 11, have your space explorers discover a murdered planet that apparently was murdered last Wednesday. And not from a civil war, but instead by Something From Outside. Indeed by Something that might still be lurking in the general area so GO TO BATTLE STATIONS RIGHT NOW AND DOUSE THAT LIGHT!!

Planets with no life are rather common (just look at our own solar system) and are rather boring. But nothing can beat the grim feeling of mortality engendered by examining a planet that used to have life. Especially if all the life died off rather abruptly.

A Forerunner planet is not too depressing if the culture basically died of old age. No more depressing than your average archeological dig. But if the entire planet still glows blue from an age-old nuclear armageddon, well, the explorers can't help but wonder if the political situation back home has taken a turn for the worse while they've been away.

If the survey team is lucky they will have advanced warning about the presence of a dead planet when astronomers light-years away detect necrosignatures.

How can planets die? Let me count the ways. The standard ways are:

...keeping in mind that most of these methods work equally well for a planetary civilization committing suicide or a planetary civilization exterminated by alien invaders. For more exotic apocalypses go here.


(ed note: in the ANTARES universe, starships move FTL by utilizing naturally-occurring "foldpoint." The planet Alta around the star Valeria was colonized from the planet New Providence around the star Napier. One fine day, Valeria's sole foldpoint vanishes. Valeria is cut off from the other human worlds

120 years later, the people at Valeria observe the star Antares going supernova as the wave front of the explosion reaches Valeria. Since Antares is exactly 120 light-years away, astronomers quickly realize the supernova is the reason the foldpoint vanished. And the distance is the reason why the foldpoint has abruptly reappeared.

An expedition to their mother world of New Providence is set up. But they realize the results will be grim. New Providence is only 15 light-years from Antares, so the radiation from the supernova sterilized the entire New Providence system. Hopefully they had at least one foldpoint that was not disrupted by the supernova, otherwise three billion people died horribly.

When the Valeria expedition reaches New Providence, they do expect to see all the cities abandoned, and all plant & animal life dead. What they found was a very rude surprise)

      Drake ordered Discovery to full alert twenty days and sixteen hours after leaving the foldpoint. As the General Quarters alarms wailed through the ship, New Providence was a blue-white marble on the main control room viewscreen. Off to one side was Laertes, New Providence’s rather sizable moon, a gray-white sphere that early New Providential poets had compared to Earth’s Luna.
     Shortly after the fleet had rounded Napier, Drake had met with Discovery’s scout pilots. “Before I commit the fleet to a close orbit of New Providence, gentlemen, I want to make damned sure that it’s safe to do so. Therefore, we will launch all four armed scouts while the fleet is still two million kilometers from the planet. Catherine and Drunkard will make a quick pass just outside the atmosphere to obtain reconnaissance views of two major urban areas on opposite sides of the globe. You can use the old maps to pick your targets. Flying Fool and Gossamer Gnat will follow close behind, but will decelerate sufficiently to enter opposing north-south polar orbits. I want at least two complete circuits of the planet before the fleet arrives.
     “Unless one of you waves us off, Discovery will take up a high guard, north-south parking orbit while City of Alexandria does the same close in. The two tankers will take up positions at the New Providence-Laertes L4 and L5 points, where they will act as ground-to-orbit communications relays, if and when such are required.”

     The scouts had spent the rest of the voyage refining the basic plan. By the time Discovery reached the specified distance from New Providence, they were eager to be on their way.
     “Are you ready, Lieutenant Hall?” Drake asked.
     “Ready, sir,” the commander of Discovery’s scout force said from out of the screen at Drake’s console. As in the approach to Conqueror, Drake planned to send his scouts in before risking any of the fleet’s ships. He wondered if he was again sending them to rendezvous with a derelict.
     “You may launch when ready,” Drake said to Hall.
     “Understood, Captain. We are launching now. Open hangar bay doors!”

     The first pictures from Catherine and Drunkard began coming in some four hours later. Discovery’s crew had been on full alert for all that time, scanning their instruments and checking their weapons. For all that time, the tension had been building aboard the battle cruiser. Every second that passed without someone detecting the presence of man on the ancestral home of all Altans brought with it a firmer realization that their worst fears might well be confirmed. New Providence had been a world of three billion souls; and now it was as silent as a tomb.
     The first long-range tele-views came from Scout Boat Drunkard. It showed a planetary limb, a blue ocean, and the unfamiliar shoreline of a continent. As they watched, the continent grew in size with surprising rapidity, an indication of the speed with which the scout was closing on the planet.
     “What is Drunkard’s target?” Drake asked.
     “Regensburg,” Lieutenant Cristobal answered. “The records indicate that it is the major metropolis in the northern hemisphere. Catherine will arrive five minutes later, and will over-fly a city named Terra Nova.”
     The view jumped once as Scout-Pilot Marman ordered a switch to a higher magnification. The scene was suddenly frozen on the screen as the computer chose a single frame from Drunkard’s orbital mapping camera. The view was of the outskirts of the city of Regensburg taken at a slant angle of 45 degrees.
     Regensburg had been built on a series of rolling, forested hills. The screen showed equal parts of city and forest. The forest was dead. Bare trunks jutted skyward, sprouting stick-like branches in geometric symmetry. Many trees had been uprooted by windstorms. Their corpses lay scattered randomly among the upright bodies of their brethren. In some areas, the tangle of deadwood approached jungle proportions, as if the natural process of decay had been halted.
     “No microorganisms,” Drake muttered to no one in particular. “The planet must be sterile.”
     He switched his gaze to the city. It, too, was the color of dead plants; and like the forest, showed signs of weather damage; yet with a degree of preservation unexpected in a hundred-year-old ruin.
     “Scout Marman reports his flyby complete. He is headed out into space,” Slater reported from the communicator’s station.
     “How many frames did he get?”
     “Fifty thousand, Captain, all received and ready for processing. Catherine reports coming up on Terra Nova.”

     Drake turned his attention back to the main viewscreen. Again, there was a view of the planet’s limb. Again, the camera was switched over to high magnification, and a single frame was frozen on the control room viewscreen. This time the view was centered on a large city. However, where Regensburg had looked as though its inhabitants had stepped away for a moment, Terra Nova was a shambles. Everywhere, blackened steel frameworks jutted skyward from piles of masonry, toppled towers lay where they had smashed across parked groundcars, and hollow shells stood guard over collapsed interiors. The sight of the destruction sent a shiver through Drake’s soul.
     “Some kind of out-of-control fire?” Argos Cristobal asked.
     “It was an out-of-control fire, all right,” Bethany Lindquist responded, her voice filled with horror. “Look at the way the outlying buildings all seem to have toppled away from the central point. I have seen that pattern before in history tapes. That city did not burn of its own accord. Someone exploded a nuclear weapon on it!

     It had taken the fleet four hours after the initial flybys to reach New Providence. For half that time, the expedition’s scientists had pored over the panoramic views transmitted by Drunkard and Catherine, or had watched the unfolding of still greater panoramas as the other two armed scouts took up their stations just outside the atmosphere. The additional observations confirmed what they had already surmised. New Providence was indeed a dead world.
     Everywhere they looked, they found desolation and the remains of once-living things. As far as could be seen from orbit, nothing lived on the surface of the planet. Nor had the world died peacefully. Terra Nova was not to the only city that had died by the sword. The orbital survey crews counted more than five hundred blast-damaged areas on the planet, including many that had been the victims of more than one strike.

From ANTARES DAWN by Michael McCollum (1986)

“It must be a beacon, a marker—but for whom—run by whom—?”

“Must it be run by anyone?” asked Rolth thoughtfully. “Remember Tantor—”

Tantor, the sealed city. Its inhabitants had been overwhelmed by a ghastly plague two centuries ago. Yes, he recalled Tantor well. Once he had flown above the vast bubble which enclosed it in an eternal prison for the safety of the galaxy, and had watched the ancient machines going about their business below, running a city in which no living thing walked or ever would walk again. Tantor had had its beacons too, and its appeals for help streaming into the skies mechanically long after the hands which had set them going had been dust. Behind those hills ahead might well rest another Tantor—it would explain the puzzle of a fair but deserted world.

From STAR RANGERS by Andre Norton, 1953.
Collected in STAR SOLDIERS (2001), currently a free eBook in the Baen free library.

Every so often in the kaleidoscope of life, they would be shown something they came to call a black world. They came close to the first one six months after the division.

They found themselves looking down on a planet which had once been like the others, but was now black waste and ruined cities. The mountains of the planet had jutted treeless into the sky like the exposed bones of a corpse, and the sky itself was black where once it had been blue and green and orange.

