How to Write Science Fiction and Fantasy (7 page)

But if you tell the story with no humans at all, then your point-of-view characters will have to be alien, and since they have never seen a human, they cannot realistically provide a contrast. They can’t even explain anything, unless you resort to tactics like this: “Digger-of-Holes imagined for a moment what it would be like if his eyes were on the front of his head, with overlapping vision, like the tiny shrew on the branch in front of him. How could the creature see what was happening behind it? And how could its tiny brain make sense of two overlapping but different fields of view?” This is sensible enough, but how often do you think you can get away with this before the reader gets quite impatient with a supposedly alien character who keeps thinking about things pertaining to humans that he’s never seen?

(Usually, of course, such things are handled even more ineptly-by having Digger-of-Holes imagine binocular vision without seeing a treeshrew, for instance-or, worse yet, having an alien scientist give a brief lecture on the benefits of binocular vision. Such techniques get the facts across, all right-but at the cost of shattering the believability of the characters and forcing the readers to be aware of how the author is manipulating the story.)

In any event, your story happens to be one that requires the presence

of human beings, so you don’t face the problems of the aliens-only story. However, now you
do
face the problems of travel between star systems.

Why? Your story isn’t
about
space travel! At the beginning, the humans have already arrived on the alien planet (or, perhaps, the aliens have already arrived on Earth/.

I assure you, though, that you
must
determine the rules of interstellar flight in your story’s universe, and, at some point early in the story, you must let the reader know what those rules are. The reason for this will become clear as we go over the possible rules.

The problem of interstellar flight is two-fold: the speed of light, and the ratio of fuel mass to fuel energy.

Let’s take the speed of light first. According to Einstein’s theory, lightspeed is the absolute ceiling on the speed of any motion in the universe.
Nothing
can go faster than light. Furthermore, anything that actually
goes
the speed of light
becomes
energy. So you can’t get from one star system to another any faster than a bit more than one year per light-year of distance between them. To get from Earth to a star system thirty light-years away would take, say, thirty-one years. Your human characters, who were in their twenties when they left, are now in their fifties.

What are the strategies for getting around the lightspeed barrier?

Hyperspace.
Though this goes by many different names, the idea is as old as the 1940s at least, and there’s really no reason to make up a new term, since if hyperspace is ever found to exist it will almost certainly be
called
hyperspace-the way that when robots were finally created, they were
called
robots because science fiction writers had been calling artificial mechanical men by that name ever since Czech writer Karl Capek coined the term in his play
RUR
back in the 1930s. You can call it hyperspace-in fact, you probably
should
call it hyperspace, since most of your readers will be quite familiar with that term and will recognize it instantly.

Hyperspace is based on the idea that space, which seems three-dimensional to us, is really four-dimensional (or more!/; and that in another dimension, our space is folded and curved so that locations that seem far apart to us are really quite close together, provided you can find a way to get out of our three-dimensional space, pass through hyper-dimensional space, and then come back out at the point you desire.

This passage through hyperspace is usually called “the jump,” and there are many different rules associated with it. Isaac Asimov had a robot story

in which the jump to hyperspace caused human beings to temporarily cease to exist, a sort of mini-death that drove a robot pilot mad trying to take humans through the jump.

Timothy Zahn’s “Cascade Point” and other stories set in that same universe propose that at the moment of the jump, there is an infinite array of possible points of emergence, in most of which you die; but since it is only the jumps that you survive that you remember, you’re never aware of the universes in which you are dead.

Other versions of hyperspace require that you have to be near a large star in order to make the jump, or that you can’t be near a large gravity source or the jump gets distorted. In some stories Heinlein allows an infinite number of possible jumps, with your emergence depending on elaborately careful calculations of your velocity and trajectory leading to the jump. Others, like Frederik Pohl with his Heechee novels, have written stories allowing only a limited number of gateways through space, each leading consistently to its own destination-which, until all the gateways are mapped, might as easily be an inhabited world or the edge of a black hole.

And some versions of hyperspace don’t even require a spaceship. They place “doorways” or “gates” or “tunnels” on or near a planet’s surface, and if you simply walk through the right spot, going in the correct direction, you end up on-or near-the surface of another planet!

Another version of this, often used by Larry Niven, is that such doorways are not natural, but are machines that create passages through hyperspace. And in one variation of this, hyperspace isn’t used at all. You get into a device that looks a bit like an old-fashioned phonebooth, which analyzes your body, breaks it down into its constituent parts, and then transmits an image of it at lightspeed to a booth on another planet (or elsewhere on Earth) that carefully reconstructs you. In either case, booths can only send you to other booths, so that somebody has to make the long journey to other planets at sub-lightspeed first, in order to assemble the booth that will allow others to follow them instantaneously.

The advantage of hyperspace in all its variations is that it allows relatively quick, cheap passage between worlds. How quick and how cheap is up to you. Think of it as being like voyages between the New World and the Old World. In 1550, the voyage was uncertain; some passengers and crew on every voyage died before they reached land, and some ships disappeared without a trace. By the mid-1800s, the voyage was much faster and

death far less likely, though the trip was still miserable. In the age of steam, there were still wrecks and losses, but the voyage was cut down to a week or two. Today, it can take only a few hours on the Concorde. You can have starflight using hyperspace that functions at any one of these danger levels. It’s as safe and fast as the Concorde-or it’s as dangerous and slow and uncertain as a caravel navigating with a quadrant and an unreliable clock.

