Artifacts

by Greg Egan

  And he’d look me in the eye and say: I have plenty of room to spare. Let me show you.

  It was half past seven in the morning. Ben worked in a music shop; I knew that much from the stolen data. He’d be on his way, soon enough. All I had to do was wait.

  So I stood by the stairwell, swaying, dizzy with fear. I knew this was my only chance. If I failed, I’d vanish from the face of the Earth. If I failed, my loneliness would open up its jaws and swallow me. If I failed, I’d die.

  I still don’t know, to this day, what it was you wanted from us. Some kind of vicarious happiness? Some kind of second-hand love? Out of twenty thousand people, then, why did you choose the loneliest, the saddest; why did you choose the ones with so little hope?

  Unless in your heart, you knew that you were just like us. Just like me: a human-shaped object, nothing more. Not to be mistaken for the real thing.

  The door opened, and Ben stepped out. I was suddenly very calm. He didn’t look threatening, or unapproachable. I’d been afraid that he might be impossibly―unattainably―handsome; he wasn’t. I knew I could talk to him. Maybe it was my imagination, but I would have sworn that I could make out the faint scar on the back of his neck, proof that I’d come to the right place, proof that I’d found the right person.

  He didn’t look at me as he approached; he stared at the ground, just as I would have done. Desperate for guidance, I imagined myself in his place, imagined a friendly stranger trying to strike up a conversation. Then the fog cleared from my brain, and I knew exactly what I’d feel: suspicion, then disbelief … and then sheer panic. At the first sign of the threat of human contact, I’d recoil. I’d flee.

  I kept silent. He walked past me, down the stairs.

  I found an unvandalised phone booth, took the black box from my suitcase, and plugged it in. It came alive at once, red lights flashing, dragging the overdue data out of my head in one long, silent scream.

  Afterwards, I walked aimlessly, until I stumbled across a small café. There were no other customers; I sat there sipping coffee, staring at the jukebox in the corner. It was playing an ad for Pepsi, or the latest song from Radical Doubt; I couldn’t tell which.

  I put a coin in the slot, and then knelt beside the machine―so close that the image on the screen became nothing but a blur of coloured light.

  And you sang:

  Dry your eyes

  Don’t be sad

  You’re worthless

  Your tears mean nothing at all

  If you live and you die

  In a dream, in a lie

  Who will ever be the wiser?

  Close your eyes

  Don’t be sad

  You’re worthless

  Your pain means nothing at all

  Unseen and unknown

  Alive but alone

  Why end a life

  That’s no life at all?

  You were right, of course. And I swallowed no pills; instead, I bought myself a map, walked out to the highway, and hitch-hiked all the way home.

  That was your last song―before the Azciak people fixed the glitch, corrected the aberration. The official story (from the PR release, to the torrent of instant “biographies”, to the sleeve notes of the tasteful, black-lined, Memorial Collected Works boxed set): the lead singer of Worthless had overdosed on vodka and Nembutal, victim of a broken heart. I still have photos from the magazines of crowds of sobbing fans, carrying “your” picture aloft.

  I never joined those tearful mobs. I never even mourned you in private. I don’t know if you’re still in there, somewhere; concealed, transformed, unrecognisable. It’s not impossible, is it? (After all, would you recognise me?)

  And if you’re not? If you really have gone forever?

  Then here I am again. Caring about the wrong things, again.

  And talking to myself.

  REIFICATION HIGHWAY

  “It’s down there, Khali: the mother lode, the keystone, the reason for everything in crystalline form. Solid logic, just waiting to be mined ”

  I gazed sceptically at the asteroid my mother, Elena, insisted on calling Chalmer’s Rock: a heavily cratered, reddish-grey oblate lump, one hundred and sixty kilometres wide, orbiting a K0 star unlisted on any of our catalogues—except for the one we’d bought from Chalmer himself, of course. Obscurity itself, made stone.

  “The spectral analysis says nickel-iron, and assorted silicates.”

