Incandescence

by Greg Egan

  The spider started at the rim of the frame and began secreting a glistening polymer film, more like a metallic-looking tape than a silken thread. Mobile electrons in the polymer made it as reflective as silver, but it was lighter and stronger than any metal. The precise molecular structure of the polymer was being constantly tweaked as it was synthesized, tailoring the natural curvature of the film to fit the parabolic shape of the mirror to within a fraction of a wavelength.

  The frame was rotating, so the spider only had to inch its way slowly toward the center, depositing the film in a tightly wound spiral while the growing mirror turned beneath it. Rakesh watched patiently as the annular strip finally reached a sufficient size for him to glimpse the blaze of the central cluster reflected back at him, a view so sharp that it looked more like some kind of rift in space than a mere reflection.

  When this segment was completed and moved into position, an array of precision accelerometers measuring the phase difference between counter-rotating superconducting currents would track its orientation, and a faint breath of ions from its attitude thrusters would keep it perfectly aligned. The insect-eyed instrument package that sat at the telescope's focus was already complete, and undergoing testing and calibration. Once a million or so of the ten billion segments were in place, some worthwhile data collection could take place, albeit far more slowly than it would when the full light-collecting area was brought into play. At that point, the telescope would be imaging the accretion disks of thousands of neutron stars simultaneously, hunting for the telltale spectrum of an Ark's synthetic walls.

  Probes had scoured the rubble-strewn center of the sole Ark that remained in this system, but had found neither artefacts nor the mummified remains of its original inhabitants. Though the higher tiers of the wind-fed ecosystem had probably collapsed quite quickly, there was a sufficient population of microbes even now to make short work of anything organic, and the slow grinding of the rubble over the millennia had milled any remnants of the inhabitants' material culture down to dust. Rakesh didn't dare to guess what the chances were that any of the Arks captured by the neutron star had thrived — even briefly, let alone for fifty million years — but he had written off the cousins prematurely before, and he was not about to make the same mistake again.

  He turned away from the mirror and let his avatar drift, spinning slowly. He shifted his vision down the spectrum, into the infrared and microwave bands, dimming the fierce stars but revealing the eerie world of gas and dust in which they were embedded, full of structures more subtle, delicate and diffuse. Shells of plasma from thousand-year-old supernovas hung in space like the smoke from some slow-motion fireworks display. Half a dozen glowing filaments lined up perpendicular to the galactic plane shone with the synchrotron radiation of electrons spiraling along magnetic field lines. From a ring of gas a dozen light years wide that circled the galactic center, a surreal double helix stretched across the sky: the infrared glow of dust trapped by a wave in the magnetic field that was anchored to, and twisted by, the orbiting gas.

  Somehow, the Aloof had mastered this beautiful, perilous place and claimed it as their own. While Rakesh's hapless cousins had been hammered relentlessly by the forces of nature, perhaps to the point of extinction, the Aloof had overcome or circumvented the same hardships, to make this their jealously guarded home. Whether they'd matured in the disk first and only come here once they were armed with sophisticated technology, or whether their whole mode of existence had rendered them impervious to the dangers of the bulge from the start, was anybody's guess. Rakesh did not expect answers from them, at least not directly, but he couldn't entirely surrender the naive hope that merely being allowed inside the fence and permitted to see what the Aloof had seen, to steep his body in the same radiation and feel the same stellar winds and tides, might yet crystallize some insight about their nature that could never have formed from idle speculation back in the disk.

  Parantham spoke, puncturing his reverie.

  "We have company."

  This assertion was so bizarre and unexpected that Rakesh simply floated in silence for a while, refusing to abandon his sanctuary among the spiders to see if she was joking.

  "What do you mean?" he finally replied.

  "Someone has sent us a messenger. I've already asked it what it wishes to say, but it insists on speaking to us together."

  Rakesh took his senses out of the avatar, back to his body slumped in a couch in the control room of Lahl's Promise.

