Permutation City

by Greg Egan

  She said, “Chiang’s version was three-dimensional, wasn’t it?”

  “Much better. N-dimensional. Four, five, six, whatever you like. That leaves plenty of room for data within easy reach. In two dimensions, the original von Neumann machine had to reach further and further – and wait longer and longer – for each successive bit of data. In a six-dimensional TVC automaton, you can have a three-dimensional grid of computers, which keeps on growing indefinitely – each with its own three-dimensional memory, which can also grow without bound.”

  Maria said numbly, “Where are you supposed to fit into all of this? If you think translating human biochemistry into Autoverse terms is difficult, how are you going to map yourself into a six-dimensional world designed solely to support von Neumann machines?”

  “The TVC universe is one big, ever-expanding processor cluster. It runs a Copy of me—”

  “I thought the whole point was to do away with Copies!”

  “ – in a VR environment which lets me interact with the TVC level. Yes, I’ll be a patchwork Copy, as always – there’s no alternative to that – but I’ll also be linked to the cellular automaton itself. I’ll witness its operation, I’ll experience its laws. By observing it, I’ll make it a part of what has to be explained.

  “And when the simulated TVC universe being run on the physical computer is suddenly shut down, the best explanation for what I’ve witnessed will be a continuation of that universe – an extension made out of dust.”

  Maria could almost see it: a vast lattice of computers, a seed of order in a sea of a random noise, extending itself from moment to moment by sheer force of internal logic, “accreting” the necessary building blocks from the chaos of non-space-time by the very act of defining space and time.

  Visualizing wasn’t believing, though.

  She said, “What makes you so sure? Why not another deluded psychiatric patient, who believes he was – briefly – a Copy being run on a TVC automaton being run on a processor cluster in another world?”

  “You’re the one who invoked Occam’s Razor. Wouldn’t you say that a self-contained TVC universe is a simpler explanation, by far?”

  “No. It’s about the most bizarre thing I can imagine.”

  “It’s a lot less bizarre than yet another version of this universe, containing yet another version of me, with yet another set of convenient delusions.”

  “How many of your clients believed all this? How many think they’re coming along for the ride?”

  “Fifteen. And there’s a sixteenth who, I think, is tempted.”

  “They paid—?”

  “About two million each.” He snorted. “It’s quite funny, the significance the police have attached to that. Some large sums of money have changed hands, for reasons more complex than usual – so they assume I must be doing something illegal. I mean, billionaires have been known to make donations larger than that to the Church of the God Who Makes No Difference.” He added hastily, “None of mine.”

  Maria was having some trouble with the scale of things herself. “You found fifteen Copies willing to part with two million dollars after hearing this bullshit? Anyone that gullible deserves to lose their money.”

  Durham took no offense. “If you were a Copy, you’d believe the dust theory, too. You’d feel the truth of it in your non-existent bones. Some of these people carried out the same experiments as I did – computing themselves in randomized fragments – but others didn’t need to. They already knew that they could scatter themselves across real time and real space, and they’d still find themselves. Every Copy proves the dust theory to itself a million times a day.”

  It suddenly occurred to Maria that Durham might have invented all of this for her sake, alone – while telling his clients exactly what Hayden had assumed: some fraudulent but utterly non-metaphysical tale of a hidden supercomputer. But she couldn’t see what he had to gain by confusing her … and too many details made too much sense, now. If his clients had accepted the whole mad vision, the problem of making them believe in a non-existent supercomputer vanished. Or at least, changed from a question of evidence to a question of faith.

  She said, “So you promised to fit a snapshot of each of your ‘backers’ into the Garden-of-Eden configuration, plus the software to run them on the TVC?”

  Durham said proudly, “All that and more. The major world libraries; not quite the full holdings, but tens of millions of files – text, audio, visual, interactive – on every conceivable subject. Databases too numerous to list – including all the mapped genomes. Software: expert systems, knowledge miners, metaprogrammers. Thousands of off-the-shelf VR environments: deserts, jungles, coral reefs, Mars and the moon. And I’ve commissioned Malcolm Carter, no less, to create a major city to act as a central meeting place: Permutation City, capital of the TVC universe.

  “And of course, there’ll be your contribution: the seed for an alien world. Humanity is going to find other life in this universe, eventually. How can we give up hope of doing the same? Sure, we’ll have our own software descendants, and recreated Earth animals, and no doubt novel, wholly artificial creatures as well. We won’t be alone. But we still need a chance to confront the Other. We mustn’t leave that possibility behind. And what could be more alien than Autoverse life?”

  Maria’s skin crawled. Durham’s logic was impeccable; an endlessly-expanding TVC universe, with new computing power being manufactured out of nothing in all directions, “would” eventually be big enough to run an Autoverse planet – or even a whole planetary system. The packed version of Planet Lambert – the compressed description, with its topographic summaries in place of actual mountains and rivers – would easily fit into the memory of a real-world computer. Then Durham’s Copy could simply wait for the TVC grid to be big enough – or pause himself, to avoid waiting – and have the whole thing unfold.

  Durham said, “I’ve been working on the software which will run the first moments of the TVC universe on a real-world computer. I can probably finish that myself. But I can’t complete the Autoverse work without you, Maria.”

