Vacuum Diagrams

by Stephen Baxter

  And that was all.

  Their hard language of "particles" and "waves" and "here" and "now" reflected their limited perception, stony words to describe shadows. But he, Paul, the boy with no past, could sometimes see the entire surface of the pond — and even catch hints of the depths which lay below.

  He watched wave functions ripple away from the Edge, diminishing softly into prismatic shades of improbability, and felt his consciousness drawn out like a sword from its scabbard. He looked down at his body, bent awkwardly in its ill-fitting pressure suit; at the two stick men standing over it, obviously blind to the kaleidoscopic probability sparkles all around them.

  The Face of the Sugar Lump was a window. He drifted through it.

  He floated like a snowflake, wafted by probability winds. The Sugar Lump was full of wonders.

  Here was an array of crystals which would grow at a touch into a fleet of a thousand night fighters, unfurling glistening wings like dark butterflies. Twist this flowerlike artifact just so and a city would unfold in a storm of walls and ceilings. Point this other at a star — and watch it collapse softly into nova.

  And here, rank on rank of shadowy forms, were Xeelee themselves, features smoothed-over and indistinct, embryonic.

  The Sugar Lump was a seed pod.

  Something watched him. Paul twisted, scattered his being like diffusing mist...

  Call it the antiXeelee.

  It was as old as the Xeelee race, and as young. Inside the vessel men called the Sugar Lump — and, simultaneously, within a million similar vessels scattered through the galaxies — it waited out aeons, brooding.

  The antiXeelee took Paul as if in the palm of a hand. Paul tried to relax. The gaze was all-knowing, full of strength... but not threatening.

  Gently he was shepherded to the gleaming walls and released.

  He opened his eyes. And moaned.

  He was back in the world of the stick men.

  Green's face, lined with concern, hovered before him. "Take it easy," he said. "We've brought you inside the Edge car." He slid a hand behind Paul's neck, tilted his head forward and helped him sip coffee. "How do you feel?"

  Paul felt the softness of the seat beneath him, saw the warm brown light of the car interior. Beyond the windows the glow of the Sugar Lump seemed different. Harsher? Sharper? Shadows raced through the interior. "What's happening, Commander? Where's Taft?"

  "At the controls of the car. He got a call from his team at the City site; some kind of problem." Green leaned over him hungrily. "Paul. You were inside the Lump, weren't you?"

  "...Not really. It isn't like that." Paul reached for the coffee cup and took another mouthful. "You taught me what's happening. I have a non-local perception. Like a quantum wave function I'm not limited to the here and now; I perceive events spacelike-separated from—"

  "Paul," Green said urgently, "skip it. Tell me what you saw. I have to know. My career is hinging on this moment. Is it the Xeelee?"

  "I... Yes. It's the Xeelee." He groped for analogies. "It's like a huge hangar in there. There are Xeelee, waiting, whole populations of them. Thousands of ships, ready to be — ripened. Artifacts of all kinds."

  Green smiled. "Weapons?"

  "Yes." Over Green's shoulder Paul could see Taft approach quietly.

  "What are they doing?"

  "I don't know. But, Commander, I don't think they mean us any harm. You see, there's another presence which—"

  Taft's bearded face was twisted with a kind of pain. He raised two clasped fists over Green's head.

  "Commander!" Paul jerked convulsively.

  Green half-rose, turned his head. Two fists hit his skull with a sound like wood on wood. The reaction carried Taft perhaps a foot into the air. He cried out. His hands came away bloody.

  Green tumbled into Paul's lap; then he slid to the floor of the car.

  Paul stared at the blood on Taft's hands. Memories stirred impossibly. So it is coming to pass, as I knew/remembered. But how...?

  "Paul, I — " Taft spread his hands, palms upwards. Paul couldn't read his face, the shining artificial Eyes. "I'm sorry. I have to do this." With clumsy hands he fitted Green's helmet into place and sealed the neck; then he began hauling the huge, limp body towards the airlock. "My team back in the City are being evacuated. Forcibly, by Green's damnable Navy goons."

  "Why? What's happened?"

