by Greg Egan
Durham said, “Time to dip a toe in the water.” On a second window, he duplicated the grassland scene, then zoomed in at a dizzying rate on a point in midair, until a haze of tumbling molecules appeared, and then individual Autoverse cells. The vacuum between molecules was shown as transparent, but faint lines delineated the lattice.
He said, “One red atom. One tiny miracle. Is that too much to ask for?”
Maria watched the commands stream across the TVC map: instructions to a single processor to rewrite the data which represented this microscopic portion of the Autoverse.
Nothing happened. The vacuum remained vacuum.
Durham swore softly. Maria turned to the window. The City was still standing; Elysium was not decaying like a discredited dream. But she felt herself break out in a sweat, felt her body drag her to the edge of panic. She had never really swallowed Durham’s claim that there was a danger in sharing their knowledge with the other Elysians – but now she wanted to flee the room herself, hide her face from the evidence, lest she add to the weight of disbelief.
Durham tried again, but the Autoverse was holding fast to its laws. Red atoms could not spontaneously appear from nowhere – it would have violated the cellular automaton rules. And if those rules had once been nothing but a few lines of a computer program – a program which could always be halted and rewritten, interrupted and countermanded, subjugated by higher laws – that was no longer true. Zemansky was right: there was no rigid hierarchy of reality and simulation any more. The chain of cause and effect was a loop, now – or a knot of unknown topology.
Durham said evenly, “All right. Plan B.” He turned to Maria, “Do you remember when we discussed closing off the Autoverse? Making it finite, but borderless … the surface of a four-dimensional doughnut?”
“Yes. But it was too small.” She was puzzled by the change of subject, but she welcomed the distraction; talking about the old days calmed her down, slightly. “Sunlight would have circumnavigated the universe and poured back into the system, in a matter of hours; Planet Lambert would have ended up far too hot, for far too long. I tried all kinds of tricks to change the thermal equilibrium – but nothing plausible really worked. So I left in the border. Sunlight and the solar wind disappear across it, right out of the model. And all that comes in is—”
She stopped abruptly. She knew what he was going to try next.
Durham finished for her. “All that comes in is cold thermal radiation, and a small flux of atoms, like a random inflow of interstellar gas. A reasonable boundary condition – better than having the system magically embedded in a perfect vacuum. But there’s no strict logic to it, no Autoverse-level model of exactly what’s supposed to be out there. There could be anything at all.”
He summoned up a view of the edge of the Autoverse; the atoms drifting in were so sparse that he had to send Maxwell’s Demon looking for one. The software which faked the presence of a plausible interstellar medium created atoms in a thin layer of cells, “next to” the border. This layer was not subject to the Autoverse rules – or the atoms could not have been created – but its contents affected the neighboring Autoverse cells in the usual way, allowing the tiny hurricanes which the atoms were to drift across the border.
Durham sent a simple command to the atom-creation sub-process – an instruction designed to merge with the flow of random requests it was already receiving: inject a red atom at a certain point, with a certain velocity.
It worked. The atom was conjured up in the boundary layer, and then moved into the Autoverse proper, precisely on cue.
Durham sent a sequence of a thousand similar commands. A thousand more atoms followed, all moving with identical vectors. The “random inflow” was no longer random.
Elysium was affecting the Autoverse; they’d broken through.
Repetto cheered. Zemansky smiled enigmatically. Maria felt sicker than ever. She’d been hoping that the Autoverse would prove to be unbreachable – and then, by symmetry, Elysium might have been equally immune to interference. The two worlds, mutually contradictory or not, might have continued on their separate ways.
She said, “How does this help us? Even if you can make this program inject the puppets into deep space, how would you get them safely down to Planet Lambert? And how could you control their behavior once they were there? We still can’t reach in and manipulate them – that would violate the Autoverse rules.”
