Vacuum Diagrams

by Stephen Baxter

  Start with, say, a square mile of construction material. I made educated guesses about its surface density. Suppose it gets from the nova and surrounding stars about what the Earth receives from the Sun — something over a thousand watts a square yard. Assume total efficiency of conversion: mass equals energy over cee squared.

  That gave it a doubling time of fifteen years. I dreamed of numbers: one, two, four, eight, sixteen... It was already too big to handle. It would be the size of the Earth after a couple of centuries, the size of Sol a little later.

  Give it a thousand years and you could wrap up the Galaxy like a birthday present. Doubling series grow fast. And no one knew how to cut Xeelee construction material.

  The Universe waltzed around me; I stroked the placid buttlebot. My tongue was like leather; the failing recycling system of my suit left a taste I didn't want to think about.

  I went over my figures. Of course, the growing flower's power supply would actually be patchy, and before long the edge would be spreading at something close to the speed of light. But it would still reach an immense size. And the Xeelee hadn't shown much interest in natural laws in the past. We drifted into its already monstrous eclipse; the buttlebot snuggled closer.

  This was the sort of reason the Xeelee didn't leave their toys lying around, I supposed. The flower would be a hazard to shipping, to say the least. The rest of the Galaxy weren't going to be too pleased with the Squeem...

  These thoughts sifted to the bottom of my mind, and after a while began to coalesce.

  The secret of the hyperdrive: yes, that would be a fitting ransom. I imagined presenting it to a grateful humanity. Things would be different for us from now on.

  And a little something for myself, of course. Well, I'd be a hero. Perhaps a villa, overlooking the cliffs of Miranda. I'd always liked that bust-up little moon. I thought about the interior design.

  It was a sweet taste, the heady flavor of power. The Squeem would have to find a way to turn off the Xeelee flower. But there was only one way. And that was in my suit pocket.

  Oh, how they'd pay. I smiled through cracked lips.

  Well, you know the rest. I even got to keep the buttlebot. We drifted through space, dreaming of Uranian vineyards, waiting for the Squeem to return.

  The images faded.

  "I liked Jones," I said.

  "Because he didn't give up. I know you, Jack."

  "And he won, didn't he?"

  "Yes. Jones's small victory would, indeed, prove to be the turning point in human oppression by the Squeem..."

  The yoke of the Squeem was cast off. Humans were free again, able to exploit themselves and their own resources as they saw fit. Not only that, the Squeem occupation had left humans with a legacy of high technology.

  The lost human colonies on the nearby stars were contacted and revitalized, and a new, explosive wave of expansion began, powered by hyperdrive. Humans spread like an infection across the Galaxy, vigorous, optimistic once more.

  And everywhere, they encountered the footprints of the Xeelee...

  More Than Time or Distance

  A.D. 5024

  MY ONE-WOMAN FLITTER DROPPED into the luminous wreckage of an old supernova. I peered into the folded-out depths of the dead star, hoarding details like coins for Timothy.

  The star remnant at the heart of the wreck was a shrunken miser; its solitary planet was a ball of slag pockmarked with shallow craters. Once this must have been the core of a mighty Jovian. I landed and stepped out. Feel how the surface crackles like glass, Tim... I imagined four-year-old eyes round with wonder. Except, of course, my memory of my son was five years and a thousand light years out of date. But I felt Tim's presence, somehow — when you get close enough to someone you're never really alone again. And maybe if my prospector's luck changed here, it wouldn't be five years before I held him again.

  Above me violet sails of gas drifted through a three-dimensional sky. Around me a thousand empty light years telescoped away. And ahead of me stood a building — plain, cuboid, a bit like a large shoe box.

  But a shoe box at the center of a nebula — and made of Xeelee construction material.

  I stood stock still, the hairs at the back of my neck prickling against the lining of my pressure suit. An original Xeelee relic, the dream of prospectors from a thousand races... and intact, too.

