Incandescence

Roi was pleased. «It will be good to have you there. You've been away for too long.» She hadn't been close to anyone near the end of their life before, and she was never sure what to expect. Zak's strength came and went, and every time it declined she was afraid he was dying, but a few shifts' rest, some good news about the team, and a problem worth thinking about were often enough to revive him. He'd never travel all the way to the garm-sharq edge again, but he might survive at the Null Line for dozens more shifts.

She bid him farewell, and launched herself across the chamber to the point on the web where her own equipment was set up. Every shift, she counted a few cycles of the three periodic motions to see if anything had changed in their relationship. Once Ruz's clock was declared trustworthy as a standard in its own right she'd start using it to measure the absolute durations of the cycles, but until then she was content to record the ratios between them.

She set everything in motion and then watched patiently, counting the passage of the cycles using a trick she'd picked up from Gul, a recruit who'd worked in a storage depot: sliding a series of stones threaded on wires, rather than trusting everything to memory or wasting precious skin by making a scratch for each event. Though all three motions slowly diminished over time — however thin the air the stones were moving through, however well-greased the pivots on the Rotator's spinning bar — the periods she was measuring were unaffected, and as long as each cycle could be clearly tracked this gradual decay caused no problem.

As Roi watched the stones, in her mind's eye she pictured the way their paths might have looked to some impossible cosmic observer, floating in the Incandescence high above the Splinter's orbit. The problem of how these paths wrapped around the Hub entranced and infuriated her. If the Map of Weights could be believed, then long ago — and, presumably, further from the Hub — anything falling freely would have traveled endlessly along the same closed curve. Whether it was simply going around in a circle, or whether it was also detouring up and down or in and out made no difference, because the periods for all three motions were the same. Now, it was as if something had taken that simple pattern and squeezed and twisted it, forcing the different cycles to break ranks, and yet miraculously preserving Zak's balance of weights.

She finished her count. In eighty-five cycles of the shomal-junub stones, the plane of the rotating bar turned sixty-eight times, and the looping stone completed forty-five loops. These numbers hadn't changed since she'd begun measuring them.

Roi recorded the results with the usual mixed feelings. Any change would be the cause of great excitement, the start of a new opportunity to prise apart the mysteries of weight and motion. The numbers had spoken eloquently when she and Zak had first identified the three cycles, but their silence since then had been disappointing.

At the same time, she knew that any change would mean far more than an intellectual impetus for the team. If the weights increased, the strength of the rock beneath her would be tested, and everyone in the Splinter would be at risk. However great her hunger for revelation, she could not deny a powerful sense of relief that the numbers continued to seem immutable, and that she might yet live out a quiet life merely contemplating their mysteries without ever feeling their sting.

The overview meeting was held in a chamber a few dozen spans from the Null Line. This place was large enough for the whole team to fit, clinging to the walls, but not so large that people could split up into individual project groups with the members audible only to each other.

Tan spoke about his group's continued efforts to explain natural motion geometrically. «First, we need to extend the idea of direction to include speed. We can understand the direction 'three spans garm for every one span rarb', so why not also include the idea of speed, and talk about 'three spans garm for every heartbeat that passes'? But then, if we talk about the garm direction, the rarb, and the shomal, there is a fourth simple direction we must add to the list: time. In fact, every path that's traveled includes some component in that direction; we can't travel garmwards a single span without some time also passing.