Permutation City

by Greg Egan

  “One thousand milliseconds.”

  But … what was going on, in between? The equations controlling the model were far too complex to solve in a single step. In the process of calculating the solutions, vast arrays of partial results were being generated and discarded along the way. In a sense, these partial results implied – even if they didn’t directly represent – events taking place within the gaps between successive complete descriptions. And when the whole model was arbitrary, who was to say that these implied events, buried a little more deeply in the torrent of data, were any “less real” than those which were directly described?

  “Two thousand milliseconds.”

  “One. Two. Three. Four.”

  If he seemed to speak (and hear himself speak) every number, it was because the effects of having said “three” (and having heard himself say it) were implicit in the details of calculating how his brain evolved from the time when he’d just said “two” to the time when he’d just said “four.”

  “Five thousand milliseconds.”

  “One. Two. Three. Four. Five.”

  Besides, hearing words that he’d never “really” spoken wasn’t much stranger than a Copy hearing anything at all. Even the standard millisecond clock rate of this world was far too coarse to resolve the full range of audible tones. Sound wasn’t represented in the model by fluctuations in air pressure values – which couldn’t change fast enough – but in terms of audio power spectra: profiles of intensity versus frequency. Twenty kilohertz was just a number here, a label; nothing could actually oscillate at that rate. Real ears analyzed pressure waves into components of various pitch; Paul knew that his brain was being fed the pre-existing power spectrum values directly, plucked out of the non-existent air by a crude patch in the model.

  “Ten thousand milliseconds.”

  “One. Two. Three.”

  Ten seconds free-falling from frame to frame.

  Fighting down vertigo, still counting steadily, Paul prodded the shallow cut he’d made in his forearm with the kitchen knife. It stung, convincingly. So where was this experience coming from? Once the ten seconds were up, his fully-described brain would remember all of this … but that didn’t account for what was happening now. Pain was more than the memory of pain. He struggled to imagine the tangle of billions of intermediate calculations, somehow “making sense” of themselves, bridging the gap.

  And he wondered: What would happen if someone shut down the computer, just pulled the plug – right now?

  He didn’t know what that meant, though. In any terms but his own, he didn’t know when “right now” was.

  “Eight. Nine. Ten.”

  Squeak. “Paul – I’m seeing a slight blood pressure drop. Are you okay? How are you feeling?”

  Giddy – but he said, “The same as always.” And if that wasn’t quite true, no doubt the control had told the same lie. Assuming…

  “Tell me – which was I? Control, or subject?”

  Squeak. Durham replied, “I can’t answer that – I’m still speaking to both of you. I’ll tell you one thing, though: the two of you are still identical. There were some very small, transitory discrepancies, but they’ve died away completely now – and whenever the two of you were in comparable representations, all firing patterns of more than a couple of neurons were the same.”

  Paul grunted dismissively; he had no intention of letting Durham know how unsettling the experiment had been. “What did you expect? Solve the same set of equations two different ways, and of course you get the same results – give or take some minor differences in round-off errors along the way. You must. It’s a mathematical certainty.”

  Squeak. “Oh, I agree.” The djinn wrote with one finger on the screen:

  (1 + 2) + 3 = 1 + (2 + 3)

  Paul said, “So why bother with this stage at all? I know – I wanted to be rigorous, I wanted to establish solid foundations. But the truth is, it’s a waste of our resources. Why not skip the bleeding obvious, and get on with the kind of experiment where the answer isn’t a foregone conclusion?”

  Squeak. Durham frowned reprovingly. “I didn’t realize you’d grown so cynical, so quickly. AI isn’t a branch of pure mathematics; it’s an empirical science. Assumptions have to be tested. Confirming the so-called ‘obvious’ isn’t such a dishonorable thing, is it? And if it’s all so straightforward, why should you be afraid?”

  “I’m not afraid; I just want to get it over with. But … go ahead. Prove whatever you think you have to prove, and then we can move on.”

