Xeelee: An Omnibus: Raft, Timelike Infinity, Flux, Ring

by Stephen Baxter

  Suddenly the reality of it hit him. He had travelled outside the lifedome. He was beyond its protective hull - perhaps the first human to have ventured outside in half a millennium - and now he was suspended in the emptiness which made up most of the forbidding, lifeless Universe.

  ‘Arrow Maker. Talk to us.’

  Arrow Maker laughed, his voice shrill in his own ears. ‘I’m suspended in a glass bubble, surrounded by emptiness. I can see the lifedome. It’s like—’

  ‘Like what?’ Morrow’s voice, sounding intrigued.

  ‘Like a box of light. Quite - beautiful. But very fragile-looking . . .’

  Uvarov cut in, ‘Oh, give me strength. What else, Arrow Maker?’

  Arrow Maker twisted his head, to left and right.

  To the right of the pod, an immense pillar of sculpted metal swept through space. It was huge, quite dwarfing the pod, like the trunk of some bizarre artificial tree. It merged seamlessly with the lifedome, and it was encrusted with cups, ribs and flowers of shaped metal.

  Maker described this.

  ‘The spine,’ Uvarov said impatiently. ‘You’re travelling parallel to the spine of the GUTship. Yes, yes; just as I told you. Arrow Maker, can you see the Interface? The wormhole—’

  Arrow Maker leaned forward and peered down, past the seats and stanchions, through the pod’s base. This spine descended for a great distance, its encrustation of parasitic forms dwindling with perspective, until the spine narrowed to a mere irregular line. The whole form was no less than three miles long, Uvarov had told him.

  Beyond the spine’s end was a sheet of light which hid half the sky. The light was eggshell-blue and softly textured; it was like a vast, inverted flower petal, ribbed with lines of stronger, paler hue. As Arrow Maker watched he could see a slow evolution in the patterns of light, with the paler lines waving softly, coalescing and splitting, like hair in a breeze. The light cast blue highlights, rich and varying, from the structures along the spine.

  He was looking at the GUTdrive: the light came from the primeval energies, Uvarov had told him, which had hurled the ship and all its cargo through space and time for a thousand years.

  Silhouetted against the sheet of creation light, just below the base of the spine, was a dark, irregular mass, too distant for Arrow Maker to resolve: that was the tethered ice asteroid, which still - after all these years - patiently gave up its flesh to serve as reaction mass for the great craft. And—

  ‘Uvarov. The Interface. I see it.’

  There, halfway down the spine’s gleaming length, was a tetrahedral structure: edged in glowing blue, tethered to the spine by what looked like hoops of gold.

  ‘Good.’ He heard a tremulous relief in Uvarov’s voice. ‘Good. Now, Arrow Maker - look around the sky, and describe the stars you see.’

  Arrow Maker stared, beyond the ship. The spine, the Interface, were suspended in darkness.

  Uvarov’s speech became rushed, almost slurred. ‘Why, we might be able to place our position - and the date - by the constellations. If I can find the old catalogues; those damn survivalists in the Decks must have retained them. And—’

  ‘Uvarov.’ Arrow Maker tried to inject strength into his voice ‘Listen to me. There’s something wrong.’

  ‘There can’t be. I—’

  ‘There are no constellations. There are no stars.’ Beyond the ship there was only emptiness; it was as if the great ship, with its flaring drive and teeming lifedome, was the only object in the Universe . . .

  No, that wasn’t quite true. He stared to left and right, scanning the equator of the grey-black sky around him; there seemed to be something there - a ribbon of light, too faint to make out colour.

  He described this to Uvarov.

  ‘The starbow.’ Uvarov’s voice sounded much weaker, now. ‘But that’s impossible. If there’s a starbow we must be travelling, still, at relativistic velocities. But we can’t be.’ The old, dead voice cracked. ‘Maker, you’ve seen the stars yourself.’

  ‘No.’ Arrow Maker tried to make his voice gentle. ‘Uvarov, all I’ve ever seen were points of light in a skydome . . . Maybe they weren’t stars at all.’

  If, he thought ruefully, the stars ever existed at all.

