Probability Space

by Nancy Kress

  However, she looked much less concerned when she reappeared on the observation deck two-and-a-half hours later. Kaufman and a very silent Marbet had been given tiny quarters with four bunks. Kaufman had dumped Essa in one of them … better the alien girl stayed with Marbet, who could at least talk to her, than at the mercy of Magdalena, self-proclaimedly “Sans Merci.” The room opened off a corridor leading to Magdalena’s stateroom, her bodyguards’ flanking rooms, a galley separate from the crew’s mess or officers’ wardroom, and, at the end of the corridor, the observation deck, filled with comfortable furniture and with a spectacular view of stars. Magdalena’s personal domain.

  She entered the observation deck briskly. Kaufman and Marbet had been talking in low voices, and even Kaufman knew that nothing they said mattered as much as what they didn’t say. Marbet was disappointed in him: for allowing Magdalena to bring Essa, for leaving World on Magdalena’s ship instead of their own, for his confused sense of what he was doing now. Look for Tom? Where? How? Three months ago, he had said there was no point in looking for Tom.

  Ah, but that was when I thought I had a purpose for being on World, Kaufman didn’t say. What was his purpose in looking for Tom Capelo?

  What was his purpose if he didn’t look for Tom?

  “You’re all right,” Magdalena said, with her mocking smile. The blue of her coverall darkened her eyes to sapphire. “McChesney will pass us through the tunnel without boarding. He’ll never know you two are my highly illegal passengers.”

  “And then what?” Marbet said evenly.

  To Kaufman’s surprise, Magdalena answered her. “McChesney won’t know anything about the political situation, not this far out at the rat’s ass end of the galaxy. We go through the tunnel to Caligula space. It’s military, I know people there. Pierce hasn’t had time to change the commands at remote outposts, at least I hope not. But everybody will be very stirred up. A few people I know may be in considerable danger. It may be possible to arrange … deals.”

  Her smile was intended for Kaufman, he knew, the ex-soldier. He put deliberate amusement into his voice. “Magdalena, I hope you’re not implying that I don’t know there is corruption in Stefanak’s military. That assumption would be beneath you.”

  “And you, Lyle. But you may not know how much corruption. Always clean, weren’t you? Like McChesney. And always loyal to Sullivan, too.”

  It was the first time Kaufman had ever heard anyone use General Stefanak’s first name. He didn’t ask why McChesney, if he was so clean, was dealing with Magdalena at all. He didn’t really want to know the answer.

  Marbet said, “The war with the Fallers doesn’t concern you at all, does it? Except as a source of profit.”

  “It’s a dirty universe, Sensitive.”

  Light footsteps ran down the corridor. The next moment, Essa, still in her gaudy celebration tunic, burst onto the observation deck. She saw the dear wall of stars against black space, with World a blue-green dwindling orb in one corner. The alien girl stopped dead.

  Marbet rose swiftly. “Essa, don’t be frightened. We—”

  Essa said something in rapid World. Kaufman remembered that she had been in space once before, among the nine aliens Ann had brought up to the Alan B. Shepard.

  Marbet answered soothingly in World, reassuring.

  “Space!” Essa said in English. She threw herself at Magdalena’s feet, looking up adoringly, her black eyes bright as stars and her skull ridges so crinkled that her head looked like a prune.

  It appeared that Kaufman had been wrong again. Essa did not look frightened or displaced.

  “Space! Essa!” she said, and Magdalena looked mockingly at Marbet and laughed.

  SIXTEEN

  AT SPACE TUNNEL #438

  It took Magdalena’s ship four days to reach the tunnel. That was at an acceleration of nearly two gees, which made everyone uncomfortable. People stayed still in their chairs a lot, except for Essa.

  She was all over the spacious ship. An irate officer dragged her onto the observation deck by one skinny arm. “This alien was in the engine room!” Kaufman refused to say he was sorry. Essa wasn’t his responsibility.

