Diaspora

With Poincare, delusions of normality were untenable from the start; even its outline confounded his old world notions of curvature and proportion. Orlando could see at a glance that the star's four-dimensional disk filled only about one third of the tesseract he imagined framing it—far less than a circle inscribed within a square—and this made some ill-adapted part of him expect it to sag inward as it arced between the eight points of contact with the tesseract. It didn't, of course. And since the polis had come close enough for the star's continents to he resolved, he'd been bedazzled. The borders of these giant floating slabs of crystallized minerals were intricate beyond the possibilities of three-dimensional nature; no wind-carved landscape, no coral reef could have been as richly convoluted as this silhouette of dark rock against glowing magma.

"Orlando?"

He moved slowly, consciously, thinking it through, following his body's suggestions but refusing to act on autopilot. Paolo was to his rear-left-dexter-gauche, and he turned first in the horizontal plane, then the hyperal. Orlando was blind to signatures, but his visual cortex had been rewired to grant five-dimensional facial cues the same significance as the old kind, and he recognized the approaching four-legged creature immediately as his son.

Bipeds in the macrosphere would have been even less stable than pogo sticks on Earth; with sufficient resources devoted to dynamic balancing, anything was possible, but no one in C-Z had opted for such an unlikely 5-body. Quadrupeds on a four-dimensional hypersurface had just one degree of instability; if the left and right pairs of feet defined orthogonal lines in the hyperal Plane, it created a kind of cross-bracing, leaving only the problem of swaying forward or backward—no more than bipeds faced on two-dimensional ground. Six-legged macrosphereans would be as stable as Earth's quadrupeds, but there was some doubt as to whether they could mutate into an upright species with two arms; eight limbs seemed to allow an easier transition. Orlando was more interested in the choices available to the Transmuters than the dynamics of natural selection, but like Paolo he'd opted for four arms and four legs. No centaur-like extensions to their trunks had been required; the hyperal space around their hips and shoulders provided more than enough room for the extra joints.

Paolo said, "Elena's been looking at absorption spectra around the coastal regions. There's definitely some kind of local, catalyzed chemistry going on there."

"'Catalyzed chemistry'? Why isn't anyone willing to say the word 'life'?"

"We're on uncertain ground. In the home universe, we could say confidently which gases could only be present if they were biogenic. Here, we know which elements are reactive, but we're just guessing when it comes to whether or not they could he replenished by some inorganic process. There is no simple chemical signature that screams 'life.'"

Orlando turned back to the view of Poincare. "Let alone one that screams 'Transmuters, not natives.'"

"Who needs a chemical signature for that? You just ask them. Or do you think they'll have forgotten who they are?"

"Very funny." He felt a chill, though. As acclimatized as he was—able to stand four-legged in the middle of a penteract without collapsing into gibbering insanity—he couldn't imagine forgetting his own past, his own body, his own universe. But the Transmuters had been here a billion times longer.

Paolo said, "My Swift-self says they've started inscribing a copy of the polis on the surface of Kafka." There was resigned disgust in his voice; if the core burst turned out to be a misunderstanding, the digging of these giant trenches would go down in history as the crassest act of defilement since the age of barbarism. "Models of the reconstruction robots still look dodgy, though. It's a pity the Transmuters didn't mention anything about the neutrino spectrum; a total energy dose for all particles at all frequencies is almost useless for predicting damage, and our own estimates are wildly uncertain, since we have no idea how or why the core's supposed to collapse." He laughed dryly. "Maybe they didn't expect anyone to try riding it out. Maybe they knew it would be unsurvivable. That's why they left us the keys to the macrosphere, instead of hints for building neutrino-proof machines: once it was too late to flee the galaxy, they knew this would be the only escape route."

Orlando knew he was being goaded, but he replied calmly, "Even if the core burst's unsurvivable, this doesn't have to be the end of the line. The vacuum here is made of four-dimensional universes. Even if it's impossible to break into them, there must be other singularities, other links already created from within. In all those universes, there must be other species as advanced as the Transmuters."

"There might. They must be rare, though, or the place would be swarming with them."