  The exploded star washed blank walls with light like milk. I expected a giant to step through that low doorway... I thought of one of Timothy's jokes. What do you call a giant alien monster with a zap gun?

  You know it. Sir.

  I stepped through the doorway. The wall material was sword-thin.

  The ceiling was translucent; supernova filaments filled the place with violet and green shadows. My eyes were drawn to a flicker of light, incongruously playful: about five yards from the doorway a small pillar supported a hoop of sky blue, which was maybe two feet wide. The hoop was polished and paper-thin, and a sequence of pink sparks raced around its circumference.

  About thirty yards further down the long axis of the hall was a second pillar bearing an identical hoop. The two circles faced each other, chattering bits of light.

  That was all. But it was enough to stop my heart. Because whatever this place was, it was still working — and working for the Xeelee, lurking like watchful spiders in their Prime Radiant at the Galaxy's core — only three days away in their magical ships.

  I stepped forward with my portable data desk and began to mark and measure.

  The sequence of sparks in the hoop nearest the door was random, as far as I could tell. So was the sequence in the other hoop — but it was an exact copy of the first sequence, delayed by a nanosecond.

  I worked out the implications of that, and then I leaned carefully against a low pillar and breathed deep enough to mist up my face plate.

  Think about it. Ring A was talking to ring B, which got the message delayed by a nanosecond. Each ring was a light nanosecond across. And the rings were placed a hundred light nanoseconds apart.

  So all the delay was in the structure of the rings — and the communication between them was instantaneous.

  My face plate fogged a bit more. Instantaneous communication: it was a technological prize second only in value to the hyperdrive itself...

  The secret had to be quantum inseparability. When a single object is split up, its components can still communicate instantaneously. That's high school stuff, Bell's theorem from the twentieth century. But, everyone had thought, you couldn't use the effect to send meaningful messages.

  The Xeelee had really got their fingers into the guts of the Universe this time. It was almost blasphemous.

  And very, very profitable.

  My sense of awe evaporated. I found myself doing a sort of dance, still clinging to the pillar, booted heels clicking. Well, I had an excuse. It was the high point of my life.

  And at just that moment, in walked a giant alien monster with a zap gun. Wouldn't you know it?

  At least it wasn't a Xeelee. About all we know of them is that they're small, physically. My superstitious terror faded to disgust.

  "You tailed me," I said into my suit radio. "You sneaked up on me, and now you're going to rob me and kill me. Right?" I looked at the zap gun and remembered the joke. "Right, sir?"

  I don't suppose it got it. Silhouetted against a violet doorframe was a humanoid sketch in gun-metal gray. Its head was a cartoon; all the action was in a porthole in its stomach, through which I caught grotesque hints of faces. It was like an inside-out bathyscaphe with weird sea-bottom creatures peering out of darkness.

  And it had the zap gun. The details of that don't really matter; it was essence of gun and it was pointing at me.

  I labeled it the Statue.

  The silence dragged on, maybe for dramatic effect, more likely because the Xeelee-derived translator box I saw strapped to one metal thigh was having trouble matching up our respective world pictures. Finally it spoke.

  "Allow me to summariz
e the situation." The box's voice was a machine rasp; the stomach monster twitched. "I have discontinued your vessel. I estimate your personal environment will last no more than five human days. You have no weapons, or any means of communication with your fellows — none of whom are in any event closer than a thousand light years."

  I thought it over. "Okay," I said, "I'm prepared to discuss terms for your surrender."

  "The logic of the situation is that you will die. You will therefore move outside this structure—"

  Actually the logic was that I was dead already. I thought fast, looking for the edge. "Of course, you're right." I stepped forward —

  — and whirled like a leaf — and snapped one sky blue hoop off its pillar — and draped it around my neck.

  It was over before either of us had a chance to think about it. The whirling pink sparks faded and died.

