Seveneves

by Neal Stephenson

  Or at least that had been the original plan. In practice, its sweep was limited to the Blue part of the ring that began at Dhaka and ran westward about two-thirds of the way around the ring to the fringe of the Julian segment. At both of those locations, barriers—literal turnpikes, consisting of long splinters of nickel-iron laid directly across the ring—had been constructed by Red to physically block movement of the Eye into “their” segment. So instead of sweeping around like the hand of a clock, it bounced back and forth between the turnpikes, confining itself to Blue habitats. During the ensuing century and a half, Red had been at work on something huge that appeared to be an anti-Eye in the making, and that would presumably sweep back and forth, in like manner, over their segment. But it had never budged from its geostationary orbit above the Makassar Strait, and no one in Blue really knew how soon it might become operational.

  The Great Chain, as the rotating city was called, lined a circular opening, like an iris, in the middle of the Eye. To either side of it, the Eye tapered to a point. One of those points was always aimed toward the center of Earth and the other was always aimed away from it. A cable, or rather a redundant, self-healing network of them, emerged from each of those two points. The inner one hung almost all the way down to the Earth’s surface, where a thing called Cradle dangled from it. The outer cable stretched for some distance beyond the habitat ring and terminated in the Big Rock, which served as a counterweight. By adjusting the length of the latter cable it was possible to move the whole construct’s center of gravity closer to or farther away from Earth, causing it to speed up or slow down in its orbit relative to the habitats in the ring. Thus it could sweep around like the hand of a clock, passing around each habitat along the way, or pausing for a time as needed. And when it was encircling a particular habitat it could easily exchange people and goods with it, via flivvers, or cargo shuttles, or swarms of nats, or mechanical contraptions that could snake out like tentacles.

  To be in a habitat—even a quite large and cosmopolitan one—when the Eye came around was, in pre-Zero terms, a little bit like being in a small town on the prairie and having a mobile Manhattan suddenly roll over the horizon, surround you, have a hundred kinds of intercourse with you, and then move on. Among its many other functions, it was a passenger ferry: the most straightforward way of moving among habitats. This was why Kath Two needed to remind herself of where it was at the moment and which direction it was moving.

  The answer was that it was about twenty degrees west of their projected apogee, encircling a large new habitat called Akureyri, and heading generally in the direction of the Cape Verde boneyard that separated the Greenwich segment from the Rio segment. Which meant that it would soon be in the predominantly Ivyn part of the ring.

  “Whip over high and catch the Eye?” she asked.

  This amounted to a proposal that they should avail themselves of a kind of huge aluminum bullwhip—a very common device on the ring—to project their flivver into a higher orbit. As they curved slowly through apogee out beyond the ring, everything below them—the entire contents of the habitat ring, including the Eye—would speed past them on the inside track, so that by the time they looped back to it, the Eye would have caught up with them. They could dock their flivver to any of its hundreds of available ports, pass through Quarantine in relative comfort, and go their separate ways, using the Eye as a ferry to take them wherever they wanted to go, or as a transit hub where they could change to passenger flivvers or liners that might transport them more directly to other places in the system. Or they could ride the elevator down to Cradle. Or they could just remain on the Eye, a habitat in its own right where many people lived their entire lives. When possible, “catching the Eye” was almost always preferable to ending up on some random habitat whence it might take days or even weeks to get transit onward, and so proposals like this one were rarely controversial.

  “Works for me,” Rhys said immediately.

  Kath Two glanced toward Beled and saw him looking back at her. She understood that the Teklan had, in a manner unchanged through thousands of years of racial subspeciation and acculturation to the social and cultural environment of space, been checking her out.

  She raised an eyebrow at him, just slightly.

  “Of course,” said Beled.

  “Unanimous. I’ll punch it in,” Rhys announced, and went to work at the interface panel.

