The speed of light is way too slow. Crawling along at a mere 186,000 miles per second, light takes a whole four years to reach us from even the nearest star. When Einstein's relativity theory postulated that nothing could be accelerated beyond the speed of light, this looked like bad news for science fiction writers who wanted to create star-hopping heroes and vast galactic empires. In the early days of the pulps, few authors allowed scientific accuracy to impede their stories, but in the so-called Golden Age of SF, writers began to take issues of plausibility more seriously. It became necessary to acknowledge the light-speed barrier, and find ways around it. John W. Campbell is credited with inventing the term "hyperspace," perhaps still the most common enabling device for faster-than-light travel -- although, like a shifty organ-smuggler, it tends to operate under a variety of aliases.

Hyperspace

"Our spiral galaxy, which is about eighty thousand light-years across, is in the lambda dimension about a mile and a half wide." --Star Smashers of the Galaxy Rangers, Harry Harrison

Hyperspace, sub-space, the lambda dimension -- whatever they call it, few science fiction writers can do without it. It is, after all, the only way in which our roguish starship captain can maintain a girl in every port, without them all dying of old age while he's en route.

But flying through hyperspace can bring its own problems. The Guild navigators in Dune become so grossly deformed that one must imagine they find it hard to attract women in spaceport bars. And some pilots have to become cyborgs, or abandon their bodies entirely: no "one small step" for them, not without feet to step with.

Of course, there may be progress to look forward to. In "Scanners Live In Vain" by Cordwainer Smith, the eponymous scanners become resentful of a new piloting method that no longer requires the sacrifice of becoming a cyborg. They attempt to kill the inventor, but he luckily turns out to also know how to reverse the cyborgisation process, and so they all live happily ever after (except for the guy who died).

These transhuman navigators and cyborgs hint at the underlying difficulty of giving human characters any plausible role at all. Star travel looks to be some way off yet, and by then it seems likely that computers will have advanced to the point where they can not only fly the ship, but also plug their memoirs on chat shows afterward. Larry Niven cunningly circumvented this problem by explaining that "the mass sensor was a psionic device," and needed the input of a human brain to stop the ship crashing into nearby stars. The human didn't actually need to do anything except sit in the pilot's seat: he could drink beer and scratch himself all day, and the job would still get done. (Wish I had a job like that.)

In his "Known Space" stories, Niven also addressed the issue of velocity. He fixed the travelling speed at three days per light year, which meant that getting around in the galaxy was a reasonable amount of work, and allowed his heroes to get places fairly quickly but not too quickly. When, in later stories, Niven needed to give his characters a bit more zip, he had them discover that speed was quantised: three days per light year was Quantum I, and Quantum II was one heckuva lot faster. A similar effect is seen in Star Trek when characters in the Enterprise series (set earlier than the original) get all excited about reaching Warp Factor Five -- in Next Generation, of course, the speed goes up to Warp Factor Ten. No doubt a future episode of Star Trek will star Christopher Guest as a captain explaining that his ship is better because it goes all the way up to 11.

Most writers make the convenient assumption that hyperspace allows faster than light travel. In George R. R. Martin's "FTA," however, scientists discover hyperspace but find that its limiting speed is in fact slower than light. Perhaps significantly, this is a very short story.

Hyperspace is usually assumed to permeate the whole universe, allowing travel anywhere. C. J. Cherryh adds the complicating premise that ships can only enter or exit hyperspace near a significantly-sized mass, such as a star. This lets her have crowded vicinities full of starships from different alien races, none of whom ever seem to get on with each other.

Cherryh also posits that hyperspace is such an abnormal place that the human mind cannot cope with it, and people have to be drugged to go through the jump. Hyperspace travel apparently causes these stone-cold tranquillised people to become hungry and thirsty and tired and mentally dysfunctional, and start shedding hair and dead skin. Diana Wynne Jones parodies this syndrome in her story "nad and Dan adn Quaffy," in which the characters' sufferings during hyperspace travel are a projection of the author's sufferings during long stretches typing at the computer.

One aspect of hyperspace rarely addressed is the matter of what's in it. Writers tend to imagine hyperspace as a nullity, even emptier than 'real' space. The trend is taken to its ultimate by Larry Niven, who posits that hyperspace cannot be seen at all by the human eye: it's a blind spot around which any real objects will warp to fill up the field of vision. Clever tricks such as this save authors from the effort of having to think up some scenery.

