Ring xs-4

by Stephen Baxter

  Spinner sat with Louise within the safe, enclosing glass walls of a pod. Louise, with a touch on the little control console before her, guided the pod around the Xeelee nightfighter; neighboring pods slid across space, bubbles of light and warmth. The wings were immense sculptures in space, black on black. Spinner could hear Mark whispering in Louise’s ear, and numbers and schematics rolled across a data slate on Louise’s lap.

  Spinner’s faceplate dangled at her back, and she relished the feel of fresh air against her face. It was wonderful simply not to breathe in her own stale exhalations.

  She’d dug her father’s arrow-head out of her suit so that it dangled at her chest; she fingered it, rubbing her hands compulsively over its smooth lines.

  Louise glanced at Spinner. “Are you all right now?” She sounded apologetic. “Mark got to you as quickly as he could. And — ”

  Spinner-of-Rope nodded, curtly. “I wasn’t hurt.”

  “No.” Louise glanced down at her slate again; her attention was clearly on the data streaming in about the activated nightfighter. She murmured, “No, you did fine.”

  “Yeah,” Spinner grunted. “Well, I hope it was worth it.”

  Louise looked up from her slate. “It was. Believe me, Spinner; even if it might be hard for you to see how. The very fact that you weren’t harmed, physically, by that little jaunt has told us volumes.”

  Now Mark’s voice sounded in the air. “You traveled tens of thousands of miles in a fraction of a second, Spinner. You should have been creamed against the bars of that cage. Instead, something protected you…”

  Louise looked at Spinner. “He has a way of putting things, doesn’t he?”

  They laughed together. Spinner felt a little of the numbness chip away from her.

  “Mark’s right,” Louise said. “Thanks to you, we’re learning at a fantastic rate about the nightfighter. We know we can use it without killing ourselves, for a start… And, Spinner, understanding is the key to turning anything from a threat into an opportunity.”

  Louise took the pod on a wide arc around the unfurled wings of the Xeelee craft. The wings were like a star-free hole cut out of space, beneath Spinner-of-Rope; they retained the general sycamore-seed shape of the construction-material framework, but were vastly extended. Spinner could see ’bots toiling patiently across the wings’ surface.

  “This far out, the mass-energy of the wing system is actually attracting the pod, gravitationally,” Louise murmured. “The wings have the mass equivalent of a small asteroid… I can see from my slate that the pod’s systems are having to correct for the wings’ perturbation.

  “Let’s go in a little way.”

  She took the pod on a low, sweeping curve over the lip of one wing and down toward its surface. The wing, a hundred miles across, was spread out beneath Spinner like the skin of some dark world; the little pod skimmed steadily over the black landscape.

  Louise kept talking. “The wing is thin — as far as we can tell its thickness is just a Planck length, the shortest distance possible. It has an extremely high surface tension — or, equivalently, a high surface energy density — so high, in fact, that its gravitational field is inherently non-Newtonian; it’s actually relativistic… Is this making any sense to you, Spinner?”

  Spinner said nothing.

  Louise said, “Look: from a long way away, the pod was attracted to the wings, just as if they were composed of normal matter. But they’re not. And, this close, I can detect the difference.”

  She drew the pod to a stop, and allowed it to descend, slowly, toward the wing surface.

  Spinner, gazing down, couldn’t tell how far away the nightblack, featureless floor was. Was Louise intending to land there?

  The pod’s descent slowed.

  Louise, working her control console, caused the pod’s small vernier rockets to squirt, once, twice, sending them down toward the wing surface once more. But again the pod slowed; it gradually drifted to a halt, then, slowly, began to rise, as if rebounding.

  Louise’s face was alive with excitement. “Spinner, could you feel that? Do you see what’s happening? This close, the wing surface is actually gravitationally repulsive. It’s pushing us away!”

  Spinner eyed her. “I know you, Louise. You’ve already figured out how a discontinuity drive would work. You were expecting this antigravity stunt, weren’t you?”

