by Greg Egan
Tchicaya was growing tired of trying to keep his balance on the sloping roof; he sat down, his back slumped against the fin. It was lukewarm, body temperature. Once Slowdown ended, it would be hotter than the boiling point of water. So which extreme did the native life favor? Had it grown here before the Slowdown, and then managed to cling on in the relative cool? Or had it blown out of the icy wastes and only colonized the radiator once the Slowdown had rendered this tiny niche benign?
Mariama sat beside him. “We'll have to leave,” she said.
“Can't that wait until morning?”
“I don't mean us, now. We'll have to leave Turaev. They'll evacuate the planet. We'll all have to go somewhere else.” She smiled, and added with a kind of mock jealousy, “I always wanted to be the one to shake this place out of its stupor. But it looks as if you've beaten me to it.”
Tchicaya sat motionless, scowling slightly. The words refused to sink in. He knew that she was right: it was a universal principle, accepted by every space-faring culture. In each of the other three cases, the planet in question had been strictly quarantined and left to its own fate. Only one of those worlds had been settled, though. Native life was supposed to have been ruled out, long before the colonists' first spores were launched. However microscopic, and however sparsely distributed, it should have left some detectable chemical signature in the atmosphere.
Tears stung his eyes. In his euphoria, he'd never thought beyond the unlikely confirmation that his own world, his own town, held the fourth known example of extraterrestrial life. He could have lived down the shame of this childish escapade, half-excused by that serendipitous discovery. But he'd been more than disobedient, more than disrespectful of the customs that bound the people of Turaev together. He'd destroyed their whole world.
He didn't want to weep in front of Mariama, so he stammered out an incoherent stream of words instead. Everything he'd planned, everything he'd pictured for the future, had just turned to ashes. He might have traveled one day, like Erdal, but he would never have left his friends and family behind, never lost synch. Fifty-nine generations had made this planet their home; he could never belong anywhere else. Now it would all be torn away from him. And nine million people would suffer the same fate.
When he stopped to catch his breath, Mariama said soothingly, “Everything here can be moved! Every building, every field. You could wake up on New Turaev, a thousand light-years away, and if you didn't check the stars you'd never know.”
Tchicaya replied fiercely, “You know it will never happen like that! Five minutes ago, you were crowing about it!” He wiped his eyes, struggling not to turn his anger against her. He'd always understood what she wanted; he had no right to blame her for that. But any reassurance she offered him was hollow.
Mariama fell silent. Tchicaya buried his head in his hands. There was no escape for him: only adults had the right to shut down their Qusp, to choose extinction. If he threw himself from the roof and broke his spine, if he doused himself in oil and set himself alight, it would only make him more contemptible.
Mariama put an arm around his shoulders. “On how many worlds,” she said, “do you think they've found life?”
“You know the answer. Three, since Earth.”
“I don't know that. There might have been ten. There might have been hundreds.”
Tchicaya's skin crawled. He looked up and searched her eyes in the starlight, wondering if she was testing him. What she was proposing now was infinitely worse than anything they'd done so far.
She said, “If you believe it will hurt so many people, so badly, then I'll listen to you.” Tears were trickling down his cheeks again; she wiped them away with the back of her hand. “I'll trust you.”
Tchicaya looked away. She had the power to incinerate everything around her, the power to break through every stifling absurdity she'd railed against from the day they'd met. When they'd spoken of the future, it was all she had ever talked about: finding a way to force the world to change. Now she could gut the planet with its own stupid rules, and nothing would ever be the same.
Unless he asked her to stay her hand.
Tchicaya slept through the end of Erdal's Slowdown, and woke from deep dreams, refreshed but disoriented. He lay in bed, listening to the wind, thinking over what had happened in the last two hundred and seventy-two years.
Erdal had traveled to Gupta, a hundred and thirty-six light-years away, and stayed for ten days. When he rose from the crib, back in his birth flesh, he would find that ten days had passed on Turaev, too. He would be the one bearing news, eagerly describing his travels to his family and friends. He would not be a stranger to them, greeted with an incomprehensible litany of change.
The whole planet had waited for him. What else should they have done? Turaev's sun would burn for four billion years. How much greed and impatience would it take to begrudge the wait, to cast someone aside for the sake of a few centuries?
Tchicaya felt more pride than guilt. Despite his lapse, his heart was still in the right place, and he had resolved never to be so weak again.
As he was dressing, his gaze ran over the scar on his leg. His was sure that his parents had noticed it, but neither of them had asked him to explain its meaning. It was his right to decide who to tell, and when.
Above the scar, between his legs, the skin was newly red and swollen. Tchicaya sat on the edge of his bed and probed the swelling gingerly. Touching it was like tickling himslef; it made him smile faintly, but there was no disguising the fact that he'd much rather be tickled by someone else.
He finished dressing, moving about the room slowly. He hadn't thought it would happen so soon. Some people were fourteen, fifteen, sixteen. He was tall, but he wasn't strong for his age. He was nothing like his mother or father yet. He wasn't ready. It was some kind of sickness, some kind of mistake.