The seas which had been the womb of life were its final refuge, for there bacteria, the last things to survive, fought to consume the floating debris washed down by the flood Waters of a thousand years, and to turn it into an all-embracing scum which would s eventually suffocate even this activity.

It was a long time before they saw another world which had shared a similar fate, and they never approached so closely again.

From NOAH II by Roger Dixon (1970)

(ed note: The free trader crew of the Solar Queen purchase the rights to a planet in a Survey Auction. And quickly discover they've bought a pig in a poke.)

      THEY WERE ALL in the mess cabin again, the only space in the Queen large enough for the crew to assemble. Tang Ya set a reader on the table while Captain Jellico slit the packet and brought out the tiny roll of film it contained. Dane believed afterwards that few of them drew a really deep breath until it was fitted into place and the machine focused on the wall in lieu of the regular screen.
     “Planet—Limbo—only habitable one of three in a yellow star system—” the impersonal voice of some bored Survey clerk droned through the cabin.
     On the wall of the Queen appeared a flat representation of a three world system with the sun in the centre. Yellow sun—perhaps the planet had the same climate as Terra! Dane’s spirits soared. Maybe they were in luck—real luck.
     “Limbo—” that was Rip wedged beside him. “Man, oh, man, that’s no lucky name—that sure isn’t!”
     But Dane could not identify the title. Half the planets on the trade lanes had outlandish names didn’t they—any a Survey man slapped on them.
     “Co-ordinates—” the voice rippled out lines of formulae which Wilcox took down in quick notes. It would be his job to set the course to Limbo.
     “Climate—resembling colder section of Terra. Atmosphere—” more code numbers which were Tau’s concern. But Dane gathered that it was one in which human beings could live and work.

     The image in the screen changed. Now they might be hanging above Limbo, looking at it through their own view ports. And that vision was greeted with at least one exclamation of shocked horror.

     For there was no mistaking the cause of those brown-grey patches disfiguring the land masses. It was the leprosy of war—a war so vast and terrible that no Terran could be able to visualize its details.
     “A burnt off!” that was Tau, but above his voice rose that of the Captain’s.
     “It’s a filthy trick!”

     “Hold it!” Van Rycke’s rumble drowned out both outbursts, his big hand shot out to the reader’s control button. “Let’s have a close up. North a bit, along those burn scars—”
     The globe on the screen shot towards them, enlarging so that its limits vanished and they might have been going in for a landing. The awful waste of the long ago war was plain, earth burned and tortured into slag, maybe still even poisonous with radioactive wastes. But the Cargo-Master had not been mistaken, along the horrible scars to the north was a band of strangely tinted green which could only be vegetation. Van Rycke gave a sigh of satisfaction.
     “She isn’t a total loss—” he pointed out.
     “No,” retorted Jellico bitterly, “probably shows just enough life so we can’t claim fraud and get back our money.”

     “Forerunner ruins?” the suggestion came from Rip, timidly as if he felt he might be laughed down.
     Jellico shrugged. “We aren’t museum men,” he snapped. “And where would we have to go to make a deal with them—off Naxos anyway. And how are we going to lift from here now without cash for the cargo bond?”
     He had hammered home every bad point of their present situation. They owned ten-year trading rights to a planet which obviously had no trade—they had paid for those rights with the cash they needed to assemble a cargo. They might not be able to lift from Naxos. They had taken a Free Trader’s gamble and had lost.

     Only the Cargo-Master showed no dejection. He was still studying the picture of Limbo.
     “Let’s not go off with only half our jets spitting,” he said mildly. “Survey doesn’t sell worlds which can’t be exploited—”
     ”Not to the Companies, no,” Wilcox commented, “but who’s going to listen to a kick from a Free Trader—unless he’s Cofort!”
     “I still say,” Van Rycke continued in the same even tone, “that we ought to explore a little farther—”
     “Yes?” Jellico’s eyes held a spark of smouldering anger. “You want us to go there and be stranded? She’s burnt off—so she’s got to be written off our books. You know there’s never any life left on a Forerunner planet that was assaulted—
     “Most of them are just bare rock now,” Van Rycke said reasonably. “It looks to me as if Limbo didn’t get the full treatment. After all—what do we know about the Forerunners—precious little! They were gone centuries, maybe even thousands of years, before we broke into space. They were a great race, ruling whole systems of planets, and they went out in a war which left dead worlds and even dead suns swinging in its wake. All right.
     “But maybe Limbo was struck in the last years of that war, when their power was on the wane. I’ve seen the other blasted worlds—Hades and Hel, Sodom, and Satan, and they’re nothing but cinders. This Limbo still has vegetation. And because it isn’t as badly hit as those others I think we might just have something—

     He is winning his point, Dane told himself—noticing the change of expression on the faces around the table. Maybe it’s because we don’t want to believe that we’ve been taken so badly, because we want to hope that we can win even yet. Only Captain Jellico looked stubbornly unconvinced.
     “We can’t take the chance,” he repeated, his lips in an obstinate line. “We can fuel this ship for one trip—one trip. If we make it to Limbo and there’s no return cargo—well,” he slapped his hand on the table, “you know what that will mean—dirt-side for us!”
     Steen Wilcox cleared his throat with a sharp rasp which drew their attention. “Any chance of a deal with Survey?” he wanted to know.
     Kamil laughed, scorn more than amusement in the sound. ”Do the Feds ever give up any cash once they get their fingers on it?” he inquired.

     No one answered him until Captain Jellico got to his feet, moving heavily as if some of the resilience had oozed out of his tough body.
     “We’ll see them in the morning. You willing to try it, Van?”
     The Cargo-Master shrugged. “All right, I’ll tag along. Not that it’ll do us any good.”
     “Blasted—right off course—”
     Dane stood again at the open hatch looking out into a night made almost too bright by Naxos’ twin moons. Kamil’s words were not directed to him, he was sure. And a moment later that was confirmed by an answer from Rip.

     “I don’t call luck bad, man, ’til it up and slaps me in the face. Van had an idea—that planet wasn’t blasted black. You’ve seen pictures of Hel and Sodom, haven’t you? They’re cinders, as Van said. This Limbo, now—it shows green. Did you ever think, Ali, what might happen if we walked on to a world where some of the Forerunners’ stuff was lying around?”
     “Hm—” the idea Rip presented struck home. “But would trading rights give us ownership of such a find?”
     “Van would know—that’s part of his job. Why—” for the first time Rip must have sighted Dane at the hatch, “here’s Thorson. How about it, Dane? If we found Forerunner material, could we claim it legally?”
     Dane was forced to admit that he didn’t know. But he determined to hunt up the answer in the Cargo-Master’s tape library of rules and regulations.
     “I don’t think that the question has ever come up,” he said dubiously. “Have they ever found usable Forerunner remains—anything except empty ruins? The planets on which their big installations must have been are the burnt off ones—

     “I wonder,” Kamil leaned back against the hatch door and looked at the winking lights of the town, “what they were like. All of the strictly human races we have encountered are descended from Terran colonies. And the five non-human ones we know are all as ignorant of the Forerunners as we are. If they left any descendants we haven’t contacted them yet. And—” he paused for a long moment before he added, “did you ever think it is just as well we haven’t found any of their installations? It’s been exactly ten years since the Crater War—
     His words trailed off into a thick silence which had a faint menacing quality Dane could not identify, though he understood what Kamil must be aiming at. Terrans fought, viciously, devastatingly. The Crater War on Mars had been only the tail end of a long struggle between home planet and colonist across the void. The Federation kept an uneasy peace, the men of Trade worked frantically to make that permanent before another and more deadly conflict might wreck the whole Service and perhaps end their own precarious civilization.
     What would happen if weapons such as the Forerunners had wielded in their last struggle, or even the knowledge of such weapons, fell into the wrong Terran hands? Would Sol become a dead star circled by burnt off cinder worlds?
     “Sure, it might cause trouble if we found weapons,” Rip had followed the same argument. “But they had other things besides arms. And maybe on Limbo—”

From SARGASSO OF SPACE by Andre Norton (1955)

(ed note: Brad is showing Ivo views from planets thousands of light-years away by using handwavium technology called a Macroscope)

"You're being subjective," Brad said. "Compare these."

And the screen showed an angelic humanoid face, feminine and altogether lovely. The eyes were great and golden, the mouth small and sweet. Above the still features flowed a coiffure of down, neither hair nor feathers, greenish but softly harmonious. Below the face a silken robe covered a slender body, but Ivo could tell from its configuration that the gentle curves of the torso were not precisely mammalian. It was as though a human woman had evolved into a more sublime personage, freed from the less esthetic biological functions.

It was a painting; as Brad decreased the magnification the frame came into view, then the columns and arches of an elegant setting. A museum, clean and somber, styled by a master architect.

"Intelligent, civilized, beautiful," Ivo murmured. "But where are the living ones?"

