Seveneves: A Novel (74 page)

TerReForm had continued anyway, through ad hoc cooperation between scientists and labs straddling the Red/Blue borders. Twenty-three years later, however—practically as soon as New Earth’s atmosphere had become breathable without artificial aids—had begun the War on the Rocks, a struggle carried out partly in space but mostly on the still-nude surface of New Earth. This had been terminated in
4895 by what was now called First Treaty, which stipulated among other things how subsequent TerReForm activity was going to proceed. It had thus paved the way for the Great Seeding, which was responsible for the trees that Kath Two had been flying over this morning. In subsequent decades, larger and larger animals had been set loose on the surface as part of a planned program to jump-start whole ecosystems.

Some of those—the ones Kath Two had been worried about this morning—were canids. When Rhys said that they were “going epi,” he meant that they were passing through some kind of epigenetic shift.

If the Agent had blown up the moon a couple of decades earlier, Eve Moira wouldn’t have known about epigenetics. It was still a new science at the time she was sent up to the Cloud Ark. During her first years in space, when she and her equipment had been coddled in the most protected zones of Izzy and
Endurance,
she’d had plenty of time to bone up on the topic. Like most children of her era, she’d been taught to believe that the genome—the sequence of base pairs expressed in the chromosomes in every nucleus of the body—said everything there was to say about the genetic destiny of an organism. A small minority of those DNA sequences had clearly defined functions. The remainder seemed to do nothing, and so were dismissed as “junk DNA.” But that picture had changed during the first part of the twenty-first century, as more sophisticated analysis had revealed that much of that so-called junk actually performed important roles in the functioning of cells by regulating the expression of genes. Even simple organisms, it turned out, possessed many genes that were suppressed, or silenced altogether, by such mechanisms. The central promise of genomics—that by knowing an organism’s genome, scientists could know the organism—had fallen far short as it had become obvious that the phenotype (the actual creature that met the biologist’s eye, with all of its observable traits and behaviors) was a function not only of its genotype (its DNA sequences) but also
of countless nanodecisions being made from moment to moment within the organism’s cells by the regulatory mechanisms that determined which genes to express and which to silence. Those regulatory mechanisms were of several types, and many were unfathomably complex.

Had it not been for the sudden intervention of the Agent, the biologists of Old Earth would have devoted at least the remaining decades of the century to cataloging these mechanisms and understanding their effects—a then-new science called epigenetics. Instead of which, on Cleft, in the hands of Eve Moira and the generations of biologists she reared, it became a tool. They had needed all the tools they could get, and they had wielded them pragmatically, bordering on ruthlessly, to ensure the survival of the human races. When creating the children of the other six Eves, Moira had avoided using epigenetic techniques. She had felt at liberty, however, to perform some experiments on her own genome. It had gone poorly at first, and her first eight pregnancies had been failures. But her last, the only daughter of Moira to survive, had flourished. Cantabrigia, as Moira had named her after the university of Cambridge, had founded the race of which Kath Two was a member.

By the time the Great Seeding was in the works, thousands of years later, epigenetics was sufficiently well understood to be programmed into the DNA of some of the newly created species that would be let loose on the surface of New Earth. And one of the planks in the Get It Done platform was to use epigenetics for all it was worth. So rather than trying to sequence and breed a new subspecies of coyote that was optimized for, and that would breed true in, a particular environment, as the TOT school would have had it, the GID approach was to produce a race of canines that would, over the course of only a few generations, become coyotes or wolves or dogs—or something that didn’t fit into any of those categories—depending on what happened to work best. They would all start with
a similar genetic code, but different parts of it would end up being expressed or suppressed depending on circumstances.

And no particular effort would be made by humans to choose and plan those outcomes. They would seed New Earth and see what happened. If an ecosystem failed to “take” in a particular area, they would just try something else.

In the decades since such species had been seeded onto New Earth, this had been going on all the time. Epigenetic transformation had been rampant—and, since Survey was thin on the ground, largely unobserved by humans. Still, when it led to results that humans saw, and happened to find surprising, it was known as “going epi.” Use of the phrase was discouraged for being unscientific, but Rhys Alaskov knew how to get away with it.

Rhys brought up a rendering of the habitat ring and zoomed in on the whitish segment at its top. Their projected route was superimposed as a crisp green arc that curled through apogee near a succession of relatively small habitats just to the east of Greenwich. For the first habitats constructed in each segment—close to the seeds of Greenwich, Rio, et al.—had naturally tended to be smaller than the ones that came along later, when the construction process had hit its stride. The closer to a boneyard you got, the larger the habitats generally became. As Rhys panned and zoomed around, habitat names came and went on the screen: Hannibal, Brussels, Oyo, Auvergne, Vercingetorix, Steve Lake. The latter aroused a flicker of interest. Kath One had had an old friend living there. But the friendship wouldn’t likely have survived the transition to Kath Two.

She brought the same thing up on her varp and zoomed out to remind herself of the current location of the Eye.

If the habitat ring as a whole was like the dial of a clock, then the Eye, with its inner and outer tethers—one depending toward Earth, the other reaching out beyond the habitat ring—was a hand.

Any description of the Eye had to begin by mentioning that it
was the largest object ever made. Most of its material had come from Cleft. It was, in a sense, the thing Cleft had ultimately shape-shifted into. Its innermost piece was a spinning, ring-shaped city of sufficient diameter—some fifty kilometers—that even the largest space habitats could pass through its center with plenty of room to spare. This made the Eye capable of sweeping all the way around the ring, encompassing in turn each of the ten thousand separate habitats.

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.