Phase Space

by Stephen Baxter

  Sun-Cloud watched as Cold-Current ascended towards her.

  They were going to discuss Sun-Cloud’s sister, Orange-Dawn. Orange-Dawn was a problem.

  Cold-Current was a lenticular assemblage of corpuscles twice Sun-Cloud’s size, who nevertheless rose with an awesome unity. The ranks of impellers at Cold-Current’s rim churned at the thick waters of the Ocean, their small cilia vibrating so rapidly that they were blue-shifted.

  The Song suffused the waters around Sun-Cloud, as it always did; but as Cold-Current lifted away from the Deep the complex harmonics of the Song changed, subtly.

  Sun-Cloud, awed, shrank in on herself, her structural corpuscles pushing in towards their sisters at her swarming core. Sun-Cloud knew that she herself contributed but little, a few minor overtones, to the rich assonance of the Song. How must it be to be so grand, so powerful, that one’s absence left the Song – the huge, world-girdling Song itself – audibly lacking in richness?

  Cold-Current hovered; a bank of optic corpuscles swivelled, focusing on Sun-Cloud. ‘You know why I asked to meet you,’ she said.

  ‘Orange-Dawn.’

  ‘Yes. Orange-Dawn. I am very disturbed, Sun-Cloud. Orange-Dawn is long overdue for Dissolution. And yet she persists; she prowls the rim of the Song, even the Surface, intact, obsessed. Even to the extent of injuring her corpuscles.’

  ‘I know that Orange-Dawn wants to see out another hundred Cycles,’ Sun-Cloud said. ‘Orange-Dawn has theories. That in a hundred Cycles’ time –’

  ‘I know,’ Cold-Current said. ‘She believes she has Coalesced with ancient wisdom. Somehow, in a hundred Cycles, the world will be transformed, and Orange-Dawn will be affirmed.’

  ‘But it’s impossible,’ Sun-Cloud said. ‘I know that; Orange-Dawn must see that.’

  But Cold-Current said, absently: ‘But it may be possible, to postpone Dissolution so long.’ Sun-Cloud, intrigued, saw a tight, cubical pattern of corpuscles move through Cold-Current’s corpus; individual corpuscles swam to and fro, but the pattern persisted. ‘Possible,’ Cold-Current said. ‘There is old wisdom. But such a thing would be – ugly. Discordant.’ Perhaps that cubical pattern contained the fragment of old knowledge to which Cold-Current hinted.

  Cold-Current rotated grandly. ‘I want you to go and talk to her. Perhaps you can say something … Nobody knows Orange-Dawn as well as you.’

  That was true. Orange-Dawn had helped Sun-Cloud in her earliest Coalescence, as Sun-Cloud struggled towards sentience. Orange-Dawn had hunted combinations of healthy corpuscles for her sister, helped her coax the corpuscles into an orderly shoal. Together the sisters had run across the Surface of the Ocean, their out-thrust optic corpuscles blue-tinged with their exhilarating velocity …

  Cold-Current began to sink back into the glimmering depths of the Ocean, her disciplined impellers beating resolutely. ‘You must help her, Sun-Cloud. You must help her put aside these foolish shards of knowledge and speculation, and learn to embrace true beauty …’

  As Cold-Current faded from view, the light at the heart of the world brightened, as if in welcome, and the Song’s harmonies deepened joyously.

  The world was very old. Sun-Cloud’s people were very old. They had accreted many fragments of knowledge, of philosophy and science.

  A person, on Dissolution, could leave behind fragments of insight, of wisdom, in the partial, semi-sentient assemblies called sub-corpora. Before dissolving in their turn into the general corpuscle shoals, the sub-corpora could be absorbed into a new individual, the knowledge saved.

  Or perhaps not.

  If they were not incorporated quickly, the remnant sub-corpora would break up. Their component mentation-corpuscles would descend, and become lost in the anaerobic Deep at the heart of the world.

  Sun-Cloud returned to the Surface of the Ocean.

  She saw that the sun had almost set; a last sliver of crimson light spanned one horizon, which curved sharply. Above her the sky was clear and utterly black, desolately so.

  Her corpuscles transmitted their agitation to each other.

  She raised a lantern; cold light bloomed slowly across the sea’s oily meniscus.

  She roamed the Ocean, seeking Orange-Dawn.

  At last the creeping lantern light brought echoes of distant motion to her optic corpuscles: a small form thrashing at the Surface in lonely unhappiness.