  The Statue's limbs were motionless but its stomach thrashed. I felt breathless and foolish; the hoop around my neck was like a lavatory seat put there during a drunken teenage party. "Logic's not my strong point," I apologized.

  You see, I had a plan. It wasn't a very good plan, and I was probably dead even if it came off. But it was all I had, and I noticed I was still breathing.

  The Statue stared. "You have damaged the artifact."

  "You see, there had to be a reason why you didn't shoot me in the back before I knew about it. And that reason's got to be your ignorance of humans. Right?" I snapped. "Despite the fact that you and your kind have been tailing me for months—"

  "Actually years. We find humans are resourceful creatures, worthy of study."

  "Years, then — if you zapped me, maybe I'd explode, or melt, or in general make a horrible mess of the Xeelee equipment. And you won't hurt me now for fear of doing even more damage." I clung to the frail hoop around my neck.

  The Statue moved further into the building, the interesting end of the zap gun unwavering. We stood along the axis of the structure. The Statue said patiently, "But even with this awareness you are scarcely at an advantage."

  I shrugged.

  "You are still isolated and without resources." The Statue seemed confused. "All I have to do is wait five days, when you will die in undignified circumstances and I will retrieve the artifact."

  "Ah," I said mysteriously. "A lot can happen in five days." In fact, maybe in three — I kept that to myself.

  The stomach monster thrashed.

  I walked around the pillar and sat down, taking care not to squash my catheter. "So we wait." I settled the hoop more comfortably around my neck.

  Giant wings of gas flapped slowly beyond the translucent ceiling, and the hours passed.

  Time stretches like a lazy leopard when it wants to.

  I spent a day staring out a statue and not thinking about my catheter — or Tim.

  I snapped out, "You've no idea what you're stealing from me here."

  The Statue hesitated. "I believe I do. This is clearly a Xeelee monitoring station. Presumably one of a network spread through the Galaxy."

  Instantly I wished I hadn't spoken. If it had thought through as far as that... to distract it, I said, "So you watched my experiments?"

  "Yes. What we see must be a test rig for the instantaneous communication device."

  "How do you suppose it works?" Stick to details; keep it off the Xeelee—

  A longer pause. Through the ceiling skin I watched a cathedral of buttressed smoke. The Statue said, "I fear the translator box cannot provide the concepts... At one time these two hoops were part of a single object. And an elementary particle, an electron perhaps, would be able to move at random between any two points of that object, without a time lapse."

  "Yeah. This is quantum physics. The electron we perceive is an 'average' of an underlying 'real' electron. The real electron jumps about over great distances within a quantum system, quite randomly and instantaneously. But the average has to follow the physical laws of our everyday experience, including the speed of light limit."

  "The point," it said, "is that the real electron will travel at infinite speed between all parts of an object — even when that object has been broken up and its parts separated by large distances, even light years."

  "We call that quantum inseparability. But we thought you could use it only to send random data, no information-bearing messages."

  "Evidently the Xeelee do not agree," the Statue said dryly. "It took many generations before my species could be persuaded that the elusive 'real' electron is a physical fact, and not a mathematical invention."

  I smiled. "Mine, too. Maybe our species have got more in common than they realize."

  "Yes."

  Well, that was a touching thought which augured hope for the future of the Galaxy. But I noticed it didn't touch the zap gun.

  The thing in the Statue's stomach started to feed on something; I turned away. The gloom deepened as the pale supernova remnant was eclipsed by the edge of the ceiling. I tried to sleep.

  The first day was bad enough, but the second was the worst. Except for the third.

  For me, anyway. The suit had water and food — well, a syrup nipple — but the recycling system wasn't designed for a long vacation. I didn't want to lose face by sluicing out my plumbing system all over the floor. And so, when I went for my regular walks around the bereft pillar, I sloshed.

  By contrast, the Statue was unmoving, machinelike. Bizarre fish swam in its stomach, and the zap gun tracked me like the eye of a snake.

