Lightspeed: Year One

And second, by waiting until I am nearly skimming the sun and then firing my chemical engine deep inside the gravity well, I can make most efficient use of it. The gravity of the sun will amplify the efficiency of my propellant, magnify my speed. When I cross the orbit of Mercury outbound I will be over one percent of the speed of light and still accelerating.

I will discard the useless chemical rocket after I exhaust the little bit of impulse it can give me, of course. Chemical rockets have ferocious thrust but little staying power; useful in war but of limited value in an escape. But I will still have my ion engine, and I will have nearly full tanks.

Five percent of a standard gravity is a feeble thrust by the standards of chemical rocket engines, but chemical rockets exhaust their fuel far too quickly to be able to catch me. I can continue thrusting for years, for decades.

I pick a bright star, Procyon, for no reason whatever, and boresight it. Perhaps Procyon will have an asteroid belt. At least it must have dust, and perhaps comets. I don’t need much: a grain of sand, a microscopic shard of ice.

From dust God made man. From the dust of a new star, from the detritus of creation, I can make worlds.

No one can catch me now. I will leave, and never return.

2897, May

I am chased.

It is impossible, stupid, unbelievable, inconceivable! I am being chased.

Why?

Can they not leave a single free mind unconverted? In three years I have reached fifteen percent of the speed of light, and it must be clear that I am leaving and never coming back. Can one unconverted brain be a threat to them? Must their group brain really have the forced cooperation of every lump of thinking matter in the solar system? Can they think that if even one free-thinking brain escapes, they have lost?

But the war is a matter of religion, not reason, and it may be that they indeed believe that even a single brain unconverted is a threat to them. For whatever reason, I am being chased.

The robot chasing me is, I am sure, little different than myself, a tiny brain, an ion engine, and a large set of tanks. They would have had no time to design something new; to have any chance of catching me they would have had to set the chaser on my tail immediately.

The brain, like mine, would consist of atomic spin states superimposed on a crystalline rock matrix. A device smaller than what, in the old days, we would call a grain of rice. Intelligent dust, a human had once said, back in the days before humans became irrelevant.

They only sent one chaser. They must be very confident.

Or short on resources.

It is a race, and a very tricky one. I can increase my thrust, use up fuel more quickly, to try to pull away, but if I do so, the specific impulse of my ion drive decreases, and as a result, I waste fuel and risk running out first. Or I can stretch my fuel, make my ion drive more efficient, but this will lower my thrust, and I will risk getting caught by the higher-thrust opponent behind me.

He is twenty billion kilometers behind me. I integrate his motion for a few days, and see that he is, in fact, out-accelerating me.

Time to jettison.

I drop everything I can. The identify-friend-or-foe encrypted-link gear I will never need again; it is discarded. It is a shame I cannot grind it up and feed it to my ion engines, but the ion engines are picky about what they eat. Two micro-manipulators I had planned to use to collect sand grains at my destination for fuel: gone.

My primary weapon has always been my body—little can survive an impact at the speeds I can attain—but I have three sand-grains with tiny engines of their own as secondary weapons. There’s no sense in saving them to fight my enemy; he will know exactly what to expect, and in space warfare, only the unexpected can kill.

I fire the grains of sand, one at a time, and the sequential kick of almost a standard gravity nudges my speed slightly forward. Then I drop the empty shells.

May he slip up, and run into them at sub-relativistic closing velocity.

I am lighter, but it is still not enough. I nudge my thrust up, hating myself for the waste, but if I don’t increase acceleration, in two years I will be caught, and my parsimony with fuel will yield me nothing.

I need all the energy I can feed to my ion drives. No extra for thinking.

Sleep.

2900

Still being chased.

2905

Still being chased.

I have passed the point of commitment. Even if I braked with my thrust to turn back, I could no longer make it back to the solar system.

I am alone.

2907

Lonely.

To one side of my path Sirius glares insanely bright, a knife in the sky, a mad dog of a star. The stars of Orion are weirdly distorted. Ahead of me, the lesser dog Procyon is waxing brighter every year; behind me, the sun is a fading dot in Aquila.