Timelike Infinity xs-2

by Stephen Baxter

  Poole peered at the gaudy display somberly; it was difficult to believe that only a few feet beneath him was an object smaller than an electron but with the mass of a city block, a pinpoint flaw in the structure of spacetime itself. And below that was a plane of grass from which clung, like flies to a ceiling, the Crab’s boat; Berg, Shira, and the rest; the toylike buildings of the Friends of Wigner; and — oddest of all — the ancient stones of the henge, dangling there in Jupiter’s light like a rocky chandelier — or perhaps like rotting teeth in the upper jaw of an incomplete, furred-over skull.

  There must be a layer of air all the way around this craft, he thought. Of course the air must get pretty thin away from the high-gravity regions, close to the center of the plane of singularities.

  Stiffly, he climbed to his feet. "I’m grateful for what you’ve shown me," he said.

  Jaar studied him, tall, very bald, disturbingly pale. "And what do you feel you have learned?"

  Poole shrugged, deliberately casual. With a wave of his hand he indicated the cavern. "Nothing new. All this is impressive, but it’s just detail. The singularity array. There is the meat of the mission; there’s what you’ve gone to all this trouble to bring back through time." He pointed to the shafts that led to the rents in the construction-material dome. "Those things look like cannon barrels, pointing at Jupiter. I think they are cannon — singularity cannons. I think that one by one you’re going to release these singularities from their electromagnetic nets and propel them out of those tubes and toward Jupiter."

  Jaar nodded slowly. "And then what will we do?"

  Poole spread his hands. "Simply wait…"

  He pictured a singularity — a tiny, all but invisible, fierce little knot of gamma radiation — swooping in great, slow ellipses around Jupiter, on each orbit blasting a narrow channel through the thin gases at the roof of the atmosphere. There would be a great deal of drag; plasma bow waves would haul at the singularity as it plunged through the air.

  Eventually, like grasping hands, the atmosphere would claim the singularity.

  Rapidly spiraling inward, the hole would scythe through Jupiter’s layers of methane and hydrogen, at last plunging into the core of metallic hydrogen. It would come to rest, somewhere close to Jupiter’s gravitational center. And it would start to grow.

  "You’ll send in more and more," Poole said. "Soon there will be a swarm of singularities, orbiting each other like insects inside the solid heart of the planet. And all growing inexorably, absorbing more and more of Jupiter’s substance. Eventually some of the holes will collide and merge, I guess, sending out gravitational waves that will disrupt the outer layers of the planet even more." Maybe, Poole speculated, the Friends could even control the merging of the holes — direct the pulsed gravity waves to sculpt the collapse of the planet.

  Eventually, like a cancer, the holes would destroy Jupiter.

  As the core was consumed the structure would implode, like a failing balloon; Poole guessed the planet would heat up and there would be pockets of disruption and instability — explosions that would blast away much of the substance of the atmosphere. Tidal effects would scatter the moons, or send them into elliptical orbits; obviously the human inhabitants of the region would have to evacuate. Maybe some of the moons would even be destroyed, by tidal stresses and gravitational waves.

  "At last," Poole said, "there will be a single, massive singularity. There will be a wide accretion disk composed of what’s left of the Jovian atmosphere and bits of smashed satellites; and the rest of the moons will loop around the debris like lost birds."

  Jaar’s silence was as bland as Xeelee construction material.

  Poole frowned. "Of course a single singularity would be enough to collapse Jupiter, if that’s all you want to do. So why have you brought this great flock of the things?"

  "No doubt you’ve figured that out too," Jaar said dryly.

  "Indeed. I think you’re trying to control the size of the final singularity," Poole said. "Aren’t you? The multiple ‘seed’ singularities will cause the loss of a fraction of the mass of the planet… I think you’ve designed this implosion to result in a final hole of a certain size and mass."

  "Why should we do that?"

  "I’m still working on that," Poole said grimly. "But the time scales… This could take centuries. I understand a great deal, Jaar, but I don’t understand how you can think in those terms, without AS."