  With a rare sense of urgency Sun-Cloud ordered her impeller corpuscles into motion. It didn’t take long for her to accelerate to a significant fraction of lightspeed; the impellers groaned as they strained at relativity’s tangible barrier, and the image of the lonely one ahead was stained with blue shift.

  Wavelets lapped at her and air stroked her hide; she felt exhilarated by her velocity.

  She slowed. She called softly: ‘Orange-Dawn?’

  Listlessly Orange-Dawn raised optic corpuscles. Orange-Dawn was barely a quarter Sun-Cloud’s size. She was withered, her corpus depleted. Her corpuscles lay passively over each other, tiny mouths gaping with obvious hunger.

  ‘Do I shock you, Sun-Cloud?’

  Sun-Cloud sent small batches of corpuscles as probes into Orange-Dawn’s tattered carcase. ‘Orange-Dawn. Your corpuscles are suffering. Some of them are dying. Cold-Current is concerned for you –’

  ‘She sent you to summon me to my Dissolution.’

  Sun-Cloud said, ‘I don’t like to see you like this. You’re introducing a harshness into the Song.’

  ‘The Song, the damnable Song,’ Orange-Dawn muttered. Moodily she began to spin in the water. The corpuscles’ decay had so damaged her corpus’s circular symmetry that she whipped up frothy waves which lapped over her upper carapace, the squirming corpuscles there. She poked optic corpuscles upwards, but the night sky was blind. ‘The Song drowns thought.’

  ‘What will happen in a hundred Cycles, Orange-Dawn?’

  Orange-Dawn thrashed at the water. ‘The data is partial …’ She focused wistful optic corpuscles on her sister. ‘I don’t know. But it will be –’

  ‘What?’

  ‘Unimaginable. Wonderful.’

  Sun-Cloud wanted to understand. ‘What data?’

  ‘There are some extraordinary speculations, developed in the past, still extant here and there … Did you know, for instance, that the Cycle is actually a tide, raised in our Ocean-world during its passage around the sun? It took many individuals a long time to observe, speculate, calculate, obtain that fragment of information. And yet we are prepared to throw it away, into the great bottomless well of the Song …

  ‘I’ve tried to assemble some of this. It’s taken so long, and the fragments don’t fit more often than not, but –’

  ‘Integrate? Like a Song?’

  ‘Yes.’ Orange-Dawn focused her optic corpuscles. ‘Yes. Like a Song. But not the comforting mush they intone below. That’s a Song of death, Sun-Cloud. A Song to guide you into non-being.’

  Sun-Cloud shuddered; little groups of her corpuscles broke away, agitated. ‘We don’t die.’

  ‘Of course not.’ Orange-Dawn rotated and drifted towards her. ‘Watch this,’ she said.

  Quickly, she budded off a whole series of sub-corpora, each tiny body consisting of a few hundred corpuscles. Instantly the sub-corpora squirmed about the Surface, leaping and breaking the meniscus, blue-shifted as they pushed into lightspeed’s intangible membrane.

  Sun-Cloud felt uneasy. ‘Those sub-corpora are big enough to be semi-sentient, Orange-Dawn.’

  ‘But do you see?’ said Orange-Dawn testily.

  ‘See what?’

  ‘Blue shift. The sub-corpora – see how, instinctively, they strain against the walls of the prison of lightspeed. Even in the moment of their Coalescing. Light imprisons us all. Light isolates us …’

  Her words filtered through Sun-Cloud, jarring and strange, reinforced by bizarre chemical signals.

  ‘Why are you doing this, Orange-Dawn?’

  ‘Watch.’ Now Orange-Dawn sent out a swarm of busy impeller corpuscl
es; they prodded the independent sub-corpora back towards Orange-Dawn’s corpus. Sun-Cloud, uneasy, watched how the sub-corpora resisted their tiny Dissolutions, feebly.

  ‘See?’ Orange-Dawn said. ‘See how they struggle against their immersion, in the overwhelming Ocean of my personality? See how they struggle to live?’

  Sun-Cloud’s own corpuscles sensed the suffering of their fellows, and shifted uneasily. She flooded her circulatory system with soothing chemicals. In her distress she felt a primal need for the Song. She sent sensor corpuscles stretching into the Ocean beneath her, seeking out the comfort of its distant, endless surging; its harmony was borne through the Ocean to her by chemical traces.

  … But would she struggle so, when it came time for her to Dissolve, in her turn, into the eternal wash of the Song?