  Louise smiled and waved a hand at the Xeelee craft. “Well, okay. Maybe I made a few educated guesses. This ship isn’t magic. Not even this antigravity effect. It’s all just an exercise in high physics. Of course we couldn’t build one of these.” Her eyes looked remote. “Not yet, anyway…”

  “Tell me how it works, Louise.”

  At extremes of temperature and pressure, spacetime became highly symmetrical (Louise told Spinner). The fundamental forces of physics became unified into a single superforce.

  When conditions became less intense the symmetries were broken. The forces of physics — gravity, nuclear, electromagnetic — froze out of the superforce.

  “Now,” Louise said, “think of ice freezing out of water. Think back to what we saw on Callisto — all those flaws inside the ice, remember? The freezing of water doesn’t happen in an even symmetrical way. There are usually defects — discontinuities in the ice.

  “And in just the same way, when physical forces freeze out of the unified state, there can be defects — but now, these are defects in spacetime itself.”

  Space was three-dimensional. Three types of stable defects were possible: in zero, one or two dimensions. The defects were points — monopoles — or lines — cosmic strings — or planes — domain walls.

  The defects were genuine flaws in spacetime. Within the defects were sheets — or points, or lines — of false vacuum: places where the conditions of the high-density, symmetrical, unified state still held — like sheets of liquid water trapped within ice.

  “These things can form naturally,” Louise said. “In fact, possibly many of them did, as the Universe expanded out of the Big Bang. And maybe,” she went on slowly, “the defects can be manufactured artificially, too.”

  Spinner stared out of the pod at the nightfighter. “Are you saying — ”

  “I’m saying that the Xeelee can create, and control, space-time defects. We think that the ‘wings’ of this nightfighter are defects — domain walls, bounded about by loops of cosmic string.

  “Spinner-of-Rope, the Xeelee use sheets of antigravity to drive their spacecraft…”

  The domain walls were inherently unstable; left to themselves they would decay away in bursts of gravitational radiation, and would attempt to propagate away at speeds close to that of light. The Xeelee nightfighter must actually be stabilizing the flaws, actively, to prevent this happening, and then destabilizing the flaws to gain propulsion.

  Louise believed the Xeelee’s control of the domain-wall antigravity effect must be behind the ship’s ability to shield the pilot cage from acceleration effects.

  “All this sounds impossible,” Spinner said.

  “There’s no such word,” Louise said aggressively. “Your trip was a real achievement.” Louise, clearly excited by the Xeelee’s engineering prowess, sounded as alive and full of enthusiasm as Spinner had ever heard her. “You gave us the first big break we’ve made in understanding how this nightfighter operates — and, more significantly, how we can use it without destroying ourselves.”

  Spinner frowned. “And is that so important?”

  Louise looked at her seriously. “Spinner, I need to talk this out properly with you. But I suspect how well we use this nightfighter is going to determine whether we — the human species — survive, or perish here with our Sun.”

  Spinner gazed out at the Xeelee craft, at the scores of drone ’bots which clambered busily across the face of its wings.

  Perhaps Louise was right; perhaps understanding how something worked did make it genuinely less threatening. The Xeelee nightfighter wasn’t a monster. It was a t
ool — a resource, for humans to exploit.

  “All right,” she said. “What next?”

  Louise grinned. “Next, I think it’s time to figure out how to take this nightfighter on a little test jaunt around the Solar System. I’d like to see what in Lethe happened here. And,” she said, her face hardening, “I want to know what’s happening to our Sun…”

  18

  Milpitas put down his pen.

  Annoyingly, it drifted away from the surface of his desk and up into the air, cart-wheeling slowly; Milpitas swiftly scooped up the offending item and swept it into a drawer, where it could drift about to its little insensate heart’s content.

  He climbed stiffly from his chair and made his slow way from the office.

