Phase Space

by Stephen Baxter

At last Cold finished.

  Shine found herself drawing subtly closer. ‘You sing well,’ she said.

  Cold emitted a kind of laugh, and she spun. ‘And so you come to me. Of course you do. That was how our songs began: as simple tripling calls. Look at me. Hear how well I sing! Think how well we could merge, how strong and dense with structure our children would be … But the songs have become more than that. Passed from one generation to the next, they have become elaborate. They have come to tell what happened before: of great beauties, of spectacular triples – and of the Ocean itself, the Waves and the frost.’

  Harmony, moodily, spun away. ‘I don’t like this game.’

  ‘Shine – Harmony – I have heard this happen. I have heard the songs grow, just a phrase or two at a time, from triple to triple. And so I thought back. I imagined the songs being stripped of their layers of meaning, becoming simpler, more elemental, until – in the beginning – they were no more than a mating cry.’

  Shine was still struggling to comprehend the idea that she might live in a universe in which the past might be different from the future. It was almost impossible for her to absorb Cold’s efforts to describe how she had observed a trend.

  Of her kind, Shine saw, Cold was a genius: but hers was a chill, repellent brilliance, and Shine felt herself shrink away.

  Cold seemed to observe this, and withered regretfully.

  Harmony, despite herself, seemed intrigued. ‘If the songs tell stories, what do they say?’

  ‘That the Ocean is not limitless,’ Cold said quickly. ‘That is the first thing, despite what most people believe. The songs tell of the Waves. Everyone knows that. But over enough time – so the songs say – the same Waves return. It is as if the Ocean is a single body, like yours, Harmony, within which Waves echo back and forth, subtly changing. That is how I know the Ocean is a small place.

  ‘And here is the next thing. The Ocean will not last forever. It changes. I am old enough now to have seen it for myself –’

  Shine, reluctantly, understood. ‘You’re talking about the frost.’

  ‘Yes. There is more of it – always more, never less.’

  Shine tried to think like Cold. Before, less. Now, more. If this goes on … ‘Soon all the Ocean will be frost. That is what you are saying.’

  ‘Yes,’ Cold said, but with a kind of exultance. ‘At last somebody hears me! That is what is going to happen.’

  Harmony spun and spat bits of light, growing agitated.

  Shine tried to imagine a universe full of lifeless, static frost. ‘How will we live? Where will we go? What about the Waves, the triples?’

  ‘There will be nowhere to go,’ said Cold harshly. ‘It will happen all at once, everywhere. When the next Wave comes –’

  ‘These are terrible things to be saying!’ Harmony cried suddenly. ‘You are stupid and ugly, Cold, and I don’t want to finish up like you!’ And with a final dazzling burst she surged away, leaving Shine and Cold alone.

  Shine said, ‘I should go after her.’

  ‘She is smart,’ Cold said. ‘She understands too, despite herself. That is why she is frightened.’

  Frightened and repelled, Shine thought.

  ‘You must help me, Shine.’

  ‘Help you?’

  Cold spun around, a ragged cloud. ‘Look at me. Unless I triple soon, I will die. And I will not triple. I will not let my mind dissolve.’

  ‘You will not live long enough to see the next Wave. That is what you are saying … Ah. But I could.’

  Cold came to her anxiously. ‘It will be up to you,’ she said. ‘I will be long dead. You must make them see …’

  Suddenly Shine was angry. ‘I don’t want such a life. I wish I was as old as you. I would rather die.’

  ‘No,’ said Cold urgently. ‘You must not forget what I have told you. You must not lose it in the tripling – for then, you doom your mindless offspring to die in your place.’

  Shine flinched from her chill logic.

  Cold, it seemed to her, was not natural. She had put aside the ultimate joy of the triple; this dismal knowledge scarcely seemed a consolation.

  But then – if Cold was right – what was the natural thing to do?

  Shine said slowly, ‘We are evanescent. Here and gone, like a song.’

  ‘What are you saying?’