  Squeak. “That’s the plan. But I think we could both use a break now. I’ll enable your communications – for incoming data only.” He turned away, reached off-screen, and hit a few keys on a second terminal.

  Then he turned back to the camera, smiling – and Paul knew exactly what he was going to say.

  Squeak. “By the way, I just deleted one of you. I couldn’t afford to keep you both running, when all you’re going to do is laze around.”

  Paul smiled back at him, although something inside him was screaming. “Which one did you terminate?”

  Squeak. “What difference does it make? I told you, they were identical. And you’re still here, aren’t you? Whoever you are. Whichever you were.”

  #

  Three weeks had passed outside since the day of the scan, but it didn’t take Paul long to catch up with the state of the world; most of the fine details had been rendered irrelevant by subsequent events, and much of the ebb and flow had simply canceled itself out. Israel and Palestine had come close to war again, over alleged water treaty violations on both sides – but a joint peace rally had brought more than a million people onto the glassy plain that used to be Jerusalem, and the two governments had been forced to back down. Former US President Martin Sandover was still fighting extradition to Palau, to face charges arising from his role in the bloody coup d’état of thirty-five; the Supreme Court had finally reversed a long-standing ruling which had granted him immunity from all foreign laws, and for a day or two things had looked promising – but then his legal team had discovered a whole new set of delaying tactics. In Canberra, another leadership challenge had come and gone, with the Prime Minister remaining undeposed. In a week-old report, one journalist described this, straight-faced, as “high drama.” Paul thought: I guess you had to be there. Inflation had fallen by half a percentage point; unemployment had risen by the same amount.

  Paul scanned the old news reports rapidly, skimming over articles and fast-forwarding scenes which he felt sure he would have studied scrupulously, had they been fresh. He felt a curious sense of resentment, at having “missed” so much – it was all there in front of him, now, but that wasn’t the same at all.

  And yet, he wondered, shouldn’t he be relieved that he hadn’t wasted his time on so much ephemeral detail? The very fact that he was now less than enthralled only proved how little of it had really mattered, in the long run.

  Then again, what did? People didn’t inhabit geological time. People inhabited hours and days; they had to care about things on that time scale.

  People.

  Paul plugged into real-time TV, and watched an episode of The Unclear Family flash by in less than two minutes, the soundtrack an incomprehensible squeal. A game show. A war movie. The evening news. It was as if he was in deep space, rushing back toward the Earth through a sea of Doppler-shifted broadcasts. The image was strangely comforting: his situation wasn’t so bizarre, after all, if flesh-and-blood humans could find themselves in much the same relationship with the world as he did. Nobody would claim that the Doppler shift could rob someone of their humanity.

  Dusk fell over the recorded city. He ate a microwaved soya protein stew – wondering if there was any good reason, moral or otherwise, to continue to be a vegetarian.

  He listened to music until long after midnight. Tsang Chao, Michael Nyman, Philip Glass. It made no difference that each note “really” lasted seventeen times as long as it should have, or that the
audio ROM sitting in the player “really” possessed no microstructure, or that the “sound” itself was being fed into his model-of-a-brain by a computerized sleight-of-hand that bore no resemblance to the ordinary process of hearing. The climax of Glass’s Mishima still seized him like a grappling hook through the heart.

  And if the computations behind all this had been performed over millennia, by people flicking abacus beads, would he have felt exactly the same?

  It was outrageous to admit it – but the answer had to be yes.

  He lay in bed, wondering: Do I still want to wake from this dream?

  The question remained academic, though; he still had no choice.

  Chapter 4

  (Remit not paucity)

  November 2050

  Maria had arranged to meet Aden at the Nadir, an Oxford Street nightclub where he sometimes played, and often went to write. He could usually get them both in for free, and the door – an intimidating, airlock-like contraption of ribbed black anodized steel – let her pass unchallenged after a brief security scan. Maria had once had a nightmare in which she’d been trapped in that chamber, a knife inexplicably strapped to her right boot – and, worse, her credit rating canceled. The thing had digested her like an insect in a Venus flytrap, while Aden stood on stage, singing one of his cut-up love songs.

