Vacuum Diagrams

by Stephen Baxter

  It was like watching the death of a magnificent animal. "They're destroying it," I said. "But how?"

  "The handgun must be a gravity wave laser," the Qax said slowly. "The coils on the butt of that handgun are small synchrotrons. Subatomic particles move at fantastic velocities in there; the thing emits a coherent beam of gravity waves which—"

  "I thought you needed large masses to get significant gravity waves."

  "No. As long as you move a small mass fast enough... the energy must come from the same source as your ship's — from the structure of space itself."

  "Handguns to break stars, eh?"

  A shadow moved across my vision. I glanced about quickly. A dozen Xeelee slid across the blue-shifted sky and gathered into a close sphere around me.

  "They've noticed me." Rapidly I thought over my options. Before me was the reassuring red glow of the hyperspace button: my escape hatch, if things got too hot... but, I quickly decided, I'd come too far to go home without seeing the Great Attractor itself.

  I spread my wings as far as they would go and dragged them downwards in one mighty swoop. I shot head first out of the closing trap and kept going, heading deeper into the blue-tinged star cloud. My breath was loud in my helmet.

  "What now?" I gasped.

  "Run!" said Lipsey.

  I ran for hours. I dodged stars only light minutes apart, their surfaces distorted into surreal shapes by their proximity to each other. The bank of grayish light beyond the mist grew remorselessly brighter and wider — and all the time the Xeelee formation was a spear pointing at my shoulder blades.

  At last, abruptly, I burst out of the star mist. The naked light ahead was dazzling. Heart thumping, I wrenched at the wings and skidded to a halt. I found myself in a region clear of stars and debris... and the curtain of stars on the other side was tinged blue.

  So I was at the center. The bottom of the pit; the place all the stars were falling into. And at the heart of it all, flooding space with a pearly light, was the Great Attractor itself.

  It was a loop, a thing of lines and curves, a construct of some immense cosmic rope. My nightfighter was positioned somewhere above the plane of the loop. The near side of the construct formed a tangled, impenetrable fence, twisted exuberantly into arcs and cusps, with shards of galaxy images glittering through the morass of spacetime defects. And the far side of the object was visible as a pale, braided band, remote across the blue-shifted sky.

  And it was — astonishingly, unbearably — a single object, an artifact, at least ten million light years across.

  The rough disc of space enclosed by the artifact seemed virtually clear.

  ...Clear, I saw as I looked more carefully, save for a single, glowing point of light, right at the geometric center of the loop.

  "Qax," I croaked. "Speak to me."

  "A massive rotating toroid," murmured the Qax. "A made thing, of cosmic string. The Xeelee have manipulated one-dimensional space-time discontinuities, just as — in their night-fighter intrasystem drive — they manipulate two-dimensional discontinuities."

  Lipsey said, "I didn't imagine anything like this. A ring, an artifact of cosmic string. As large as a giant galaxy. The audacity..."

  "But — why? What's the point?"

  The Qax paused. "Well, this fits one of our hypotheses. Look in the central region, Bolder."

  The hole in the ring hurt my eyes. It was a sheet of space that was somehow — tilted. I saw muddled space, stars streaked like cream in coffee.

  "Do you know about the Kerr metric?" asked the Qax. "No? The Great Attractor is a massive toroid rotating extremely quickly. Your own theory of relativity predicts some odd effects with such a structure. There may be closed lines in space and time, for instance—"

  "Come again?"

  "Time travel," said Lipsey. "And more... Bolder, the Kerr metric describes Interfaces between Universes. Do you understand? It's as if—"

  "What?"

  "As if the Xeelee don't like this Universe, so they're building a way out."

  I focused my monitors on the dust that walled the cavity in the stars. I saw ships — an aviary of all shapes and sizes, uncountable trillions of them.

  A few light minutes from me I made out a particularly monstrous ship, a disc that must have been the size of Earth's Moon. Hundreds of cup freighters nestled into neat pouches in the disc's upper surface, dumping out stolen star material. Vents in the underside of the main ship emitted a constant rain of immense crystalline shafts, as if it were some huge sieve leaking rainwater.