  She laughed sharply. “You want me to keep working for you? You lie to me. You get me visited by the fraud squad. You confess to a history of mental illness. You tell me you’re the twenty-third incarnation of a retailing millionaire from a parallel world—”

  “Whatever you think about the dust theory – and whatever you think about my psychological health – I can prove to you that I’m not a criminal. My backers will vouch for that; they all know exactly what their money’s being used for. None of them are victims of fraud.”

  “I accept that. I just—”

  “Then accept the payment. Finish the work. Whatever the police have told you, you have every right to the money, and I have every right to give it to you. Nobody’s going to take you to court, nobody’s going to throw you into prison.”

  Maria was flustered. “Just, hold on. Will you give me a chance to think?” Durham’s sheer reasonableness was beginning to be as exhausting as the impassioned rhetoric of any obvious fanatic. And so much ground had shifted in the last half hour that she hadn’t had a chance to even start to reappraise her own situation: legally, financially … and morally.

  She said, “Why don’t your backers tell the police all this? If they can confirm your story for me, why can’t they do the same for the cops? By refusing to talk, they’re just fueling suspicion.”

  Durham agreed. “Tell me about it. It makes everything ten times harder – but I’m just going to have to keep on living with that. Do you think they’d risk the truth becoming public knowledge? There have already been some embarrassing leaks – but so far we’ve been able to muddy the water by putting out our own misinformation. Copies with de facto control of billion-dollar business empires would much rather have people linking them to some dubious salesman and his breakthrough supercomputer – and have the rumors fizzle out from lack of substantiation – than let the world know that they plan to send a clone into a
n artificial universe which runs without hardware. The share markets can get nervous enough when people start wondering if a certain board of directors have all taken up playing virtual Caligula in their spare time. If word got out that a Copy in a position of power had done something which might be construed as a sign that they no longer felt obliged to give a shit about their corporate responsibilities, their personal wealth, or the continued existence of planet Earth…”

  Maria walked over to the window. It was open, but the air outside was still; standing by the insect screen she might as well have been standing by a solid brick wall. People were arguing loudly in the flat above; she’d only just noticed.

  When Durham had first approached her, she’d wondered, half seriously, if she’d be taking advantage of a man who’d taken leave of his senses. Now, she couldn’t just shrug that off as a hypocritical insult to a fellow eccentric. This wasn’t a matter of an artificial life fanatic with more money than sense. An ex-psychiatric patient was planning to spend thirty million dollars of other people’s money to “prove” his own sanity – and lead the clones of his followers into a cybernetic paradise which would last for about twenty seconds. Taking a cut seemed just a tiny bit like doing the catering for the Jonestown massacre.

  Durham said, “If you don’t agree to finish the biosphere seed, who would I get to replace you? There’s nobody else who could even begin to grasp what’s involved.”

  Maria eyed him sharply. “Don’t start flattering me. And don’t kid yourself about the seed, either. You asked for a package of persuasive data, and that’s all you’ll be getting – even if I finish the work. If you’re counting on Planet Lambert’s inhabitants rising up on their hind legs and talking to you … I can’t guarantee that happening if you ran the whole thing a billion times. You should have simulated real-world biochemistry. At least it’s been shown that intelligent life can arise within that system … and you’d supposedly have the computing power to do it.”

  Durham said reasonably, “A. lamberti seemed simpler, surer. Any real-world organism – modeled subatomically – would be too big a program to test out in advance on any physical computer. And it’d be too late to change my mind and try another approach if I failed to get it to work – stuck in the TVC universe, with plenty of books and journals, but no pool of expertise.”

  Maria felt a deep chill pass through her; every time she thought she’d accepted just how seriously Durham took this lunacy, he gave an answer like that which drove it home to her anew.

  She said, “Well, Autoverse life might turn out just as useless. You might have A. hydrophila spewing out useless mutations, generation after generation, with nothing you can do to fix it.”

  Durham seemed about to reply, but then stopped himself. Maria felt the chill return, at first without knowing why. A second later, she glared at him, outraged, as furious as if he’d come right out and asked her.

  “I will not be there to fix it for you!”

  Durham had the grace to look cowed, momentarily – but instead of denying that the thought had ever crossed his mind, he said, “If you don’t believe in the dust theory, what difference would it make if there’s a scan file of you in the Garden-of-Eden data?”

  “I don’t want a Copy of me waking up and living for a few subjective seconds, knowing that it’s going to die!”

  “Who said anything about waking it? Running a Copy on a simulated TVC grid is a computer-intensive operation. We can’t afford to wake more than one Copy while we’re still running on a physical computer. Mine. As far as you’re concerned, your scan file would never even be used to build a Copy; the data would just sit there, completely inert. And you could sit outside at a terminal, overseeing the whole operation, making sure I kept my word.”

  Maria was scandalized – although it took her a second to weave through Durham’s infuriating logic to find a target.

  “And you – certain that I’d eventually wake – would happily take me on board under false pretenses?”