  Inside, the place was crowded for a Thursday night, and poorly lit as always; she finally spotted Aden sitting at a table near a side wall, listening to one of the bands and jotting down music, his face catching the glow of his notepad. So far as Maria could tell, he never seemed to be unduly influenced by anything he listened to while composing, but he claimed to be unable to work in silence, and preferred live performances for inspiration – or catalysis, or whatever it was.

  She touched him on the shoulder. He looked up, took off his headset, and stood to kiss her. He tasted of orange juice.

  He gestured with the headset. “You should listen. Crooked Buddhist Lawyers on Crack. They’re quite good.”

  Maria glanced at the stage, although there was no way of telling who he meant. A dozen performers – four bands in all – stood enclosed in individual soundproof plastic cylinders. Most of the patrons were tuned in, wearing headsets to pick up one band’s sound, and liquid crystal shades, flickering in synch with one group of cylinders, to render the other bands invisible. A few people were chatting quietly – and of the room’s five possible soundtracks, Maria decided that this tranquil near-silence best suited her mood. Besides, she never much liked using nerve current inducers; although physically unable to damage the eardrums (sparing the management any risk of litigation), they always seemed to leave her ears – or her auditory pathways – ringing, regardless of the volume setting she chose.

  “Maybe later.”

  She sat beside Aden, and felt him tense slightly when their shoulders brushed, then force himself to relax. Or maybe not. Often when she thought she was reading his body language, she was making signals out of noise. She said, “I got some junk mail today that looked just like you.”

  “How flattering. I think. What was it selling?”

  “The Church of the God Who Makes No Difference.”

  He laughed. “Every time I hear that, I think: they’ve got to change the name. A God that makes no difference doesn’t rate the definite article or the pronoun ‘who.’”

  “I’ll rerun the program, and the two of you can fight it out.”

  “No thanks.” He took a sip of his drink. “Any non-junk mail? Any contracts?”

  “No.”

  “So … another day of terminal boredom?”

  “Mostly.” Maria hesitated. Aden usually only pressed her for news when he had something to announce himself – and she was curious to find out what it was. But he volunteered nothing, so she went on to describe her encounter with Operation Butterfly.

  Aden said, “I remember hearing something about that. But I thought it was decades away.”

  “The real thing probably is, but the simulations have definitely started. In a big way.”

  He looked pained. “Weather control? Who do they think they’re kidding?”

  Maria suppressed her irritation. “The theory must look promising, or they wouldn’t have taken it this far. Nobody spends a few million dollars an hour on supercomputer time without a good chance of a payoff.”

  Aden snickered. “Oh yes they do. And it’s usually called Operation something-or-other. Remember Operation Radiant Way?”

  “Yes, I remember.”

  “They were going to seed the upper atmosphere with nanomachines which could monitor the temperature – and supposedly do something about it.”

  “Manufacture particles which reflected certain wavelengths of solar radiation – and then disassemble them, as required.”

  “In other words, cover the planet with a giant thermostatic blanket.”

  “What’s so terrible about that?”

  “You mean, apart from the sheer technocratic hubris? And apart from the fact that releasing any kind of replicator into the environment is – still, thankfully – illegal? It wouldn’t have worked. There were complications nobody had predicted – unstable mixing of air layers, wasn’t it? – which would have counteracted most of the effect.”

  Maria said, “Exactly. But how would anyone have known that, if they hadn’t run a proper simulation?”

