Incandescence

This wasn't the disk, though. Grand histories, here, were prone to truncation. A neighboring star had come too close, and either captured the planet or ejected it into interstellar space.

Rakesh said, «The meteor is about fifty million years old. The interloper passed through this system perhaps a hundred million years before then. That's why the meteor's path didn't match its chemistry; the whole planet had been traveling away from its home star for a hundred million years before the meteor was blasted off it.»

«Yet the meteor still bore life,» Parantham said. «That DNA was the same age as the meteor itself, not a remnant from an earlier epoch. Whatever the parent world endured for those hundred million years, it wasn't enough to sterilize it.»

Rakesh looked out across the stained patina of metal. «Microbes survived. But what about the probe builders?» It seemed too cruel a coincidence to believe that the interloper had come along just as they were developing the technology that might have allowed them to survive the encounter. Perhaps that had even been a trigger; perhaps they had been locked in some kind of cultural stasis until their astronomers realized that their world was in peril.

«We'll scour the system,» Parantham declared. «There might be some more clues here, they might have left something on one of the gas giants' moons.»

Rakesh agreed. «And then we go after them.» They would follow the meteor back to its source, and retrace the path of these unlucky exiles, deep into the crowded heart of the bulge.

10

As Roi launched herself across the Null Chamber, it struck her that she had never seen the place so alive with activity. She counted seven distinct groups, each numbering six people or more, gathered together on the walls and along the web, making measurements, adjusting machinery, talking excitedly, testing ideas.

She and Zak had scoured the Splinter from garm to sard in their hunt for recruits, braving libraries and workshops, abattoirs and storage depots, risking ambush every step of the way. Now the hard times were over; they had built their team, and its numbers bolstered their loyalty in a way that mere reason never could.

Near the Null Line, Ruz and his apprentices were working on their new clock, tinkering with the mechanism as they calibrated it against a cycling pair of shomal-junub stones. Zak had set them a wildly ambitious target: to create something small enough for a traveler to carry anywhere in the Splinter, oblivious to the varying weights and accurate enough to be trusted for thirty-six shifts without recalibration. After trying out many unwieldy designs, they had devised a system in which two spiral coils of metal ribbon were joined at their centers to small shafts. The first and larger of the coils was tightened by turning its shaft with a lever, and then the force as it unwound was eked out slowly and employed to feed a gentle, to-and-fro rocking of the other coil's shaft. Rendering this complex mechanism perfectly regular was a serious challenge, but the team never seemed to be short of new ideas to try, and each refinement so far had improved on the last.

Ruz had been a metalworker for most of his life. It had taken Roi more than a dozen shifts to recruit him, but he had later admitted that the instant he'd seen Roi's «Rotator» — her contraption for demonstrating the Splinter's spin — he had been hooked in equal measure by a fascination with the idea that the world could be secretly turning, and a conviction that he could do a far better job at making the kind of gadgets needed to quantify that motion. Happily, his conviction had turned out to be entirely justified.

Roi drifted past the clockmakers and landed against the wall, close to the point where Tan was talking with a small group of students. «What is natural motion?» he asked. «Looked at closely, and in the absence of spin, it seems as if a weightless stone is trying to follow a straight path. Yet over large enough distances, that path can curve around into a circle, or other kinds of curves. What's happening?» He lifted up a complicated patchwork he'd made by gluing together dozens of fragments of skin. «See this line, marked across this surface?» He indicated a path he'd dyed in ink. «On every small piece of the surface, it's a straight line. But the line as a whole isn't straight; it can't be, because the surface itself isn't flat. So how can we determine exactly which paths can be made by small, straight lines joined together in this way? That will depend on the way the parts of the surface are connected to each other. We need a precise, mathematical expression of the nature of that connection, in order to understand which paths are as straight as they can be, given the geometry of the surface.»