  Fine white ropes had been strung out along the Temple’s warren of corridors. By judiciously sliding one’s closed fists along the rope, one could quite easily maintain the illusion — for oneself and others — of walking, as normal. He passed another Planner, a junior woman with her tall, shaven dome of a scalp quite gracefully formed. Her legs were hidden by a long robe, so that — at first glance anyway — it could have been that she was walking. Milpitas smiled at the girl, and she nodded gravely to him as they passed.

  Excellent, he thought. That was the way to deal with this ghastly, offensive situation of zero-gee, of course: by not accepting its reality, by allowing no intrusion into the normal course of things — into the usual, smooth running of their minds. By such means they could survive until gravity was restored. He moved through the corridors of his Temple, past Planner offices which had been hastily adapted to serve as dormitories and food stores. Beyond the closed doors he heard the slow, subdued murmur of the voices of his people, and beyond the Temple walls there continued the steady, sad wailing of the klaxon.

  He worked his way out from the bowels of the building, out toward the glistening skin of the Temple. He had conducted an inspection tour like this every shift since the start of the emergency. His assistants formed a complex web of intelligence throughout the Temple, of course, and reports were ready for him whenever he requested them. Some contact had even been maintained with the other Temples, thanks to carefully selected runners. But, despite all that data, Milpitas still found there was no substitute for getting out of his office and seeing for himself what was going on.

  And, he flattered himself to think, perhaps it comforted the people — the lost children he’d gathered here into his protection, in the midst of this, their greatest crisis — to be aware that he, Milpitas, their Planner, was among them.

  But, he thought, what if gravity were never returned?

  He pulled at his chin, his fingernails lingering on the network of AS scars they found there.

  They would have to adjust. It was as simple as that. He evolved vague schemes for stringing networks of ropes across the Decks; there was really no reason why normal life — at least, a close semblance of it — should not resume.

  The discipline of the Planners had already persisted for almost a thousand years. Surely a little local difficulty with the gravity wasn’t going to make any difference to that.

  Still, he thought, some events — however unwelcome — did force themselves into one’s awareness. Such as the moment when the gravity had died. Milpitas remembered clinging to his own chair, watching in horror as the artifacts on his desk — the ordinary, humdrum impedimenta of everyday life — drifted away into the treacherous air.

  In the Decks, there had been panic.

  Milpitas had sounded the klaxon — and it still sounded now — calling the people to him, to the protection of the Temple.

  Slowly, one by one, or in little groups clinging to each other fearfully, they had come to him. He had lodged them in offices, giving them the security of four stout walk about them.

  People had been stranded helplessly in mid-air. Ropes had been slung between the Decks, huge nets pulled through the air to gather in the flopping human fish. All of them had been brought to him, some almost catatonic with fear, their old young faces rigid and white.

  He reached the tetrahedral outer hull of the Temple. The skin was a wall of golden glass which inclined gracefully over him, softening the harsh light of the Decks; the wall’s framework cast long, soft-edged shadows across the outer corridors.

  …But the light, today, had changed, he noticed now. He glanced up, quickly, above his head. Shafts of gray Deck daylight, raw and unfiltered, came seeping through holes in the golden wall. At each gap in the wall a sentry hovered, fixed to the glass wall by a loose sling of rope.

  The holes had been punched out, in the last few minutes or hours, by the sentries; they must have seen someone, somehow, approaching the Temple.

  The nearest sentry glanced down at Milpitas’ approach. It was a woman, Milpitas saw; she held her cross-bow up against her chest, nervously.

  He smiled at her and waved. Then, as soon as he felt he could, he dropped his eyes and moved on.

  Damn. His composure, the gestalt of his mood, had been quite disrupted by the sight of the sentries and the knocked-out glass panes. Of course he himself had posted the sentries up there as a precaution (a precaution against what, he hadn’t cared to speculate). He’d really hoped that the sentries wouldn’t need to be used, that no more irruptions from outside would occur.

  Evidently that hope hadn’t yet been fulfilled. His plans to repopulate the Decks would have to be postponed for a while longer.

