Incandescence (36 page)

Roi looked to Ruz, to hear his objections.

"The principles appear sound," he said. "But we can't be sure that we can shape the metal to the necessary precision. And how can we test it, when our one passage to the surface is taken up completely with the system we need, and that we know is reliable? How can we disrupt all our observations to gamble on this?"

"I understand."

Roi struggled to weigh up the risks. They desperately needed to understand the nature of the Wanderer. If Nis's idea was right then the geometry that wrapped it would influence the Splinter's path, and while as yet she had no idea how to combine the Hub and the Wanderer's geometry into a single shape, the sooner they learned exactly what the geometry close to the Wanderer was, the better their chances of making sense of that complex interaction before it was too late.

At the same time, the present system was certainly running smoothly for the void-watchers. If they disassembled Cho's first invention to make room for his second, they would have to resort to observers clambering back and forth from the surface every junub dark phase. They would lose observations, or even people, in the rush.

She could always ask Bard to close the tunnel, to buy them more time. The Wanderer had its own schedule, though. If they kept delaying their ascent, the Wanderer would come to the Splinter, she was sure of that. To pass it by in its present large orbit was one thing; to be wedged in by it, this close to the Hub, would almost certainly be fatal.

"How thoroughly have you explored the area around here?" she asked Ruz.

Ruz knew exactly what she was asking. "There are no other cracks," he said.

"When we first came here," Roi recalled, "the one we were looking for, the one from Zak's map, was closed. It was sheer luck that we found an open one. But how much work would it take to reopen the old one?"

Ruz's posture shifted slightly, growing defensive, as if she had accused him of neglecting his duty. "I don't have enough people to do that job, to open it up."

Roi said, "Stop thinking the old way, my friend. Everyone is your team-mate now. We don't have to lure them away from their colleagues and recruit them, one by one. We just have to explain the need, and the urgency. We just have to make sense."

"You can have what you asked for," Zey told Rakesh. "You can take a part of me to study."

She had just finished her shift and had come out from the depot. The other workers were still milling around, talking among themselves before heading into the tunnels to sleep.

Rakesh felt no need to ask if she was sure; everything they'd spoken about for the last dozen shifts had been for the sake of informing her decision. He did feel he owed her a small moment of drama, though, so rather than admitting that, thanks to their long proximity, his own avatar was already plastered in her cells and he had no need to collect a sample, he reached out with one claw and gently scratched a soft part of her nearest leg.

Nanomachines inside his avatar swarmed over the cells, dissecting some destructively, infiltrating others to watch their components in action. The DNA sequences were only part of the analysis; they would be meaningless without the full context of cellular biochemistry.

Parantham spoke to him, back in the cabin. "You might have done this when I first suggested it, instead of elevating your own need for customary formalities over the real ethical issues." Rakesh ignored her.

He took the nanomachines' data and ran coarse-grained simulations of morphogenesis, precise enough to give a clear picture of the way the Arkdwellers' bodies were shaped generically, and to map out the strongest genetic and environmental influences on each individual, but not so precise that the simulation itself would experience anything.

The generic map of the Arkdwellers' brain that the simulation produced made visible what Rakesh had long suspected: their ability to form and manipulate abstract symbols was powerful enough to grant all of them general intelligence as a birthright. Though the data came solely from Zey's DNA, there were far too many genes involved for her to have mutant variants of
all
of them; the generic map encompassed the whole species. As for every human born since the Stone Age, as for the ancestors of every member of the Amalgam, there was nothing the universe was capable of doing that the Arkdwellers were not capable of comprehending. They were not mere clever-looking animals, with some hard-wired repertoire of impressive but inextensible skills. With sufficient motivation and freedom from distractions — and perhaps a modest boost in longevity — they could have grasped anything. Apart from the subjectivities of art and language, where everyone needed tweaking to cross the species barriers, there was nothing in the Amalgam's million-year-old storehouse of knowledge that would have been beyond their reach.

That was the ability, the potential in every one of them. There was, however, no drive to realize it: no curiosity, no joy in discovery, no restlessness, no dissatisfaction. The Arkdwellers needed their full intellectual toolkit in order to master the complex tasks allotted to them in the present social order, so it was
not
a useless vestigial genetic fossil. It was the living, breathing embodiment of matter's ability to comprehend itself, but it was tamed and caged in a manner that Rakesh had never encountered before. It could rise to the occasion to overcome a limited range of mundane setbacks and challenges, but it would never soar.

Rakesh was not surprised by any of this, inasmuch as it applied to the Arkdwellers as a whole. It fitted his observations of their behavior perfectly. He did not yet understand Zey, though. Her team-mates could not be too different from her genetically, but he'd expected her to carry two copies of some rare, recessive gene that could explain why she alone was compelled to make full use of her intellectual abilities. If that had been the case, though, the coarse-grained simulation would have had no way of knowing what the ordinary version of the gene was, and erasing Zey's atypical urges from the generic map.

This proved that whatever had made her different could not have been entirely genetically determined. The simulation had smoothed out the possible environmental influences on brain development into a plausible average, but in doing so it had clearly missed something that had made all the difference to Zey.

Rakesh probed the data more deeply, looking for genes that might have been triggered only rarely, rather than being rare themselves. He simulated the chemistry of the developing embryo in more detail, looking for possible surges in morphogens, and the wave of changes they might bring.

When he found what he'd been looking for, it was like an elephant stepping out of the wallpaper. There was a vast network of linked genes and proteins that could influence neural structures
both in the embryo and in adulthood
, and it bore the clear fingerprints of an engineered design. The Arkmakers had had their hands all over this part of their children's genome.

