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.