  On the third day I stood by my pillar, swaying in unstable equilibrium. I didn't have to feign weakness. I sneaked glances at the futuristic sky. I had to time things just right—

  At length, the Statue said, "You are weakening and will surely die. But this has always been inevitable. I do not understand your motivation."

  I laughed groggily. "I'm waiting for the cavalry."

  The stomach creature twitched uneasily. "What is this 'calvary'?"

  Too uneasy. I shut myself up with the truth. "Maybe I just don't like being robbed. I'm a prospector for Xeelee gold, but it's not just for me. Can you understand that? It's for my son. My off-spring. That's what you're taking from me, and I don't even know what you are."

  A flicker in the sky like the turn of a page.

  It was time. I stumbled to my knees.

  The Statue said, not unkindly, "You have been a worthy opponent. I will allow you to end your life according to the custom of your species."

  "Thank you. I — I guess it's over." I forced myself to my feet, took the hoop from my neck, and laid it reverently atop the little pillar. I began walking stiffly towards the door, feeling ashamed of my trickiness. Amazing, isn't it. "I'd like to die outside," I said solemnly.

  The Statue glided away from the doorway, respectfully lowering its zap gun.

  I got outside the building. Another shudder across the weird sky. I limped around the corner of the building—

  —and ran for my life. My legs were like string, shivering from under use. A bar of light swept behind the stars. There were tiny explosions in my peripheral vision; it was as if something was solidifying out of the layer of space that cloaked the planet.

  The Xeelee didn't believe in a quiet entrance.

  I tumbled face first into a shallow crater and stayed that way. It didn't feel deep enough; I imagined my backside waving like a flag to the marauding Xeelee.

  A giant started stomping around me. I held onto my head and waited for the pounding to stop. I glimpsed wings, night-dark, hundreds of miles wide, beating over the planet, eclipsing the glowing gas.

  The planet stopped shivering.

  I tried to move. My muscles were like cardboard. Pieces crackled off the back of my suit, which was burnt to a crisp. I walked from the crater scattering scabs like an unearthly leper.

  I reached the site of the Xeelee station. I was a fly at the edge of a saucer; the hole was a perfect hemisphere, a hundred yards wide. I skirted it carefully, heading for a sparkle of twisted metal be
yond it.

  The Statue lay like Kafka's cockroach, its sketch of a head battered into concavity, its limbs and torso crumpled. Fluid bubbled through a crack in the porthole, and something inside looked out at me listlessly.

  The translator box was hesitant and scratchy, but intelligible. "I... wish to know."

  I knelt beside it. "Know what?"

  "How you knew when... they would come."

  "Neat timing, huh?" I shrugged. "Well, the clues were there for both of us."

  "Quantum inseparability?"

  "Signals will pass instantaneously between a communicator's two halves. But those halves must once have been in physical contact. Once joined, they can never be truly parted. Like people," I mused. "It takes more than time or distance—"

  "I begin to... understand."

  "The components of this station, and all its clones throughout the Galaxy, must have been carried here from a central exchange. That's where the repairmen we've just, ah, encountered, must have come from. And the exchange has to be at the Xeelee home base, at the Galaxy core. Three days' travel for the Xeelee."

  "So they had to come. But the Xeelee Prime Radiant is a matter of speculation. You did not know—"

  I grinned ruefully. "Well, I knew for sure I'd had it unless I took a long shot. Your precious logic demonstrated that."

  More bubbles from the stomach, and the voice grew weaker. "But your... ship is destroyed. Your victory does not bring success."

  "Yeah." I sat in crunchy dirt beside the dying Statue. "I guess I didn't like to think this far ahead." The depth of focus seemed to shift; light years expanded around me.

  Even the Statue was company. "You have been a worthy... opponent."

  "You're repeating yourself," I said rudely.

  "My ship is at... the planet's nearer pole, one day's journey from here. You may be able to adapt its life system to your purposes."