"There are no living creatures on Planet Mbsleuti. This is a royal tomb, as nearly as we can ascertain — one of the few to be buried deeply enough to endure."

"Endure what?"

Suddenly the scene was a heaving sea of sludge, breaking against a barren beach. Ivo could almost smell the contamination of the smoky atmosphere.

"Total pollution," Brad said. "Earth, air, water. We have analyzed the content and determined that all of it is artificial. They became dependent on their machines for their existence, and could not control the chemical and atomic waste products. Want to bet where they got their fresh meat, just before the end? But it only hastened their extinction as a species."

The picture of the royal woman was back, mercifully, but Ivo still saw her devastated world. "Because they overextended their resources?" he asked, requiring no answer. "Would not limit themselves until Nature had to do it for them?" He shook his head.

From MACROSCOPE by Piers Anthony (1969)

As if beckoned by those who had gone before, I half-floated between the titanic snowdrifts, quivering and afraid, into the sightless vortex of the unimaginable.

Screamingly sentient, dumbly delirious, only the gods that were can tell. A sickened, sensitive shadow writhing in hands that are not hands, and whirled blindly past ghastly midnights of rotting creation, corpses of dead worlds with sores that were cities, charnel winds that brush the pallid stars and make them flicker low. Beyond the worlds vague ghosts of monstrous things; half-seen columns of unsanctifled temples that rest on nameless rocks beneath space and reach up to dizzy vacua above the spheres of light and darkness. And through this revolting graveyard of the universe the muffled, maddening beating of drums, and thin, monotonous whine of blasphemous flutes from inconceivable, unlighted chambers beyond Time; the detestable pounding and piping whereunto dance slowly, awkwardly, and absurdly the gigantic, tenebrous ultimate gods the blind, voiceless, mindless gargoyles whose soul is Nyarlathotep.

From NYARLATHOTEP by H. P. Lovecraft (1920 )

As has happened so often in the past, the challenge may be too great. We may establish colonies on the planets, but they may be unable to maintain themselves at more than a marginal level of existence, with no energy left over to spark any cultural achievements.

History has one parallel as striking as it is ominous, for long ago the Polynesians achieved a technical tour-de-force which may well be compared with the conquest of space. By establishing regular maritime traffic across the greatest of oceans, writes Toynbee, they "won their footing on the specks of dry land which are scattered through the watery wilderness of the Pacific almost as sparsely as the stars are scattered through space."

But the effort defeated them at last, and they relapsed into primitive life. We might never have known of their astonishing achievement had it not left, on Easter Island, a memorial that can hardly be overlooked.

There may be many Easter Islands of space in the aeons to come — abandoned planets littered not with monoliths but with the equally enigmatic debris of another defeated technology.

From PROFILES OF THE FUTURE by Arthur C. Clarke

I met a traveler from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shatter'd visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamp'd on these lifeless things,
The hand that mock'd them and the heart that fed.
And on the pedestal these words appear:
"My name is Ozymandias, king of kings:
Look on my works, ye mighty, and despair!"
Nothing beside remains: round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.

From "OZYMANDIAS" by Percy Bysshe Shelley (1818)

(ed note: Percy Shelley and his friend Horace Smith were in a friendly competition to write a sonnet about the new statue of Ramesses II in the British Museum. Smith's sonnet is similar in story and moral point, but includes a science fiction bit about a hunter of the future looking at the ruins of London. Sort of like an 1800's version of the ending of Planet of the Apes.)

In Egypt's sandy silence, all alone,
Stands a gigantic Leg, which far off throws
The only shadow that the Desert knows:—
"I am great OZYMANDIAS," saith the stone,
"The King of Kings; this mighty City shows
"The wonders of my hand."— The City's gone,—
Nought but the Leg remaining to disclose
The site of this forgotten Babylon.

We wonder,—and some Hunter may express
Wonder like ours, when thro' the wilderness
Where London stood, holding the Wolf in chace,
He meets some fragment huge, and stops to guess
What powerful but unrecorded race
Once dwelt in that annihilated place

From OZYMANDIAS by Horace Smith (1818)

Thundering Worlds

If you are fixated on the concept of "bigger is better," then it is hard to beat the idea of a spaceship the size of a planet. Or a planet converted into a spaceship.

Well, maybe if you converted a Ringworld into a Bussard Ramjet to make a starship one astronomical unit in radius. That would be bigger.

Hang on, you could turn a star into a Shkadov thruster and turn an entire freaking solar system into a spaceship. Please pardon me, I have to go lie down a minute, my head hurts.

Please note that in our galaxy there are some real stars that are moving unusually fast.

Runaway stars are clipping along at around 100 kilometers per second. They are thought to be binary stars which passed too close to another star so one star got sling-shotted out. Or one star of a binary star system where the other blew up in a supernova. For science fictional purposes some sinister alien race converted their sun into a Shkadov thruster so they could go cruising for trouble.

A good example is Barnard's Star aka "Barnard's Runaway Star" or "Greyhound of the Skies". Astronomers measured the lateral speed and the radial velocity to calculate a space velocity of 142 km/s which is smokin'. And it is only 1.8 parsecs away (5.98 light-years), making it the fourth-closest star to the Sun. Jack Williamson used this in his novel The Legion of Space, home of the dreaded giant jellyfish-like Medusae who drive their solar system like a rocketship to invade innocent planets.

Hypervelocity stars on the other hand are screaming along like the proverbial bat-outta-hell. They move at about 1,000 km/s, which is quite a bit more than the galaxy's escape velocity. They are thought to have been sling-shotted by the Sagittarius A* supermassive black hole at the center of the galaxy. For science fictional purposes they are Shkadov thruster stars with the pedal to the metal, doing their best to get the heck outta Dodge ASAP. The important plot question being: what do they know that we don't? Apparently there is some awful thing that terrifies a civilization powerful enough to thrust their entire solar system up to a thousand klicks a second.


(ed note: Bussard Ramjet pilot Corbett was sent by The State totalitarian regime on an interstellar trip, but he goes his own way. Later he comes back to Terra after a relativistic trip lasting a few hundred millennia. He notices many small changes, such as the sun is burning hotter and Terra is now orbiting Jupiter. The State seems to have died out, replaced by two genetically engineered factions called the Boys and the Girls.)

      "Watch the show.”
     Certain stars glowed more brightly than others… and planetary systems circled them, greatly enlarged for effect. Now all but two of these systems turned sullen red—turned enemy. These were the worlds that had turned against the State.
     One of the red systems sparkled and faded into the background, its colony destroyed.
     The two neutral systems went red.
     Another system faded out.
     The view closed on Sol system… on more of Sol system than Corbell had known, with three dark gas giants beyond Pluto, and countless swarming comets.
     Fleets of spacecraft moved out toward the renegade colonies. Other fleets invaded. Sometimes they came like a hornet’s nest, many ships clustered around a Bussard ramjet core. Sometimes like a Portuguese man-of-war: thousands of ships as weights around the fringe of a great silver light-sail. Early fleets included hospital ships and return fuel; later there were massive suicide attacks.
     It went on for centuries. The State utopia became a subsistence civilization, turning all its surplus energy to war. The fleets moved at just less than lightspeed. News of success or failure or need for reinforcements moved barely faster. The State was Boys and Girls and dictators all united for the common good. Corbell hurt with the loss of that unity.

     He watched a beam of light bathe Sol system: laser cannon firing from Farside colony. Farside launched warships by light-sail at terrific accelerations. The ships dropped their sails and decelerated most of the way to Sol, arriving just behind the beam itself, long before the State could prepare. Corbell squirmed in his chair; he wanted to cry warning. For the State beat the invaders back, but failed to stop their hidden treachery.
     The war continued. Farside, economically ruined by its effort, fell before the counterattack. It took a man’s lifetime… too much time, before Astronomy noticed what the Farside traitors had done in the dark outside their dazzling light beam, in the distraction provided by the invasion.
     The State had looked for the light of fusion spacecraft, not the dim watery light of a new planet. The trans-Plutonian planet called Persephone had had a peculiar orbit, tilted nearly vertical to the plane of the solar system. Its new path had already taken it deep into the system.
     10 to the power 23 tons of hydrogen and hydrogen-compound ices were aimed to strike the sun at solar-escape velocity. Earth’s oceans would boil…

     The State did what it could. Tens of thousands of fusion bombs, Sol system’s entire armory, were set off at the dawn side of Persephone, just above the atmosphere. A thick rind of the planet’s atmosphere peeled away and streamed off like a comet’s tail, its mass pulling at Persephone’s dense core. A streamer of gas far more massive than the Earth broke free, and rounded the sun, and sprayed back toward the cometary halo.
     If the bombs could have been placed earlier, Persephone’s core would have done the same. It was rock and iron, yellow-hot, and it glowed X-ray hot as it streaked into the solar photosphere and disappeared.