  Somehow, she was Marbet’s. Marbet spent hours with Essa every day, teaching her English. “She’s very intelligent, Lyle, but one of the least fearful people I’ve ever seen. She isn’t scared of anything unless it’s physically threatening her life at that very moment. She’s terribly vulnerable. What are we going to do with her?”

  “I didn’t think we were going to do anything with her. Magdalena is.”

  Marbet said quietly, “You know that’s not true. It would be criminal to leave a child like that with Magdalena.”

  “Marbet, when we return to Sol I won’t know if my false passport had been discovered. I don’t know if I’m subject to criminal charges. I don’t know where we’re going to live, or how I’m going to earn a living. Do you really think it’s fair to saddle me with an alien child?”

  “No, I don’t. But as Magdalena so helpfully pointed out, it’s a dirty universe. We’ve got her.” Marbet paused. “Or at least, I do.”

  Kaufman didn’t like the implications of that. “Are you saying that when we get back to Mars, or Luna, or wherever, we’re not going to be together?”

  “I’m not saying that, no, I am saying that you need to make some decisions, and you’re not making them. You’re just drifting, and it’s turning you jumpy and unpleasant. At least find something to do with yourself on ship, Lyle.” She turned and left. Kaufman could hear Essa calling for her from the observation deck.

  Kaufman knocked on Magdalena’s stateroom door. Rory, the older bodyguard, lounged in a chair outside. Kaufman ignored him.

  “Yes?”

  “It’s Lyle Kaufman. May I come in?”

  The door’s e-lock clicked.

  Her cabin was large and lavish. Rory followed him in. Magdalena lay on the enormous bed, listening to a music cube. She wore a coverall the intense blue of her eyes, and her black hair was loose on the pillow. Damn it, she was older than he by at least ten years, maybe fifteen, she should not have this effect on him. Nor know it. Marbet was right; he wasn’t balanced.

  He said testily, “I want to ask if I can have unrestricted access to your ship’s library, and if you regularly download scientific journals into it.”

  She studied him. “Why?”

  “I want to read the physics journals for the last six months, if you have them.”

  “Can you understand physics journals, Lyle?” She smiled.

  He kept his voice even. At least, unlike Marbet, she couldn’t deduce his thoughts from minute changes in body language. “Not most of the math. But there are abstracts and conclusions, and there are journals that translate breaking events for the educated laymen.”

  “What events do you think are breaking?”

  “I don’t know. That’s the point. But if you want me to help you find Tom—and Laslo—I need to know as much about who took him as possible, and why. Maybe it’s connected to something he was working on.”

  She frowned. “I’m sure the police and the reporters thought of that already.”

  “Probably. But I’d like to look anyway.” For something to occupy myself with, he didn’t say aloud.

  “All right. I’ll instruct the system to let you in. It’s retina-keyed. But, Lyle … just so you know. There’s nothing personal in the ship’s library. In case you thought you’d break some firewalls.”

  “I’m not interested in your personal files,” he snapped, and regretted snapping. It gave her a small victory. He made himself say, “Thank you,” and was disturbed all over again by the mocking smile she gave him in return.

  Damn her.

  * * *

  Kaufman couldn’t use the terminal in his room; Marbet spent too much time there, teaching Essa English while lying on her bunk (which, because of Essa, was pointedly not “their” bunk). The acceleration was harder on Marbet than anyone else. She’d lived for year
s on Luna; she’d spent six months on Mars; World had point-nine Earth’s gravity. She spent much of her time lying down. Kaufman, energetic by temperament, was irritated by her constant horizontal position. It seemed lazy. He knew this was unfair.

  The only other terminal available to Kaufman was on the observation deck. Magdalena had purchased the most comprehensive commercial packet available, automatically fed to her system as soon as the packet arrived in whatever area of space she happened to be occupying. The Sans Merci had apparently passed through Space Tunnel #438 in August, so the library included journals and commentary through then. Kaufman sat in a comfortable chair, heavy hands on the armrests, and talked to the computer for the next three days, trying to follow Tom Capelo’s thoughts through his published papers.