  It was, she realized, a question she had never even framed before.

  Now, gathering her corpuscles closely around her, Orange-Dawn turned from Sun-Cloud, and began to beat across the Surface with a new determination.

  ‘You must come with me, Orange-Dawn,’ Sun-Cloud warned.

  ‘No. I will see out my hundred Cycles.’

  ‘But you cannot …’ Unless, she found herself thinking, unless Cold-Current is right. Unless there is some lost way to extend consciousness.

  ‘If I submit to Dissolution, I will lose my sense of self, Sun-Cloud. My individuality. The corpus of knowledge and understanding I’ve spent so long assembling. What is that but death? What is the Song but a comfort, an anaesthetic illusion to hide that fact? …’

  ‘You are damaging the unity of the Song, Orange-Dawn. You are – discordant.’

  Orange-Dawn was receding now; she raised up a little batch of acoustic corpuscles. ‘Good!’ she called.

  ‘I won’t be able to protect you!’ cried Sun-Cloud.

  But she was gone.

  Sun-Cloud raised lantern-corpuscles, sending pulses of slow light out across the Ocean’s swelling surface. She called for her sister, until her corpuscles were exhausted.

  In some ways, Sun-Cloud’s people resembled humans.

  Sun-Cloud’s component corpuscles were of very different ancestry.

  Mentation-corpuscles – the neuron-like creatures that carried consciousness in tiny packets of molecules – were an ancient, anaerobic race. The other main class, the impellers and structure corpuscles, were oxygen breathers: faster moving, more vigorous.

  Human muscles usually burned glucose aerobically, using sugars from the air. But during strenuous activity, the muscles would ferment glucose in the anaerobic way evolved by the earliest bacteria. Thus human bodies, too, bore echoes of the earliest biosphere of Earth.

  But, unlike a human body, Sun-Cloud’s corpus was modular.

  Despite their antique enmity, the two phyla within Sun-Cloud would cooperate, in the interests of the higher creature in which they were incorporated.

  Until Sun-Cloud weakened.

  A mass of corpora, sub-corpora and shoals of trained impeller corpuscles rose from the Deep in a great ring.

  Not five Cycles had passed since Sun-Cloud’s failed attempt to bring Orange-Dawn home. Now, they had come for Orange-Dawn.

  Sun-Cloud found her sister at the centre of the hunt. She was shrunken, already fragmented, her corpuscles pulsing with fear.

  ‘I don’t want to die, Sun-Cloud.’

  Anguish for her sister stabbed at Sun-Cloud. She sent soothing chemical half-words soaking through the Ocean. ‘Come with me,’ she said gently.

  Exhausted, Orange-Dawn allowed herself to be enfolded in Sun-Cloud’s chemical caresses.

  Commingled, the sisters sank into the Ocean. Their ovoid bodies twisted slowly into the depths; light shells from curious individuals washed over them as they passed.

  The light faded rapidly as they descended. Soon there were few free sub-corpora; and of the people they saw most were linked by corpuscle streams with at least one other, and often in groups of three, four or more.

  The Song was a distant, strengthening pulse from the heart of the Ocean beneath them.

  Now Cold-Current rose up to meet them, huge and intimidating, her complex hide pulsing with lantern-corpuscles. The rim of her slowly rotating corpus became diffuse, blurred, as her corpuscles swam tentatively towards Orange-Dawn.

  Cold-Current murmured, ‘You are old, yet very young, Orange-Dawn. Your unhappiness is caused by ignorance. There is no other Ocean. Only this one. There is no change and never has been. These facts are part of what we are. That’s why your speculations are damaging you.

  ‘You have to forget your dreams, Orange-Dawn …’

  Orange-Dawn hardened, drawing her corpuscles into a tight little fortress. But Cold-Current was strong, and she forced compact biochemical packets into Orange-Dawn’s corpus. Sun-Cloud, huddling close, picked up remote chemical echoes of the messages Cold-Current offered.

  … Hear the Song, Cold-Current’s corpuscles called. Open up to the Song.

  Their bodies joined, her impeller-corpuscles herding Orange-Dawn tightly, Cold-Current began to guide Orange-Dawn deeper into the lattice of mingled persons.

  Sun-Cloud followed, struggling to stay close to her sister. Orange-Dawn’s pain suffused the waters around her with clouds of chemicals; Sun-Cloud suffered for her and with her.

