Diaspora

by Greg Egan

  Yatima consciously invoked full retrieval of the fragment’s context. As ve’d aged, ve’d opted for memory layering — rather than degradation or outright erasure — to keep vis thoughts from being swamped with a paralyzing excess of recollections. They’d taken two abandoned gleisners for a ride! Just the two of them, when Yatima was barely half a gigatau old. They’d been gone for something like eighty megatau — which must have seemed like an eternity at that age, though as it turned out even Inoshiro’s parents had been unfazed by the whole juvenile stunt. The jungle. The city surrounded by fields. They’d been afraid of quicksand — but they’d found a guide.

  For a moment, Yatima was too ashamed to speak. Then ve said numbly, “I’d buried them. Orlando, Liana ... the bridgers. I’d buried them all.” Over time, ve’d let the whole experience sink from layer to layer to make room for more current preoccupations — until it could no longer enter vis thoughts by chance at all, interact with other memories, sway vis attitudes and moods. Until fleshers were just fleshers again: anonymous and remote, exotic and dispensable. The apocalypse could have come and gone, and ve would have done nothing.

  Inoshiro said, “There isn’t much time. Are you with me, or not?”

  Atlanta, Earth

  24 046 380 407 629 CST

  5 April 2996, 21:20:04.783 UT

  The gleisners were exactly where they’d left them, twenty-one years before. Once they were awake, they each had the drone pass them a file of instructions for the robots’ maintenance nanoware. Yatima watched nervously as the programmable sludge flowing in fine tubes throughout vis body began reconstructing the tip of vis right index finger into something alarmingly like a projectile weapon.

  That was the easy part. When the delivery system was completed, the maintenance nanoware’s small sub-population of assemblers was instructed to begin manufacturing Introdus nanoware. Yatima had been worried that the gleisners’ assemblers, never designed for such demanding work, might not be capable of meeting the necessary tolerances, but the Introdus system’s self-testing procedure returned an encouraging report: less than one atom in ten-to-the-twentieth incorrectly bonded.

  Working on feedstock in the gleisner, the assemblers managed to build three hundred and ninety-six doses; if more were needed, the bridgers would probably be able to supply the necessary raw materials. There were well-stocked portals scattered across the planet where any flesher who wished to enter the Coalition could do so, but it had always been judged politically insensitive to place them too close to the enclaves. The nearest one to Atlanta was over a thousand kilometers away.

  Inoshiro used vis own gleisner’s nanoware to build a pair of relay drones to keep them in touch with Konishi; no one had yet been able to trick the satellites into reshaping their footprints to include the enclaves. Yatima watched the glistening insectile machines forming in a translucent cyst on Inoshiro’s forearm, then burrow out and disappear into the canopy. They’d based the design on existing drones, but these bootleg versions were entirely unfettered by prior instructions and treaty obligations, and would shamelessly fool the satellites into accepting a signal re-routed from within the forbidden region.

  They stepped across the border. To test their link to the Coalition, Yatima glanced at a C-Z scape based on a feed from TERAGO. Two dark spheres limned by gravitationally-lensed starlight moved through a faintly sketched spiral tube, the tight record of past orbits widening out into the uncertainty of extrapolation; the hypothetical meson jets were omitted altogether. The neutron stars broadcast gestalt tags with their current orbital parameters, while points on the spiral at regular intervals offered past and future versions.

  The orbit had shrunk by a “mere” 20 percent so far — 100,000 kilometers — but the process was highly non-linear, and the same distance would be crossed again in roughly seventeen hours, then five, then one, then under three minutes. These predictions were all subject to error, and the exact moment of the burst remained uncertain by at least an hour, but the most likely swath of possibilities all placed Lacerta well above the horizon at Atlanta. For a hemisphere stretching from the Amazon to the Yangtse, the ozone layer would be blasted away in an instant. In Atlanta, it would happen beneath the blazing afternoon sun.

  The path Orlando had taken when escorting them out of the enclave was still stored in the gleisners’ navigation systems. They pushed through the undergrowth as fast as they could, hoping to trigger alarms and attract attention.

