Artifacts

by Greg Egan

  Clouds swirl over the early morning sky of the Philippines, Indonesia, Papua New Guinea, northern Australia. Left to right, sunrise sweeps down across the southern Indian Ocean, exposes the tip of Sumatra, misses Vietnam, brushes the Chinese coast. The line of dawn is skewed against the unavoidable imaginary lines of longitude: advanced in the south, lagging in the north; the idea of the seasons laid out before my eyes as clearly as the notion of day and night.

  The entire view stretches almost precisely from forty-five degrees south to forty-five north—albeit foreshortened and hazy at the edges—and the geometry dictates that these ninety degrees of latitude also fill ninety degrees of the Tereshkova’s sky. Madame Mityashin swears that the hotel’s orbit, twenty-seven hundred kilometres high, was chosen solely as a compromise between economic factors and the need to avoid the peak concentration of twentieth-century space junk. I believe her—but if anything, the curious symmetry is more delightful if it’s coincidental.

  Sunrise touches the Malaysian peninsula, directly beneath me; I reach for my binoculars, and catch the shadows of Singapore’s towers as they come rushing in. I’d happily follow the steady progress of daylight for hours, but we glide away impatiently towards the sunlit Pacific. The pace of our motion—ten orbits a day—is the only thing I’d change about this view; I wish we could magically hover above the terminator, watching the planet below turn in its own good time.

  My phone chimes. I tilt it up so I can see the screen, without unclipping it from my belt. Zoe.

  “Martin—”

  “I was just thinking about you. I was hoping you’d call.”

  “Liar. Shut up for ten seconds; this isn’t social. I’m leaving in eight minutes for OMAF; they’ve had some kind of accident there. If you want to come along, I can swing it, but you have to be at airlock three in five minutes, with your suit.”

  “What kind of accident?”

  “We won’t know until we get there. Yes or no?”

  “Yes, but—”

  Her image vanishes. I reach behind my back and take hold of the lattice that covers the “floor,” pull myself around to face it, and start hauling myself unsteadily towards the exit.

  Accident. Suit. Airlock.

  The free-fall nausea I thought I’d banished days ago starts to make a rapid come-back. What did I tell Zoe? Here to cover the Microgravity Industries Conference for SciNet: junket of a lifetime, but to be honest boring me shitless. You’re a standby medic with OES? Fantastic! I’m only here for three more days, but if you happen to get called out—

  I might even have meant it at the time. Postcoital bravado syndrome. If I don’t turn up … what? They won’t hang around waiting for me, not for a second. Nobody will be so much as inconvenienced. I can invent an excuse: ordered by my editor to attend the session on New Horizons in Asteroid Metallurgy, at all costs. No tacky orbital life-and-death drama scoops for SciNet.

  I swing through ninety degrees into a cylindrical corridor/shaft, thinking of myself as climbing now, rather than crawling across a horizontal surface. “Climbing down” for the sake of consistency soon gives way to “climbing up” for the sake of sanity. My brain seizes on any local axis of symmetry and declares it to be “vertical”—a pragmatic choice: losing your bearings horizontally is no great trauma, but it’s nice to pretend to know which way is up. Even if it can’t last long: I turn again, and my reference frame turns with me.

  My room is cubic, but the bed defines a floor. I stow my binoculars, pull my packed suit from its locker, check the time, propel myself out of the room. I realize now that I’ve made up my mind to go, although I’m not sure why. I’m a science journalist, not an ambulance-chasing halfwit—and if I wanted a tour of the Orbital Monopole Accelerator Facility, turning up in the aftermath of an accident is hardly the way to go about it. Why, then? Am I hoping for one more lesson in weightless sex with Zoe? The truth is, it’s better on the ground. Much better. Standing, lying, sitting; at least you know what position you’re in.

  The Hotel Tereshkova is a disc, one hundred and fifty metres across, nonspinning. The staff commute from a nearby pair of tethered habitats, while the guests experience the novelty of free fall for a week or two, with no lasting ill effects.