  He stared at the mass of the spine as it slid upwards past him, suddenly relishing its immensity, its detail. He was glad there were no stars. If this ship was all that existed, anywhere in the Universe, then it would be enough for him. He could spend a lifetime exploring the worlds contained within its lifedome, and there would always be the forest to return to. And—

  Light filled the cabin: a storm of it, multicoloured cubes and spheres which swarmed around him, dazzling him. Then, as suddenly as they had appeared, the cubes hurtled together and coalesced.

  There was a man sitting beside Arrow Maker, inside the pod, dressed in a grey-silver tunic and trousers. His hands were in his lap, folded calmly, and through his belly and thighs Arrow Maker could see the quiver of arrows he’d left on the chair - he could actually see the quiver, through the flesh of the man.

  The man smiled. ‘My name’s Mark - Mark Bassett Friar Armonk Wu. Don’t be frightened.’

  Arrow Maker screamed.

  Lieserl swam with the photino birds through the heart of the bloated Sun. The photino birds appeared to relish Sol’s new incarnation. Plasma oscillations caused energy to flood out of the core, in neutrino-antineutrino pairs, and the birds swooped around the core, drinking in this glow of new radiance.

  The matter in the inert, collapsing core had become so compressed it was degenerate, its density so high that the intermolecular forces that governed its behaviour as a gas had broken down. Now, the gravitational infall was balanced by the pressure of electrons themselves: the mysterious rule of quantum mechanics called the Pauli Exclusion Principle, which ensures that no two electrons can share the same energy level.

  But this new state of equilibrium couldn’t last for long, Lieserl realized. The shell of fusing hydrogen around the core continued to burn its way outward, raining helium ash down on the core; and so the core continued to grow, to heat up.

  Now that the inner planets were gone, she felt utterly isolated.

  Why, even the stone-faced bureaucrats of the Assimilation period had been contact of a sort. She’d found it immensely valuable to be able to share impressions with somebody else - somebody outside her own sensorium. In fact she wondered if it were possible for any human being to remain sane, given a long enough period without communication.

  But then again, she thought wryly, she wasn’t a human being . . .

  Into Lethe with that. She closed her eyes and stretched. She took a slow, careful inventory of her Virtual body-image. She wriggled her fingers, relishing the detailed feel of sliding tendons and stretching skin; she arched her back and felt the muscles at the front of her thighs pull taut; she worked her feet forward and back, as if she were training for some celestial ballet, and focused on the slow, smooth working of her ankles and toes.

  She was human, all right, and she was determined to stay that way - even despite the way she’d been treated by humans themselves, in her brief, but still vivid, corporeal life. What had she been but a freak, an experiment that had ultimately been abandoned?

  She didn’t owe people anything, she told herself.

  Maybe.

  But again that buried urge to communicate all this gripped her: she felt she had to tell someone about all this, to warn them.

  But those feelings weren’t logical, she knew. Since the wormhole telemetry link had been shut down she had no way to communicate anyway. And while she had dreamed, here inside the imperilled heart of the Sun, five million years had worn away in the Solar System outside. For all she knew there might be no humans left alive, anywhere, to hear whatever she might have to say.

  . . . Still, she itched to talk.

  Again, maser radiation shone out of a convection cell and sparkled over her, bright and coherent.

  Intrigued, she followed the
path of one of the convection cells as it swept out of the heart of the Sun, bearing its freight of heat energy; she tried to trace the source of the maser light.

  The radiation, she found, was coming from a thin trace of silicon monoxide in the mantle gas. Collisions between particles were pumping the gas with energy, she saw - leaving the monoxide molecules in an unstable, excited state, rotating rapidly.

  A photon of just the right frequency, impacting a pumped molecule, could cause the molecule to tip out of its unstable state. The molecule shed energy and emitted another photon of the same frequency. So the result was two photons, where one had been before . . . And the two photons stimulated two more atoms, resulting in four photons . . . A chain reaction followed, growing geometrically, with a flood of photons from the stimulated silicon monoxide molecules - all at the same microwave frequency, and all coherent - with the same phase.