     The sun grew bright.

     Oceans shrank, crops withered, tens of millions died before the State could place a disk of reflecting tinsel between Earth and Sol. It was a temporary measure. The sun’s new heat was permanent, at least on the human scale of time. Fusion would run faster in Sol’s hotter interior. The buried heat would leak to the photosphere and out.

     The State had one chance for survival. It could move the Earth by the method Farside had used to stop Persephone cold in its orbit.
     The State had had to abandon the Mercury mines: a serious industrial handicap. Nonetheless they were building something out there in the asteroid belt—something huge, like a starship big enough to carry the whole human race to safety. But no, that wasn’t it. Corbell was fascinated. He knew it might be the memory RNA, but he was fascinated anyway. He hardly heard what Skatholtz was saying: “It was sensible, Corbell. The Girls who made the light show ruled the sky. You are familiar with such things. Do you know now who hurled a moon at us?”
     “Not yet. Shut up and let me…”
     They had finished the thing. Two tubes, concentric, each a hundred miles long; the inner tube a mile wide, with thick walls of complex construction; the outer tube thinner and twice as wide. At one end, a bell-shaped rocket nozzle. At the other… Corbell knew more than he was seeing. Reworked military laser cannon, and vents, and a flared skirt, and thick stubby fins, there at the bottom end. Now temporary liquid hydrogen tanks were attached. Now the structure moved under its own power… it was a tremendous fusion motor… moving outward, circled by tiny ships… yeah.

     Corbell said, “How do you climb down off an elephant?”
     “Should I know that?”
     “You don’t climb down off an elephant. You climb down off a duck.” (1950s era grade-school joke. No, it wasn't funny back then either)
     “It’s so much safer. How do you move the Earth?
     Small wonder if the light show meant little to Skatholtz. Watching the construction of the motor—in the naked sunlight and sharp-edged, totally black shadows of space—was bewildering. The diagrams made sense to an architect, but they were only rotating lines to Skatholtz. But without bottled memory and without Corbell’s career in space, Skatholtz was still bright enough to makesome sense of what he was seeing.

     “You move something else,” Skatholtz said. “The damage done by the rocket’s thrust and by mistakes you might make will not kill anyone if nobody lives on the working body. Then the working body can be moved until the world falls toward it as a rock falls to the ground. What was the working body? Ganymede?”
     “Uranus. Can you stop the light show at that picture?”
     The lecture froze on an “artist’s conception”: a blurred, curved arc of Uranus’s upper atmosphere. The motor looked tiny floating there. Corbell said, “You see? It’s a double-walled tube, very strong under expansion shock. It floats vertical in the upper air. Vents at the bottom let in the air, which is hydrogen and methane and ammonia, hydrogen compounds, like the air that the sun burns. You fire laser cannon up along the axis of the motor, using a… color hydrogen won’t let through (light frequency that hydrogen absorbs). You get a fusion explosion along the axis.
     “I don’t understand all your words. Fusion?”
     “Fusion is the way a star burns. You probably used fusion bombs against the Girls.”
     “Okay. The hydrogen fusions in the middle of the motor—
     “—and the explosion goes out and up. It’s hottest along the axis, cooler when it reaches the walls of the motor. The whole mass blasts out the top, through the flared end. It has to have an exhaust velocity way higher than Uranus’s escape velocity. The motor goes smashing down into deeper air. You see there’s a kind of flared skirt at the bottom. The deep air builds up there at terrific pressure, stops the tube and blasts it back up. You fire it again.

     “Elegant,” said Skatholtz.
     “Yeah. Nobody’s there to get killed. Control systems in orbit. The atmosphere is fuel and shock absorber both—and the planet is mostly atmosphere. Even when it’s off the motor floats high for awhile, because it’s full of hot hydrogen compounds. If you let it cool off it sinks, of course, but you can bring it back up to high atmosphere by heating the tube with the laser, firing it almost to fusion. Start the light show again, will you?”
     Skatholtz barked something at Krayhayft. Corbell watched: Earth held out, barely. Heat-superconducting cables had to be run to the north polar cap to borrow its cold. The cap melted.
     Millions died anyway. No children were born; there wasn’t shelter for them. It took over a century to drop Uranus into place, six million miles ahead of the Earth in Earth’s orbit. The planet accelerated slowly, drawing Earth after it… and then sped up, to leave Earth behind, in a wider orbit. They lost the Moon.
     The sun expanded via its own internal heat. Light was reddened, but the greater surface lost more heat to space… to Earth. By now the Girls had charge of Uranus and the floating fusion motor. They moved the Earth again.
     Five times the Earth had to be moved. At one time it was circling precisely opposite Mars. Later, further out. Internally Sol’s fusion furnace had stabilized; but the photosphere was still growing. And the Earth must be moved a sixth time.

From A WORLD OUT OF TIME by Larry Niven (1976)

(ed note: the protagonist Louis Wu has been "hired" by an alien of the species Pierson Puppeteer to pilot a mission to a megastructure called a Ringworld. But first they have to stop at the Puppetter homeworld.)

     The pilot’s cabin was crowded. Louis hunched over the instrument panel, protecting buttons from the puppeteer’s careless hooves.
     “Spectroanalysis … yes. Now the blue-and-yellow double at two o’clock …
     “I have my bearings. Swing to 348, 72.”
     “What exactly am I looking for, Nessus? A cluster of fusion flames? No, you’d be using thrusters.”
     “You must use the scope. When you see it, you will know.”
     On the scope screen was a sprinkling of anonymous stars. Louis ran the magnification up until … “Five dots in a regular pentagon. Right?”
     “That is our destination.”
     “Good. Let me check the distance. — Tanj! (expletive. Acronym for There Ain't No Justice) That’s wrong, Nessus. They’re too far away.”
     No comment.
     “Well, they couldn’t be ships, even if the distance meter isn’t working. The puppeteer fleet must be moving at just under lightspeed. We’d see the motion.”
     Five dim stars, in a regular pentagon. They were a fifth of a light year distant and quite invisible to the naked eye. At present scope magnification they would have to be full sized planets. In the scope screen one was faintly less blue, faintly dimmer than the others.

     A Kemplerer rosette (sic. Should be Klemperer). How very odd.
     Take three or more equal masses. Set them at the points of an equilateral polygon and give them equal angular velocities about their center of mass.
     Then the figure has stable equilibrium. The orbits of the masses may be circular or elliptical. Another mass may occupy the center of mass of the figure, or the center of mass may be empty. It doesn’t matter. The figure is stable, like a pair of Trojan points.
     The difficulty is that there are several easy ways in which a mass can be captured by a Trojan point. (Consider the Trojan asteroids in Jupiter’s orbit.) But there is no easy way for five masses to fall accidentally into a Kemplerer rosette.

     “That’s wild,” Louis murmured. “Unique. Nobody’s ever found a Kemplerer rosette …” He let it trail off.
     Here between the stars, what could be lighting those objects?
     “Oh, no you don’t,” said Louis Wu. “You’ll never make me believe it. What kind of an idiot do you take me for?”
     “What is it that you will not believe?”
     “You know tanj well what I won’t believe!” (that the Puppeteers created the rosette)
     “As you please. That is our destination, Louis. If you will take us within range, a ship will be sent to match our velocity.”
     The rendezvous ship was a #3 hull, a cylinder with rounded ends and a flattened belly, painted shocking pink, and windowless. There were no engine apertures. The engines must be reactionless thrusters of the human type, or something more advanced.
     On Nessus’s orders Louis had let the other ship do the maneuvering. The Long Shot, on fusion drives alone, would have required months to match velocities with the puppeteer “fleet”. The puppeteer ship had done it in less than an hour, blinking into existence alongside the Long Shot with her access tube already reaching like a glass snake toward the Long Shot’s airlock.

     In the airlock the kzin stopped, suddenly caught by the sight of an expanding pentagon of stars.
     He could hardly have had a better view.
     The Long Shot, edging close in hyperdrive, had stopped half a light-hour ahead of the puppeteer “fleet”: something less than the average distance between Earth and Jupiter. But the “fleet” was moving at terrible speed, falling just behind its own light, so that the light which reached the Long Shot came from much further away. When the Long Shot stopped the rosette had been too small to see. It had been barely visible when Teela left the lock. Now it was impressively large, and growing at enormous speed.
     Five pale blue dots in a pentagon, spreading across the sky, growing, spreading …
     For a flashing instant there were five worlds around the Long Shot. Then they were gone, not fading but gone, their receding light reddened to invisibility.