  Peering deeper into the mist of craft I could see fantastic bucket-chains of the disc-ships descending to the Great Attractor, dwindling to pinpoints against the vast carcass of the ring. Returning ships, I saw, were diverted to clouds of cup freighters for reloading.

  I began to see the pattern. "So the disc-ships are huge, ah, dumper trucks," I said. "They're tending the Great Attractor, bringing it matter and energy. Using that crystalline stuff to grow the string, knitting it together strand by strand, with a patience that's lasted billions of years..."

  There was a flicker in my peripheral vision. My posse. They whirled around me and began to close up once more.

  I closed up my wings and prepared to punch the red button. "Lipsey, I've seen enough. We've got to spread this news around all the races in our region — find a way to stop the Xeelee before they wreck our Universe. We've time to plan—"

  He coughed apologetically. "Ah — look, Bolder, this information is Qax commercial property. You know that."

  I hesitated. "You're kidding. We're doomed if the Qax keep this knowledge to themselves."

  He sighed. "The Qax don't think on those timescales. They can't, remember. They think about profit, today."

  I forced my hand away from the escape button; a cold knot in my stomach started to tighten. Suddenly this wasn't a game. If I tried to go home after what I'd just blurted out, the Qax wouldn't hesitate to use their Spline warships to blast me out of the sky. Abruptly my isolation telescoped into a vivid reality, and the cage around me seemed absurdly fragile... And the Xeelee whirled tighter, reminding me that hanging around here wasn't an option either.

  I had to find more time. To my right, obscured now by the fog of fighters around me, was that dumper truck with its attendant freighters. I opened up my wings, clutched at space and lurched out of the trap. Soon I was thrusting my way into the crowded freighter formation, my wings tucked tight. The fighters blurred after me.

  I rammed thoughts through my sleep-starved brain as I flew. Could I evade the waiting Spline? Maybe I could divert the ship's hyperspace flight — but how? Prise open the melted control box? Change the ship's mass, to change the distance I arrived from the Qax sun?

  Of course I could abandon ship before I reached the Qax system, at one of the later jump points. I had that Spline emergency beacon; I'd be picked up. And if I kept quiet I could hide from the Qax, for years maybe...

  But, damn it, if I did that humanity and a few hundred other races would one day end up falling into the Xeelee pit. Hiding wasn't good enough.

  I dipped under the lip of the dumper truck and dodged the processed Great Attractor material sleeting from the truck's base. The huge icicles fell a few thousand miles and then broke up into a fine mist... and as I stared abstractedly at that mist I realized there was a way out of this. It was stupid, crazy, nearly unworkable. And my only chance.

  "All right, Qax," I said. "I'll come home. But first..."

  I dropped, spread my wings as far as they would go and whirled like a seagull through the crystal rain. The wings plated over rapidly and grew stiff and cumbersome.

  "Bolder, what are you doing?"

  "Wrecking this beautiful ship," I told Lipsey with real regret.

  The Xeelee fighters finally closed around me, shutting out the rain.

  I pressed the button.

  The Xeelee trap disappeared; I'd jumped back to the blue-tinged light of the star cloud. And then—

  J
ump. Jump. Jump — jump — jump — jumpjumpjump—

  The skies became a blur. I slumped into sleep.

  I fell towards the welcoming pool that was my home Galaxy. I peered out of my glazed-over cage as the stars' flickering began to slow. For the first time in a month I unbuckled the straps that bound me to my couch, and prized the translator box free of the strut over my head.

  Lipsey and I said our goodbyes. "Do me a favor," I said. "Whatever happens, keep talking. Tell me what you see."

  "Whatever you say." I imagined his noble face gazing out over the seething Qax ocean. "Bolder... I want you to know I'm sorry."

  "Yeah." The ship — jumped — to the dumbbell binary system. It was dazzling; I'd arrived much closer than I remembered from my visit on the way out. I bunched a gloved fist in triumph. This was going to work—

  —jump—

  A compact yellow star at the heart of the Galaxy, searingly close to the ship. Last stop. Time to get out.