Durham had thought it all through. “One, we put them in a spaceship and drop that in. Two, we make them radio-controlled – and beam a signal at them from the edge of the model. If we can persuade the gas inflow software to send in a spaceship, we can persuade the cold thermal radiation software to send in a maser beam.”
“You’re going to sit here and try to design a spaceship which can function in the Autoverse?”
“I don’t have to; it’s already been done. One of the old plans for contact involved masquerading as ‘aliens’ from another part of the Autoverse, to limit the culture shock for the Lambertians. We would have told them that there were billions of other stars, hidden from view by dust clouds shrouding their system. The whole idea was immoral, of course, and it was scrapped thousands of years ago – long before there were sentient Lambertians – but the technical work was completed and filed away. It’s all still there, in the Central Library; it should take us about an hour to assemble the components into a working expedition.”
It sounded bizarre, but Maria could see no flaw in the plan, in principle. She said, “So … we’re crossing space to meet the aliens, after all?”
“It looks that way.”
Repetto echoed the phrase. “Crossing space to meet the aliens. You must have had some strange ideas, in the old days. Sometimes I almost wish I’d been there.”
#
Maria gave in and learned how to use a mind’s eye control panel to switch between her Elysian body and her Autoverse telepresence robot. She stretched the robot’s arms and looked around the glistening flight deck of the Ambassador. She was lying in an acceleration couch, alongside the other three members of the crew. According to the flight plan, the robot was almost weightless now – but she’d chosen to filter out the effects of abnormal gravity, high or low. The robot knew how to move itself, in response to her wishes, under any conditions; inflicting herself with space sickness for the sake of “realism” would be absurd. She was not in the Autoverse, after all – she had not become this robot. Her entire model-of-a-human-body was still being run back in Elysium; the robot was connected to that model in a manner not much different from the nerve-induction link between a flesh-and-blood visitor to a VR environment, and his or her software puppet.
She flicked a mental switch and returned to the cloned apartment. Durham, Repetto and Zemansky sat in their armchairs, staring blankly ahead; little more than place markers, really. She went back to the Ambassador, but opened a small window in a corner of her visual field, showing the apartment through her Elysian eyes. If she was merely running a puppet in the Autoverse, she wanted to be clear about where her “true” body was supposed to be located. Knowing that there was an unobserved and insensate shop-window dummy occupying a chair on her behalf was not quite enough.
From the acceleration couch, she watched a – solid – display screen, high on the far wall of the flight deck, which showed their anticipated trajectory, swooping down on a shallow helical path toward Planet Lambert. They’d injected the ship through the border at the nearest possible point – one hundred and fifty thousand kilometers above the orbital plane – with a convenient pre-existing velocity; it would take very little fuel to reach their destination, and descend.
She said, “Does anyone know if they ever bothered to rehearse a real landing in this thing?” Her vocal tract, wherever it was, felt perfectly normal as she spoke – but the timbre of her voice sounded odd through the robot’s ears. The tricks being played on her model-of-a-brain to edit out the growing radio time lag between her intentions and the robot’s acti
ons didn’t bear thinking about.
Durham said, “Everything was rehearsed. They recreated the whole pre-biotic planetary system for the test flights. The only difference between then and now was that they could materialize the ship straight into the vacuum, wherever they liked – and control the puppet crew directly.”
Violating Autoverse laws all over the place. It was unnerving to hear it spelled out: the lifeless Autoverse, in all its subatomic detail, had been a mere simulation; the presence of the Lambertians had made all the difference.
A second display screen showed the planet itself, an image from a camera outside the hull. The view was no different from that which the spy software had shown her a thousand times; although the camera and the robot’s eyes were subject to pure Autoverse physics, once the image was piped into her non-Autoverse brain, the usual false-color conventions were employed. Maria watched the blue-and-white disk growing nearer, with a tightening in her chest. Free-falling with the illusion of weight. Descending and staying still.