  I hurry towards the rim. My arms tire quickly, because I’m moving inefficiently: never letting go of the lattice completely, maintaining the illusion of “climbing.” People drift past me on expertly judged ballistic trajectories, zig-zagging from wall to wall—and not just hotel staff; many of the conference participants must spend a month or two a year in orbit.

  I turn a corner, and the airlock’s ahead of me. Zoe is there, with a man and a woman I haven’t met. All three are suited. Zoe says, “You’re just in time. Our window’s in three minutes. Suit up.”

  This, at least, I’ve practised. I move away from the packed suit, and manage to hook my feet into the two anchoring cavities on the first attempt. The suit asks nonchalantly, “You want to wear me?” I say, “Yes.” It unfolds itself around me rapidly; there’s a brief but compelling illusion of falling into a body-shaped cavity that’s opened up in another dimension. When the helmet panels snap together, the whole thing inflates slightly with gas released from the polymer enzyme electrodes which will turn my exhaled carbon dioxide into oxygen and soot. The suit says cautiously, “Measurements suggest that I’m vacuum tight. So far, all systems seem to be okay.”

  We pass through the hotel airlock’s two chambers, and then the single airlock of the bus—all without a glimpse of the outside of the vehicle, but I’ve seen that on video. The Orbital Transfer Bus is cylindrical, some fifteen metres long and five wide; one third of its length is fuel cells and ion drive.

  There are two rows of seats running along the length of the bus, and I take my bearings from them, rather than treating the axis as vertical. As we strap in, Zoe says, “Martin Chen, Lena Rykov, Franz Abbas.” My suit whispers, “I’ve just been allocated a radio channel to communicate with these people, if we end up in vacuum.”

  Abbas turns to me and says, “You don’t have a camera?”

  I point a thumb to my eye. “Visual and auditory cortex taps.”

  “Yeah? Where’s the storage?”

  “Abdominal cavity. Four hundred terabytes—too large to fit in the skull.”

  The autopilot says, “Sixty seconds to launch. Do I have your final approval?”

  Zoe says, “Yes.”

  The bus is undocked and lowered into the launch tube; the motion is barely detectable. Rykov, across the aisle from me, points out a display showing the orbits of the hotel and OMAF, and the path we’ll follow between them. “It’s just a twenty-minute flight,” she says, reassuringly.

  I didn’t realize I looked so worried. I say, “What’s going on up there, anyway? Has someone been injured?”

  “We don’t know. OMAF had some major equipment failure after their last experiment. A repair crew went in about four hours ago; they’ve been silent for the last hour.”

  “How many people?”

  “Three. Engineers from Sakharov; they have a contract with OMAF—and half a dozen other uncrewed facilities that need occasional repairs. Sakharov would have sent a rescue team themselves, but we had an earlier window.”

  “So … what do you think’s happened?”

  She shrugs. “We’ll find out soon enough.”

  “Back” turns to “down”—barely more than one gee, but it’s a shock after six days of weightlessness. The hotel is ejecting us electromagnetically, to save shipboard energy and propellant. A few seconds later, we’re out of the launch tube, and the milder thrust of the ion drive takes over.

  Zoe says, “I still think there’s something perverse about sweeping the asteroid belt with magnetic scoops for a decade, finding a few thousand precious monopoles … and then destroying half of them by smashing them together.”

  I laugh. “Sure—but if I were a particle physicist, and I got my hands on something ten-to-the-sixteenth times as massive as a
proton, something that would let me pack so much energy into so little volume—”

  Abbas says, “I must admit I’ve lost track of what they’re up to. I know they reached supersymmetric energies a while ago; last I heard they were still hoping to detect the Higgsino—”

  “They found it six months ago.”

  “Yeah? They’ll be putting themselves out of work soon. They’ve found every particle in the New Standard Model. They’ve made femtoplasmas as hot as the Big Bang. They’ve unified all four forces. Where do you go from there?”

  “Onwards and upwards. Or backwards and upwards. At Big Bang temperatures, the symmetry between the forces is restored … but there’s one more step to take. At higher temperatures, space-time itself can absorb enough energy for all four dimensions to become equivalent. Or so the theory goes.”