  "You've stirred up the Xeelee with your quantum jaunt," Taft said acidly. "The glow of the surface is brighter. And it's getting hotter. In some places the meteorite debris is already red hot. So we're being evacuated — at the point of a gun." Taft sealed up his own helmet. "So I've got to stop this, you see, Paul. I'm sorry. It's for the good of the species. The Xeelee have to understand we're not continually going to attack them. The colony has to be built."

  "What are you going to do?"

  "I'm going to get Green back to the Face car. Then I'll return here and—"

  Paul felt his breath grow shallow. "And what?"

  Without replying Taft turned away and stepped through the airlock; the membrane closed behind Green's booted feet.

  Paul sat for long minutes. The humming of the car's instruments was the only sound. Through the windows Taft and Green were silhouetted against a glowing Face, the pair of them looking like a single, struggling insect.

  Paul imagined Taft's return, those bloodied, space suited hands reaching for him, as they had for Green—

  There was a joystick at the front of the car.

  He pushed himself out of his chair and stood swaying. He took cautious steps along the narrow aisle, looking neither to left nor right.

  Nervously he pushed at the joystick. The car lurched a few yards; Paul stumbled back, grabbing the arm of the nearest chair. He felt a grin spread over his face. Had Taft expected him to sit patiently and wait to die? He pushed the stick once more. Motors whirred and the car slid along the Edge.

  Taft dumped Green's inert form and came floundering back up the slope, a toy figure gesturing in tiny frustration.

  Paul settled into a seat and let the satisfaction of the small victory settle over him. There would be plenty of time to face the future later... when the car reached Corner Mountain, with nowhere else to go.

  The car patiently climbed the Edge's increasing slope. The brightness of the Faces continued to increase; at last the car's lower windows opaqued automatically.

  Paul could see Taft following, a silver-suited doll riding an open maintenance buggy up the dizzying slopes of the Edge. For the first few hours Paul let Taft speak to him. When the half-rational arguments turned to sobbed pleas for understanding Paul snapped the radio off.

  The Corner Mountain became visible as a sharp angle against the stars. The car slowed to a halt, tipped up at about thirty-five degrees.

  Paul closed his helmet and stepped through the airlock. His footsteps were light, airy; Green had told him how, this far from the mass center of the Lump, gravity would be down to a third that at the City. The brilliance of the surface hit him with a soft impact. Heat soaked through the soles of his boots. With an odd sense of calm he worked his way up the slope to the summit, his feet on the tilted surfaces to either side of the Edge.

  At last he stood unsteadily at the summit itself, feet wrapped around the sharp-edged point, arms extended for balance. The vertical lurched around him as his inner ear sought the way to the center of mass of the Sugar Lump.

  Taft had abandoned his vehicle and was scrambling up the dazzling ridge. Paul felt a huge peace, as if he were once more in the metaphorical palm of the antiXeelee. He turned slowly, feet working around the summit. Three square Faces as wide as Earth shared corners at the point where he stood; he saw Edges disappear into infinity, watched Faces collapse into glowing lines of abstraction.

  Sugar Lump. Edge. Corner Mountain. He found himself laughing. Harmless words used to shield men from the astonishing truth of a world shaped like a cube, of a made thing whirling and sparkling in space.

  T
aft stood before him. The light showed him to be a machine of pulleys, cables and gears; quantum functions sparkled unnoticed around his eyes and fingers.

  Paul smiled. And jumped backwards.

  Taft stumbled forward, reaching. Then he was gone, eclipsed by an Edge.

  Paul let his limbs dangle. Spline warships paddled across his view like agitated fish.

  He was approaching a glowing Face. What next? Would he strike, bounce away, proceed skipping and sliding? Would the impacts crush his bones? Would the heat of the surface reach through the suit and boil his flesh?

  The certainty of his death was unreal, intangible, un-threatening.

  Now, why should that be? Was his death to be as great a mystery as his origin? Would he die ignorant of the answers of both the great questions of his existence — where did I come from? and where am I going to?

  Or perhaps the two answers were somehow linked...