  Yatima heard branches move suddenly, off to their left. Ve called out hopefully, “Orlando?” They stopped and listened, but there was no reply. Inoshiro said, “It was probably just an animal.”

  “Wait. I can see someone.”

  “Where?”

  Yatima pointed out the small brown hand holding a branch, some twenty meters away — trying to release it slowly, instead of letting it spring back into place. “I think ve’s a child.”

  Inoshiro spoke loudly but gently in Modern Roman. “We’re friends! We have news!”

  Yatima adjusted the response curve of the gleisner’s visual system, optimizing it for the shadows behind the branch. A single dark eye stared back through a gap between the leaves. After a few seconds, the hidden face shifted cautiously, choosing another peephole; Yatima reconstructed the blur into a jagged strip of skin joining two lemur eyes.

  Ve showed the partial image to the library, then passed the verdict to Inoshiro. “Ve’s a dream ape.”

  “Shoot ver.”

  “What?”

  “Shoot ver with the Introdus!” Inoshiro remained motionless and silent, speaking urgently in IR. “We can’t leave ver to die!”

  Isolated by the frame of leaves, the dream ape’s eye appeared eerily expressionless. “But we can’t force ver —”

  “What do you want to do? Give ver a lecture in neutron star physics? Even the bridgers can’t get through to dream apes! No one’s going to explain the choices to ver — not now, not ever!”

  Yatima insisted stubbornly, “We don’t have the right to do it by force. Ve’d have no friends inside, no family —”

  Inoshiro made a sound of disgust and disbelief. “We can clone ver some friends! Give ver a scape just like this, and ve’d barely know the difference.”

  “We’re not here to kidnap people. Imagine how you’d feel, if some alien creature reached into the polis and dragged you away from everything you knew —”

  Inoshiro almost screamed with frustration. “No, you imagine how this flesher will feel, when vis skin’s burnt so badly that the fluid beneath starts seeping out!”

  Yatima felt a wave of doubt sweep through ver. Ve could picture the whole, hidden dream ape child, standing there waiting fearfully for the strangers to pass — and though ve could barely comprehend the idea of physical pain, images of bodily integrity resonated deeply. The biosphere was a disordered world, full of potential toxins and pathogens, ruled by nothing but the chance collisions of molecules. A ruptured skin would be like a wildly malfunctioning exoself that let data flood across its borders at random, overwriting and corrupting the citizen within.

  Ve said hopefully, “Maybe vis family will find a cave to shelter in, once they notice the effects of the UV. That’s not impossible; the canopy will protect them for a while. They could live on fungi —”

  “I’ll do it.” Inoshiro grabbed Yatima’s right arm, and swung it toward the child. “Give me control of the delivery system, and I’ll do it myself.”

  Yatima tried to pull free. Inoshiro resisted. The struggle confused their separate copies of the interface, which was too stupid to realize it was fighting itself; they both overbalanced. As ve toppled into the undergrowth, Yatima almost felt it: the descent, the inevitable impact. Helplessness. Ve could hear the child running away.

  Neither of them moved. After a while, Yatima said, “The bridgers will find a way to protect them. They’ll engineer some kind of shield for their skin. They could release the genes in a virus —”

  “And they’ll do al
l this in a day? Before or after they work out how to feed fifteen thousand people when their crops are wilting, the ground is frozen, and the rain’s about to turn into nitric acid?”

  Yatima had no reply. Inoshiro rose to vis feet, then pulled ver up. They walked on in silence.

  Halfway to the edge of the jungle, they were met by three bridgers, two females and a male. All were fully grown, but younG-1ooking, and wary. Communication proved difficult.

  Inoshiro repeated patiently, “We are Yatima and Inoshiro. We came here once before, twenty-one years ago. We’re friends.”

  The man said, “All your robot friends are on the moon; none of them are here now. Leave us in peace.” The bridgers remained several meters away; they’d retreated in alarm when Yatima had approached them with an outstretched hand.