  Kath Two had felt a mildly embarrassing faint tingle between her legs, a sort of blush, accompanied by a bit of warmth in the face. She expected that Beled was reciprocating at some level. But Teklans were trained not to show their feelings, out of a belief, supposedly traceable all the way back to the ancient Spartans, that emotions such as fear resulted from their visible expression, rather than the other way around.

  Perhaps sensing what was going on between Kath Two and Beled, Rhys focused on his task somewhat more intently than was really needed. The complications, as always, had to do with avoiding collisions and respecting what was still called “air space” around habitats, even though it had no air in it and might more properly have been called “space space.” Kath Two, keeping half an eye on the brief and businesslike conversation between Rhys and Parambulator (which, to her eyes, had nothing whatsoever in common with whatever was meant by “punching it in”—but this was just how Dinans liked to express themselves), saw that they would pass through the twenty-kilometer-wide gap between habitats named Saint-Exupéry and Knutholmen. Midway between them was a whip station. Almost every habitat of significance was bracketed between two of these installations. The whip stations were small habitats, crewed by half a dozen or so humans who got rotated out every few months so they would not go crazy from boredom. Their job was to look after thousands of flynks: the latest generation of a lineage of robots that went all the way back to Rhys Aitken’s work aboard Izzy. He had been working with fingernail-sized nats. The ones on whip stations performed the same functions, but they were much bigger. The chains that they formed had the mass and momentum of pre-Zero freight trains, capable of undulating and cracking like a whip, or reaching out at distant targets like the fly on the end of a fishing line. Some wear and tear was involved. Flynks could have been inspected and repaired by other robots, but Blue’s overall cultural bias in favor of having humans in the loop had led to much of the work being done by flesh-and-blood crew members. In any case, supposing those people had been doing their job, keeping their fleet of flynks ready for use, and assuming that no other space travelers had already reserved that time slot on that whip station, the flivver carrying Kath Two, Rhys, and Beled would, in something like twelve hours’ time, rendezvous with the tip of an aluminum bullwhip that would then snap it into a circular orbit with a slightly higher radius than that of the ring. A few hours later, they would dock at Port 65 in the Quarantine Section of the outer limb of the Eye.

  The Eye observed whatever time was local on the part of Earth lying directly below it. Currently, it was about eight in the morning there. She could look forward to some serious jet lag—another term from the pre-Zero era that had become embedded in the language despite the obsolescence of its literal meaning. According to one convention, they should switch over to Eye time now, so that they could begin adjusting. But they had all finished long days on New Earth and were too exhausted at this moment to maintain the pretense that it was first thing in the morning for them. They would have plenty of time to adjust in Quarantine. Kath Two reserved a Moiran-friendly bed and meal plan at Port 65, then plummeted into sleep.

  THE IRIS OF THE EYE WAS TOO BIG TO HAVE BEEN FABRICATED AS A single rigid object. It had been built, beginning about nine hundred years ago, out of links that had been joined together into a chain; the two ends of the chain then connected to form a loop. The method would have seemed familiar to Rhys Aitken, who had used something like it to construct Izzy’s T3 torus. For him, or anyone else versed in the technological history of Old Earth, an equally useful metaphor would have been that it was a train, 157 ki
lometers long, made of 720 giant cars, with the nose of the locomotive joined to the tail of the caboose so that it formed a circular construct 50 kilometers in diameter.

  An even better analogy would have been to a roller coaster, since its purpose was to run loop-the-loops forever.

  The “track” on which the “train” ran was a circular groove in the iron frame of the Eye, lined with the sensors and magnets needed to supply electrodynamic suspension, so that the whole thing could spin without actually touching the Eye’s stationary frame. This was an essential design requirement given that the Great Chain had to move with a velocity of about five hundred meters per second in order to supply Earth-normal gravity to its inhabitants.