Wormholes

"A wonderful new method of crossing vast interstellar distances in a mere nothingth of a second, without all that tedious mucking about in hyperspace" --The Hitch Hiker's Guide to the Galaxy, Douglas Adams

In this section I use "wormhole" to mean any system for instantaneously travelling from one point to another, without having to crawl through hyperspace at three days per light-year, or any other finite speed.

A system for travelling directly from any spot in the universe to any other spot would be extraordinarily useful, and indeed wormholes are so convenient that in order to generate sufficient obstacles for a plot, the writer usually has to invent difficulties to restrict their use. In David Langford's novel The Space Eater, large wormholes have the unfortunate side-effect of causing stars to explode. The physicists calculate that a safe wormhole must have an aperture not wider than 1.9 centimetres. One can't help pitying the poor Forceman guy chosen to go through the wormhole -- "Scalpels, bonesaws, heavy cutters, whittling me down. . ." -- and then get regrown in an untested vat at the other end.

In Niven & Pournelle's The Mote in God's Eye, there are only a few wormholes at certain points in space. The bad guys have just one wormhole in their solar system, which leads to another wormhole inside a star. Despite the novel's premise that the aliens are smarter than humans, and have millennia of civilisation behind them, only humans have invented the shielding technology that allows this wormhole to be safely traversed. Phew -- we're safe. What rotten luck for those aliens, though. It's almost as if some cosmic card-sharp deliberately dealt them a losing hand.

Bob Shaw's novel Night Walk imagines a system whereby the wormholes' topology is so complex that Earth has been reduced to sending out millions of probes in the hope that some will, by chance, emerge at a comfortable spot. The chain of portals required may be hundreds of jumps long. And the nonlinearity of null-space means that if you stray from the established route, you are lost for ever. When this happens to the novel's protagonist, he makes a heroic effort and -- with the help of a rat he finds on his spaceship -- manages to work out the super-complex topology, enabling him to get home.

In "Think Like A Dinosaur" by James Patrick Kelly, the wormhole technology does not transport the original person, but creates a duplicate at the other end. In order to "balance the equation," it is then necessary for the original to die -- the author doesn't bother to explain why, but instead resorts to vague handwaving about "harmony." The aliens who invented the technology are sufficiently comfortable with using it that the redundant originals happily zap themselves. Unsurprisingly, humans aren't quite so keen on doing this.

"The Shobies' Story," by Ursula Le Guin, tells how a spaceship crew test a new instantaneous drive, "the controls of which essentially consisted of an on-off switch." They find it difficult to agree on whether it works, and on what happened when they pressed the switch. Their perceptions conflict: some think they've arrived, others that they've never left, and others that they can simultaneously see everywhere. The situation is ultimately resolved by the crew jointly telling a story. Apparently poets are not only the unacknowledged legislators of the world, but also of hyperspace.

One variant of instantaneous transportation doesn't work on matter, and projects only the mind. Usually this comes as an uncomfortable surprise to the receiving body, which may well already have a mind in it. In John Wyndham's Chocky, an alien lands in the mind of a human child, who then starts behaving rather strangely. Judging by the kids round my way, this must be happening a lot lately.

In Piers Anthony's "Cluster" series, physical teleportation is possible but fantastically expensive; somewhat cheaper is a form of mind-travel available to those with strong Kirlian auras. Sex is significant: the travellers can only land in a host body of the same gender, and they spend much of their time frantically coupling with other travellers, or locals, or indeed anyone who doesn't move away fast enough. The popularity of these books may mean that many people have gone through a phase of feeling the only way they could ever get laid would be to mind-travel to the Andromeda Galaxy and do it in someone else's body. (Or is that just me?)

Clifford Simak's novel Time Is The Simplest Thing is a less sex-obsessed version of the mind-travel theme. The blurb on the back of the book gives a fair summary: "Finally came the time when Earth's astronauts were forced to abandon all attempts to probe the stars. It was then that telepathic exploration was developed, and eventually men could project their minds into the farthest reaches of space. With numerous missions behind him, Shepherd Blaine ranked high among the Telepaths. Until in one terrifying moment he found his mind invaded by an alien creature." One can almost feel the superhuman restraint of the blurb-writer as he holds himself back from adding an exclamation point to that final sentence.

Simak recycled the basic idea in his later novel Project Pope, in which a bunch of robots send human minds to scour the galaxy for information with which to build an infallible mechanical pope. They are somewhat surprised and discomfited when one of the mind-travellers appears to reach Heaven.

Some authors have restricted their universes so that faster-than-light travel is impossible, but FTL communication is allowed. The terminology of choice for this concept is nowadays the "ansible," from the novels of Ursula Le Guin, although James Blish earlier used the same concept and called it a Dirac communicator. In these universes there is little point in using the ansible to send out a Mayday signal, since it would take decades for any help to reach you. I am reminded of this every time my computer breaks down and I call the helpdesk, which I can only assume is located on Tau Ceti III.