  He found he hoped Taft and Green would survive.

  The Face rushed at him. Wave functions rippled like grass in a breeze.

  Folded ships hung around him like moths.

  There was a sense of motion, a thrumming of huge engines somewhere; as if the Sugar Lump and its contents were a great liner, forging through some huge sea.

  The antiXeelee cradled him. It studied him dispassionately, huge and cold. Paul felt knowledge wash over him, and slowly understanding grew.

  The cube planet had been created at that moment — far in the future of mankind — when the Xeelee reached their full glory. And were ready to depart.

  (Depart? Where to? Why? The answers were — awesome; beyond his comprehension.)

  On its completion the cube — with its guardian, the antiXeelee, and with a million others — had been sent on an impossible voyage, forging back through the unfolding ages to the birth time of the Xeelee themselves. The Xeelee would erupt fully developed from the cubes, shaking out the wings of their beautiful spacecraft and ready for their huge projects. Paul sought human words to capture the vast concepts sailing around him. Vacuum diagrams! The cube worlds were antiparticles, moving back through time to initiate their own creation. The whole of Xeelee history was a single, vast vacuum diagram, closed and complete of itself.

  But... what of me?

  Now Paul sensed a monstrous amusement. He was cupped within gigantic palms for an unmeasurable period; the time engines surged steadily into the past—

  And then he was lifted up and released like a captive bird.

  He looked down. He was outside the Sugar Lump, falling towards it. Spline ships converged. There was the City, still alive with the hopes of Taft and the rest, spreading over the meteorite debris. On the rim of the debris was a fallen figure, a young man in a soiled spacesuit lying facedown on the glowing surface.

  Understanding came at last.

  I have no beginning. I have no end. My lifeline is caught up in the vast Xeelee expedition into the past. I am a vacuum diagram, too, closed on myself. He remembered the absurd refrain: "We're here because we're here because we're here..."

  He tumbled into the head of the fallen man. Skull darkness hit him like a physical shock, and he felt the pieces of his understanding shatter like a dropped vessel, his memories seep away.

  In the end he was left only with a vast amusement. Then even that fell away.

  Paul opened his eyes.

  His body ached. He lay facedown on a surface that glowed with white light. Grass, or fine hair, washed over the surface.

  What is this place? How did I get here? And...

  What's my name?

  His face grew slick with sweat; his breath sawed through his mouth. He perceived the shape of answers, like figures seen through a fog. He writhed against the shining ground.

  The answers floated away.

  A meaningless jingle ran around his mind: "We're here because we're here because we're here because we're here..."

  The grass vanished. He waited, hollow.

  A hundred heroes, a hundred fragments — but understanding did not come: What was the goal of the Xeelee? Why were they trying to rebuild their own history?

  And what was the significance of Bolder's Ring? — why were the Xeelee trying to escape from the Universe itself?

  Like leaves, the centuries fell away. Humanity's growth in power and influence grew exponentially. But the legend of Xeelee achievements — the manipulation of space and time, the Ring itself — grew into a deep-rooted mythology.

  At last, only the Xeelee themselves were more potent than mankind...

  Humans railed against the Tyranny of Heaven.

  More legends were written, as waves of human assaults pounded against the great Xeelee sites. It was a remote, inhuman time. I watched, repelled, terrified.

  PART 5

  ERA: The War to End Wars

  FRAGMENTS. SHARDS...

  Humans even reached into the Prime Radiant of the Xeelee.

  Here was a warship, its engine blazing, falling through Bolder's Ring — and into a new Universe.

  The ship imploded, and fell into a compact, glowing nebula. Crew members hurried through the corridors of their falling ship; smoke filled the passageways as lurid flames singed the air. The hull was breached; the raw air of the nebula scoured through the cabins, and through rents in the silver walls the crew saw flying trees and huge, cloudy whales, all utterly unlike anything in their experience...

  Gradually they came to understand. Gravity was the key to the absurd place they were stranded in. Gravity here was a billion times as strong as in the Universe they'd come from. Here their home planet would have a surface gravity of a billion gees — if it didn't implode in an instant.