Why must you decide all these things, when your story begins after the voyage is over? First, because the characters who did the traveling-human or alien-have just finished the voyage, and their relationship with each other and their attitude toward this new world and toward authorities on the old one will be largely shaped by what the voyage back entails.

If another ship can’t come for months, if the whole voyage was at risk of death and some
did
die, and if there’s only a 60-40 chance of getting back home alive, then the voyagers will be determined to survive on the new planet, and will be grimly aware that if they don’t make things work, their lives may end. They also won’t take faraway authorities on their home planet half so seriously.

But if they reached the planet by taking a six-hour flight, and traffic between this, world and the home planet will be easy and frequent, they have much less at stake, and their attitude will be far more casual. Furthermore, homeworld authorities will be much more involved, and reinforcements or replacements will be easy to obtain.

Why must you establish clearly what the rules of space travel are? So that the reader understands why the characters are getting so upset-or why they’re not getting terribly upset-when things go wrong. So that the reader knows just what’s at stake.

And-not a trivial consideration-so that the experienced science fiction reader will recognize your proper use of a standard device and feel confident that the story is being written by somebody who knows how this is done. Even if you plan to be rebellious and not use standard devices, you still must address the same issues; the effect on the reader is still reassuring.

Generation ships.
You’ve decided you don’t want to use hyperspace, either because it strikes you as nonsense science or because you don’t want all that coming and going on your new planet. Another alternative is to send a ship at sublightspeed and let the voyage take as long as it takes.

Without getting into the science of it (primarily because I don’t under

stand it in any kind of detail myself), the problem with sublight voyages is that they take a
long
time. And you have to carry all your fuel with you. The good news is that you can coast most of the way- there’s little friction in space, and once you reach a certain speed, you should continue traveling at that speed in the same direction until something happens to turn you or slow you down. So most of the voyage needs no fuel at all.

The bad news is that your fuel is part of the mass that your fuel has to lift. There comes a point where the fuel to accelerate any more will add enough weight that you either can’t lift it or can’t design a sturdy enough ship to hold it. Furthermore, because it takes just as much fuel to slow you down at the end of your voyage so you don’t just sail right on past your destination, you have to save exactly half your fuel for the slowdown, plus any fuel required for maneuvering into orbit. That means that the fuel must be able to accelerate more than twice its own mass. Worse yet, if there isn’t any more fuel
at
your destination, you’re either not coming home again or you’re going to have to carry more than
four times
the fuel needed to accelerate you to your traveling speed.

So that you don’t waste fuel trying to lift a huge ship out of the gravity well of a planet like Earth, such ships are usually assumed to have been built out in space and launched from a point as far as possible from the Sun. Thus, when they arrive at the new world, they put their huge ship into orbit and use landing vehicles or launches or (nowadays) shuttles to get down to the planet’s surface.

Using the technology I’ve just described, you’ll be lucky to get to ten percent of lightspeed. That’s pretty fast- about 67 million miles an hour but at that rate, it will take your ship more than
three hundred years
to get to a star system thirty lightyears away. And that doesn’t even allow for acceleration time!

That’s why such ships are called “generation ships.” Assuming that the ship is a completely self-contained environment, with plants to constantly refresh the atmosphere and grow food, a whole human society lives aboard the ship. People are born, grow old, and die, and the elements of their bodies are processed and returned to the ecosystem within the ship. This idea has been well-explored in many storiesparticularly stories about ships where the people have forgotten their origin, forgotten even that the ship is a ship-but it has a lot of life left in it.

The problem with this (besides the fact that a completely self-contained ecosystem would be almost impossible to create) is that none of the people

who reach the new world have any direct memories of their home planet. Their whole history for generations has been inside a ship-why would they even
want
to go out onto a planet’s surface? The fact of living inside a ship for so long is so powerful that it almost takes over the story. If your story is
about
that, like Rebecca Brown Ore’s brilliant debut story, “Projectile Weapons and Wild Alien Water,” then that’s fine-but if your story is about something else, a generation ship is hard to get over.

Cryo-travel.
Another alternative is to have the crew travel for all those years in a state of suspended animation-either frozen or otherwise kept viable until the ship itself, or a skeleton crew, wakens the sleepers at the voyage’s end. This has the advantage of not requiring living space and supplies for so many people for so many years, and it still achieves the result of malting frequent voyages between the new world and the home planet unthinkable-or at least impractical.

The drawback is that if suspended animation is possible at all in your future universe, then you have to let it be used for anything it’s needed for. Characters who get sick or critically injured or even killed must be rushed back to the ship and popped into a suspended animation chamber until a cure or repair can be worked out. Also, there are bound to be people who try to abuse the system to prolong their lives beyond the normal span of years. You can’t have a technology exist for one purpose and then ignore it for another-not unless you want to earn the scorn of your more critical and vocal readers.

A variation on cryo-travel is to send colony ships that contain no human beings at all, but rather frozen human embryos; when the ship’s computer determines that the starship has reached a habitable planet, some of the embryos are revived and raised to adulthood by computers or robots inside the ship. They come to the new planet as virtually new creations, having known neither parents nor any human society except the one they form. Obviously, this is a one-way trip with no hope of later visits or help from the home planet, since no one on the home world will even know
whether
the colony ship happened to find a habitable planet, let alone
where.