She said, “Why show ourselves to the Lambertians, immediately? Why not send Mouthpiece ahead to prepare the ground – to make sure that they’re ready to face us? There are no animals down there larger than a wasp – and none at all with internal skeletons, walking on their hind legs. Humanoid robots one hundred and eighty centimeters tall will look like something out of their nightmares.”
Repetto replied, “Novel stimuli aren’t disabling for the Lambertians. They’re not going to go into shock. But we’ll certainly grab their attention.”
Durham added, “We’ve come to reveal ourselves as the creators of their universe. There’s not much point being shy about it.”
They hit the upper layers of the atmosphere over the night side. Land and ocean alike were in almost perfect darkness: no moonlight, no starlight, no artificial illumination. The ship began to vibrate; instrument panels on the flight deck hummed, and the face of one display screen audibly cracked. Then radio contact was disrupted by the cone of ionized gas around the hull, and they had no choice but to return to the apartment, to sit out the worst of it. Maria stared at the golden towers of the City, weighing the power of their majestic, self-declared invulnerability against the unassailable logic of the buffeting she’d just witnessed.
They returned for the last seconds of the descent, after the parachutes had already been deployed. The impact itself seemed relatively smooth – or maybe that was just her gravity filter coddling her. They left their acceleration couches and waited for the hull to cool; cameras showed the grass around them blackened, but true to predictions the fire had died out almost at once.
Repetto unpacked Mouthpiece from a storage locker, opening the canister full of robot insects and tipping them into the air. Maria flinched as the swarm flew around aimlessly for several seconds, before assembling into a tight formation in one corner of the deck.
Durham opened the airlock doors, outer first, then inner. The robots didn’t need pneuma of any kind, but the Ambassador’s designers must have toyed with the possibility of mapping human biochemistry into the Autoverse – actually creating “aliens” who could meet the Lambertians as equals – instead of playing with elaborate masks.
They stepped out onto the scorched ground. It was early morning; Maria blinked at the sunlight, the clear white sky. The warmth on her robot skin came through loud and clear. The blue-green meadow stretched ahead as far as she could see; she walked away from the ship – a squat ceramic truncated cone, its white heat-shield smoke-darkened in untidy streaks – and the highlands to the south came into view behind it. Lush vegetation crowded the slopes, but the peaks were bare, rust-red.
A chorus of faint chirps and hums filled the air. She glanced at Mouthpiece, but it was hovering, almost silently, near Repetto; these sounds were coming from every direction. She recognized some of the calls – she’d listened to a few of the non-sentient species, in a quick tour of the evolutionary history leading up to Lambertian communication – and there was nothing particularly exotic about any of them; she might have been hearing cicadas, bees, wasps, mosquitoes. When a faint breeze blew from the east, though, carrying something which the robot’s olfactory apparatus mapped to the scent of salt water, Maria was suddenly so overwhelmed by the modest cluster of sensations that she thought her legs might give way beneath her. But it didn’t happen; she made no deliberate attempt to swoon, so the robot just stood like a statue.
Durham approached her. “You’ve never been on Lambert before, have you?”
She frowned. “How could I?”
“Passively. Most Autoverse scholars have done it.” Maria remembered Zemansky’s offer of a VR representation, when she first met the Contact Group. Durham bent down and picked a handful of grass, then scattered the blades. “But we could never do that before.”
“Hallelujah, the Gods have landed. What are you going to do if the Lambertians ask for a miracle? Pluck a few leaves as a demonstration of your omnipotence?”
He shrugged. “We can always show them the ship.”
“They’re not stupid. The ship proves nothing. Why should they believe that we’re running the Autoverse, when we can’t even break its laws?”
“Cosmology. The primordial cloud. The convenient amounts of each element.” She couldn’t help looking skeptical. He said, “Whose side are you on? You designed the primordial cloud! You sketched the original topography! You made the ancestor of the whole Lambertian biosphere! All I want to do is tell them that. It’s the truth, and they have to face it.”