  The crew adapted, and survived. Gradually humans spread through the nebula...

  Stowaway

  A.D. 104,858

  IT WAS THE END OF REES'S WORK shift. Wearily he hauled himself through the foundry door. Cool air dried the sweat from his brow.

  He pulled himself along the ropes and roofs towards his cabin, inspecting his hands and arms with some interest. When one of the older workers had dropped a ladle of iron, Rees had narrowly dodged a hail of molten metal; tiny droplets had drifted into his flesh, sizzling out little craters which—

  A huge shadow flapped across the Belt. Air washed over his back. He looked up; and wonder settled at the base of his skull.

  The tree was a wheel of wood and foliage fifty yards wide, magnificent against the crimson sky. Its dozen radial branches and their veil of leaves turned with a calm possession; the trunk was like a mighty wooden skull which glared around at the ocean of crimson air.

  Its rotation slowing, the tree lowered itself reluctantly into the gravity well of the star kernel.

  Pallis, the tree-pilot, was hanging by hands and feet below the knotty trunk of the tree. The star kernel and its churning Belt mine were behind his back. The Belt itself was a circle eight hundred yards wide, a chain of battered dwellings and work places connected by ropes and tubes. At the center of the Belt was the mine itself, a cooled-down star kernel a hundred yards wide; lifting cables dangled from the Belt to the surface of the star kernel, scraping the rusty meniscus at a few feet per second. Here and there, fixed to the walls and roofs of the Belt, were the massive, white-metal mouths of jets; every few minutes a puff of steam emerged from one of those throats and the Belt tugged imperceptibly faster at his heels, shaking off the slowing effects of air friction...

  It was a spectacular sight, but it was of little interest to Pallis.

  With a critical eye he peered up through the mat of foliage at the smoke which hung raggedly over the upper branches. The layer of smoke wasn't anywhere near thick enough: he could clearly see starlight splashing through to bathe the tree's round leaves. He moved his hands along the nearest branch, felt the uncertain quivering of the fine blade of wood. Even here, at the root of the branches, he could feel the tree's turbulent uncertainty.

  Two imperatives acted on the tree. It strove to flee the deadly gravity w
ell of the star — but it also sought to escape the shadow of the smoke cloud, which drove it back into the well. A skillful woodsman should have the two imperatives in fine balance; the tree should hover in an unstable equilibrium at the required distance.

  Now the tree's rotating branches bit into the air and it jerked upwards by a good yard. Pallis was almost shaken loose. A cloud of skitters came tumbling from the foliage; the tiny wheel-shaped creatures buzzed around his face and arms as they tried to regain the security of their parent.

  Damn that boy—

  He hauled himself through the foliage to the top side of the tree. The ragged blanket of smoke and steam hung a few yards above his head, attached tenuously to the branches by threads of smoke. The damp wood in at least half the fire bowls fixed to the branches had, he soon found, been consumed. And Gover, his so-called apprentice, was nowhere to be seen.

  "Gover! By the Bones themselves, what do you think you are doing?"

  A thin face appeared above one of the bowls near the rim of the tree. Gover shook his way out of a nest of leaves and came scurrying across the platform of foliage, a pack bouncing against his narrow back. He shoved the back of his hand against his nose, pushing the nostrils out of shape; the hand came away glistening. "I'd finished," he mumbled.

  Pallis stabbed a finger at Gover's pack. "You're still carrying half your stock of wood. The fires are dying. And look at the state of the smoke screen. More holes than your damn vest. My tree doesn't know whether she's coming or going, thanks to you. Can't you feel her shuddering? Now move it."

  With a flurry of motion Gover pulled himself to the nearest pot and began hauling wood from his pack. Soon fresh billows of smoke were rising to join the depleted cloud, and the shuddering of the tree subsided.

  His exasperation simmering, Pallis watched the boy's awkward movements. Oh, he'd had his share of poor apprentices in the past, but in the old times most of them had at least been willing to learn. To try. And gradually, as hard shifts wore by, those young people had grown into responsible men and women, their minds toughening with their bodies.