     “Of course not,” said the puppeteer. “Doubtless you have been wondering about —”
     “Flying worlds,” the kzin interrupted.
     “And Kemplerer rosettes,” said Louis. “Okay, speak to us. Why flying worlds? Somehow it doesn’t seem safe to throw habitable worlds about with such gay abandon.
     “Oh, but it is, Louis!” The puppeteer was terribly earnest. “Much safer than this craft, for instance; and this craft is very safe compared to most human-designed craft. We have had much practice in the moving of worlds.
     “Practice! How did that happen?”
     “To explain this, I must speak of heat … and of population control. You will not be embarrassed or offended?”…

     …“But it does relate, Speaker. Half a trillion civilized beings produce a good deal of heat as a byproduct of their civilization. We had long since run out of farming land, and had been forced to terraform two worlds of our system for agriculture. For this it was necessary to move them closer to our sun.”
     “Your first experience in moving worlds. You used robot ships, of course.”
     “Of course … After that, food was not a problem. Living space was not a problem. We built high even then, and we like each other’s company.”…
     …“Our sole and only problem, at the time of which I speak, was heat.”
     “Heat is produced as a waste product of civilization.”
     “I fail to understand,” said Speaker-To-Animals.
     “An example. You would wish a light source at night, would you not, Speaker? Without a light source you must sleep, whether or not you have better things to do.”
     “This is elementary.”
     “Assume that your light source is perfect, that is, it gives off radiation only in the spectra visible to kzinti. Nonetheless, all light which does not escape through the window will be absorbed by walls and furniture. It will become randomized heat.
     “Another example. Earth produces too little natural fresh water for its eighteen billions. Salt water must be distilled through fusion. This produces heat. But our world, so much more crowded, would die in a day without the distilling plants.
     “A third example. Transportation involving changes in velocity always produces heat. Spacecraft filled with grain from the agricultural worlds produce heat on reentry and distribute it through our atmosphere. They produce more heat on takeoff.”
     “But cooling systems —”
     “Most kinds of cooling systems only pump heat around, and produce more heat for power.”
     “U-u-urr. I begin to understand. The more puppeteers, the more heat is produced.”
     “Do you understand, then, that the heat of our civilization was making our world uninhabitable?”

     “Incredible,” said Speaker-To-Animals. “Why didn’t you leave?”
     “Who would trust his life to the many deaths of space? Only such a one as me. Should we settle worlds with our insane?”…
     …They were of equal size: perhaps twice the angular diameter of the full Moon as seen from Earth. They formed a pentagram. Four of the worlds were circled by strings of tiny, glaring lights: orbital suns giving off artificial yellow-white sunlight. These four were alike in brightness and appearance: misty blue spheres, their continental outlines invisible at this distance. But the fifth …
     The fifth world had no orbital lights. It glowed by its own light, in patches the shapes of continents and the colors of sunlight. Between the patches was a black that matched the black of surrounding space; and this black, too, was filled with stars. The black of space seemed to encroach on continents of sunlight.
     “Incredible,” said Speaker-To-Animals. “I hardly dared believe it. You took your worlds with you.”
     “Puppeteers don’t trust spacecraft,” Louis said absently.…

     “But how?”
     “I had explained,” said Nessus, “that our civilization was dying in its own waste heat. Total conversion of energy had rid us of all waste products of civilization, save that one. We had no choice but to move our world outward from its primary.”
     “Was that not dangerous?”
     “Very. Then was much madness that year. For that reason it is famous in our history. But we had purchased a reactionless, inertialess drive from the Outsiders. You may guess their price. We are still paying in installments. We had moved two agricultural worlds; we had experimented with other, useless worlds of our system, using the Outsider drive. In any case, we did it. We moved our world.
     “In later millenia our numbers reached a full trillion. The dearth of natural sunlight had made it necessary to light our streets during the day, producing more heat. Our sun was misbehaving.
     “In short, we found that a sun was a liability rather than an asset. We moved our world to a tenth of a light year’s distance, keeping the primary only as an anchor. We needed the farming worlds and it would have been dangerous to let our world wander randomly through space. Otherwise we would not have needed a sun at all.”…
     …“Yes. Shortly after we finished moving our world, our sun began the process of expansion. Your fathers were still using the upper thigh bone of an antelope to crack skulls. When you began to wonder where our world was, you were searching the wrong orbits, about the wrong Suns.
     “We had brought suitable worlds from nearby systems, increasing our agricultural worlds to four and setting them in a Kemplerer rosette. It was necessary to move them all when the sun began to expand, and to supply them with sources of ultraviolet to compensate for the reddened radiation. You will understand that when the time came to abandon galaxy (when Beowulf Shaeffer discovered the galactic core was undergoing an explosion that would eventually sterilize the entire Milky Way), two hundred years ago, we were well prepared. We had had practice in moving worlds.”

From RINGWORLD by Larry Niven (1970)

      Runaway sun! Red, feeble, dying dwarf. Racing north­ward out of the constellation Ophiuchus, in mad flight from the Serpent and the Scorpion. Long ago christened "Barnard's Runaway Star," from its discoverer and its remarkable proper motion, it was the nearest star of the northern sky and the nearest found to have a habitable planet.
     "Please don't think I planned it, John! But the Medusae have tricked Eric—and the rest of us, it seems. They bargained to help us restore the Empire, in return for a shipload of iron. Now it seems they intend taking a good deal more."
     His gaunt frame shuddered.
     "They told me more of their history, just now, than Eric ever learned—and it's quite a history. They're old, John. Their sun is old. Their race was old, on that ghastly planet, before our Earth was ever born. They're too old, John—but they don't intend to die.
     "The remarkable motion of Barnard's Star, they tell me now, is a thing of their own accomplishment. Because the mineral resources of their own planet were used up long ago, they've arranged to visit others. In their career across the Galaxy, they live by looting the worlds they pass, and sometimes plant a colony—that's to be the fate of Earth, they tell me."
     He shook his white head with a sick, slow motion.
     "Please, John," he whispered, "don't think I ever intended that!"
     John Star and Jay Kalam stood voiceless with shock. The thing was unthinkable, but John Star knew it must be true. Reason insisted that the Medusae would scarcely join an interstellar war for a single cargo of iron. And Adam Ulnar's horrified remorse appeared sincere enough.
     Dazed, John Star pictured the doom of humanity. The System couldn't fight a science that built these black spider-ships of space and armed them with atomic suns for weapons; a science that fortified a planet with a belt of artificial satellites, and guided a star itself like a red corsair across the Galaxy.

From THE LEGION OF SPACE by Jack Williamson (1934)




Stellar scale

Most stellar scale Megastructure proposals are designs to make use of the energy from a sun-like star while possibly still providing gravity or other attributes that would make it attractive for an advanced civilization.

  • The Alderson disk is a theoretical structure in the shape of a disk, where the outer radius is equivalent to the orbit of Mars or Jupiter and the thickness is several thousand miles. A civilization could live on either side, held by the gravity of the disk and still receive sunlight from a star bobbing up and down in the middle of the disk.
  • A Dyson sphere (also known as a Dyson Shell) refers to a structure or mass of orbiting objects that completely surrounds a star to make full use of its solar energy.
  • A Matrioshka brain is a collection of multiple Concentric Dyson Spheres which make use of different wavelengths of light.
  • A Stellar engine either uses the temperature difference between a star and interstellar space to extract energy or serves as a Shkadov thruster.
  • A Shkadov thruster accelerates an entire star through space by selectively reflecting or absorbing light on one side of it.
  • Topopolis (also known as Cosmic Spaghetti) is a large tube that rotates to provide artificial gravity.

Planetary scale

  • An Orbital is a space habitat similar to but much smaller than a Niven Ring. Instead of being centered on a star, it is orbiting a star, thus its diameter is typically on the order of magnitude of a planet. By giving a tilt to its orbit, there's a convenient day and night experience on its surface.
  • Globus Cassus is a hypothetical proposed project for the transformation of Planet Earth into a much bigger, hollow, artificial world with the ecosphere on its inner surface. This model serves as a tool to understand the World's real functioning processes.
  • Cloud Nine is Buckminster Fuller's proposal for a tensegrity sphere of size a mile in radius which would be large enough so that it would float in the sky if heated by only one degree above ambient temperature, creating habitats for mini cities of thousands of people in each "Cloud Nine".

Orbital structures

  • Orbital ring is an enclosed loop slightly larger than the circumference of the Earth so that it can maintain low earth orbit.
  • The Bernal sphere is a proposal for a space colony with a maximum diameter of 16 kilometers.
  • The Stanford torus is a different design with a diameter just under 1.7 kilometers.
  • The O'Neill cylinder is yet another space colony proposal.