  Each of the links had approximately the footprint of a Manhattan city block on Old Earth. And their total number of 720 was loosely comparable to the number of such blocks that had once existed in the gridded part of Manhattan, depending on where you drew the boundaries—it was bigger than Midtown but smaller than Manhattan as a whole. Residents of the Great Chain were acutely aware of the comparison, to the point where they were mocked for having a “Manhattan complex” by residents of other habitats. They were forever freeze-framing Old Earth movies or zooming around in virtual-reality simulations of pre-Zero New York for clues as to how street and apartment living had worked in those days. They had taken as their patron saint Luisa, the eighth survivor on Cleft, a Manhattanite who had been too old to found her own race. Implicit in that was that the Great Chain—the GC, Chaintown, Chainhattan—was a place that people might move to when they wanted to separate themselves from the social environments of their home habitats, or indeed of their own races. Mixed-race people were more common there than anywhere else.

  As in Manhattan, the discretization of the space imposed form on how it had developed, with each link of the chain—each city block—acquiring its own skyline and identity. Groups of consecutive blocks had long since coalesced into neighborhoods. Each block was, in effect, a fully independent space vehicle with its own system for keeping the air from leaking out. But each was connected to its two neighbors by a bundle of passageways routed through its foundation slab, which made it possible to move easily from one to the next in the same way that the Londoners of Old Earth had used underground passages—“subways” in the London sense of that word—to cut beneath crowded intersections. Some of the subways were sized for human pedestrians. Four of them carried trains: locals and express service running both directions around the full circuit of the Great Chain. Still others were reserved for robotic vehicles programmed to carry cargo. Beyond that was a wide range of smaller conduits carrying air, water, power, and information. All of them went by the name of subways—this was a conflation of the old London and New York senses of the word. At each end of each block was a system of airlocks; these would seal themselves off in the event that a block were to depressurize. People ran marathons through them—four consecutive marathons made up about one circuit around the entire Chain.

  Every fifth link in the Chain was public property. These tended to be parks, though some served as cultural facilities. So you were never more than two links away from green, or at least open, space. The other 576 links were privately owned, and constituted a commercial and residential real estate market that would have been easily recognizable to any pre-Zero property magnate. The Great Chain had been likened more than once to the ancient board game of Monopoly. Some stretches of the loop were more high-rent, others less so. The pattern was interrupted in several places by special links, or short series of links, placed there to serve industrial and civic requirements, such as making the transit system work.

  One of those was the Ramp Link, whose purpose was to make connections, every five minutes, with the On Ramp and the Off Ramp. Since the Great Chain was moving at about five hundred meters per second with respect to the nonrotating frame of the Eye, persons wishing to get from the latter to the former needed to be accelerated to a fairly spectacular velocity—almost Mach 1.5—before they could set foot on the Ramp, or any other, Link. And those wishing to dechain, as the expression had it, needed to be decelerated by the same amount. The acceleration and the deceleration were handled by machines built into a place on the rim of the “iris” of the Eye. Though some efforts had been made to camouflage their essential nature, they were really just guns for shooting humans, albeit humans strapped into comfortable, pressurized bullets.

  Outside of the Great Chain, the rest of the Eye was lightly infested with human beings, heavily so with robots. Most of it existed in microgravity, since the entire contraption—Great Chain, tethers, and all—was in geosynchronous orbit, hence free fall, around Earth. As you moved away from its center, toward the two extremities of the Eye where the tethers emerged, you might begin to notice tidal forces, which would show up as very mild gravity-like tugs. These shifted whenever the Eye adjusted its orbit to move around the habitat ring, and people who spent a lot of time there could always feel in their bones when a move was under way, like Old Earthers predicting the weather in their knees.