  Shine watched the ugly frost evaporating as the Ocean’s warmth gushed over it. ‘If you are right – if all this must pass – perhaps we should accept what is to come.’

  Cold was very still.

  The young cosmos expanded relentlessly.

  It was a bath of plasma, almost at thermodynamic equilibrium, with no large-scale energy flows, no large structure. But still, on small scales, there was unevenness and instability, undulations in the background density. And so there were flows of energy, heat cancelling cold.

  Where energy flowed, life fed. Life: even in this chaotic, glowing soup.

  And there were the Waves.

  In its first instants this universe had endured a pulse of drastic inflation, during which it had ballooned from a region of space smaller than a proton to the size of the Earth. And as spacetime was stretched so dramatically, some of the pulsing cosmic energy condensed to matter.

  It was as if rocks had been thrown into a great opaque pond.

  Though light was hindered by the plasma, sound waves could travel freely. The ripples cast by that inflationary explosion were tremendous acoustic pulses of compression and decompression that marched across the swelling cosmos. With time, the oscillations developed on ever larger scales.

  The growing universe was filled with a deepening roar.

  But as it grew, so it cooled.

  Already the Wave could be seen in the glimmering distance, like a bank of spotlights approaching through a glowing fog. Already its throaty roar could be heard.

  The We Who Sing began to cluster, like migrant birds.

  By now, Shine herself had grown old.

  And she had learned that Cold was right. All you had to do was look around.

  You could even hear change in the Wave itself. The Waves were stretching, their tone deepening. The Ocean was filled with great descending groans, as if immense creatures were dying.

  But not one in a hundred of the great soaring throng around her understood this. Not one of them was old enough to remember a time when this fast-evolving world of theirs had been any different – and few would listen to Shine.

  Just like Cold, Shine had gradually become ostracized by We Who Sing. It was Shine now who had endured long past her time of tripling, she whose ragged, slowly decohering form repelled those around her.

  But Shine was not Cold. Whatever became of her, without tripling she would forever be incomplete. And she dreaded following the final destiny of poor Cold, who, in the end, had evaporated, her precious, hoarded memories lost forever in the currents of light.

  Often she wished she had defied Cold’s wishes and embraced the tripling. The chill logic of a coming extinction seemed to her a poor reward for the loss of such terminal joy.

  But Shine, resolutely, put such thoughts aside.

  In the midst of the gathering gaiety, she brought together those who followed her. There was a bare hundred of them – no more, even after a lifetime of Shine’s increasingly impassioned proselytizing. Now they clustered around Shine, gathering almost as tightly as partners keen to triple.

  ‘I don’t like this,’ said Harmony. ‘I don’t want this to happen.’

  Others assented, swarming closer.

  ‘I know,’ said Shine, as soothing as she could be, despite her own fear. ‘We must stay together. We must stay close. It is the only way.’

  This was not Harmony herself, but one of her triple-daughters. The old Harmony had been unable, in the end, to resist the brilliant lure of the triple. But Shine had wooed her triple-daughters, and she had been rewarded to find much of Harmony’s character lingering in them: high intelligence mixed with a stubborn r
efusal to believe the worst.

  Thus Shine had sought to find in the daughters what she had perceived in their mothers. It was just as Cold had once pursued her. She had often wondered whether it was herself that Cold was after, or something she had seen in Shine’s triple-parents …

  ‘Oh,’ said one young beauty called Glimmer. ‘Oh, but the tripling has begun. They sing the songs already. Can you hear?’

  Of course they could. The songs emerged from the swelling, swooping crowd of the We Who Sing, songs of sex, of light-filled, orgasmic instants of birth and death, of an Ocean-world like a womb. The dances were beginning too. Patterns, beautiful, in three dimensions and on a vast scale, were soon emergent from the people’s unconscious flocking.

  ‘I don’t want it to be true,’ moaned Harmony. ‘How can this end? I want to go to the dance, to the triples. Let us go, Shine. Oh, let us go!’

  Some of the rest joined in this desolate chorus. The group spun and pulsed, confused, unstable.