  Elena nodded, without looking away from the screen—missing my sarcasm, or choosing to ignore it. “That’s right. This is the one. Size, composition, orbital parameters … they all fit.”

  “More or less. Like how many other pieces of debris in this system? And we might not even have the right star.”

  Elena turned to me and laughed, convinced of her good fortune, refusing to be goaded into anger. “It’s the fourth-closest star to the coordinates. The age-corrected spectrum is a near-perfect match. And—” She hit a few keys and brought a contoured radar map of the asteroid’s surface onto the screen beside the real-time optical view, then she summoned up Chalmer’s own map of his Rock, and had the computer compare them. Aligned and superimposed, they did look similar, for what that was worth. “Seventy per cent of the topography coincides to within fifty metres. There are a couple of hundred craters missing, a couple of hundred extra ones here and there. If this universe contains the same object at all, this is it.”

  I thought: And one of those missing craters is certain to mean that the logic deposit is missing, too.

  It wasn’t just adolescent perversity; I had every reason to be pessimistic. Planets of reportedly unsurpassed beauty had turned into grey airless rocks, for me. Entire, allegedly glorious, civilizations had vanished, or collapsed into premature barbarism. One way or another, everything in the galaxy that I’d ever heard lauded had turned out to be a disappointment, once I’d reached a version of it, myself.

  That’s the catch with FTL: travelling faster than light in one reference frame is the same as travelling backwards in time in another—and you can’t travel into your own past, only someone else’s alternative. If you speed away from a planet at sub-light relativistic velocity, and then wormhole-jump back towards it, you can arrive before you left … but you don’t end up on the same world, with the chance to prevent your own departure. Every would-be closed time-like loop turns out to be a helix instead, winding its way across the multiverse, side-stepping any possibility of causality violation—and it makes no difference whether your intention was to travel back in time, or “merely” to cross a few hundred light years in an instant. There are no round trips—not even hypothetical ones made by joining up the paths of different travellers. Not only can you not go back, you can’t go where anyone you’ve ever met had been before you met them.

  So, even if this “was” Chalmer’s Rock, it certainly wasn’t the one that the Robert Chalmer we’d done business with had personally visited, and gutted.

  Which was why the information he’d sold us wasn’t—necessarily—worthless. And if he ever chose to “return” to the region, in the hope of making a second fortune, it was highly unlikely—although not quite literally impossible—that he’d arrive to find that Elena and I had been there before him. Which was why he’d been willing to sell her the coordinates and other details for a microscopic fraction of the worth of the deposit he’d found the first time.

  As for the likelihood of this particular version of the Rock containing anything of value—let alone the biggest logic deposit I’d heard of in all our travels—that was unknown. We’d made fifteen jumps to the region over a period of five ship years, and this was the first time we’d come across anything bearing even the slightest resemblance to the asteroid in question—so I could understand, begrudgingly, why Elena was hopeful. But the shape of the Rock alone couldn’t tell us whether or not a nugget of reified logic was buried here; a few tens of kilometres, a few seconds of orbital motion, could have turned the crucial impact into a near miss, and the prize we w
ere seeking could have sailed on for another ten thousand light years before encountering ordinary matter again.

  Elena said, “It’s down there. I’m sure it is.”

  I said, “I doubt it. But let’s go see who’s right.”

  The Rock had negligible gravity, about a hundredth of a gee—but fortunately, a slow enough spin at forty hours for centrifugal force to be orders of magnitude less. On a body with negative surface attraction we would have used remotes, and although I wasn’t expecting to find anything, I was still glad to get out of the ship.

  Stalker set down near the first, and most promising, of six suggestive mass anomalies. I followed Elena out onto the fissured red plain. We were on the night side, starlit, many-shadowed. My exoskin thickened in the vacuum, all but blotting out my sense of touch, but walking barefoot across the jagged ground on this space-cold mote, twenty thousand light years from Earth, still gave me a thrill of vulnerability. Twenty thousand light years from Earth, if there was an Earth; for all we knew, we might have been the only two humans in this universe.