  As they descended, individuals became less and less distinct, and free corpuscles swam through the lattice’s closing gaps. At last they were falling through a sea of corpuscles which, with endless intelligent grace, swam over and around each other. Sun-Cloud’s structurals and impellers felt enfeebled here, in this choking water; the effort of forcing her way downwards seemed to multiply.

  Perhaps this was like Dissolution, she thought.

  At last there was only one entity, a complex of mingled bodies that filled the Ocean. The living lattice vibrated with the Song, which boomed around them, joyous and vibrant.

  ‘The Deep,’ Cold-Current whispered to Orange-Dawn. ‘The Song. Now you will join this, Orange-Dawn. Uncountable billions of minds, endless thoughts straddling the world eternally. The Song will sustain your soul, after Dissolution, merged with everyone who has ever lived. You’ll never be alone again –’

  Suddenly, at the last, Orange-Dawn resisted. ‘No! I could not bear it. I could not bear –’

  She was struggling. Jagged images filled Sun-Cloud’s mind, of being crushed, swamped, stultified.

  Immediately a host of sub-corpora and corpuscles, jagged masses of them, hurled themselves into Orange-Dawn’s corpus. Sun-Cloud heard a single, agonized, chemical scream, which echoed through the water. And then the structure of the corpus was broken up. Corpuscles, many of them wounded, came hailing out of the cloud of Dissolution; some of them spiralled away into the darkness, and others rained down towards the glowing Deep. Sub-corpora formed, almost at random, and wriggled through the water. They were semi-sentient: bewildered and broken images of Orange-Dawn.

  Sun-Cloud could only watch. Loss stabbed at her; her grief was violent.

  Cold-Current was huge, complex, brilliantly illuminated. ‘It is over. It is better,’ she said.

  Sun-Cloud’s anger surged. ‘How can you say that? She’s dead. She died in fear and agony.’

  ‘No. She’ll live forever, through the Song. As will we all.’

  ‘Show me what you know,’ Sun-Cloud said savagely. ‘Show me how Orange-Dawn might have extended her life, through another ninety Cycles.’

  ‘It is artificial. Discordant. It is not appropriate –’

  ‘Show me!’

  With huge reluctance, Cold-Current budded a tight, compact sub-corpora. It bore the cubical pattern Sun-Cloud had observed earlier. ‘Knowledge is dangerous,’ Cold-Current said sadly. ‘It makes us unstable. That is the moral of Orange-Dawn’s story. You must not –’

  Sun-Cloud hurled herself at the pattern, and forcibly integrated it into her own corpus. Then – following impulses she barely recognized – she rose upwards, away from the bright-glowing Deep.

/>   She passed through the cloud of Orange-Dawn’s corpuscles, and called to them.

  The Song boomed from the Deep, massive, alluring, stultifying; and Cold-Current’s huge form glistened as she called her. Sun-Cloud ignored it all.

  She ascended towards the Surface, as rapidly as she could. Orange-Dawn’s fragmentary sub-corpora followed her, bewildered, uncertain.

  The place Sun-Cloud called the Deep was an anaerobic environment. Only mentation-corpuscles could survive here. They lay over each other in complex, pulsing swarms, with neural energy flickering desultorily between them.

  The Song was a complex, evolving sound-structure, maintained by the dense shoals of mentation-corpuscles which inhabited the heart of the world, and with grace notes added by the Coalesced individuals of the higher, oxygen-rich layers of the Ocean.

  At the end of their lives, the mentation structures of billions of individuals had dissolved into the Deep’s corpuscle shoals. The Song, they believed, was a form of immortality.

  Embracing this idea, most people welcomed Dissolution.

  Others rejected it.

  Sun-Cloud gathered around her central corpus the cubical pattern of Cold-Current, and Orange-Dawn’s sad remnants, integrating them crudely. She grew huge, bloated, powerful.

  And now, as she broke the thick Surface of the Ocean, she made ready.

  She wondered briefly if she had gone mad. Perhaps Orange-Dawn had infected her.

  But if it were so, let it be. She must know the answer to Orange-Dawn’s questions for herself, before she submitted to – as she saw it now, as if through her sister’s perception – the sinister embrace of the Song.

  She enfolded Cold-Current’s compact data pattern, and let its new wisdom flow through her …

  Of course. It is simple.

  She began to forge forward, across the Ocean.

  A bow wave built up before her, thick and resisting. But she assembled her impellers and drove through it. At last the wave became a shock, sharp-edged, travelling through the water as a crest.