  Kaufman was not trained in physics. But he had always been fascinated by it. And because he had been there when Tom formulated his great breakthrough about probability, Kaufman had followed the evolution of that theory ever since. The theory’s evolution, the resistance it met, the confirmations made by other scientists, the objections and loopholes—all the give and take of scientific discourse.

  Actually, the entire Solar System had been fascinated by Dr. Thomas Capelo’s theory, even those who didn’t know a proton from a protein. The theory, people knew, somehow had produced the disrupter beams that let Faller ships shrug off human particle-beam weapons. Even more important, it somehow had produced the Protector Artifact that kept the enemy from frying the Solar System.

  That last, Kaufman knew, wasn’t accurate. The artifact worked whether humans understood the science behind it or not. Capelo had explained why it worked, but that fact had been far less interesting to the Solar Alliance Defense Council than the fact that it did work. Soldiers were neither physicists nor engineers. They had wanted Capelo to discover what each setting on the artifact did. He had done that. But he had also discovered why.

  As Kaufman understood it, Capelo had justified, both in a model and mathematically, the existence of a particle he’d named a “probon.” Each probon, like all fundamental particles, was made of tiny vibrating threads, and each was a smear of probabilities. It existed at the quantum level, in the seething roiling frenzy that is the quantum world, in which particles are constantly deflected, constantly breaking apart and reforming, constantly erupting from the energy of the vacuum and disappearing again.

  The probon was a messenger particle, just as gravitons were messenger particles for gravity and gluons for the strong force. The message the probon carried, the force it transmitted, was probability. In the universe as human physics knew it, probability decreed that the path an object took was the average of all paths, the path resulting from wave function amplitudes squared, the path that gravity-warped-by-mass made into the path of least resistance. Mass told space how to curve; space told mass how to move.

  But actually, as physicists had known for two hundred years, a particle took all possible paths. A proton beam fired from a warship traveled directly to its target, traveled obliquely to its target, reached its target by detouring first to the Andromeda Galaxy. All possible paths. Including through the six curled-up dimensions of spacetime, the tiny Calabi-Yau spaces. The proton beam traveled through the Calabi-Yau dimensions countless times because the dimensions were so tiny, returning each time to its starting place. But, ultimately, the average of all these circuitous journeys was the least-resistance sumover-paths integral, because that’s the force probons carried and it operated everywhere, just as gravitons made gravity operate everywhere.

  Large masses could warp gravity, sometimes to extremes, which was why black holes existed. The Protector Artifact, that strange leftover from an unimaginable race, warped probability.

  The artifact focused probons, shot a huge number of them at an incoming particle stream, just as a laser focused and shot photons. The artifact thus warped probability, in the same way huge mass warped gravity. The energy to do that was certainly available; the strength of the force transmitted by a messenger particle was inversely proportional to the tension on its threads, and Capelo had calculated fairly low tension for the probon, let alone the energy in the protons. All the energy of these tiny vibrating threads brought about a different path, one of low but not zero probability under “normal” circumstances, and now of 100 percent probability. So the proton beam went not into its target but into one of the six Calabi-Yau spaces, the curled-up dimensions of the universe.

  Once it was there, it couldn’t just lose all that energy; the law of conservation of energy didn’t allow it. So the energy brought into the Calabi-Yau dimension, energy which hadn’t been there before, did something else. It effected a space-changing flop transition, changing the shape of that tiny, curled-up dimension into a different shape. Without affecting our larger, three-extended-dimension universe at all. The energy started by making a tiny tear, and to repair the tear, the Calabi-Yau shape evolved into a different shape, which mathematicians had known was possible almost as long as they had known of Calabi-Yau shapes. The process was called a flop transition.

  The enormous energy needed to alter the beam’s probable path, to change the vibration of its threads, exactly equaled the net energy of the heavier probons minus the energy lost to quantum agitation. The new vibrational energy exactly equaled the energy needed to effect a space-changing flop transition in a Calabi-Yau dimension of a certain probable configuration. A piece of the dimension was unfolded, and then refolded into a subtly different shape, like refolding a part of a complex origami. All the equations balanced, led into one another with natural rightness.