  Inoshiro complained in IR, “Even if they’re too young to remember ... our last visit should be legendary.”

  “Apparently not.”

  Inoshiro persisted. “We’re not gleisners! We’re from Konishi polis; we’re just riding these machines. We’re friends of Orlando Venetti and Liana Zabini.” The bridgers showed no sign of recognizing either name; Yatima wondered soberly if it was possible that they were both dead. “We have important news.”

  One of the women asked angrily, “What news? Tell us, then leave!”

  Inoshiro shook vis head firmly. “We can only give our news to Orlando or Liana.” Yatima agreed with this stand; a garbled account, half-understood, would do untold damage.

  Inoshiro asked in IR, “What do you think they’d do if we just marched into the city?”

  “They’d stop us.”

  “How?”

  “They must have weapons of some kind. It’s too risky; we’ve both used up most of our maintenance nanoware — and anyway, they’re never going to trust us if we barge in uninvited.”

  Yatima tried addressing the bridgers verself. “We are friends, but we’re not getting through to you. Can you find a translator?”

  The second woman was almost apologetic. “We have no robot translators.”

  “I know. But you must have translators for statics. Think of us as statics.”

  The bridgers exchanged bemused glances, then went into a huddle, whispering.

  The second woman said, “I’ll bring someone. Wait.”

  She left. The other two stood guard over them, refusing to be drawn into further conversation. Yatima and Inoshiro sat on the ground, facing each other rather than the fleshers, hoping to put them at ease.

  By the time the translator arrived it was late afternoon. She approached and shook their hands, but regarded them with undisguised suspicion.

  “I’m Francesca Canetti. You claim to be Yatima and Inoshiro, but anyone could be inhabiting these machines. Can you tell me what you saw here? What you did?”

  Inoshiro recounted the details of their visit. Yatima suspected that their frosty reception was partly due to Carter-Zimmerman’s well-intentioned “assault” on the fleshers’ communications network, and ve felt a renewed pang of shame. Ve and Inoshiro had had twenty-one years in which to re-establish a secure gateway between the networks; even with the problems of subjective time differences, that might have led to some kind of trust by now. But they’d done nothing.

  Francesca said, “So what’s the news you’ve brought us?”

  Inoshiro asked her, “Do you know what a neutron star is?”

  “Of course.” Francesca laughed, clearly offended. “That’s a rich question, coming from a couple of lotus-eaters.” Inoshiro remained silent, and after a moment Francesca elaborated, in a tone of controlled resentment. “It’s a supernova remnant. The dense core left behind when a star is too massive to form a white dwarf, but not massive enough to form a black hole. Should I go on, or is that enough to satisfy you that you’re not dealing with a bunch of agrarian throwbacks who’ve regressed to pre-Copernican cosmology?”

  Inoshiro and Yatima conferred in IR, and decided to risk it. Francesca seemed to understand them as well as Orlando and Liana; stubbornly holding out for their old friends would cause too much hostility, and waste too much time.

  Inoshiro explained the situation very clearly — and Yatima resisted interjecting with provisos and technicalities — but ve could see Francesca growing ever more suspicious. It was a long, long chain of inferences from the faint waves picked up by TERAGO to the vision of a frozen, UV-blasted Earth. With an asteroid or comet, the fleshers could have used their own optical telescopes to reach their own conclusions, but they had no gravitational wave detectors. Everything had to be taken on trust, third hand.

  Finally, Francesca admitted, “I don’t understand this well enough to question you properly. Will you come into the city and address a convocation?”

  Inoshiro said, “Of course.”

  Yatima asked, “You mean we’ll talk to representatives of all the bridgers, through translators?”

  “No. A convocation means all the fleshers we can contact. Not just talking to Atlanta. Talking to the world.”

  As they made their way through the jungle, Francesca explained that she knew Liana and Orlando well, but Liana was sick, so no one had yet troubled them with the news that the Konishi emissaries had returned.