If there was a vital spark missing from the generic Arkdweller, these genes were designed to light the fire. Without imaging Zey's brain, Rakesh couldn't say just how far from the average the random biochemical detour she'd experienced in the egg had taken her, but a one-in-ten-thousand surge would have triggered a cascade of events that guaranteed a thirst for knowledge comparable to all of her other basic drives. The frequency of such individuals in the population would obviously be low, but Rakesh did not believe for a moment that Zey was an accident. The Arkmakers had wanted people like her, but not too many.

He was sure she had been born, or hatched, this way, because if the other trigger he'd found had been the cause then there was no explaining her team-mates' apathy. Extreme stress could bring on the development of the same neural structures in an adult's brain. Mild hardship wouldn't start the cascade, though; it would require a sustained, dramatic change in the environment. Depending on the circumstances, and the exact range of individual susceptibilities, it looked as if anything from thirty to sixty per cent of the population could be transformed by that route, but only if the Ark itself was subjected to a massive upheaval.

From there, the process would snowball, with an ever greater proportion of each subsequent generation driven by an urge to understand the crisis they were facing. If the threat subsided then the
status quo
would eventually return; the simulations suggested that a few dozen generations of tranquility would be enough to put out the fire. Then, as before, only a handful of individuals would exhibit the trait, until the next emergency.

Rakesh had performed the whole analysis in a couple of Zey's heartbeats, but she already had an air of impatience.

"What's your answer?" she said. "What's the nature of my sickness?"

Rakesh explained everything he'd found, as clearly as he could. He'd already told her all he knew about the Arkmakers, so the idea that her distant ancestors had shaped her people's nature did not come as a shock in itself.

"Why am I here now, though?" she said. "If the world was falling apart, of course it would be good to have people who tried to repair it, instead of just tending their herds and waiting to die. But why did they arrange for people like me to be hatched when there is no need for us?"

"I don't know," Rakesh confessed. "I can't read their minds, I can't know what they were thinking. Perhaps they wanted a kind of sentinel, a small group who would be vigilant enough to notice the first signs of danger and prepare the way, while the evidence was still below the threshold for the rest of the population. Or perhaps they wanted a route for the cultural transmission of some crucial ideas that everyone else would consider too impractical to retain."

"As long as the world is safe, though," Zey replied despairingly, "I'm useless, aren't I?"

Rakesh said, "Knowledge is good in itself. Understanding is good in itself."

Zey chirped amusement. "I can't argue with that sentiment, can I? I've been built to think like you. But you come from a world where the ones who disagree with you are the sad, strange few. You haven't spent a lifetime as the only one with that point of view."

Rakesh didn't know how to reply to her. The chasm between her and the other Arkdwellers was not something that any of them were capable of bridging. She could never be his ambassador, and he couldn't hope to enter into any kind of dialogue with them himself, slowly coaxing them out of their shells, opening them up to new possibilities, turning their faces to the stars. Without a calamity to throw the switch, they were physically incapable of caring about such things.

Zey's mind was working faster than his now. She said, "I would never ask you to bring trouble to my brothers and sisters, to damage the world, to sow fear and death. But is that the only way to bring change?"

Rakesh asked nervously, "What do you mean?"

"These genes, these molecules, these signals in our bodies. my ancestors built them to work one way, but I believe you are more powerful than my ancestors. These are all just made from atoms, aren't they? Your little machines can move them around the way I move cargo from one side of the depot to another. If you wanted to, you could ask them to make these signals appear in all of our bodies, without any reason, without any danger.

"If you wanted to, you could wake us from our sleep."

"Any progress?" Haf asked, as he wound the light machine.

Roi looked up from her template frame. "Not really," she admitted. "Be patient, though. We haven't followed this to the end yet."

She had come to the sardside for the opening of the third tunnel, and to confer with Neth and Bard. Haf had tagged along as her helper, gathering food, providing light, and checking her interminable calculations. Even as they waited in this small chamber for their hosts to call them to the big event, Roi could not put her frames aside.

Since Cho and Nis had measured the Wanderer's curvature from the tiny angle by which it bent the incoming light, she had been spending most of her time trying to discover a template for a geometry that could encompass both the Wanderer and the Hub. Without any of the old symmetries to rely on, though, the templates became vastly more complicated.

The curvature that wrapped the Wanderer was about six to the eighth times weaker than that around the Hub, so it might have been simpler to take the idealized geometry of the Hub alone as a guide to their calculations, and then rely on the observations of the void-watchers to tell them when their true position was deviating from their predictions. Like someone sliding down a steep tunnel that had been crudely mapped but never actually traversed, they could try to avoid the smaller hazards by sight, rather than aspiring to a mathematically perfect foreknowledge of every bump that lay ahead. The only problem with that eminently practical approach was that the dark phases were shrinking, so the observations of the void-watchers were already being curtailed. If it ever came to the point where the dark phases vanished, they would be skidding down the tunnel blind, entirely at the mercy of their calculations.

As the natural light dimmed, Roi handed Haf her last frame and started on a fresh one.

"Your templates are like weeds," Haf remarked helpfully. "No shape at all, they just grow where they like."

"Thanks for the encouragement. How about checking whether they're true or not, and then you can weed out all the false ones to your heart's content."

As Haf set to work, Roi stared pensively at the stones of the blank frame. Sometimes the problem really did appear to be impossible to solve, but the geometry that twisted around the Hub had once seemed almost as intractable, and now the Splinter was spiraling out along a path that was confirming that solution, shift after shift. The weights, the cycles, the view of the void, all fitted together exactly as the templates decreed. Ruz had been up to the surface a few times, and he'd told her that the strange quarter-circle was expanding: the angle of the arc, its radius and its thickness had all grown visibly larger. Part of this change was due to the Splinter traveling more slowly around its larger orbit, and part to the gentler space-time curvature as they moved away from the Hub bending the incoming light less severely.