Maria looked about, at a loss for words. It seemed clearer than ever that this world was not her creation; it existed on its own terms.
She said, “Isn’t that like saying … that your flesh-and-blood original was nothing but a lunatic with some strange delusions? And that any other, better explanation he invented for his life had to be wrong?”
Durham was silent for a while. Then he said, “Elysium is at stake. What do you want us to do? Map ourselves into Autoverse biochemistry and come here to live?”
“I’ve seen worse places.”
“The sun’s going to freeze in another billion years. I promised these people immortality.”
Repetto called out to them, “Are you ready? I’ve spotted the team, they’re not far off. About three kilometers west.” Maria was baffled for a moment, until she recalled that he still had access to all of the resources of the spy software. They were, still, outside the Autoverse looking in.
Durham yelled back, “Ten seconds.” He turned to Maria. “Do you want to be part of this, or not? It has to be done the way I’ve planned it – and you can either go along with that, or go back.”
She was about to reply angrily that he had no right to start making ultimatums, when she noticed the tiny window with its view of the apartment, hovering in the corner of her eye.
Elysium was at stake. Hundreds of thousands of people. The Lambertians would survive the shock of learning their “true” cosmology. Elysium might or might not survive the invention of an alternative.
She said, “You’re right; it has to be done. So let’s go spread the word.”
#
The team was hovering in a loose formation over the meadow. Maria had had visions of being attacked, but the Lambertians didn’t seem to notice their presence at all. They stopped about twenty meters from the swarm, while Mouthpiece went forward.
Repetto said, “This is the dance to signify that we have a message to convey.”
Mouthpiece came to a halt in a tight vertical plane, and the individual robots began to weave around each other in interlocking figure eights. The Lambertians responded immediately, aligning themselves into a similar plane. Maria glanced at Repetto; he was beaming like a ten-year-old whose home-made short-wave radio had just started to emit promising crackling noises.
She whispered, “It looks like they’re ignoring us completely … but do they think they’re talking to real Lambertians – or have they noticed the differences?”
“I can’t tell. But as a group, they’re reacting normally, so far.”
Zemansky said, “If a robot greeted you in your own language, wouldn’t you reply?”
Repetto nodded. “And the instinct goes far deeper, with the Lambertians. I don’t think they’d … discriminate. If they’ve noticed the differences, they’ll want to understand them, eventually – but the first priority will still be to receive the message. And to judge it.”
Mouthpiece began to drift into a more complex formation. Maria could make little sense of it – but she could see the Lambertians tentatively begin to mimic the change. This was it: Durham and Repetto’s cosmological package deal. An explanation for the primordial cloud, and for the deep rules underlying Autoverse chemistry: a cellular automaton, created with the cloud in place, five billion years ago. The two billion years of planetary formation which strictly hadn’t happened seemed like a forgivable white lie, for the moment; messy details like that could be mentioned later, if the basic idea was accepted.
Durham said, “Bad messages usually can’t be conveyed very far. Maybe the fact that Mouthpiece clearly isn’t a team from a nearby community will add credence to the theory.”
Nobody replied. Zemansky smiled sunnily. Maria watched the dancing swarms, hypnotized. The Lambertians seemed to be imitating Mouthpiece almost perfectly, now – but that only proved that they’d “read” the message. It didn’t yet mean that they believed it.
Maria turned away, and saw black dots against the sky. Persistence of vision was back in Elysium, in her model-of-a-brain. She remembered her dissatisfaction, clutching Autoverse molecules with her real-world hands and gloves. Had she come any closer to knowing the Autoverse as it really was?
Repetto said, “They’re asking a question. They’re asking for … clarification.” Maria turned back. The Lambertians had broken step with Mouthpiece, and the swarm had rearranged itself into something like an undulated black flying carpet. “They want ‘the rest of the message’ – the rest of the theory. They want a description of the universe within which the cellular automaton was created.”