Diaspora

5 April 2996,21:17:48.955 UT

Yatima floated in the sky above vis homescape, surveying the colossal network that sprawled across the hidden ground as far as ve could see. The structure was ten thousand delta wide and seven thousand high; winding around it was a single, elaborate curve, which looked a bit like one of the roller coaster rides ve'd seen in Carter-Zimmerman—and which ve'd ridden with Blanca and Gabriel, for the visual thrill alone. The "track" here was unsupported, just like the one in C-Z, but it weaved its way through what looked like a riot of scaffolding.

Yatima descended for a closer inspection. The network, the "scaffolding," was a piece of vis mind, based on a series of snapshots ve'd taken a few megatau before. The space around it glowed softly in a multitude of colors, imbued with an abstract mathematical field, a rule for taking a vector at any point and calculating a number from it, generated by the billions of pulses traveling along the network's pathways. The curve that wrapped the network encircled every pathway, and by summing the numbers that the field produced from the tangents to the curve along its entire length, Yatima was hoping to measure some subtle but robust properties of the way information flowed through the structure.

It was one more tiny step toward finding an invariant of consciousness: an objective measure of exactly what it was that stayed the same between successive mental states, allowing an ever-changing mind to feel like a single, cohesive entity. The general idea was old, and obvious: short-term memories had to make sense, accumulating smoothly from perceptions and thoughts, then either fading into oblivion or drifting into long-term storage. Formalizing this criterion was difficult, though. A random sequence of mental states wouldn't feel like anything at all, but neither would many kinds of highly ordered, strongly correlated patterns. Information had to flow in just the right way, each perceptual input and internal feedback gently imprinting itself on the network's previous state.

When Inoshiro called, Yatima didn't hesitate to let ver into the scape; it had been far too long since they'd last met. But ve was bemused by the icon that appeared in the air beside ver: Inoshiro's pewter surface was furrowed and pitted, discolored with corrosion and almost flaking away in places; if not for the signature, Yatima would barely have recognized ver. Ve found the affectation comical, but kept silent; Inoshiro usually viewed the fads to which ve subscribed with appropriate irony, but occasionally ve turned out to be painfully earnest. Yatima had been persona non grata for almost a gigatau after mocking the practice, briefly fashionable across the Coalition, of carrying around a framed portrait of one's icon "aging" in fast-motion.

Inoshiro said, "What do you know about neutron stars?"

"Not a lot. Why?"

"Gamma-ray bursters?"

"Even less." Inoshiro looked serious underneath all the rust, so Yatima struggled to remember the details from vis brief flirtation with astrophysics. "I know that gamma rays have been detected from millions of ordinary galaxies—one-off flashes, rarely from the same place twice. The statistics come down to something like one per galaxy per hundred thousand years… so if they weren't bright enough to be seen a few billion light years away, we probably wouldn't even know about them yet. I don't think the mechanism's been conclusively established, but I could check in the library—"

"There's no point; it's all out-of-date. Something's happening, outside."

Yatima listened to the news from the gleisners, not quite believing it, staring past Inoshiro into the scape's empty sky. Oceans of quarks, invisible meson jets, plummeting neutron stars… it all sounded terribly quaint and arcane, like some elegant but over-specific theorem at the end of a cul-de-sac.

Inoshiro said bitterly, "The gleisners took forever to convince themselves that the effect was real. We've got less than twenty-four hours before the burst hits. A group in Carter-Zimmerman is trying to break into the fleshers' communications network, but the cable is sheathed with nanoware, it's defending itself too well. They're also working on reshaping the satellite foot prints, and sending drones straight into the enclaves, but so far—"

Yatima cut in. "I don't understand. How can the fleshers be in any kind of danger? They might not he as heavily shielded as we are, but they still have the whole atmosphere above them! What portion of the gamma rays will make it to ground level?"

"Almost none. But almost all of them will make it to the lower stratosphere." An atmospheric specialist in C-Z had modeled the effects in detail; Inoshiro offered an address tag, and Yatima skimmed the file.