  But there was a price.

  As the Calabi-Yau space evolved through the tear, that affected the precise values of the masses of the individual particles—the energies in their threads. The tiny vibrating threads that made up, say, a proton beam, always smears of probability, now vibrated at a different resonance. It had, in fact, ceased to be a proton at all, and had become a different, unknown particle. This was possible because matter itself, at the deepest level, was itself a manifestation of probabilities. The probabilities had been changed.

  When you applied the equations to the large, three-extended-dimensions universe, the price became terrible.

  The probability energy focused by two artifacts was huge. It was enough to do to the three-dimensional universe what smaller amounts did, over and over, to a small, curled-up dimension of the universe: effect a space-changing flop-transition into a different shape. It did that the same way it did it in the tiny dimensions, by first tearing the fabric of spacetime.

  But in the tiny dimensions, it was a tiny tear, easily repaired with the energy pouring in at the same time from the entire probability-altering event. In the large extended three dimensions, there wasn’t enough energy. The “tear” would spread, and the total dimensional shape of the universe—now a benign hyper sphere extending fifteen billion light-years before curling back on itself—would undergo a topology-changing flop transition.

  But the vibrational patterns of the threads that make up spacetime were intimately dependent on the shape of the dimensions in which they vibrated. Not the size, but the shape. If the three extended dimensions of the universe underwent a flop transition, its threads would vibrate in different patterns, giving rise to different fundamental particles. Extended spacetime itself would be different, the disturbance to its fabric traveling outward at light speed.

  And every living thing in the universe—humans and Fallers, bacteria and viruses and genetically recreated elephants, would die.

  This much Kaufman understood, at least superficially. Now he tried to follow the work that had been done, by Capelo and others, on the probability equations and their implications. He was looking for something, anything, that might have led someone to kidnap Dr. Thomas Capelo. To keep Capelo working on some specific idea, or keep him from publishing some specific idea, or something. Anything.

  Kaufman didn’t find it.

  All he could discern from t
he masses of equations and heavy prose in the journals, or from the breathless, sensationalized speculation in the popular press, was that there was one huge hole in Capelo’s theory. It didn’t account for macro-level quantum entanglement. That was the most accepted idea about how the space tunnels worked, and Capelo had not tied together probability, as a fifth universal force, with quantum entanglement. Some physicists saw this as a flaw so fundamental that it invalidated Capelo’s whole theory. Others saw it merely as a blank to be filled in as the theory was refined and added to. Capelo himself, in the one interview with him in Magdalena’s library, seemed to see it as neither.

  It gave Kaufman a little start, seeing that thin dark face with its inevitable irritable expression, come up on the terminal. Capelo had never suffered fools gladly. He said that yes, quantum entanglement had not yet been accounted for. No, he didn’t think that invalidated his theory. No, he didn’t think he’d published prematurely, given that General Stefanak had ordered him to do so and everyone in the scientific world knew how profound was the military understanding of physics.

  Despite himself, Kaufman smiled. Same old Tom.

  But Kaufman was no nearer to any idea of why Capelo had been kidnapped. Perhaps it had, as Stefanak had claimed, been Life Now, seeking something major and emotional to blame on the Stefanak regime.

  Perhaps it had been the Stefanak regime, seeking something major and emotional to blame on Life Now.

  Perhaps it had been some third party, a ransom attempt aborted midway.

  Perhaps Tom was already dead, as Stefanak was.

  Kaufman had gotten nowhere, and had wasted three days doing it. But, then, what else did he have to do?

  “Lyle!” a voice screamed down the corridor. Marbet. “Lyle, come quick!”

  Marbet never screamed. Kaufman hurled himself out of his chair, despite the gravity, and ran clumsily to their cabin.

  * * *

  She’d spent too much time just lying on her bed, Magdalena thought, and that was bad. It wasn’t the gravity. She could handle gravity, handle her ridiculous passengers, handle McChesney and, in Caligula system, that bastard Hofsetter. What Magdalena was having trouble handling was the fear.