He sat down on the bed again, trying not to panic. Nothing was irreversible yet. Whatever his body was constructing might take another year to be completed; the first time always took longer. And he could still change his mind, change his feelings. Everything was voluntary, his father had explained. Unless you loved someone deeply, and unless they felt the same way toward you, neither of you could grow what you both needed to make love together.
Tchicaya exposed the raw skin again, and stared down glumly at the formless nub. Every couple grew something different, just as every couple would have a different child. The molecules that had already passed between them in the air would determine the pair of shapes that formed. The two of them would be bound together then, literally remade for each other, even the chemical signals that gave them pleasure fitting together in a complementary pattern as unique as their interlocking flesh.
Tchicaya whispered, “I don't love you. You're nothing to me. I don't love you.” He would picture her face and recite the words every day, once when he rose and once before he slept. If he was strong enough, stubborn enough, his body would have to listen.
Chapter 7
Sophus was far too tactful to ask Tchicaya how he and Mariama knew each other; it must have been obvious that the answer was long, complicated, and largely none of his business. Tchicaya volunteered the bare minimum that the situation seemed to require. “We grew up together, in the same town on Turaev,” he explained. “It's been a while since we last ran into each other.”
When Mariama asked to hear what was happening on the Rindler, Tchicaya deferred to Sophus, who took up the task of outlining some seventeen decades' worth of advances and disappointments. Tchicaya listened politely, hoping Mariama was taking in more than he was. His thoughts were still so scattered by the shock of her arrival that he gave up trying to pay attention; he could replay the whole conversation later.
As Sophus talked, the three of them strolled around the ship. Mariama was unfazed by the view from the walkways; she might not have been this close to the border before, but apparently she'd become accustomed to space. Then again, it would not have surprised him if she had dec
ided to choose equanimity in the new environment by fiat, even if this was her first time off-planet.
When Tchicaya tuned in to the discussion again, Mariama was saying, “So there's no prospect of using universality-class arguments to design a generally effective Planck worm, before we pin down the detailed physics?”
Sophus said, “Tarek has looked into that, and even tried some experiments, but I believe it's a dead end. For a start, we still don't know what the bulk symmetries of this system are. I've more or less given up talking about ‘the novo-vacuum’; it's too misleading. What vacuum? We don't know that there's state that lies in the null space of all annihilation operators for the Mimosan seed particles. And if there is such a state, we don't know that it will obey anything remotely analogous to Lorentz invariance. Whatever's behind the border might not even posses any kind of time-translation symmetry.”
“You're joking!”
“No. In fact, it's looking more likely every day.” Sophus glanced at Tchicaya meaningfully, as if he was waiting for the Preservationists' laudable openness to be acknowledged.
Tchicaya said, “That's right. I watched one experiment myself, just a few hours ago.” Mariama smiled at him, envious at this slight head start.
He smiled back at her, hoping his face wasn't betraying his confusion. At the instant he'd seen her standing on the observation deck, he hadn't consciously assumed anything about the faction she'd be joining; such ephemeral concerns had been swept from his thoughts entirely. Now that she'd casually revealed in passing that she'd come here to support the side that he would have sworn she'd be committed to opposing, the one part of his mind that resonated with this fact was the oldest, crudest model he had of her: someone whose only role in life was to confound and unsettle him. The original Mariama, who he had imagined would go to any lengths, not so much to spite him as to prove that he had no hope of pinning her down.
Tchicaya dragged his thoughts back to Sophus's comments.
Kadir and Zyfete had been nowhere near as explicit, but then they'd not been in the friendliest of moods. Kadir's despair made more sense now, though; it went beyond his growing fears for his home world, and one more ordinarily frustrating encounter with the border.
Time-translation symmetry was the key to all their hopes of predicting how the novo-vacuum would behave. In ordinary physics, if two people performed the same experiment, one starting work at midnight while the other began at noon, their separate versions could be compared, very easily: you merely added or subtracted half a day, and all their data could be superimposed. That sounded too obvious to be worth stating, but the fact that it was possible, and the fact that any laws of physics had to be compatible with this process of sliding the two sequences of events together, was a powerful constraint on the forms such laws could take.
Everything that happened in the universe was unique, on some level. If that were not true, there'd be no such thing as memory, or history; there'd be no meaningful chronology at all. At the same time, it was always possible to unpick some features of an event from the complicated tapestry of its context, and demand that this tiny patch of reality look the same as countless others, once you knew how to orient them all for the purpose of comparison. Taking a step north on Turaev on your eighteenth birthday could never be the same as taking a step west on Pachner four thousand years later, but in analyzing these two admittedly singular activities, you could safely abstract the relevant joints and muscles from the surrounding thicket of biographical and planetological detail, and declare that the applicable laws of mechanics were precisely the same in both cases.
It had been obvious since the accident that whatever the Mimosans had created in the Quietener did not possess the same symmetries as ordinary space-time, which allowed the unique location, time, orientation, and velocity of any physical system to be stripped away, revealing its essential nature. Still less had anyone expected the Mimosan vacuum to obey the “internal” symmetries that rendered an electron's phase or a quark's color as arbitrary as the choice of a planet's prime meridian.