Stellar scale

  • The Dyson shell (including its variation, the ringworld) has appeared in many works of fiction, including the Star Trek universe.
  • Larry Niven's series of novels beginning with Ringworld centered on, and originated the concept of a ringworld, or Niven ring. A ringworld is an artificial ring with a radius roughly equal to the radius of the Earth's orbit (1 AU). A star is present in the center and the ring spins to create g-forces, with inner walls to hold in the atmosphere. The structure is unstable, and required the author to include workarounds in subsequent novels set on it.
  • In the manga Blame! the Megastructure is a vast and chaotic complex of metal, concrete, stone, etc., that covers the Earth and assimilates the Moon, and eventually expands to encompass a volume greater than the orbit of Jupiter.
  • In White Light by William Barton and Michael Capobianco, a Topopolis is presented as taking over the entire universe.
  • In the Heechee books by Frederik Pohl the race of pure energy beings called The Foe have constructed the Kugelblitz, a black hole made of energy and not matter.
  • In the Xeelee series of books by Stephen Baxter, the eponymous alien race constructed the Ring, a megastructure made of cosmic strings, spanning over 10 million light years.
  • In Freelancer, The Dom'Kavosh's Dyson shell that is inhabited by a drone race created by the Dom'Kavosh, Nomads. This is reached via a hyper gate, created by the same creators as the Dyson sphere.
  • The Saga of Cuckoo series novel Wall Around a Star mentions a proposal to build a super dyson sphere, completely enclosing the Galactic Center.
  • The title of the novel Helix by Eric Brown directly references a stellar-scale helical megastructure. Different types of environments and habitats are interspersed along the structure, while their varying distance from the central star affects the climate.
  • The Quarg in the game Endless Sky are shown building a massive ring around one of their stars, which is most likely around one astronomical unit in diameter. A completed version of this can also be found in another location.
  • In Space Empires 4 and 5, the player can construct sphereworlds and ringworlds around stars.

Planetary scale

  • Several structures from the fictional Halo universe:
    • The original twelve Halos, seen in Halo: Cryptum, were 30,000 kilometers in diameter; a separate array of six Halos are 10,000 kilometers in diameter, with one of the original twelve later being reduced to this size in Halo: Primordium.
    • The Ark is a 127,530 km diameter structure from which the Halo Array can be activated and capable of building 10,000 km Halos. The "greater" Ark, seen in Cryptum and Primordium, is capable of producing 30,000 km Halos.
    • Onyx is an artificial planet made entirely out of Forerunner Sentinels (advanced replicating robots). At its core is a "shield world", contained within slipstream space, that is approximately one astronomical unit in diameter. The much smaller Shield World 0459, (approximately 1,400 km in diameter), is the setting for the latter half of Halo Wars. A third shield world, Requiem, is the primary setting for Halo 4. Requiem is an artificial hollow planet encased in a kind of Dyson Sphere.
    • High Charity, the Covenant's mobile planetoid station
  • Death Star from Star Wars
  • In Sonic Adventure 2 and Shadow The Hedgehog, the Eclipse Cannon is a WMD built inside of the Space Colony Ark. It fires a laser so strong that it can destroy planets and pierce stars. The Eclipse Cannon can't work on its own, and requires at least one Chaos Emerald for it to be functional. Even with only a few Chaos Emeralds powering it, it is still capable of destroying entire cities.
  • Buster Machine III from Gunbuster.
  • Culture Orbital
  • In the 2013 CGI anime movie, Space Pirate Captain Harlock, the Jovian Accelerator is an ancient, Death Star-like Weapon of mass destruction that uses energy from Jupiter's atmosphere to create a large beam of intense light strong enough to destroy an entire planet.
  • Trantor, the capital of an interstellar empire in Isaac Asimov's Foundation series, is an ecumenopolis, a planet entirely covered in one huge metal clad building, with only one small green space: the Emperor's palace grounds.
  • Coruscant, capital city in the Star Wars universe, entirely covers its host planet. It serves as capital of first the Republic and then later the First Galactic Empire.
  • The Galaxy Gun from the Star Wars universe, a large space station designed to destroy entire planets from across the galaxy could be considered a megastructure because its size is more than seven kilometers long.
  • The Centerpoint Station, from the Star Wars universe, a 350 km spherical space station at the Lagrangian point between the planets Talus and Tralus in the Corellia system. It was a gigantic and ancient hyperspace tractor beam with which an ancient race, known as Celestials, created the Corellia star system. With the help of the tractor beam whole planets could be moved through hyperspace and arranged into their actual orbits acound the central star. On the other hand, the same technology could be used as weapon to destroy even stars. On the inside of the main sphere a huge living space called Hollowtown was home to many people in similar fashion as on the inside of a dyson sphere.
  • The Ori Supergate seen in a number of episodes of Stargate SG1 could be classed as a megastructure
  • In The Hitchhiker's Guide to the Galaxy series, Earth, as well as other planets, were artificial megastructures. Earth was intended to function as a gigantic computer, and was built by a race of beings who made their living by manufacturing other planets.
  • The Star Forge from Star Wars: Knights of the Old Republic
  • Mata-Nui in the BIONICLE franchise is classifiable as a megastructre. In the story he is a massive robot as tall as a planet, and inside his body, every inhabitant of the BIONICLE Universe (Matoran, Toa, etc.) all live, unaware that they live inside a massive, space-traveling entity.
  • In the Robotech Sentinels novels, Haydon IV is an artificially constructed cyber-planet with android citizens.
  • In the Invader Zim episode "Planet Jackers", two aliens surround the Earth with a fake sky in order to throw it into their sun.
  • Nightmare's fortress from Kirby: Right Back at Ya! can be classified as a megastructure because it's the size of a small planet.
  • In several works, Arthur C. Clarke writes about a colossal hollow tube, first described in Rendezvous with Rama (1973), and inhabited by different races.
  • The Citadel in the Mass Effect universe is an enormous space station constructed by an ancient race of machines called the Reapers millions of years before the games in the series. At the time of Mass Effect 2, its population is 13.2 million.
  • In the game Airforce Delta Strike a large Space Elevator called the Chiron Lift is used to send supplies out into outer space.
  • In the Warhammer 40,000 series, the Imperial Palace (site of the Golden Throne wherein the Emperor of Mankind is kept alive indefinitely) could be considered a megastructure. The palace is a complex of continent-wide structures with the Golden Throne being located in an area stretching across the whole of the Himalayan mountains.
  • In the film Elysium, a luxury space station (a Stanford Torus) called Elysium houses the wealthy population of the human species.

Megascale structures

Structures that might not be classified as "Megastructures" because they do not meet the requirements, but are indeed "Mega" sized structures/constructions.

Stellar scale

From the Wikipedia entry for MEGASTRUCTURE


     Robert Heinlein’s early story “Universe” has been imitated countless times by most of the writers in the business.
     The idea was this: Present-day physics poses a limit on the speed of an interstellar vehicle. The ships we send to distant stats will be on one-way journeys, at least at first. They will have to carry a complete ecology they couldn’t carry enough food and oxygen in tanks. Because they will take generations to complete their journeys, they must also carry a viable and complete society.
     Clearly we’re talking about quite a large ship, with a population in the hundreds at least: high enough to prevent genetic drift. Centrifugal force substitutes for gravity. We’re going to be doing a lot of that. We spin the ship on its axis, and put all the things that need full gravity at the outside, along the hull. Plant rooms, exercise rooms, et cetera. Things that don’t need gravity, like fuel and guidance instruments, we line along the axis. If our motors thrust through the same axis, we will have to build a lot of the machinery on tracks, because the aft wall will be the floor when the ship is under power
     The “Universe” ship is basic to a discussion of life in space. We’ll be talking about much larger structures, but they are designed to do the same things on a larger scale: to provide a place to live, with as much security and variety and pleasure as Earth itself offers-or more.

     The fourth method is to accelerate all the, way, making turnover at the midpoint and decelerating the rest of the way. This works fine. Over interstellar distances it would take an infinite fuel supply—and by God we may have it, in the Bussard ramjet. A Bussard ramlet would use an electromagnetic field to scoop up the interstellar hydrogen ahead of it—with an intake a thousand miles or more in diameter—compress it, and burn it as fuel for a fusion drive. Now the multi-generation ship would become unnecessary as relativity shortens our trip time: four years to the nearest star, twenty.ŕne years to the galactic hub, twenty-eight to Andromeda galaxy—all at one gravity acceleration.
     The Bussard ramjet looks unlikely. It’s another ultimate, like generated gravity. Is the interstellar medium sufficiently ionized for such finicky control? Maybe not. But it’s worth a try.
     Meanwhile; our first step to other worlds is the “Universe” ship-huge, spun for gravity, its population in the hundreds, its travel time in generations.