  Standing beside Parantham was a figure resembling Csi, as Rakesh had perceived him back in the node: the same bald head, the same serious demeanor, the same barely visible hint of a smile. Unlike Csi himself, it was meaningless to ask what this messenger really looked like; as an insentient courier it had no self-perception, let alone any need for a physical embodiment. Their hosts had simply loaded it into one of the habitat's processors and let it communicate with them via Amalgam-standard protocols.

  Rakesh rose to his feet and embraced the messenger. "Welcome to the bulge!" This was not his old friend, but it was designed to communicate as if it were, and perhaps to take a reply back to the sender. Some people became self-conscious in the presence of messengers, but Rakesh's policy was to treat them as if they were the sender, and only to retreat from that stance if it led to real absurdities. To embrace this insentient hallucination was no more foolish than responding with warmth and sincerity to a written letter or a video message. "What's been happening? Where have you come from?"

  "Darya-e-ghashang. A few years after you and Parantham left the node, a traveling festival came through: the Ocean of Ten Million Worlds. I fell in with them, and I've been with them ever since."

  "The Ocean of Ten Million Worlds?"

  "Every month, we swim, sail, or dive in the waters of a different planet."

  Rakesh smiled, recalling his sodden farewell from the node. "That sounds wonderful." These festivals were really just large groups of friends traveling together, but they were usually dressed up with some kind of distinguishing paraphernalia: claiming to offer some new social structure or artistic milieu, or to choose their destinations in order to celebrate some particular aspect of life. Their real attraction was that they offered a satisfying mixture of stability and novelty. As long as you stayed with the group, you didn't have to cut ties with everyone you knew just for a change of scenery.

  Parantham said, "So what made you think of us, out of the blue?"

  "I heard some news about Lahl," the messenger said.

  "Lahl?" Rakesh was almost as surprised by this as he had been by the messenger's arrival. "What did she do to become famous?"

  "She came out of the bulge without entering it."

  Rakesh said, "I see." If that was true, it was worth a degree of notoriety.

  "The inter-network traffic report from the node she'd claimed as her entry point finally reached the node where she'd emerged," the messenger explained. "It took a while, because she'd told the truth when she'd said there'd been a temporary shortage of encryption keys linking the two. When that shortage was remedied and the two nodes compared data, it was clear that she'd lied about her origins."

  Parantham said, "Does that really mean she never went into the bulge? She might have entered at a different point, and the data just hadn't been brought together for matching, the last you heard."

  "That wasn't literally impossible when I left Darya-e-ghashang," the messenger conceded, "but even then the remaining opportunities for that were slim. It's widely believed now, around much of the western inner disk, that the Aloof created her: that they used their knowledge of all the unencrypted travelers they've been able to study over the millennia to manufacture a plausible citizen of the Amalgam, and then they sent her out to do, well. who knows what?"

  "So where is she now?" Rakesh asked.

  "Nobody knows. There is no record of her departing from the node where we met her."

  Rakesh laughed. He was not convinced that Lahl was anything but an ordinary
traveler who preferred not to leave behind detailed records of her movements; perhaps her story about the synchronization clan had been a cover for something more complicated and nefarious. And even if she really was a messenger from the Aloof — whose lack of social skills might have led them to phrase their request for a "child of DNA" to investigate the meteor in this mildly dishonest fashion — was that anything to worry about?

  "I'm glad that you decided to share this news with us," Rakesh said, "but it's not going to change our plans. I don't approve of deceit, but Lahl's basic message was genuine. Has Parantham told you about our discoveries?"

  "Yes."

  "So what should we do? If the Aloof meant us harm, it's already too late to prevent it, and the very fact that you've reached us to pass on these suspicions makes it seem even less likely that they do."

  "I didn't come to warn you about the Aloof," the messenger said. "I came to warn you about the Amalgam."

  "Oh." Rakesh felt a real twinge of unease now.