  It felt as if Shine herself was tearing apart. How wonderful it would be to think that even now, if she let herself dissolve into the burning light of a triple, something of herself would go on, enduring forever, in an Ocean without end, a song without limits!

  Oh, she thought, I love it all.

  But she knew that beneath the dazzling dance of the people lay the chill, implacable logic of Cold. There was no escape.

  ‘It is time,’ she said, sadly. ‘We must do as Cold instructed us. Come now.’

  She swam up to Glimmer and let her perimeter soften, so that they overlapped, the complex weft of their cores overlaying. It was like a tripling, but they kept their identities separate.

  Now another joined them, and another, so that they grew into a huddle, an increasingly dense, glowing mass that looked, from the outside, undifferentiated – and yet the individuals were sustained within, like palimpsests.

  ‘I don’t like this,’ whispered Glimmer – very bright, very immature, terrified by the clarity of her own thinking. ‘It feels strange.’

  ‘Cold thought it might help us survive –’

  ‘Survive what?’ Harmony’s pulsing voice was full of anger and fear. ‘The death of the Ocean itself? Do you really believe that, Shine?’

  ‘If you wish to leave,’ Shine said, ‘you may.’ Like her triple-mother, Harmony sought nothing so much as somebody to punish.

  But now their argument was ended. The Ocean itself shuddered – and it dimmed.

  The We Who Sing could not ignore the dimming: even the youngest, the most foolish of them. Striving to continue their anxious dancing before the approaching Wave, they swarmed, agitated.

  Harmony stayed where she was, embedded deep in the huddle.

  It was just as Cold had forecast. Despair clamp down inside Shine, the last impossible hope evaporate.

  She felt Glimmer within her, as if snuggling close.

  ‘Shine –’

  ‘You’re frightened. It’s all right. So am I.’

  ‘What will we see?’

  Shine struggled to answer. What would be left if the Ocean vanished? – for the Ocean was the world. ‘Perhaps there is a greater Ocean,’ she said at last. ‘In which our Ocean is embedded. As one becomes embedded in the three of a triple.’

  ‘And,’ Glimmer said suddenly, ‘perhaps there is a greater Ocean beyond that. And then another.’

  This keen, intelligent insight startled Shine. But as she tried to imagine an infinite hierarchy of Oceans, each contained within the next, she recoiled, bewildered.

  Now the Ocean’s light flickered again, like a failing lightbulb, visibly dimmer.

  The swarming people were confused, agitated. Some of them even strove to join Shine’s huddle.

  But it was too late.

  The great Wave broke, a last defiant burst of light that swept them all before it.

  The We Who Sing shrieked and danced and sang, and they tripled madly. Young emerged in silent starbursts. They raced over the Wave’s swelling face, exhilarated to find themselves suddenly alive.

  Even now, Shine longed to join them.

  But once again the light dimmed. The Wave’s rushing front was disrupted, becoming turbulent. The dances were broken, and the songs of the people turned to wails of fear, the bewildered young crying for comfort.

  Shine gathered her acolytes close. She said, ‘I think –’

  But there was no more time.

  At last a critical temperature was reached. Suddenly, atomic matter was able to condense out of the stew of electrons and nuclei.

  The photons – no longer energetic enough to smash open the fledgling atoms, no longer impeded – were free to fly their geodesic courses to infinity. The plasma glow died.

  For the first time the sky became transparent, a transition as abrupt as a clash of cymbals.

  With the dissipation of the plasma, the great acoustic waves had no medium in which to travel. But they did not vanish without trace. Where a wave had compressed the particle soup, it had been made hotter, the photons more energetic. And so as the photons began their endless journey through swelling spacetime, they carried in their energy distribution images of the last sound waves.

  Thus the last birthing cry of the universe was caught forever in a thinning, reddening sea of primordial photons.

  Meanwhile the matter that had suddenly frosted out of the great bath of radiation began to gather in swirls and clumps, arranged in a great lacy tapestry that hung over the universe. It was a wispy frost of hydrogen and helium, slowly collapsing under gravity: a frost that would condense into galaxies and stars and superclusters and planets, places where new forms of life could prosper.