  I didn’t feel lonely, though. I’d spent thirteen years crisscrossing the galaxy, leaving everyone but Elena behind with every jump. Nor did I feel intimidated by the void, Space was barren, life was rare, everything of beauty seemed to flee from me—but here I was, standing on this ugly rock, defying the odds with my presence. I opened my mouth, raised my membrane-sealed oesophagus to the stars, and yelled wordless electromagnetic defiance.

  Elena set a surveying machine tracking across the surface, bombarding the rock below with neutrons, and looking for the gamma rays that came back in response—or rather, those that didn’t. Reified logic wasn’t made of atoms, and had no nuclei to absorb the neutrons, then decay. It experienced gravity, and electromagnetism—allowing it to embed in ordinary matter, and making it possible to handle—but it didn’t feel the strong force, so neutrons passed right through it. A mixture of metallic nickel and iron in the right proportions might have the same density, but would return a characteristic gamma ray signature.

  Elena hummed to herself. The bioelectronics in her lips and pharynx interpreted the action and broadcast the result to me; the receiving organs in the flesh of my ears made their own “acoustic” sense of the signal, giving it distance and direction. If the Rock had had an atmosphere, the effect would have been almost the same.

  The surveyor announced its findings: nickel, iron, silicon, oxygen, magnesium, aluminium. Traces of uranium and gold. Gravimetrically, everything added up. The rock below us was denser than the average for the asteroid as a whole, but the anomaly was made of ordinary matter.

  Elena said, “What did you expect? Success at the very first site?” Her sheathed eyes glistened in the starlight. I said nothing.

  Stalker lifted, almost imperceptibly. I sat in the open airlock, holding on to a safety strap, swinging my legs and looking down as the Rock receded and turned slightly, then loomed towards us again.

  We were equipped to take the asteroid apart if we found anything, even though we’d done very little mining in the past; there was no point in exploration if you weren’t ready to follow it through on the spot. But we were traders, really—exchanging gadgets, works of art, and invariant knowledge between worlds separated by distance and history, worlds whose ordinary inhabitants had good reason to stay put. We didn’t need a lot to survive; Stalker fed on stellar radiation, and our adapted bodies could recycle their own metabolites almost endlessly, phosphorylating ADP by an alternative pathway powered by alpha decay. Inside specialized liver cells, clusters of plutonium atoms were wrapped in giant multilayered enzymes, which stole energy from the alpha particles in small enough increments to avoid being torn apart. The repair mechanisms which kept us safe from cosmic ray damage dealt with any leakage, but there wasn’t much. We were about as independent as any living creatures could be.

  So, what would we do with a Chalmer-sized fortune? Give up trading, and settle down somewhere? Elena had talked about that; I hated the idea. In any case, this kind of treasure hunt was no sane way to try to get rich. When Elena had swapped a cargo of rarely invented non-Turing computers for Chalmer’s record of his find, I’d been dumbstruck. The mining log was certified in ways that would have been difficult to fake—but genuine or not, it was still contingent information, tied to a specific history; the antithesis of invariant knowledge.

  And, worst of all, it was insidious. We could spend our lives returning to this place again and again, never finding anything of value—but however many times that happened, the search would not be over. There’d always be the chance that if we came back one more time, our luck would change.

  The second site was shinier, smoother than the first, probably melted by a more recent impact. We’d come down close to the terminator; a dazzling sliver of the nameless K0 sun showed on the horizon when I stood on my toes, although the light didn’t reach the ground. I crouched down to make the sun vanish, then stretched up again to find that it had set. A bright point of light just above the horizon might have been Chalmer’s “home world”—uninhabited here. “This” asteroid belt hadn’t been the boondocks, for him—every last pebble had been mined by the people of his planet, who’d colonized the system generations before. He’d made his fortune before making a single FTL jump, and he’d never told us why he’d chosen to leave everything he knew behind—but then, translated through an ancient common root language, it had been a stilted exchange.