  "Unencrypted, unauthenticated travelers taking the short cut through the bulge have always done so at their own risk. It's not just a question of what the Aloof might do with them; the receiving nodes on the other side of the bulge are actually under no obligation to embody, or re-route, unauthenticated data. Since the days of Leila and Jasim, and the first wave of excitement when they discovered the Aloof's network, it's been the common practice for the people of the inner disk to make exceptions for data taking the short cut. With rumors spreading that the Aloof aren't dealing with us openly — that they're manufacturing impostors and spitting them out into our networks, to act as spies and saboteurs — that easy-going policy is being questioned."

  Parantham said, "So when we're finished here, and the time comes for us to leave—"

  "It might not be as simple as you expected," the messenger said. "The Amalgam might not be willing to take you back."

  14

  "Thirty-three," Roi counted, vigorously waving her back left leg, followed by her front left leg.

  "THIRTY-THREE!" the hatchlings replied in unison, mimicking her actions precisely.

  "Thirty-four." Roi waved her back left leg, then her middle left.

  "THIRTY-FOUR!" echoed the hatchlings.

  "Thirty-five." Back left leg once, then once again.

  "THIRTY-FIVE!"

  "Thirty-six." Roi leaped off the floor as high as she could, struggling to wave her front right leg twice, clearly and distinctly, before she touched the ground again.

  "THIRTY-SIX!" The hatchlings couldn't jump as high as she had, but they were all nimble and energetic enough to repeat her gestures before they had even begun to descend.

  Roi rolled over on to her back, exhausted. The hatchlings, of course, copied even this unintended flourish. They really were infuriating sometimes.

  "I'm getting too old for this," she rasped to Gul.

  "You just need to spend less time at the Null Line."

  "Maybe."

  While she rested, Gul took over the class, pouring a fine colored powder on to the floor and scraping furrows in the shape of simple words. As Roi watched the hatchlings copy him, her tiredness and irritation faded. She knew it would be a joy to teach these children, to bring them to an understanding of the world.

  It was also a daunting responsibility, but she believed she had grown better at the job. She had tutored seven groups of hatchlings so far, and from the last three groups she was sure that everyone had left her class with a clear understanding of the basic facts about the Splinter. They would carry that knowledge with them throughout their lives, and spread it among their team-mates.

  The great tunnel that Bard had planned, to unbalance the force of the wind and drag the Splinter to safety, remained unbuilt. While Bard, Neth and a few dozen others continued to survey, and recruit, and try their best to explain the tunnel's purpose to the people of the sardside whose factories, storerooms and grazing areas they wanted to turn to rubble, so far they had failed to recruit a workforce large enough to make a scratch in the rock, and the locals remained largely hostile to the whole idea. Roi couldn't see the situation changing while the threat of the Splinter descending into an unstable orbit around the Hub remained an incomprehensible notion to most people. She suspected that it would take at least two generations for Zak's vision to permeate the culture to the point where everyone could understand the danger, but at least she and Gul, and a dozen other teams, were nudging things in the right direction. Move the people, and the rock might follow.

  The hatchlings completed tracing the words for "left" and "right" and began smoothing the powder into its blank state again, ready for the next word. Suddenly the weight changed, and Roi, Gul, hatchlings and powder were flung high into the chamber. An instant later, the Incandescence brightened, sixfold, thirty-six-fold, searing everything into invisibility.

  Roi thought: This is the end. So soon. No warning, just death—

  She struck the floor, right way up. After a moment she flexed her legs cautiously; she was sore from the impact, but she had not been injured. She heard the hatchlings mewling in distress beside her; still blinded, she instinctively chirped out words of comfort and reassurance. "Everything is fine! We're safe! Don't worry!"

  As her vision began to return, she could see that the walls around her still bore an afterglow from the burst of light, a lingering radiance far stronger than anything she'd witnessed before, even at the garm-sharq edge. She could feel the rock creaking ominously beneath her. Was the Splinter about to be broken in two? Or was it on the verge of plummeting into the Hub? This was not how she'd imagined either disaster beginning. As far as she could judge, once the disturbance that had tossed them from the floor had passed the weight had returned to normal.