  The skeleton of the Eye was a simple space frame built in the Amalthean style, which was to say that it had been carved and shaped from existing material (Cleft) as opposed to fabricated from scratch. Aesthetically, it meant that the big structural elements had a rough-hewn, space-battered look about them, a bit like a log cabin with all the knots and bark still visible. Vacancies between the big structural elements had been filled in with giant machines, most notably several immense rotating masses whose purpose was to stabilize the whole Eye gyroscopically. The nooks and crannies between the machines had been caulked with pressurized spaces where humans could move about. Some of those rotated to produce simulated gravity; they were like miniature, torus-shaped space colonies pinned to a much bigger structure. Docking ports tended to cluster near those.

  As Kath Two’s eyes closed into sleep, she was gazing at the usual ring-shaped formation of iridescent sparkles, so densely packed that they blended into each other on the varp. The Eye was a slightly larger white dot between twelve and one o’clock; it would have been difficult to see were it not for the long white line representing its tether system, which ran from just above Earth’s surface all the way through the big white dot and beyond to the Big Rock.

  Their flivver’s trajectory, a sharp green ellipse, projected from where they were now (near Earth) all the way out to slightly beyond the ring before curving back in to intersect the Eye.

  Through her eyelids she could see indistinct patterns, reminding her a little of the first thing she’d seen this morning: the flickering lights on the walls of her tent. But then the varp figured out that her eyes were closed and shut off the display.

  When she opened her eyes, the varp noticed it and came back to life, rendering the display again. Generally it looked the same, but the Eye had moved a little bit, and the dot representing the flivver had covered most of the distance to the habitat ring. Zooming in, she could see the two habitats between which they were going to pass, and the much smaller rendering of the whip station between them, exercising its long hair-thin flagellum in preparation for their arrival. She must have slept for something like ten hours. Moirans were notorious for it. Remembering the looks she had exchanged earlier with Beled, she felt, then stifled, mild embarrassment over the fact that she had spent most of the journey snoring away.

  She unstrapped and floated over to the zero-gee toilet at the end of the flivver’s cabin. When she emerged a few minutes later, she saw that Rhys was asleep, loosely strapped in before the control panel. Beled was still in his acceleration couch. He too had slipped on a varp, and she guessed from the way he was moving his hands and wiggling his fingers that he was working, as opposed to playing. He was probably filling out his Survey report. Which was what Kath Two ought to be doing.

  They represented a civilization that had, during the Fourth Millennium, executed a plan to undo the damage caused by the Agent by identifying, cataloging, reaching, corralling,
and revectoring millions of rocks in orbit around Earth, while also reaching as far as the Kuiper Belt to acquire chunks of frozen water and methane and ammonia and bring them home and smash them into the ruined planet. Essentially all of this work had been accomplished by robots. So much metal had gone into their construction that millions of humans now lived in space habitats whose steel hulls consisted entirely of melted down and reforged robot carcasses. It would have been easy for them to blanket the surface of New Earth with robots and, without ever sending down a single human being, perform a kind of survey: one that was heavy on data and light on judgment. In that version of the world, Kath Two and the others would have spent their lives in habitats, working at varps and mining data. All sorts of interesting philosophical arguments could have been framed as to whether that approach was better or worse than what they were in fact doing. But philosophy didn’t really enter into it. The decision to do it this way was driven partly by politics and partly by social mores.

  On the political front it boiled down to the terms of Second Treaty, which, eighteen years ago, had terminated the second Red-Blue war, sometimes called the War in the Woods to distinguish it from the earlier War on the Rocks. The treaty imposed strict limitations on the number of robots that either side could send down to the surface. For that matter, it also limited the number of humans; but the upshot was that, given those limits, human surveyors could gather more useful information about conditions on New Earth than could robots beaming data up to the ring.

  On the social front it was a question of Amistics, which was a term that had been coined ages ago by a Moiran anthropologist to talk about the choices that different cultures made as to which technologies they would, and would not, make part of their lives. The word went all the way back to the Amish people of pre-Zero America, who had chosen to use certain modern technologies, such as roller skates, but not others, such as internal combustion engines. All cultures did this, frequently without being consciously aware that they had made collective choices.