  Rykov nods enthusiastically. “I read a paper by one of the OMAF theoreticians, not long ago: ‘Phase transitions between Lorentzian and Positive Definite Metrics.’ Space-time happened to ‘freeze’ in such a way that one of the dimensions is different from the rest … but at high enough energies, the distinction between time and the spatial dimensions should ‘melt,’ making the structure totally symmetric. That’s what they’re aiming for at OMAF, now: a hint of this state from before the Big Bang.”

  Zoe frowns sceptically. “‘Before’ the Big Bang?”

  I say, “It’s a matter of semantics. This four-space may have been, in a sense, joined to the ‘past side’ of the Big Bang singularity. It can’t be given time coordinates, so it can’t belong to the ‘history’ of the universe. But following the trend to greater symmetry back in time, this is what you end up with … even if you’ve lost the whole idea of ‘time’ once you get there. So ‘before the Big Bang’ is as good a way to describe it as any.”

  Zoe says, “OK, that’s all very well, looking back on it now … but if there was no time, how could this ‘four-space’ ever change into anything, let alone the universe we inhabit?”

  I shrug. “Depends what you mean by ‘how,’ and by ‘change.’ If this space really was joined to our universe, it didn’t so much ‘change into it’ as … provide the initial conditions for it. As for how or why it was connected, we can only answer that from our side of the boundary: it’s what our laws of physics point to, with increasing temperature. How you ‘explain’ the join from the other side, I wouldn’t have a clue. All our physics is based on the fact that you can always distinguish a time coordinate—even if relativity means that different observers allocate it differently. That asymmetry underlies the whole idea of cause and effect. So I don’t know what ‘physics’ would apply to a timeless four-space … if any. Maybe there are no laws. No regularities. No explanations. Maybe it contains what it contains, and there’s nothing else to say.”

  There’s a long pause in the conversation, then Abbas proclaims solemnly, “Well, as Wittgenstein said: ‘About that of which we cannot speak, we must remain silent.’ ”

  Rykov’s having none of that. “Yeah—and as Laurie Anderson replied: ‘If you can’t talk about it, point to it.’ ”

  The bus is windowless, but as we approach OMAF, Zoe puts an image of our destination onto one of the display screens. The accelerator itself is a wire-thin cylinder, fifty kilometres long but only twenty metres wide. Arrays of solar panels distributed along the length feed power into the giant superconducting solenoids. The north and south monopoles travel straight line paths—a linear accelerator is the only option, since the particles pack far too much momentum to he forced into a circle of manageable dimensions—and collide head-on inside the central cluster of detectors, which is housed in a sphere about two hundred metres wide. A single pair of monopoles collide at a time; the rest mass of each is a hundredth of a microgramme, but travelling close to lightspeed, kinetic energy raises that to almost a gramme. For a particle twenty orders of magnitude smaller than a hydrogen atom, that’s heavy; the result is effectively a microscopic hot black hole—which instantly decays, by Hawking radiation, into a shower of fundamental particles.

  Nobody lives on, or even near, OMAF; there’s no need. The experiments are scheduled from Earth, and although elaborate on-site computers handle the realtime logistics of each collision, and perform the initial high-speed data acquisition, all the detailed analysis that follows is carried out on the ground. Humans are only present when something needs fixing, beyond the limited capacity of the maintenance robots.

  The closer we get to OMAF, the sadder I feel at the prospect of what we’re likely to find: three corpses. An accident that leaves your suit unable to radio for help is unlikely to have spared the contents. In the shadow of these presumed deaths, my nervousness about merely coming along for the ride seems shameful, trivial—and at the same time, more reasonable than ever. An OES emergency mission is utterly routine—but no doubt the repair mission was “utterly routine” too.

  The autopilot brings us down to orbital velocity, then nudges us towards the detector sphere’s second dock. The repair crew’s bus is still in place, and looks perfectly intact; its computers report that it’s fully functional, but unoccupied.

  The docking takes place with a barely perceptible tap of metal on metal, then the slightly louder thud of locking pins sliding into place. Zoe and Rykov have studied the repair crew’s last report—with annotations by colleagues from Sakharov, and OMAF control in Geneva—and agreed on the best route to take through the access tunnels to the point where the engineers were probably headed next. It’s Abbas’s turn to stay behind in the bus, which he seems to accept with good humour.