The ansible is a mechanical device. Another form of communication widely used in SF is telepathy, and it is sometimes conceived that such mental powers are not limited by the speed of light. Again, authors may have to invent difficulties to prevent these communication methods being used overmuch. In Langford's The Space Eater, the strongest telepathic signal is pain: "Isn't it lucky that the clever people in Comm have nerve-inductors and suchlike electrical ingenuities to ensure a clear, strong signal?"

Tell me, Professor, how does it all work?

"The churten, in lay terms, may be seen as displacing the virtual field in order to realise relational coherence in terms of the transiliential experientiality" --"The Shobies' Story," Ursula Le Guin

In the majority of stories, the actual motive power of the hyperdrive or whatnot is never explained. After all, most so-called explanations really boil down to "jargon-verbing the techno-noun" -- or in complex cases, "jargon-verbing the babble-adjective techno-noun." The later incarnations of Star Trek are particularly prone to this phenomenon: at least in the original series you always knew that everything depended on the dilithium crystals. Another example can be found in Melissa Scott's "Silence Leigh" trilogy, a space opera chiefly notable for its use of alchemy and magic -- the Art -- in place of advanced technology. The Art is evoked merely by constant reference to a large lexicon of jargon rather than any explicit system, leaving the reader with the impression that the heroine has an endless supply of rabbits in her hat.

Comic writers have naturally poked fun at the mysterious workings of the hyperdrive. In Harry Harrison's Star Smashers of the Galaxy Rangers, the "lambda dimension" is accessed by "kappa radiation" emanating from "cheddite" -- processed cheese. Douglas Adams introduced his Infinite Improbability Drive in The Hitch Hiker's Guide to the Galaxy, then superseded it in Life, the Universe and Everything with Bistromathics -- "a wonderful new method of crossing vast interstellar distances without all that dangerous mucking about with Improbability Factors" -- premised on the fact that, "Numbers written on restaurant bills within the confines of restaurants do not follow the same mathematical laws as numbers written on any other pieces of paper in any other parts of the Universe."

A more serious version of the latter theme appears in David Zindell's novel Neverness, in which starship pilots fly around the galaxy by solving mathematical theorems. The author mightily strives to make this process sound interesting. The scenario's most intriguing aspect is that travelling from A to B does not in itself generate a method of travelling from B back to A: another solution must be sought. In the end, our hero solves this problem by discovering a general theorem for reversing all routes. Hurrah!

The story "Specialist," by Robert Sheckley, posits that human beings are the type of race known galactically as "Pushers": they just set their minds to the task, and the spaceship whooshes off into the infinite. It is perhaps typical of 1950s SF that humans are so specially talented. If this story had been written somewhat later, the humans' special talent might have been for blocking up the toilets on the bridge, or something equally humble.

Norman Spinrad's novel The Void Captain's Tale extends the mind-power concept to, basically, travel by orgasm. The spaceship contains a woman, wired up to the stardrive, whose job is to be thoroughly rogered by the captain. The more powerfully she comes, the further the ship goes. Well, it certainly gives a whole new meaning to, "Did the earth move for you?"

Conclusion

So many stories have used faster-than-light travel that this article can only mention a mere fraction of the relevant literature. However, writers are usually only interested in FTL as an enabling gimmick to allow them to write the kind of story they're interested in. Most of these stories are not about the FTL drive, just as most westerns are not about horses. The different kinds of FTL are largely a function of the degrees of freedom the writer grants characters to travel and communicate in their universe.

Where a story is about the FTL drive, it's all too easy for the writer to set up a fake problem, then fake fix it, because it's all jargon anyway. This is what I think of as the Star Trek syndrome, where difficulties can usually be solved by "remodulating" something or other.

Faster-than-light travel holds out the prospect of a universe of shiny, exciting possibilities. But if it were ever invented, I believe that it would also bring its own peculiar annoyances and inconveniences -- just as the Internet brought us the wonders of spam email. For instance, FTL might turn out to create the superluminal equivalent of a sonic boom, or environmentalists could start complaining about the pollution of hyperspace. There are still many possible consequences for science fiction writers to explore.

Ian Creasey lives in Yorkshire, England. His short stories have appeared in several print magazines, and also online at Gothic.Net, The Palace of Reason and Abyss & Apex. His latest story, forthcoming in June 2003 at Planet Relish, is about one particular side-effect of the invention of teleportation.