     But we don’t really need spindizzies or generated gravity to build flying cities. In fact, we don’t really need to fill out Heinlein’s “Universe” ship. The outer hull is all we need. Visualize a ship like this:
  1. Cut a strip of Los Angeles, say, ten miles long by a mile wide.
  2. Roll it in a hoop. Buildings and streets face inward.
  3. Roof it over with glass or something stronger.
  4. Transport it to space. (Actually we’ll build it in space.)
  5. Reaction motors, air and water recycling systems, and storage areas are in the basement, outward from the street level. So are the fuel tanks. Jettisoning an empty fuel tank is easy. We just cut it loose, and it falls into the universe.
  6. We’re using a low-thrust, high-efficiency drive: ion jets, perhaps. The axis of the city can be kept clear. A smaller ship can rise to the-axis for sightings before a course change; or we can set the control bridge atop a slender fin. A ten mile circumference makes the fin a mile and a half tall if the bridge is at the axis; but the strain on the structure would diminish approaching the axis.
     What would it be like aboard the Ring City? One gravity everywhere, except in the bridge. We may want to enlarge the bridge to accommodate a schoolroom; teaching physics would be easier in free fall.
     Otherwise it would be a lot like the Generation ship. The populace would be less likely to forget their destiny, as Heinlein’s people did. They can see the sky from anywhere in the city; and the only fixed stars are Sol and the target star.
     It would be like living anywhere, except that great attention must be paid to environmental quality. This can be taken for granted throughout this article. The more thoroughly we control our environment, the more dangerous it is to forget it.



The next step up in size is the hollow planetoid. I got my designs from a book of scientific speculation, Islands in Space, by Dandrige M. Cole and Donald W. Cox.

STEP ONE: Construct a giant solar mirror. Formed under zero gravity conditions, it need be nothing more than an Echo balloon sprayed with something to harden it, then cut in half and silvered on the inside. It would be fragile as a butterfly, and huge.

STEP TWO: Pick a planetoid. Ideally, we need an elongated chunk of nickel-iron, perhaps one mile in diameter and two miles long. (it must be nickle-iron. If planetoid is stony, it will just fly into gravel when you start it spinning)

STEP THREE: Bore a hole down the long axis.

STEP FOUR: Charge the hole with tanks of water. Plug the openings, and weld the plugs, using the solar mirror.

STEP FIVE: Set the planetoid spinning slowly on its axis. As it spins, bathe the entire mass in the concentrated sunlight from the solar mirror. Gradually the flying iron mountain would be heated to melting all over its surface. Then the heat would creep inward, until the object is almost entirely molten.

STEP SIX: The axis would be the last part to reach melting point. At that point the water tanks explode. The pressure blows the planetoid up into an iron balloon some ten miles in diameter and twenty miles long, if everybody has done their jobs right.

     The hollow world is now ready for tenants. Except that certain things have to be moved in: air, water, soil, living things. It should be possible to set up a closed ecology. Cole and Cox suggested setting up the solar mirror at one end and using it to reflect sunlight back and forth along the long axis. We might prefer to use fusion power, if we’ve got it.
     Naturally we spin the thing for gravity.
     Living in such an inside-out world would be odd in some respects. The whole landscape is overhead. Our sky is farms and houses and so forth. If we came to space to see the stars, we’ll have to go down into the basement.
     We get our choice of gravity and weather. Weather is easy. We give the asteroid a slight equatorial bulge, to get a circular central lake. We shade the endpoints of the asteroid from the sun, so that it’s always raining there, and the water runs downhill to the central lake. If we keep the gravity low enough, we should be able to fly with an appropriate set of muscle-powered wings; and the closer we get to the axis, the easier it becomes. (Of course, if we get too close the wax melts and the wings come apart…)


     Let’s back up a bit, to the Heinlein “Universe” ship. Why do we want to land it?
     If the “Universe” ship has survived long enough to reach its target star, it could probably survive indefinitely; and so can the nth-generation society it now carries. Why should their descendants live out their lives on a primitive Earthlike world? Perhaps they were born to better things.
     Let the “Universe” ship become their universe, then. They can mine new materials from the asteroids of the new system, and use them to enlarge the ship when necessary, or build new ships. They can loosen the population control laws. Change stars when convenient. Colonize space itself, and let the planets become mere way-stations. See the universe!
     The concept is called Macrolife. Macrolife is large, powered, self-sufficient environments capable of expanding or reproducing. Put a drive on the inside-outside asteroid bubble and it becomes a Macro life vehicle. The ring-shaped flying city can be extended indefinitely from the forward rim. Blish’s spindizzy cities were a step away from being Macrolife; but they were too dependent on planet based society.
     A Macrolife vehicle would have to carry its own mining tools and chemical laboratories, and God knows what else. We’d learn what else accidentally, by losing interstellar colony ships. At best a Macrolife vehicle would never be as safe as a planet, unless it was as big as a planet, and perhaps not then. But there are other values than safety. An airplane isn’t as safe as a house, but a house doesn’t go anywhere. Neither does a world.


     Freeman Dyson’s original argument went as follows, approximately.
     No industrial society has ever reduced its need for power, except by collapsing. An intelligent optimist will expect his own society’s need for power to increase geometrically, and will make his plans accordingly. According to Dyson, it will not be an impossibly long time before our own civilization needs all the power generated by our sun. Every last erg of it. We will then have to enclose the sun so as to control all of its output.
     What we use to enclose the sun is problematic. Dyson was speaking of shells in the astronomical sense: solid or liquid, continuous or discontinuous, anything to interrupt the sum light so that it can be turned into power. One move might be to convert the mass of the solar system into as many little ten-by-twenty-mile hollow iron bubbles as will fit. The smaller we subdivide the mass of a planet, the more useful surface area we get. We put all the little asteroid bubbles in circular orbits at distances of about one Earth orbit from the sun, but differing enough that they won’t collide. It’s a gradual process. We start by converting the existing asteroids. When we run out, we convert Mars, Jupiter, Saturn, Uranus … and eventually, Earth.
     Now, aside from the fact that our need for power increases geometrically, our population also increases geometrically. If we didn’t need the power, we’d still need the room in those bubbles. Eventually we’ve blocked out all of the sunlight. From outside, from another star, such a system would be a great globe radiating enormous energy in the deep infrared.
     What some science fiction writers have been calling a Dyson sphere is something else: a hollow spherical shell, like a ping pong ball with a star in the middle. Mathematically at least, it is possible to build such a shell without leaving the solar system for materials. The planet Jupiter has a mass of 2 × 1030 grams, which is most of the mass of the solar system excluding the sun. Given massive transmutation of elements, we can convert Jupiter into a spherical shell 93 million miles in radius and maybe ten to twenty feet thick. If we don’t have transmutation, we can still do it, with a thinner shell. There are at least ten Earth masses of building material in the solar system, once we throw away the useless gasses.
     The surface area inside a Dyson sphere is about a billion times that of the Earth. Very few galactic civilizations in science fiction have included as many as a billion worlds. Here you’d have that much territory within walking distance, assuming you were immortal.
     Naturally we would have to set up a biosphere on the inner surface. We’d also need gravity generators. The gravitational attraction inside a uniform spherical shell is zero. The net pull would come from the sun, and everything would gradually drift upward into it.
     So. We spot gravity generators all over the shell, to hold down the air and the people and the buildings. “Down” is outward, toward the stars.
     We can control the temperature of any locality by varying the heat-retaining properties of the shell. In fact, we may want to enlarge the shell, to give us more room or to make the permanent noonday sun look smaller. All we need do is make the shell a better insulator: foam the material, for instance. If it holds heat too well, we may want to add radiator fins to the outside.
     Note that life is not necessarily pleasant in a Dyson sphere. We can’t see the stars. It is always noon. We can’t dig mines or basements. And if one of the gravity generators ever went out, the resulting disaster would make the end of the Earth look trivial by comparison.
     But if we need a Dyson sphere, and if it can be built, we’ll probably build it.
     Now, Dyson’s assumptions (expanding population, expanding need for power) may hold for any industrial society, human or not. If an astronomer were looking for inhabited stellar systems, he would be missing the point if he watched only the visible stars. The galaxy’s most advanced civilizations may be spherical shells about the size of the Earth’s orbit, radiating as much power as a Sol-type sun, but at about 1O angstroms wavelength—in the deep infrared…
     …assuming that the galaxy’s most advanced civilizations are protoplasmic. But beings whose chemistry is based on molten copper, say, would want a hotter environment. They might have evolved faster, in temperatures where chemistry and biochemistry would move far faster. There might be a lot more of them than of us. And their red-hot Dyson spheres would look deceptively like red giant or supergiant stars. One wonders.
     In The Wanderer, novelist Fritz Leiber suggested that most of the visible stars have already been surrounded by shells of worlds. We are watching old light, he suggested, light that was on its way to Earth before the industrial expansion of galactic civilization really hit its stride. Already we see some of the result: the opaque dust clouds astronomers find in the direction of the galactic core are not dust clouds, but walls of Dyson spheres blocking the stars within.