  The detector sphere is unpressurized; as the bus’s airlock empties in a frosty gust; my suit whispers direly, “We’re in vacuum.” I resist the temptation to mutter, “No shit?” Talking back only encourages them. I still don’t believe the cognitive scientists who claim that “common sense” knowledge of the world is impossible without at least a primitive kind of sentience. What they really meant was, they found it too hard to create it from scratch—and the systems they’ve copied from human brains can’t be disentangled from all kinds of other anthropomorphic paraphernalia.

  The tunnel is unlit, but the side beams from our suits scatter off the matte white surface, so there’s no trouble making out our immediate surroundings. Handholds are few and far between compared to the Tereshkova, so I watch the way Zoe and Rykov move, and try to mimic them. I’m surprised at how well I do—and the worst that can happen, after all, is a premature collision with the tunnel wall. I always have the option of using my suit’s trimming jets, but the supply of propellant is meant to be kept in reserve for emergencies.

  Several minutes pass before I realize that I’ve lost any notion of vertical. I wait for panic and vertigo to set in—or the sudden reassertion of my usual comforting illusions—but neither eventuates. The tunnel is just … the tunnel. I haven’t lost my bearings at all; I’ve simply lost the need to pretend that one direction—my imaginary “up”—is special.

  Zoe scans the walls ahead with an infrared viewer, but—unlike me—the members of the repair crew aren’t likely to have left many handprints, and in any case, the warmth of the electronics behind the panels probably would have drowned out the evidence by now. I gather that most of the equipment here is left powered on constantly, rather than shut down between collisions; start-up surges cause more damage to most components than continuous use, and switching some detectors on and off can mean waiting days or weeks for them to regain thermal stability.

  I catch up with Zoe—unnecessarily, but I hate talking without eye contact—and say, “What do you think happened? They can’t all have holed their suits, simultaneously; There’s nothing here to oxidize a fire.”

  “My guess is electrocution.”

  “But …” I raise a gloved hand.

  She shakes her head. “Suits are only moderate insulators. A few hundred kilovolts per metre would go right through them.”

  “Well, that’s nice to know. Now tell me how to mov
e without touching the walls.”

  “I’m carrying a field meter. We’re not going to be surprised.”

  “They were.”

  “They were probably elbow deep in cables. Or one or two of them were—and the third couldn’t fight the instinctive reaction to try to drag them free.”

  “I can’t believe that. Surely they would have shut off power to whatever they were working on.”

  She laughs drily. “Well, yes. And in a perfect world full of perfect people and perfect equipment, nobody—on Earth or in orbit—would ever die that way. But if the equipment was infallible, they wouldn’t even have been here, would they? We’ll have the stupid details soon enough: an isolation switch failed, or someone screwed up, ignored procedure. Whatever—”

  Rykov breaks in. “What’s that?” She shines a hand beam straight ahead. In the distance, there’s a smudge of dark colour, deep blues and reds, spread across the entire width of the tunnel.

  Zoe says, “It looks like some kind of … liquid?”

  I don’t know what, if anything, stays liquid in a vacuum, but it certainly appears that way. The colours are in motion, mixing and swirling—a bit like a fast-motion view of a gas giant’s atmosphere—but are clearly confined to a flat surface. The heaviest gas, the most sluggish mist, would have diffused forward raggedly as we watched.

  Zoe says, “I’ve never seen anything like it. Some of these detectors are full of chemicals; something must have been spilt. I think we’ll have to backtrack and I go around it, but it’s worth a closer look, first. Take it slowly.”

  The nearer we get, the stranger the spectacle becomes. Not only is the tunnel blocked by a boundary as sharply defined as the surface of the water in a well, but parts of the “liquid” are transparent, and when we peer into the depths, the convoluted, ever-changing surface patterns can be seen extending back into the distance, like bizarre extruded forms. Every motion, however rapid, however subtle—down to every tiny wisp of colour that drifts across the surface—is mimicked immediately at every depth.