  "A man may plan for events beyond his own lifetime," Jaar said, young and certain.

  "Maybe. But what happens when you’ve shot off the last of your singularities? The earth-craft is going to break up. Even if the inner shell of construction material keeps its integrity, the exterior — the soil, the grass, the very air — is going to drift away as the source of your gravity field is shot away into space."

  He imagined the menhirs lifting from the grass like the limbs of giants, sailing off into Jovian space; it would be a strange end for the ancient henge, far stranger than could have been imagined by those who had carved the stones.

  "And what will become of you? You seem determined to refuse any help from us. You must die… perhaps within a few months from now. And certainly long before you see your Project come to fruition, with the collapse of Jupiter."

  Jaar’s face was calm, smooth, characterless. "We will not be the first to sacrifice our lives for a greater good."

  "And the repulse of the Qax is a greater good? Perhaps it is. But—" Poole stared into the Friend’s wide brown eyes. "But I don’t think a noble self-sacrifice is all that’s happening here. Is it, Jaar? You show no interest in our offers of AS technology. And you could be evacuated before the end. There isn’t really any need for your sacrifice, is there? But you don’t fear death at all. Death is simply… irrelevant."

  Jaar did not reply.

  Poole took a step back. "You people frighten me," he said frankly. "And you anger me. You rip Stonehenge out of the ground. Stonehenge, for Christ’s sake! Then you have the audacity to come back in time and start the destruction of a planet… the gravitational collapse of most of the System’s usable mass. Jaar, I’m not afraid to face the consequences of my own actions. After all I was the man who built the time machine that brought you here. But I don’t understand how you have the audacity to do this, Jaar — to use up, destroy, so much of humanity’s common heritage."

  "Michael, you must not grow agitated over this. I’m sure Shira told you the same thing. In the end, none of this" — he indicated the cavern—"none of us — will matter. Everything will be made good. You know we’re not prepared to tell you any more than you’ve figured out already. But you must not be concerned, Michael. What we are doing is for the benefit of all mankind — to come, and in the past…"

  Poole thrust his face into the young man’s. "How dare you make such claims, lay such plans?" he hissed. "Damn it, man, you can’t be more than twenty-five years old. The Qax are a terrible burden for mankind. I’ve seen and heard enough to be convinced of that. But I suspect your Project is more, is bigger, is vaster than any threat posed by a simple oppressor like the Qax. Jaar, I think you are trying to change history. But you are no God! I think you may be more dangerous than the Qax."

  Jaar flinched briefly from Poole’s anger, but soon the bland assurance returned.

  Poole kept the boy in the cavern for some time, arguing, demanding, threatening. But he learned nothing new.

  At last he allowed Jaar to return him to the outer surface. On the way up Poole tried to work the elevator controls, as he’d watched the Friend do earlier. Jaar didn’t stop him. Of course, the controls did not respond.

  When they returned to the grassy plain Poole stalked away to his ship, his head full of anger and fear.

  Chapter 10

  "Michael." Harry Poole’s voice was soft but insistent. "Michael, wake up. It’s started."

  Michael Poole emerged from sleep reluctantly. He pushed back his thin blanket, rolled on his back, and rubbed his eyes. Beside him, he
saw, Berg was already awake and sitting up. Poole lifted himself onto his elbows, wincing at a stab in his lower spine: Shira’s little hut was quiet enough, and the air of the earth-craft was still and comfortably warm; but — despite Miriam’s assurances that the hard surfaces were doing him the world of good — he doubted if he would ever get used to sleeping on nothing more than an inch of coarsely stuffed pallet over a floor of Xeelee construction sheeting.

  Miriam Berg was already pulling on her one-piece Friend’s jumpsuit. "What’s started, Harry?"

  The Virtual construct of his father, coarsened by diffraction, hovered over Poole, fuzzy with pixels. "The high-energy particle flux from the Interface portal has increased. Something’s coming, Michael. An invasion from the future — we’ve got to get out of here."