  Gul limped over to her. "Any idea what's happening?"

  "None at all."

  "Do you think we should head sardwards?" That was one plan that had been mooted as a response to an impending division: head for the sardside, in the hope that the sardwards fragment of the Splinter would end up further from the Hub.

  "We're a long way from the Calm," Roi pointed out, "and the hatchlings can't move as quickly as adults. It would take us two shifts, at least. If we're breaking up, we might be heading into danger." If the Splinter divided symmetrically, the Calm was the last place you'd want to be when the halves violently parted company.

  "That's true," Gul said. "And if we're going to get thrown around again, travel is probably unwise unless we're sure our lives depend on it. Let's wait and see if we can make sense of the situation." The hatchlings were milling around them making plaintive sounds, but their small bodies were resilient and none of them appeared to have been harmed by the fall. Gul chirped soothing words to them at his most reassuring pitch.

  The walls around them were growing darker now. At first, Roi had thought it was just the afterglow from the flash continuing to fade, but as she increased the sensitivity of her vision to compensate, she realized that she was straining at the edge of her ability.

  "Am I going blind?" she asked Gul. "Or is the Incandescence fading?" Maybe the flash had damaged her sight.

  He said, "Either we're both going blind, or it's fading."

  The hatchlings fell silent, as if the darkness itself was a source of tranquility for them. Perhaps it was lulling them to sleep, just as the voluntary cessation of vision induced drowsiness. Roi could think of no other experience with which to compare it; the Incandescence might penetrate the rock more weakly in the depths of the Splinter than it did at the edge, but for the all-pervading glow to change before her eyes was unprecedented.

  As the darkness grew deeper, Roi tried to stay calm. Whatever was happening to the Splinter was not a fate that anyone had predicted, but it was better to be perplexed and alive than to face those long-anticipated cataclysms.

  "Can there be a hole in the Incandescence?" Gul wondered. "A gap, a void?"

  "If there is, why did we never pass through it before?"

  "Pe
rhaps it moves, perhaps it wanders around," he suggested. "And that flash of brightness was. a concentration of the Incandescence at the edge of the void, heaped up like the rubble dug from a hole."

  Roi had no idea if that made sense; she had never thought of the Incandescence as something you could make a hole in by any method. "Can you feel the wind?" It was a measure of how disoriented she was that she had to ask, that she couldn't trust her own senses.

  "No. There's nothing. The rock is making a sound I've never heard before, but it's not from the wind."

  Roi was relieved by this small sign of consistency. "I suppose that means we're not simply going blind. Wind and brightness, gone together." With the Incandescence gone, how would they eat? How would they survive? If the hole they had entered was not too large they should emerge from it soon, as the Splinter continued its orbit around the Hub. If it enclosed their whole orbit, though, they would remain in darkness until it moved away of its own accord.

  Roi said, "How long do you think it's been, since the darkness started?"

  Gul rasped amusement. "My mind's not that clear. I wouldn't like to guess."

  "Less than half a shomal-junub cycle, I'd say." Roi had watched the cycling stones so many times, the rhythm of it was stamped into her mind. "We don't know for sure that the Splinter's orbit has the same period, but that's what the simplest geometry implied. So if there's a gap in the Incandescence that's smaller than our orbit, we ought to emerge from it in less than one shomal-junub cycle."

  "That sounds reasonable," Gul said cautiously. "The gap itself might be moving around, complicating things, but if it's moving slowly then everything should repeat about once every orbit."

  Just a few heartbeats later, the walls began to brighten. Roi tensed, preparing herself for a recurrence of the violence that had preceded the onset of darkness, but the light from the rock climbed calmly and steadily back to its normal strength, and the wind resumed its usual susurration, unaccompanied by any sudden shifts of weight or blinding flashes.