  I climbed onto my seat, put my shoulders against the pod's crystalline plating, and pushed. For a heart-stopping moment I thought the shell was too strong — then it crumbled, and I popped into space, clutching my translator box. Below me glittered the crusted wings of the ship I'd taken so far.

  My plan had worked. The Great Attractor substance had added enough mass to the ship to shift its arrival point significantly closer to the system center. Now I had to rely on the Qax to do the rest—

  —jump—

  —and the ship disappeared and I was left alone in a cloud of fragments; they sparkled in the light of the compact star.

  I drifted there for a while, rotating slowly. Then I squeezed the Spline distress bracelet. It turned rigid and cold.

  Lipsey began to speak out of the translator box. His voice was hoarse, forced. I listened, absently picking sparkling fragments out of the space around me and stuffing them into a suit pocket.

  "You haven't come out where we expected, Bolder. What have you... you're causing the Qax a lot of confusion, I can tell that much..."

  A pause. "I think they've found you... but what are you doing there?"

  The Spline warships rotated like eyeballs, scouring space...

  Then they found my ship, inexplicably close to the Qax sun.

  The Qax panicked. They sent their shell-shaped armada roaring in towards their sun. Waves of energy pounded the Xeelee ship; the great wings sagged like melting chocolate. And in the middle of that torrent of energy was a thread of cherry-red light that arrowed through the wreck and into the sun.

  As I'd hoped, in their anxiety and confusion the Qax had thrown at my ship all they had — including their only Xeelee weapon.

  Of course, it was only a single starbreaker. I'm told it took a couple of days before the flares started.

  Lipsey died alone, surrounded by the rage of humanity's conquerors. It was the end of an undeservedly long life. But he died laughing at them. I heard him.

  A Spline freighter ingested me after a day.

  The Spline sold me access to a human news channel. I figured, why not. Since I was still broke, in spite of everything, I wasn't going to be able to pay them anyway...

  Humanity was rejoicing. Qax-owned ships were disappearing from the skies of the human worlds of the Solar System. The Qax were going to need every cubic foot of carrying capacity to get themselves off their home world before their sun blew up. They were going to be busy for a long, long time, and much too preoccupied to hunt me down.

  And once I released my news about the Xeelee, we'd be busy, too. One day we'd go back to the Great Attractor, take on the Xeelee starbreakers.

  But in the meantime I'd have to find a job. My adventure was over and I faced the dreary prospect of spending the rest of my life paying off the Spline — among others. I reached for my suit and dug out my handful of Great Attractor fragments. Cold as ice, and just as worthless, they sparkled even in the Spline's blood-tinged light—

  Worthless?

  Suddenly I imagined these stones set in platinum and resting against tanned flesh: Xeelee-made gems from half a billion light years away.

  Maybe I had a way to pay off my debts after all. Soon, AS technology would be available again. And after that I could buy my own ship, start a small line...

  I put away the stones and began to dream again.

  Eve said, "Jim Bolder was a brave, impulsive man. But he thought big. He immediately saw the significance of the knowledge of the Xeelee artifact, the thing he called the Great Attractor, to mankind.

  "Bolder lived for the moment. But his actions would resound through millions of years. It is entirely appropriate that, for humans, the artifact he found would always bear his name:

  "Bolder's Ring.

  "But the impact of his actions on the Qax was devastating..."

  The pathetic Qax evacuation armada consisted of hundreds of Spline ships.

  The craft, their spherical hulls open, settled into the Qax ocean. Each hull was lined with heaters designed to simulate the volcanism of that mother sea; convection cells were stirred to life inside the ships, and the awareness of a Qax slid reluctantly aboard each craft.

  The Spline carriers lifted cautiously from the amniotic ocean. Flares like human fists already punched out of the sun, and gales howled through the atmosphere, buffeting the stately rise of the Spline. With each jolt the delicate convection patterns were disrupted; the Qax endured the gradual paring away of their awareness.