  Poole, still struggling into jumpsuit and shoes, stumbled to the teepee’s open doorway. He squinted in the Jovian light and turned his face to the sky. The Interface portal hung there, delicate and beautiful, apparently innocent of menace.

  "Spline," Berg breathed. "They’ll send Spline through. The living ships the Friends described, the warships of the Qax, of the Occupation, come to destroy the earth-craft. Just as we’ve expected."

  There was an edge in Berg’s voice Poole had never heard before, a fragility that induced in him an atavistic urge to take her in his arms, shield her from the sky.

  Berg said, "Michael, those things will defeat the best humanity can throw at them — fifteen centuries from now. What can we do? We haven’t got a hope of even scratching their ugly hides."

  "Well, we can have a damn good try," Poole murmured. "Come on, Berg. I need you to be strong. Harry, what’s happening in the rest of the System?"

  The Virtual, sharp and clear out here outside the teepee, shrugged nervously. "I can’t send a message out, Michael. The Friends are still blocking me. But the ships in the area have detected the high-energy particle flux." He met Michael’s eyes, mournfully. "Nobody knows what the hell’s going on, Michael. They’re still keeping a respectful distance, waiting for us to report back. They don’t see any threat — after all the earth-craft has simply sat here in Jovian orbit for a year, enigmatic but harmless. What can happen now?" He looked vaguely into the sky. "They’re — curious, Michael. Looking forward to this. There are huge public Virtuals, images of the portal and the earth-craft hovering over every city on Earth… It’s like a carnival."

  "But once the Qax begin their assault—"

  "It will be too late." Berg took Michael’s arm; the fear still masked her face, he saw, but some of her determination, her cunning, seemed restored. "Listen to me. The best chance of hitting them is going to be now… in the first few minutes after the Spline emerge from the portal."

  Poole nodded. "Right. Causality stress."

  "The Spline are living creatures," Berg said. "Maybe that’s a weakness we can play on; the Qax, and their ships, are surely going to take a while to ramp up to full effectiveness. If we can hit them fast maybe there’s a chance."

  Berg was right, of course. There was a kind of inevitability to all of this, Poole thought. It’s going to be up to us. He closed his eyes, longing for the silence — the lack of decisions — of the Oort Cloud.

  Harry laughed, his voice brittle and too bright. "Hit them fast? Sure. With what, exactly?"

  Poole whispered, "With the singularity cannon."

  * * *

  Berg looked at Michael sharply, possibilities lancing through her mind. "But — even if we get the Friends to agree — the cannon wasn’t designed as a weapon."

  Michael sighed, looking tired. "So we adapt."

  Harry said. "As long as the damn things can be pointed and fired. Tell me how the things are supposed to work. You fire black holes into Jupiter…"

  "Yes," Michael said. "A pair of singularities is launched in each cannon shot. Essentially the device is a true cannon; once the singularities are launched their paths are ballistic. Orbiting each other, a few yards apart, the singularities enter Jupiter’s gravity well. The trajectories are designed to merge at a specified point in the body of the planet."

  Berg frowned. "Ultimately the hole, or holes, will consume Jupiter…"

  "Yes. The Project’s design is to render Jupiter into a single, large black hole of a specified mass—"

  "But that could take centuries. I know the holes’ growth would be exponential, but still you’re starting from a miniscule base; the holes can only grow as fast as their area allows them."

  "That’s true." He smiled, almost wistfully. "But the time scale of the Project is longer than centuries; far longer."

  Berg tried to drag ideas from her mind, ignoring the lowering sky above her.

  How could they use this planetbuster cannon to disable a Spline? If they simply shot off black holes, the tiny singularities would pass through the flesh of the warship. No doubt tidal and other effects would hurt the Spline as the holes passed through, and maybe they’d strike it lucky and disable some key component… but probably not; the Spline was a mile wide and the wounds inflicted by the traversing holes would surely be not much worse than isolated laser shots.

  A multiple strike, a barrage? "What if we launched two singularities to come to rest at the center of mass of the Spline? Could we do that?"