  Lieserl knew that to get significant maser effects, pumped molecules had to be arranged in a line of sight, to get a long path of coherence. The convection cells, with their huge, multimillion-mile journeys to the surface and back, provided just such pathways. Maser radiation cascaded up and down the long flanks of the cells, spearing into and out of the helium core.

  The maser radiation could even escape from the Sun altogether, she saw. The convection founts grazed the surface, at their most extreme points; maser energy was blasted out, tangential to the surface of the swollen Sun, forming tiny, precise beacons of coherent light.

  And the maser beacons were, she realized with a growing excitement, very, very distinctive.

  Excited, she swept back and forth through the huge convection cells. It wasn’t difficult, she found, to disrupt the form of the coherent silicon monoxide maser beams; she imposed structure on the beams’ polarization, phasing and coherent lengths.

  She started with simple signals: sequences of prime numbers, straightforward binary arrays of symbols. She could keep that up almost indefinitely; thanks to the time it took for the coherent radiation to reach their firing points at the surface, it was sufficient for her to return to the convection cells every few days to re-initiate her sequence of signals. She could trace echoes of her signals, in fact, persisting even in the downfalling sides of the cells.

  Then, as her confidence grew, she began to impose meaningful information content on her simple signal structure. With binary representations of images in two and three dimensions, and with data provided in every human language she knew, she began to relate the story of what had happened to her, here in the heart of the Sun - and of what the photino birds were doing to mankind’s star.

  Feverishly she worked at the maser signals, while the final death of the Sun unravelled.

  In the stern galley of the Great Britain, Louise sat before her data desks. The little pod from the lifedome showed up as a block of pixels sliding past a schematic of the Northern.

  Over the radio link she heard screams.

  ‘Oh, for Lethe’s sake, Mark, don’t scare him completely out of his mind.’

  Mark sounded hurt. ‘I’m doing my best.’

  Louise felt too tired, too used up, to cope with this sudden flood of events.

  She tried, sometimes, to remember how it had been to be young. Or even, not quite so old. It might have been different if Mark had survived, of course: his AS system had imploded after four centuries, not long after he and Louise had moved out of the lifedome and into the Britain. Maybe if Mark had lived, if she’d spent all these years with another person - not alone - she wouldn’t have ended up feeling so damn stale.

  She comforted herself with the thought that, whatever was going on today, the Northern’s immense journey was nearing its end, now. Another few decades, when she had shepherded the wormhole Interface and motley inhabitants of the lifedome - those who’d survived among those battling, swarming masses - through all these dreadful years, she would be able to let go at last. Maybe she would implode then, she thought, like some dried-up husk.

  She called up a projection of its trajectory. ‘Well, it’s not heading for the Britain,’ she told Virtual-Mark. ‘It’s moving past us . . .’

  A new voice came crackling out of her data desk now, ‘Arrow Maker. Arrow Maker. Listen to me. You must reach the Interface. Don’t let them stop you . . .’

  To Louise, this was a voice from the dead past. It was distorted by age, almost reduced to a caricature, echoing as if centuries were empty rooms.

  She localized the source of the transmission - a desk in the base of the lifedome, near the pod hangars - and she threw open a two-way link. ‘Uvarov? Garry Uvarov?’

  The voice fell silent, abruptly.

  She heard Mark, in the pod, saying, ‘Now just take it easy. I know this is strange for you, but I’m not going to hurt you.’ A pause. ‘I couldn’t if I tried. I’ll tell you a secret: I’m not real. See? My hand is passing right through your arm, and—’

  More screams, even shriller than before.

  Oh, Mark . . .

  ‘Come on, Uvarov,’ she said. ‘I know it’s you. I still recognize that damn Moon accent. Speak to me.’

  ‘Oh, Lethe, Louise,’ Mark reported, ‘he’s gone crazy. He’s grabbed the stick: he’s accelerating - right towards the Interface.’

  Mark was right, she saw; the craft’s speed had increased, and it was clearly heading to where the wormhole Interface was cradled in its web of superconducting hoops, bound magnetically to the structure of the GUTship.

  She punched in quick queries. Less than two minutes remained before the pod reached the Interface.