But everyone studying the novo-vacuum had been relying on the assumption that these familiar regularities had merely been replaced by more exotic ones. Mathematicians had long had a catalog of possibilities on offer that dwarfed those realized in nature: more or fewer dimensions, different invariant geometric structures, novel Lie groups for the transformations between particles. All of these things would be strange to encounter, but ultimately tractable. And at the very least, it had been taken for granted that there was some prospect of using the results of sufficiently simple experiments to deduce what would happen when those experiments were repeated. Once you lost that, prediction in the conventional sense became impossible. You might as well try to guess who you'd meet in a crowded theater on Quine by consulting the guest list for an opening night of Aeschylus.
Tchicaya said, “If you're right, we're wasting our time here.”
Sophus laughed. “I wish all Yielders were so easily discouraged.”
Tchicaya caught the change in Mariama's demeanor as he was finally labeled for her. She did not appear surprised, or cooler toward him, but a look of resignation crossed her face, as if she was letting other possibilities slip away.
He replied, “I didn't say I believed you. Now I know you're just spreading misinformation.”
Sophus said, “The data's all public; you should judge for yourself. But I'm giving a presentation later today that might interest you.”
“On why we should all give up and go home? Yielders first, of course.”
“No. On why we shouldn't, even if I'm right.”
Tchicaya was intrigued. “Dishing out despair with one hand, taking it away with the other. You're never going to drive us away like that.”
“I'm really not interested in driving anyone away,” Sophus protested. “The more people there are working on this, the sooner we'll understand it. I'm happy to share my ideas with everyone—and if some Yielder beats me to the punch line because of it, and fails to show reciprocal generosity, what have I lost?”
“You're not afraid we'll get through the border first? And shore up what you hope to annihilate?”
Sophus smiled amiably. “There might come a point when that's a real threat. If I'm ever convinced that we've reached it, I suppose I might change my strategy. For now, though, it's like a game of Quantum Pass-the-Parcel: all the players work simultaneously to tear off the wrapping, and all the players share the benefits. Why convert to the classical version? This is faster, and much more enjoyable.”
Tchicaya let the argument rest. It would have been impolite to state the obvious: when Sophus finally decided that sharing his insights had become too risky, it would not be to his advantage to announce the fact. At that point, the most logical strategy would be to continue displaying the same generosity as he'd shown in the past, but to replace the genuine, hard-won conjectures he'd revealed to his opponents in the past with equally well-crafted red herrings.
When they reached Mariama's cabin, Sophus left them. Tchicaya hung back in the corridor, unsure whether she wanted him to stay or go.
She said, “Would you come in, if you're coming in?”
He sat cross-legged on the bed while she moved around the cabin. She'd included some physical ornaments in her transmission—a handful of carved rocks and blown-glass objects that the Rindler's reception unit had obligingly re-created for her from spare materials—and now she couldn't decide where to put them.
“I traveled light, myself,” Tchicaya said teasingly. “It didn't seem fair to ask them to cannibalize the ship to provide me with knickknacks.”
Mariama narrowed her eyes. “Aren't you the puritan? Not to the point of amnesia, I hope.”
He laughed. “Not these days.” In the past, he'd left some rarely used memories behind in the Qusps of his body trail. With fullsensory recall, the amount of data mounted up rapidly, and there'd come a point when knowing precisely what it had been like to shake water out of his ear
s in a river on Gupta or roll over and fart while camping in a desert on Peldan didn't really strike him as a crucial part of his identity.
Yet he'd gathered up all the trivia again, before any of the Qusps were erased. And now that there was nowhere he could store his memories in the expectation that they'd remain secure—even if he archived them with a fleeing acorporeal community, their safety would come at the price of accessibility—they all seemed worth dragging around with him indefinitely.
Mariama finally settled on the shelf by the bed as the place for an elaborately braided variant of Klein's bottle. “Holding on to your memories is one thing,” she said. “It doesn't stop you going over the horizon.”
Tchicaya snorted. “Over the horizon? I'm four thousand and nine years old! Take out Slowdowns and travel insentience, and I've barely experienced half of that.” Information theory put bounds on the kind of correlations anyone could sustain between their mental states at different times; the details depended on the structure of your mind, the nature of its hardware, and, ultimately, on the recently rather plasticized laws of physics. If there were unavoidable limits, though, they were eons away. “I think I can still lay claim to doing a far better job of resembling myself—at any prior age—than a randomly chosen stranger.”
Mariama folded her arms, smiling slightly. “In the strict sense, obviously. But don't you think people can cross another kind of horizon? The strict definition counts everything: every aspect of temperament, every minor taste, every trivial opinion. There are so many markers, it's no wonder it takes an eternity for all of them to drift far enough to change someone beyond recognition. But they're not the things that define us. They're not the things that would make our younger selves accept us as their rightful successors, or recoil in horror.”
Tchicaya gave her a warning look that he hoped would steer her away from the subject. With a stranger, he might have asked his Mediator to handle the subtext, but he didn't believe either of them had changed so much that they couldn't read each other's faces.