  Over half the race expired.

  But after the evacuation, the inventiveness and enterprise of the Qax were reasserted. Soon traders were once more spreading Qax goods and services through the neighboring star systems. And the Qax, adrift in their Spline fleet, began to explore new homes for their delicate structures.

  They were creatures of turbulence, and they found turbulence everywhere.

  Qax awareness took root in the roiling air of Jovians... in the slow, stately gravitational rhythms of galactic orbits... and at last they learned how to colonize the structure of seething space itself.

  On their reemergence as an interstellar power the Qax sought out humanity, but — as Bolder in his blundering way had evidently hoped — the Qax's long, forced withdrawal from affairs had given mankind time to grow powerful.

  The history of the two species diverged, with humanity resuming its vigorous expansion, and the Qax beginning an introspective retreat into the structure of space.

  Soon the Qax were numberless, and had become immortal.

  But they remembered the moment at which a single human being had brought them to the brink of extinction.

  Meanwhile, humans prospered.

  Some argued that access to Xeelee technology damaged human inventiveness. It was too easy to take rather than build.

  But not all exploration was finished. And, in the course of that exploration, evidence was unturned — fragmentary and incomplete — of a technology even older than the Xeelee...

  The Quagma Datum

  A.D. 5611

  THE SOUP WAS COLD. I pushed it away. "Tell me why I'm here."

  Wyman didn't answer until the next course arrived. It was a rich coq au vin. He forked it into his mouth with an enthusiasm that told me he hadn't always been accustomed to such luxury. Earthlight caught the jewelry crusted over his fingers.

  Faintly disgusted, I lifted my eyes to the bay window behind him. Now that we'd left the atmosphere the Elevator Restaurant was climbing its cable more steeply. The Sahel ground anchor site had turned into a brown handkerchief, lost in the blue sink of Earth.

  Suddenly the roof turned clear. Starlight twinkled on the cutlery and the table talk ebbed to silence.

  Wyman smiled at my reaction.

  "Dr. Luce, you're a scientist. I asked you here to set you a scientific puzzle." His accent was stilted, a mask for his origins. "Did you read about the lithium-7 event? No? A nova-bright object fifteen billion light years away; it lasted about a year. The spectrum was dominated by one element. Doctor, the thing was a
beacon of lithium-7."

  A floating bottle of St. Emilion refilled my glass.

  I thought about it. "Fifteen billion years is the age of the Universe. So this object went through its glory soon after the Big Bang."

  Thin fingers played with coiffed hair. "So, Doctor, what's the significance of the lithium?"

  "Lithium-7 is a relic of the early Universe. A few microseconds after the singularity the Universe was mostly quagma — a magma of free quarks. Then the quarks congealed into nuclear particles, which gathered into the first nuclei.

  "Lithium-7 doesn't form in stars. It was formed at that moment of nucleosynthesis. So all this points to an early Universe event."

  "Good," he said, as if I'd passed a test.

  Our empty plates sank into the table.

  "So what's this got to do with me? I hate to disappoint you, Wyman, but this isn't my field."

  "Unified force theories," he said rapidly. "That's your field. At high enough energies the forces of physics combine into a single superforce. The principle of the old GUTdrive. Right? And the only time when such energy densities obtained naturally was right after the Big Bang. The superforce held together your quagma." He was a slight man, but the steadiness of his pale eyes made me turn aside. "So the early Universe is your field, after all. Dr Luce, don't try to catch me out. You think of me, no doubt dismissively, as an entrepreneur. But what I'm an entrepreneur of is human science. What's left of it... I've made myself a rich man. You shouldn't assume that makes me a fool."

  I raised my glass. "Fair enough. So why do you think this lithium thing is so important?"

  "Two reasons. First, creation physics. Here we have a precise location where we can be certain that something strange happened, mere moments after the singularity. Think what we could learn by studying it. A whole new realm of understanding... and think what an advantage such an understanding would prove to the first race to acquire it."

  "And what profits could be made from it," I said dryly. "Right? And the second reason?"