  Durham seemed genuinely baffled by the accusation. “False pretenses? I’ve given you all the facts, and I’ve argued my case as hard as I can; it’s not my fault if you don’t believe me. Am I supposed to feel guilty for being right?”

  Maria started to reply, but then the point seemed too ridiculous to pursue. She said, “Never mind. You won’t get a chance to feel anything about it, because I’m certainly not offering you a scan file.”

  Durham bowed his head. “It’s your decision.”

  Maria hugged herself. She was actually trembling slightly. She thought: I’m afraid of exploiting him? If what he’s doing really is legitimate … finish the job, take the money. His Copy’s going to spend a few seconds believing it’s headed for Copy Heaven – and that’s going to happen whatever I do. The fifteen clones will just sleep through it all, as if they’d never been made. That’s no Jonestown.

  Durham said, “The fee would be six hundred thousand dollars.”

  Maria said, “I don’t care if it’s six hundred million.” She’d meant to shout, but her words faded out into a whisper.

  Six hundred thousand dollars would be enough to save Francesca’s life.

  Chapter 18

  (Remit not paucity)

  May 2051

  Peer seemed to be making love with Kate, but he had his doubts. He lay on the soft dry grass of a boundless meadow, in mild sunshine. Kate’s hair was longer than usual, tickling his skin wherever she kissed him, brushing against him with an erotic precision which seemed unlikely to have been left to chance. Insect chirps and birdsong were heard. Peer could recall David Hawthorne screwing a long-suffering lover in a field, once. They’d been driving back to London from her father’s funeral in Yorkshire; it had seemed like a good idea at the time. This was different. No twigs, no stones, no animal shit. No damp earth, no grass stains, no itching.

  The perfect meadow itself was no reason for suspicion; neither of them were verisimilitude freaks, masochistic re-creators of the irritating details of real environments. Good sex was, equally, a matter of choice. But Peer still found himself wondering if Kate really had agreed to the act. She hadn’t actually made love to him for months – however many times he’d recycled the memories of the last occasion – and he couldn’t rule out the possibility that he’d merely decided to fool himself into believing that she’d finally relented. He’d never gone quite so far before – so far as he presently knew – but he had a vague memory of resolving to do a thorough job of concealing the evidence, if he ever did.

  He could clearly remember Kate beginning to flirt as they’d toured Carter’s city, and then reaching out and starting to undress him as they stood in the exit doorway. He’d shut down all limits on her access to his body while she’d been unbuttoning his shirt – and he’d bellowed with shock and delight when, in the middle of their physically plausible foreplay, an invisible second Kate, twenty times his size, had picked him up in one hand, raised him to her mouth, and licked his body from toes to forehead like a sweet-toothed giant taking the icing off a man-shaped cake.

  None of this struck him as especially unlikely; if Kate had decided to make love again, it was the kind of thing he could imagine her doing. That in itself proved nothing. He could have scripted this fantasy to fit everything he knew about her – or chosen the scenario, and then rewritten his “knowledge” of her to accommodate the action. In either case, software could have laid down a trail of false memories: a plausible transition from their meeting with Carter – which he felt certain had actually happened – to this moment. All memories of having planned the deception would have been temporarily suppressed.

  Kate stopped moving. She shook her head, spattering his face and chest with sweat, and said, “Are you here where you seem to be, or off somewhere else?”

  “I was about to ask you the same question.”

  She smiled wickedly. “Ah. Then maybe this body you hope is me only asked you first to put your mind at ease.” In the sky above her right shoulder, P
eer could see a stray cloud taking on a new shape, a whimsical sculpture parodying the bodies on the grass below.

  He said, “And then admitted as much?”

  Kate nodded, and started slowly rising. “Of course. For the very same reason. How many levels of bluffing will it take, before you get bored, and say: fuck it, I don’t care?”

  She lifted herself until they were almost apart. He closed his eyes and violated the geometry, licking the sweat from between her shoulder blades without moving a muscle. She responded by sticking her tongue in both of his ears simultaneously. He laughed and opened his eyes.

  The cloud above had darkened. Kate lowered herself onto him again, trembling very slightly.

  She said, “Don’t you find it ironic?”

  “What?”

  “Trans-humans taking pleasure by stimulating copies of the neural pathways which used to be responsible for the continuation of the species. Out of all the possibilities, we cling to that.”

  Peer said, “No, I don’t find it ironic. I had my irony glands removed. It was either that, or castration.”

  She smiled down at him. “I love you, you know. But would I tell you that? Or would you be stupid enough to pretend that I had?”

  Warm, sweet rain began to fall.

  He said, “I don’t care, I don’t care, I don’t care.”

  #

  Peer sat on the lowest of the four wooden steps leading up to the back porch of his homestead, glancing down now and then at his bare feet and thin brown arms. Ten-year-old farm boy at dusk. Kate had made both the environment and the body for him, and he liked the tranquil mood of the piece. There was no invented family, no role to play; this was a painting, not a drama. One place, one moment, lasting as long as he chose to inhabit it. The scenery wasn’t quite photorealist – there were subtle distortions of form, color, and texture which made it impossible to forget that he was inhabiting a work of art – but there were no sledgehammer techniques: no visible brushstrokes, no Van Gogh lighting effects.