“What do you mean?” Roi froze and stared at her, bewildered. How could another team have recruited one of their best workers, right in front of their eyes? “What have you become, a courier?”
“I’m not leaving the team,” Neth said. “Not as I understand it. I’m going to the sardside, to help with the tunnel.”
Roi chirped polite approval, but in truth she found this even more shocking. While surrounded by her colleagues and immersed in their distinctive brand of work, Neth had summoned up the strength for a solo, self-motivated defection; even if she chose to think of the tunnel builders as part of the same team, it was the theorists who had first captured her loyalty, and who reinforced it shift after shift. “You’re our best calculator,” Roi lamented. “The best at manipulating templates. The best at understanding what they mean.”
“That won’t be wasted with the tunnel builders,” Neth replied. “They’ll need mathematicians there, too.”
“Aren’t you still curious, though,” Roi pressed her, “to see where the theory takes us? To see our ideas refined? To see this geometry understood, to know if it’s unique, to map out all its implications?”
Neth hesitated. “Of course I’m still curious. And I hope that the next time we meet, you’ll have news about all of those things. But the tunnel is more important to me now. Twice, we’ve seen the possibility of danger. Twice, the mathematics has failed to rule it out. We haven’t proved anything, but what we’ve glimpsed in the distance is enough of a warning for me. I’m not prepared to wait for a disaster to show that we were right.”
13
Toward the center of the Nuclear Stellar Disk the density of stars began a precipitous climb. Within a cluster two hundred light years wide a billion stars sped along a complex tangle of orbits, and the deeper into this swarm you dived the more crowded and violent it became. To Rakesh, it brought to mind the image of a nest of furious ants caught in a steep subsidence, kept from falling into the depths only by the sheer energy of their motion.
At the bottom of the pit lay Goudal-e-Markaz: a black hole with the mass of three million suns, the one place from which you could fall no further. It wasn’t easy to reach this nadir: the hole’s zone of capture was barely fifty million kilometers wide, and it was rare for a star to lose so much of its angular momentum that it could execute a head-on dive into oblivion.
However, a bull’s-eye hit was not the only route to destruction. Once every hundred millennia or so a star would come close enough to Goudal-e-Markaz for tidal forces to disrupt it catastrophically. As it dived toward the hole, the star would be stretched along its orbit at the same time as it was squeezed in the orthogonal directions, a distended streak of nuclear fire growing ever hotter and more compressed. In some encounters the star would merely be torn apart and the debris sprayed across a range of orbits, but if the tidal compression was strong enough to trigger a burst of new fusion reactions, as the star swung away from the hole and the pressure was released it could explode with the force of a hundred supernovas. The remnants of these explosions could still be seen thousands of years later, tenuous but energetic shells of gas spreading out into the galactic nucleus.
Ordinary supernovas were even more common, of course, and the central cluster was littered with their remnants: white dwarfs, stellar mass black holes, and neutron stars. The Aloof’s map showed no less than fifteen million neutron stars. That was a daunting census, and the chaotic dynamics of the region made it impossible to rule out more than a few per cent as potential culprits in the death of the Arkmakers’ world.
Standing in the control room of Lahl’s Promise, looking out into the blaze of stars that hid their quarry, Rakesh asked Parantham, “Would you be willing to visit fifteen million neutron stars, one by one, until we found a living Ark?”
She replied without hesitation, “Absolutely.”
For a moment Rakesh considered calling her bluff, but he was sure his own will would crack long before hers. When the creators of de novos chose their traits, they were prone to excesses that rarely appeared in even the most technologically augmented versions of inheritance. No gene for keenness could ever compete with Parantham’s fiat-driven personality.
He said, “I think it’s time we built a decent telescope.”
She nodded assent, without betraying the slightest hint of relief that he hadn’t been serious about inspecting each candidate in person. “Where?”
“Here would be as good a place as any,” Rakesh suggested. “At least there’s plenty of raw material.” They could try to select an observation point even closer to the galactic center, but their chances of finding a closer star that still clung on to a substantial asteroid belt weren’t good.
“That’s fitting,” Parantham said. “To use a little of the Arkmakers’ world, in order to find their new home. I don’t think they’d begrudge us that.”
Rakesh felt his now habitual twinge of discomfort, at the thought that they might be risking an act of desecration. But there seemed to be nobody around to be offended, apart from the Aloof, who he was sure were looking over their shoulders constantly, ready to veto any unacceptable behavior.
From this distance, a six-hundred-meter Ark somewhere in the central cluster would in principle be resolvable with an optical telescope four million kilometers wide, but to obtain a clear spectrum that would unambiguously identify the wall material it would be prudent to aim a bit higher.
“Ten million kilometers?” he suggested.
“That sounds about right.”
Rakesh plucked some standard designs from the library and tweaked them for their specific goals and the local conditions. They could mine the rubble of the Arkmakers’ world for the raw materials, then stream the refined feedstock into an orbit clear of dust and micrometeors, where the mirror segments would be constructed. With sunlight and the stellar winds as their main energy sources the project would proceed at a leisurely pace, taking more than a year to complete. Still, that was nothing to the time they’d already spent in transit within the bulge, let alone the time it would have taken to hop from neutron star to neutron star.
Rakesh initiated the process, sending twelve delivery modules into the asteroid belt to sow the rocks with engineering spores.
“No veto from the Aloof,” he noted. “They won’t allow spores in from the outside, but they don’t mind us spreading these ones around.”
“Which either means that they trust us,” Parantham replied—making it clear from her tone what she thought of that proposition—“or they’re watching us so closely that they know exactly what these spores will and won’t do.”
Rakesh mused, “What if we tried to build a node here? Conforming to the Amalgam’s standards? We’d have our very own short cut through the bulge.”
Parantham responded cautiously, “I’d say we’re too far from the edge to establish a reliable link with the Amalgam’s network.”
“Perhaps,” Rakesh conceded. “That’s not the point, though. What if we tried it?”
Parantham said, “I think the moment we so much as formed a serious intention to contravene the rules they’ve spent the last million years enforcing, our hosts would turn our bodies into dust and feed it to Goudal-e-Markaz. We’re here on their sufferance. We shouldn’t even think about pushing our luck.” She smiled. “Do you dream, Rakesh?”
“Yes.”
“Then draw up a list of topics for your dream censor. We wouldn’t want the Aloof getting the wrong idea.”
Rakesh followed one of the mirror spiders, hovering beside it as it drank from the feedstock streaming down from the asteroid belt. Though the milky flow resembled a liquid, it was actually composed of tiny granules, each one consisting of a core of volatiles wrapped in a distinctive mineral shell that both protected it and labeled its contents. The spider’s acute vision and nimble mouthparts allowed it to extract exactly what it needed, leaving the rest for other users further downstream.