  When Atlanta came into view ahead, surrounded by its vast green and golden fields, it was as if the scale of the problems the bridgers would soon be facing had been laid out for inspection in hectares of soil, megaliters of water, tons of grain. In principle, there was absolutely no reason why suitably adapted organic life couldn’t flourish in the new environment Lacerta would create. Crops could employ robust pigments that made use of UV photons, their roots secreting glycols to melt the hardest tundra, their biochemistry adapted to the acidic, nitrogenous water and soil. Other species essential to the medium-term chemical stability of the biosphere could be given protective modifications, and the fleshers themselves could engineer a new integument to shield them from cell death and genetic damage even in direct sunlight.

  In practice, though, any such transition would be a race against time, constrained at every step by the realities of mass and distance, entropy and inertia. The physical world couldn’t simply be commanded to change; it could only be manipulated, painstakingly, step by step — more like a mathematical proof than a scape.

  There were low, dark clouds rolling over the city as they approached. On the main avenue, people stopped to watch the robots arriving with their escort, but the crowds seemed strangely lethargic in the shadowless light. Yatima could see that their clothes were damp, their faces shiny with perspiration. The gleisner’s skin told ver the ambient temperature and humidity: 45 degrees Celsius, 93 percent. Ve checked with the library; this was not generally considered pleasant, and there could be metabolic and behavioral consequences, depending on each exuberant’s particular adaptations.

  A few people greeted them, and one woman went so far as to ask why they’d returned. Yatima hesitated, and Francesca intervened. “The emissaries will address a convocation soon. Everyone will hear their news, then.”

  They were taken to a large, squat, cylindrical building near the center of the city, and led through the foyer and down a corridor to a room dominated by a long wooden table. Francesca left them with the three guards — it was impossible to think of them as anything else — saying she’d return in an hour or two. Yatima almost protested, but then ve recalled Orlando saying that it would take days to gather all the bridgers together. Arranging a planet-wide convocation in an hour — to discuss claims by two self-declared but possibly fraudulent Konishi citizens of an imminent threat to all life on Earth — would be a major feat of diplomacy.

  They sat on one side of the long table. Their guards remained standing, and the silence seemed tense. These people had heard the whole conversation about Lacerta, but Yatima wasn’t sure what they’d made of it.

  After a while, the man asked nervously, “You talked about radiation from space. Is this the start of a war?”

  In
oshiro said firmly, “No. It’s a natural process. It’s probably happened to the Earth before, hundreds of millions of years ago. Maybe many times.” Yatima refrained from adding: Only never this close, never this strong.

  “But the stars are falling together faster than they should be. So how do you know they’re not being used as a weapon?”

  “They’re falling together faster than astronomers thought they would. So the astronomers were wrong, they misunderstood some of the physics. That’s all.”

  The man seemed unconvinced. Yatima tried to imagine an alien species with the retarded morality required for warfare and the technological prowess to manipulate neutron stars. It was a deeply unpleasant notion, but about as likely as the influenza virus inventing the H-bomb.

  The three bridgers spoke together quietly, but the man remained visibly agitated. Yatima said reassuringly, “Whatever happens, you’re always welcome in Konishi. Whoever wants to come.”

  The man laughed, as if he doubted it.

  Yatima raised vis right hand, displaying his index finger. “No, it’s true. We’ve brought enough Introdus nanoware —”

  Inoshiro was sending warning tags even before the expression on the man’s face changed. He leant forward and grabbed Yatima’s hand by the wrist, then slammed it down on the table. He screamed, “Someone get a torch! Get a cutting tool!” One of the guards left the room; the other approached warily.

  Inoshiro said calmly, “We would never have used it on anyone without permission. We just wanted to be prepared to offer you migration, if things went badly.”

  The man raised his free hand toward ver in a fist. “You keep back!” Sweat was dripping from his face; Yatima was doing nothing to resist, but the gleisner’s skin reported that the man was straining hard against it, as if he was wrestling with some monstrous opponent.

  He spoke to Yatima, without taking his eyes off Inoshiro. “What’s really going to happen? Tell me! Will the gleisners set off their bombs in space, so you can herd the last of us into your machines?”