  ‘Uvarov, listen to me,’ she said urgently. ‘You must respond. Please.’ While she spoke, her hands flew over the desks; she ordered her processors to find some way to take control of the pod. She cursed herself, silently, for her carelessness. She’d had centuries, literally, to find ways of immobilizing the lifedome pods. But she’d never imagined this scenario, some crazy savage with a painted face taking a pod into the Interface while they were still relativistic.

  Well, she damn well should have imagined it.

  ‘Uvarov. You must respond. We’re still in flight.’ She tried to imagine the old eugenicist’s condition, extrapolating wildly from the few words she’d heard him speak. ‘Uvarov, can you hear me? You have to stop him - the man in the pod, this Arrow Maker. He’ll destroy himself . . .’ And, she thought sourly, maybe the whole damn ship as well. ‘You know as well as I do that the Interface can’t be used during the flight. The kinetic energy difference between our Interface and the one back in the past will make the wormhole unstable. If your Arrow Maker flies that pod in there, he’ll wreck the wormhole.’

  ‘You’re lying,’ Uvarov rasped. ‘The journey’s over. We’ve seen the stars.’

  ‘Uvarov, listen to me. We’re still relativistic.’ She turned to peer out of the galley’s small windows. The Britain was suspended beneath the belly of the lifedome, so that the dome was huge and brilliant above her; the spine pierced space a few hundred yards away. And, all around the spine, the starbow - the ring of starlight aberrated by their motion - gleamed dully, infinitely far away.

  With a small corner of her mind, she longed to shut this out, to erect some Virtual illusion to hide in.

  ‘I can see the damn starbow, Uvarov. With my own eyes, right now. We’re decelerating, but we’re still relativistic. We have decades of this journey ahead of us yet . . .’ Was it possible Uvarov had forgotten?

  In the background she could hear Mark’s voice patiently pleading with the primitive in the pod; her desks showed her endless representations of the processors’ failed attempts to override the pod’s autonomous systems, and the astonishingly rapid convergence of the pod with the Interface.

  He pushed the crude control as far forward as it would go. The pod hurtled past the spine. He felt mesmerized, bound up in the extraordinary events around him, beyond any remnants of fear.

  Once again a frame of light embraced the pod, expanding, enclosing, like a swallowing mouth. T
his time, the frame was triangular, not rectangular; it was rimmed by blue light, not silver-white. And it contained - not a bleak, charcoal-grey emptiness - but a pool of golden light, elusive, shimmering.

  There were stars in that pool. How ironic it was, thought Arrow Maker, that perhaps here at last he would find the stars of which old, mad Uvarov had dreamed.

  The ghost-man - Mark - was still speaking to him, urgently; but the ghost was crumbling into cubes of light, which scattered in the air, shrinking and melting.

  Arrow Maker barely noticed.

  Suddenly, she thought she understood.

  She spoke rapidly. ‘Uvarov, listen. Please. The skydome above the forest isn’t truly transparent. It’s semisentient - it’s designed to deconvolve the distorting effects of the flight, to project an illusion of stars, of normal sky. Garry, can you hear me? The skydome shows a reconstruction of the sky - and I think you’ve forgotten that it’s a reconstruction. The forest people can’t have seen the stars.’ She tried to find words to reach this man, whom she’d first known a thousand years ago. ‘I’m sorry, Garry. I truly am. But you must make him turn back.’

  ‘Louise.’ Mark’s voice was clipped, urgent. ‘Arrow Maker is not responding. I’m starting to break up; we’re already within the exoticity field of the Interface, and—’

  Uvarov screamed, ‘The Interface, Arrow Maker! You’ll travel back across five million years - tell them we’re here, that we made it. Arrow Maker!’

  Now there were other voices on Uvarov’s link: a man, a girl ‘Maker! Maker! Come back . . .’

  Mark’s voice faded out.

  On Louise’s desk, the gleaming, toylike images, of pod and Interface, converged.

  The blue-white framework was all around him now, its glow flooding the cabin of the pod with shadowless light and banishing the spine and lifedome, as if they were insubstantial. The pod shuddered, its framework glowing blue-violet.