  In all cosmic history it was the most dramatic instant of transition.

  But, with every transition, there is loss.

  Dark and cold, suddenly, everywhere.

  Many of the huddle had died in that first great instant of freezing.

  And now, as the mass clump collapsed, fusion began, deep in the heart of the huddle. At that moment more died, torn apart by the immense densities, the sudden fire.

  But the fusion became stable.

  In all the universe, just a single star shone.

  Shine peered out, filled with curiosity and fear, stunned by clarity and emptiness.

  Cold was right, she thought. I am alive. I lived through the end of the world. Alive! But – what happens next?

  As she watched, a second star lit up, a beacon in the endless dark.

  And then another.

  And another.

  THE GRAVITY MINE

  And perhaps (Malenfant wrote to Michael) life will persist long after we imagine it would be impossible: deep in the future, far downstream, after the Earth has died, after the sun and all the stars have expired, life finding a way to get by in the dark …

  Call her Anlic.

  The first time she woke, she was in the ruins of an abandoned gravity mine.

  At first the Community had chased around the outer strata of the great gloomy structure. But at last, close to the core, they reached a cramped ring. Here the central black-hole’s gravity was so strong that light itself curved in closed orbits.

  The torus tunnel looked infinitely long. And they could race as fast as they dared.

  As they hurtled past fullerene walls they could see multiple images of themselves, a glowing golden mesh before and behind, for the echoes of their light endlessly circled the central knot of spacetime. ‘Just like the old days!’ they called, excited. ‘Just like the Afterglow! …’

  Exhilarated, they pushed against the light barrier, and those trapped circling images shifted to blue or red.

  That was when it happened.

  This Community was just a small tributary of the Conflux: isolated here in this ancient place, the density of mind already stretched thin. And now, as lightspeed neared, that isolation stretched to breaking point.

  … She budded off from the rest, her consciousness made discrete, separated from the greater
flow of minds and memories.

  She slowed. The others rushed on without her, a dazzling circular storm orbiting the exhausted black hole. It felt like coming awake, emerging from a dream.

  Her questions were immediate, flooding her raw mind. ‘Who am I? How did I get here?’ And so on. The questions were simple, even trite. And yet they were unanswerable.

  Others gathered around her – curious, sympathetic – and the race of streaking light began to lose its coherence.

  One of them came to her.

  Names meant little; this ‘one’ was merely a transient sharpening of identity from the greater distributed entity that made up the Community.

  Still, here he was. Call him Geador.

  ‘ … Anlic?’

  ‘I feel – odd,’ she said.

  ‘Don’t worry.’

  ‘Who am I?’

  ‘Come back to us.’

  He reached for her, and she sensed the warm depths of companionship and memory and shared joy that lay beyond him. Depths waiting to swallow her up, to obliterate her questions.

  She snapped, ‘No!’ And, wilfully, she sailed up and out and away, passing through the thin walls of the tunnel.

  At first it was difficult to climb out of this twisted gravity well. But soon she was rising through layers of structure.

  Here was the tight electromagnetic cage which had once tapped the spinning black hole like a dynamo. Here was the cloud of compact masses which had been hurled along complex orbits through the hole’s ergosphere, extracting gravitational energy. It was antique engineering, long abandoned.

  She emerged into a blank sky, a sky stretched thin by the endless expansion of spacetime.

  Geador was here. ‘What do you see?’

  ‘Nothing.’

  ‘Look harder.’ He showed her how.

  There was a scattering of dull red pinpoints all around the sky.

  ‘They are the remnants of stars,’ he said.

  He told her about the Afterglow: that brief, brilliant period after the Big Bang, when matter gathered briefly in clumps and burned by fusion light. ‘It was a bonfire, over almost as soon as it began. The universe was very young. It has swollen some ten thousand trillion times in size since then … Nevertheless, it was in that gaudy era that humans arose. Us, Anlic.’