  “Common sense. This whole idea of throwing technology at problems created by technology…”

  Maria felt her patience desert her. “What would you rather do? Be humble in the presence of nature, and hope you’ll be rewarded for it? You think Mother Gaia is going to forgive us, and put everything right – just as soon as we throw away our wicked computers and promise to stop trying to fix things ourselves?” Should have made that “Nanny Gaia.”

  Aden scowled. “No – but the only way to ‘fix things’ is to have less impact on the planet, not more. Instead of thinking up these grandiose schemes to bludgeon everything into shape, we have to back off, leave it alone, give it a chance to heal.”

  Maria was bemused. “It’s too late for that. If that had started a hundred years ago … fine. Everything might have turned out differently. But it’s not enough anymore; too much damage has already been done. Tip-toeing through the debris, hoping all the systems we’ve fucked-up will magically restore themselves – and tip-toeing twice as carefully every time the population doubles – just won’t work. The whole planetary ecosystem is as much of an artifact, now, as … a city’s microclimate. Believe me, I wish that wasn’t the case, but it is – and now that we’ve created an artificial world, intentionally or not, we’d better learn to control it. Because if we stand back and leave it all to chance, it’s just going to collapse around us in some random fashion that isn’t likely to be any better than our worst well-intentioned mistakes.”

  Aden was horrified. “An artificial world? You honestly believe that?”

  “Yes.”

  “Only because you spend so much time in Virtual Reality you don’t know the difference anymore.”

  Maria was indignant. “I hardly ever —” Then she stopped herself, realizing that he meant the Autoverse. She’d long ago given up trying to drum the distinction into his head.

  Aden said, “I’m sorry. That was a cheap shot.” He made a gesture of retraction, a wave of the hand more impatient than apologetic. “Look, forget all this depressing ecoshit. I’ve got some good news, for a change. We’re going to Seoul.”

  Maria laughed. “Are we? Why?”

  “I’ve been offered a job. University Music Department.”

  She looked at him sharply. “Thanks for telling me you’d applied.”

  He shrugged it off lightly. “I didn’t want to get your hopes up. Or mine. I only heard this afternoon; I can still hardly believe it. Composer-in-residence, for a year; a couple of hours a week teaching, the rest of the time I can do what I like: writing, performing, producing, whatever. And they throw in free accommodation. For two.” />
  “Just … hold it. A few hours’ teaching? Then why do you have to go there in person?”

  “They want me, physically. It’s a prestige thing. Every Mickey Mouse university can plug into the networks and bring in a dozen lecturers from around the world—”

  “That’s not Mickey Mouse, it’s efficient.”

  “Cheap and efficient. This place doesn’t want to be cheap. They want a piece of exotic cultural decoration. Stop laughing. Australia is flavor of the month in Seoul; it only happens once every twenty years, so we’d better take advantage of it. And they want a composer-in-residence. In residence.”

  Maria sat back and digested it.

  Aden said, “I don’t know about you, but I have a lot of trouble imagining us ever being able to afford to spend a year in Korea, any other way.”

  “And you’ve said yes?”

  “I said maybe. I said probably.”

  “Accommodation for two. What am I supposed to do while you’re being exotic and decorative?”

  “Whatever you like. Anything you do here, you could do just as easily there. You’re the one who keeps telling me how you’re plugged into the world, you’re a node in a logical data space, your physical location is entirely irrelevant…”

  “Yes, and the whole point of that is not having to move. I like it where I am.”

  “That shoebox.”

  “A campus apartment in Seoul won’t be much bigger.”

  “We’ll go out! It’s an exciting city – there’s a whole cultural renaissance going on there, it’s not just the music scene. And who knows? You might find some exciting project to work on. Not everything gets broadcast over the nets.”

  That was true enough. Korea had full membership of ASEAN, as opposed to Australia’s probationary status; if she’d been living in Seoul at the right time, if she’d had the right contacts, she might have ended up part of Operation Butterfly. And even if that was wishful thinking – the right contacts probably took a decade to make – she could hardly do worse than she’d been doing in Sydney.