     I myself have dreamed up an intermediate step between Dyson spheres and planets. Build a ring 93 million miles in radius—one Earth orbit—which would make it 600 million miles long. If we have the mass of Jupiter to work with, and if we make it a million miles wide, we get a thickness of about a thousand meters. The Ringworld would thus be much sturdier than a Dyson sphere.
     There are other advantages. We can spin it for gravity. A rotation on Its axis of 770 miles/second would give the Ringworld one gravity outward. We wouldn’t even have to roof itover. Put walls a thousand miles high at each rim, aimed inward at the sun, and very little of the air will leak over the edges.
     Set up an inner ring of shadow squares—light orbiting structures to block out part of the sunlight—and we can have day-and-night cycles in whatever period we like. And we can see the stars, unlike the inhabitants of a Dyson sphere.
     The thing is roomy enough; three million times the area of the Earth. It will be some time before anyone complains of the crowding.
     As with most of these structures, our landscape is optional, a challenge to engineer and artist alike. A look at the outer surface of a Ringworld or Dyson sphere would be most instructive. Seas would show as bulges, mountains as dents. River beds and river deltas would be sculpted in; there would be no room for erosion on something as thin as a Ringworld or a Dyson sphere. Seas would be flat-bottomed—as we use only the top of a sea anyway—and small, with convoluted shorelines. Lots of beachfront. Mountains would exist only for scenery and recreation.
     A large meteor would be a disaster on such a structure. A hole in the floor of the Ringworld, if not plugged, would eventually let all the air out, and the pressure differential would cause storms the size of a world, making repairs difficult.

     The Ringworld concept is flexible. Consider:
  1. More than one Ringworld can circle a sun. Imagine many Ringworlds, noncoplanar, of slightly differing radii—or of widely differing radii, inhabited by very different intelligent races.
  2. We’d get seasons by bobbing the sun up and down. Actually the Ring would do the bobbing; the sun would stay put. (One Ring to a sun for this trick.)
  3. To build a Ringworld when all the planets in the system are colonized to the hilt (and, baby, we don’t need a Ringworld until it’s gotten that bad!) pro tem structures are needed. A structure the size of a world and the shape of a pie plate, with a huge rocket thruster underneath and a biosphere in the dish, might serve to house a planet’s population while the planet in question is being disassemb1ed. It circles the sun at 770 miles/second, firing outward to maintain its orbit. The depopulated planet becomes two more pie plates, and we wire them in an equilateral triangle and turn off the thrusters, evacuate more planets and start building the Ringworld.


     I pointed out earlier that gravity generators look unlikely. We may never be able to build them at all. Do we really need to assume gravity generators on a Dyson sphere? There are at least two other solutions.
     We can spin the Dyson sphere. It still picks up all the energy of the sun as planned; but the atmosphere collects around the equator, and the rest is in vacuum. We would do better to reshape the structure like a canister of movie film; it gives us greater structural strength. And we wind up with a closed Ringworld.
     Or, we can live with the fact that we can’t have gravity. According to the suggestion of Dan Aiderson, Ph.D., we can built two concentric spherical shells, the inner shell transparent, the outer transparent or opaque, at our whim. The biosphere is between the two shells.
     It would be fun. We can build anything we like within the free fall environment. Buildings would be fragile as a butterfly. Left to themselves they would drift up against the inner shell, but a heavy thread would be enough to tether them against the sun’s puny gravity. The only question is, can humanity stand long periods of free fall?


     What’s bigger than a Dyson sphere? Dan Alderson, designer of the Alderson Double Dyson Sphere, now brings you the Alderson Disc. The shape is that of a phonograph record, with a sun situated in the little hole. The radius is about that of the orbit of Mars or Jupiter. Thickness: a few thousand miles.
     Gravity is uniformly vertical to the surface (freshman physics again) except for edge effects.. Engineers do have to worry about edge effects; so we’ll build a thousand-mile wall around the inner well to keep the atmosphere from drifting into the sun. The outer edge will take care of itself.
     This thing is massive. It weighs far more than the sun. We ignore problems of structural strength. Please note that we can inhabit both sides of the structure.
     The sun will always be on the horizon, unless we bob it, which we do. (This time it is the sun that does the bobbing.) Now it is always dawn, or dusk, or night.
     The Disc would be a wonderful place to stage a Gothic or a swords-and-sorcery novel. The atmosphere is right, and there are real monsters. Consider: we can occupy only a part of the Disc the right distance from the sun. We might as well share the Disc and the cost of its construction with aliens from hotter or colder climes. Mercurians and Venusians nearer the sun, Martians out toward the rim, aliens from other stars living wherever it suits them best. Over the tens of thousands of years, mutations and adaptations would migrate across the sparsely settled borders. If civilization should fall, things could get eerie and interesting.


     Pat Gunkel has designed a structure analogous to the Ringworld. Imagine a hollow strand of macaroni six hundred million miles long and not particularly thick-say a mile in diameter. Join it in a loop around the sun.
     Pat calls it a topopolis. He points out that we could rotate the thing as in the illustration—getting gravity through centrifugal force—because of the lack of torsion effects. At six hundred million miles long and a mile wide, the curvature of the tube is negligible. We can set up a biosphere on the inner surface, with a sunlight tube down the axis and photoelectric power sources on the outside. So far, we’ve got something bigger than a world but smaller than a Ringworld.
     But we don’t have to be satisfied with one loop! We can go round and round the sun, as often as we like, as long as the strands don’t touch. Pat visualizes endless loops of rotating tube, shaped like a hell of a lot of spaghetti patted roughly into a hollow sphere with a star at the center (and now we call it an aegagropilous topopolis.) As the madhouse civilization that built it continued to expand, the coil would reach to other stars. With the interstellar links using power supplied by the inner coils, the tube city would expand through the galaxy. Eventually our aegagropilous galactotopopolis would look like all the stars in the heavens had been embedded in hair.


     Mathematically at least, it is possible to build a really big Dyson sphere, with the. heart of a galaxy at its center. There probably aren’t enough planets to supply us with material. We would have to disassemble some of the star of the galactic arms. But we’ll be able to do it by the time we need to.
     We put the biosphere—on the outside this time. Surface. gravity is minute, but the atmospheric gradient is infinitesimal. Once again, we assume that it is possible for human beings to adapt to free fall. We live in free fall, above a surface area of tens of millions of light years, within an atmosphere that doesn’t thin out for scores of light years.
     Temperature control is easy: we vary the heat conductivity of the sphere to pick up and hold enough of the energy from the stars within. Though the radiating surface is great, the volume to hold heat is much greater. Immustrial power would come from photoreceptors inside the shell.
     Within this limitless universe of air we can build exceptionally large structures, Ringworld-sized and larger. We could even spin them for gravity. They would remain aloft for many times the lifespan of any known civilization before the gravity of the Core stars pulled them down to contact the surface.
     The Megasphere would be a pleasantly poetic place to live. From a flat Earth hanging in space, one could actually reach a nearby moon via a chariot drawn by swans, and stand a good chance of finding selenites there. There would be none of this nonsense about carrying bottles of air along.


     One final step to join two opposing life styles, the Macrolife tourist types and the sedentary types who prefer to restructure their home worlds.
     The Ringworld rotates at 770 miles/second. Given appropriate conducting surfaces, this rotation could set up enormous magnetic effects. These could be used to control the burning of the sun, to cause it to fire off a jet of gas along the Ringworld axis of rotation. The sun becomes its own rocket. The Ringworld follows, tethered by gravity.
     By the time we run Out of sun, the Ring is moving through space at Bussard ramjet velocities. We continue to use the magnetic effect to pinch the interstellar gas into a fusion flame, which now becomes our sun and our motive power.
     The Ringworld makes a problematical, vehicle. What’s it for? You can’t land the damn thing anywhere. A traveling Ringworld. is not useful as a tourist vehicle, anything you want to see, you can put on the Ringworld itself… unless it’s a lovely multiple star system like Beta Lyrae but you just can’t get that close on a flying Ringworld.
     A Ringworld in flight would be a bird of ill omen. It could only be fleeing some galaxy-wide disaster.
     Now, galaxies do explode. We have pictures of it happening. The probable explanation is a chain reaction of novae in the galactic core. Perhaps we should be maintaining a space watch for fleeing Ringworlds… except that we couldn’t do anything about it.

From BIGGER THAN WORLDS by Larry Niven (1974)

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