  Well, there was still food and other essentials, here in the Temples. And when the supplies ran out, their AS nanobots could preserve them all for a long while; the nanobots would enable each antique human body to consume its own resources, digging deeper and deeper, to preserve the most vital functions.

  And even the failure of that last fallback would, in the end, be irrelevant, of course.

  The people would remain with him, Planner Milpitas, here in the Temple. Where they were safe. He had to protect the future of the species. That was his mission: a mission he had followed unswervingly for centuries. He had no intention of abandoning his duty to his charges now.

  Not even if it meant keeping them in here forever.

  The wings of the nightfighter loomed over the battered surface of Port Sol.

  The relativistic effects of the flight — intense blue shift ahead, the hint of a starbow girdling the sky — faded rapidly from Spinner’s sensorium. The Universe beyond her cage of construction material assumed its normal aspect, with the wizened stars scattered uniformly around the sky, and the blood-red bulk of the Sun an immense, brooding presence.

  She took her hands from the control waldoes and lay back in her couch. She closed aching eyes, and tried to still the trembling in her hands.

  She sucked apple-juice from the nipple inside her helmet. The juice tasted slightly odd — as usual, because of the nutrient supplements that had been added to it. Her legs and back felt stiff, her muscles like bits of wood, after two days in this box. The plumbing equipment she’d been fitted with was chafing again, and somewhere under her back there was a fold of cloth in her suit, a fold which dug enthusiastically into her flesh. Even the loop of rope at her waist felt tight, restricting.

  “Spinner-of-Rope. Can you hear me?” It was Louise’s voice, calling from the cozy shirtsleeve environment inside the life-lounge she’d fixed to the shoulders of the nightfighter. “Are you all right?”

  Spinner sighed. “About as all right as you’d expect me to be.” She clenched her hands together and worked her fingers through the thickness of the gloves’ material, trying to loosen up the muscles. Over-tension in her hands was probably going to be her biggest problem, she reflected. Her guidance of the ship was assisted by the processing power Louise had had installed inside the life-lounge, but still, and quite frequently. Spinner had to supply manual intervention.

  “Spinner, do you want to close up the wings?”

  Spinner stabbed at a button on the left-hand waldo. She didn’t bother to look back to watch the controlled de
fects in spacetime heal themselves over; without the wings, the quality of light in the cabin changed a little, brightening.

  “Okay. Would you like to come into the lounge for a while?”

  Another damn spacewalk? She closed her eyes; her eyeballs prickled with fatigue. “No thanks, Louise.”

  “You’ve been in that couch for thirty-six hours already, Spinner. You need to be careful with yourself.”

  “What are you worried about?” Spinner asked sourly. “Bedsores?”

  “No,” Louise said calmly. “No, the safety of the nightfighter…”

  Spinner had quickly learned that journey times in the ’fighter were going to be long. Louise had worked out that the nightfighter’s discontinuity drive could bring it to better than half lightspeed. Terrific. But most of the Solar System was empty space. It was a big place. During a ’fighter journey, little would change visibly, even from hour to hour — but that served to make the worst moments, when she came plummeting at some planet or moon, even more terrifying, with their sensations of such intense speed.

  Spinner had felt no acceleration effects, and Louise assured her that her suit and the action of the construction material cage around her — would protect her from any hard radiation, or heavy particles she might encounter… But still, she was forced to sit in this damn box, and watch the stars blue-shift toward her.

  Maybe the Xeelee had never suffered from vertigo, but she’d quickly found that she sure did.

  “Well, here we are at Port Sol. Louise, how long do you want to stay here?”

  Louise hesitated. “Not long, I don’t think. I didn’t expect to find anything here, and now that I’m here I still don’t.”

  “Then I’ll stay in the pod. The sooner we can get away, the more comfortable I’ll feel.”

  “All right. I accept that. Spinner-of-Rope, tell me what you see.”

  Spinner opened her eyes, with some reluctance, and looked beyond the construction material cage.