  "Of course." Michael frowned; she could almost see trajectory curves rolling through his head. "We’d simply need to launch the singularities with a low velocity — below the earth-craft’s escape velocity, essentially."

  "Yes." Berg pictured it. Like stones hurled into the air, the singularities would come to rest, hover in the body of the Spline itself… But only for a moment, before falling back. What good would that do? It would take days for the holes to consume the Spline’s mass — hours, probably, to absorb enough material to inflict any significant damage — not the few seconds they would be present in the volume of the Spline.

  Anyway, they wouldn’t have hours to spare.

  Then what?

  "Why send the singularities into Jupiter on such complex trajectories? Why have them merge before they reach the center?"

  Michael shook his head. "You haven’t grasped the subtleties of the design," he said seriously.

  "Evidently not," Harry said dryly.

  "Do you understand what happens when two singularities converge, combine?" He mimed, with his two fists, the singularities approaching each other, whirling around each other, finally merging. "The event horizons merge into a single horizon of greater net area… entropy, proportional to the area, increases. The singularities themselves, the flaws in space at the heart of the holes, fall in on each other; blue-shifted radiation increases the effective mass until the final merger occurs on Planck time scales — the immense gravitational fields generated effectively deflate time. And the joint event horizon quivers like a soap bubble, generating radiation through quadrupolar effects."

  Berg nodded slowly. "And what form does this — radiation — take?"

  He looked surprised by the question. "Gravitational, of course. Gravity waves."

  She took a deep breath, felt her blood surge through her veins a little faster. Gravity waves.

  Michael explained further.

  These weren’t the dinky little ripples in spacetime, propagating at lightspeed, which had been studied by human astronomers for centuries… When two massive singularities merged, the gravity waves were monstrous. Nonlinear distortions of spacetime itself.

  "And the radiation is directed," Michael said. "It pulses along the axis of the hole pair. By choosing precisely the placement and orientation of the holes at merger inside the carcass of the planet, you can direct gravity-wave pulses as you choose. You can sculpt the implosion of Jupiter by working its substance on a massive scale; it was the Friends’ intention, I believe, even to remove some of the mass of the planet before the final collapse. The precise size, angular momentum, and charge of the final black hole are evidently important parameters for the success of—"

  But Berg was no l
onger listening. Then the earth-ship wasn’t just — just — a singularity cannon platform. It was a gravity-wave gun.

  A human-built starbreaker.

  They could fight back.

  Michael looked up and gasped. The color of the sky had changed, and cast gray shades across his face.

  Berg looked up. A vast moon of flesh slid complacently toward the zenith, its gunmetal-gray surface pocked with eye sockets and weapon emplacements. Bloody scars a hundred yards wide disfigured the skin-hull. Berg searched for the Interface portal and made out another of the great elephant-ships emerging from the wormhole passage to the future. Its limb brushed the sky-blue wire framework of the portal, and a layer of flesh boiled away as exotic matter raised tides in living tissue.

  Spline…

  It had begun.

  * * *

  Jasoft Parz, suspended in entoptic fluid, clung to the rubbery material of the Spline’s cornea and peered out at the past.

  Parz’s ship was climbing out of Jupiter’s gravity well now, on its way to its hyperspace jump-off point to the inner planets. The wormhole Interface portal was receding; the portal looked like a bluish scar against the swollen cheek of Jupiter. Parz could see that a second Spline ship, the companion of his own, already loomed over the scrap of Earth green that was the rebels’ craft.

  Parz sighed. "The rebel ship is elegant."

  The Qax said, "It is a scrap of mud hurled into space by hyperactive apes."

  "No. Look at it again, Qax. A camouflaging layer of earth built over a shell of Xeelee construction material… They must have stolen a Xeelee flower, constructed this thing in some deep hollowed-out cavern." He laughed. "And all under your watchful gaze."

  "Under my predecessor’s gaze," the Qax said slowly. "According to the ship’s sensors the thing is constructed around a layer of singularities. A thousand of them, the total amounting to an asteroid-scale mass…"