  I closed my eyes and willed the ground beneath us to be nothing but rook. How could we ever give up travelling? How would we ever choose a planet to live on? Much more than language diverged with variant history and colonial isolation. When I was seven years old, Elena had let slip that she’d had a father, and had had to explain what that meant—and why I hadn’t been conceived the same way. “Even if I ran into someone with whom I wished to have a child, I’d hardly be likely to be fertile with him, in vivo—not unless we pre-infected our gametes with translator viruses to patch up all the differences. Why bother?” I wasn’t quite Elena’s clone, though; her cells, transformed to produce male gametes, had been edited with alternative traits selected from a database she’d brought with her from her home world. My “father” was a composite, assembled from a digital version of the planet’s entire gene pool.

  The surveyor announced the results I’d been hoping for. Elena smiled. We moved on.

  The third site was on the day side, peppered with small craters, and broken up by deep cracks. The surveyor abandoned its six-legged gait, and hovered above the ground on helium jets, blowing up a small red dust storm. I stayed in the airlock and watched, and Elena walked only as far from the ship as she had to, to stand apart from me and my expectations of failure.

  If we did find the cousin of Chalmer’s deposit, we would be rich. Solid logic was the one commodity that was valued almost everywhere—all the more so if it hadn’t been discovered and exploited before, because then you could sell the accompanying technology as well. Nobody knew how the abstractions of the propositional calculus became reified in the first place; the formative process was generally assumed to date back to the Big Bang, although I’d heard of theorists insisting that even that cataclysm was insufficient. The unknown origin didn’t keep anyone from using the stuff. Each kilogramme—magnetically restructured into a variant of its natural state—could bring a chosen nonstandard logic to bear upon a region extending a few cubic millimetres beyond its own boundaries. Applied to the right apparatus, the altered logic could undermine almost any law of physics—although most often, it was simply used to pump out a quantity of energy limited only by the ingenuity of the logic engineers. When exploited this way, it slowly decayed (although not before yielding far more than its mass equivalent of energy). I found that a little sad; in spite of all the paradoxes and wonders it could perform, most logic was simply burnt as fuel.

  I’d once asked Elena, “How can logic be a thing?”

  She’d laughed. “The test is, imagine removing
it. If logic went away, would that change anything?”

  “Of course.”

  “Then it’s a thing. It exists, it makes a difference—whether or not you can hold it in your hand. Neutrinos are things, aren’t they? A few billion might pass through your body unnoticed, but beta decay couldn’t happen without them. And matter interacts with logic—reified or not—far more intimately than it interacts with anything else. Think of all the atoms in the universe, endlessly ‘making sense.’ Why? We hypothesize a few ‘fundamental’ laws, and then ‘deduce’ their consequences—but why should matter care about deduction? Why should P implying Q have the slightest effect on what happens in reality? It does, though. Even quantum physics obeys standard logic; so long as you don’t try to express its results in terms of naïve macroscopic concepts, it gives rise to no inconsistencies, no contradictions.

  “There’s a certain pattern to events, a set of restrictions so pervasive that our entire reasoning process evolved around them. Logic is the thing which mediates that aspect of the world—and that’s an effect far more powerful than any force.”

  “Then how can it end up less powerful—obeying gravity and electromagnetism?”

  “Nobody knows. But … nothing’s immovable, nothing’s infinitely strong. If logic influences matter, that’s an interaction, a two-way process. It must be affected itself, however slightly. Maybe under extreme conditions, the effect can be strong enough to drag it halfway into the material world.”

  At the time, I’d nodded understanding—but thinking it all through again, there on the Rock, I wasn’t so sure that I’d really grasped anything. Logic forced matter to behave “consistently” … but what controlled the behaviour of logic—and allowed it to be reified? Another thing altogether? Or did logic act as its own metalogic, controlling itself? Could it do that? I had no idea—because I had no idea what thing controlled whether or not it could.