Probability Sun

by Nancy Kress

  Capelo said again, “Oh my dear God.” And then, flatly, “The son-of-a-bitch is a physicist.” He closed his eyes.

  The gas started then, spraying from the walls. Kaufman made himself sniff, and his knees wobbled in gratitude: not lethal. But no, of course not, he should have realized: two MPs lay unconscious in the connecting room and Kaufman’s own body blocked the door from sealing off this one. Not lethal, at least not to humans. But to the Faller … the sprays were set equidistant in all four walls of the cell …

  Kaufman had the biggest body. Marbet fell first, landing on her back, the nipples of her small naked breasts like blind eyes. Capelo next, toppling almost gracefully from where he sat. Then the Faller, sagging in his manacles, and the last thought Kaufman had before he succumbed was, If Grafton really wants the prisoner dead because he knows too much, this appears perfectly plausible. Shrewd choice.

  His mind slipped away.

  TWENTY-SEVEN

  ABOARD THE ALAN B. SHEPARD

  Capelo came slowly back to consciousness, and the Faller’s sketch came with him. The top figures weren’t flowers, as that fool Kaufman had suggested. They were Calabi-Yau spaces, the accepted configurations for the six curled-up dimensions of spacetime. The Faller’s drawing was stylized differently from humans’ stylizations, and hastily drawn as well. But Capelo was sure. The two figures inside the top half of the circle were two possible Calabi-Yau space configurations.

  Including the Calabi-Yau equations in solving the riddle of the disrupter-beam shield had, of course, occurred to him long before. It had occurred to everybody long before. But the equations didn’t work, they yielded infinity. There was no way to make them work, no matter how you diddled the data. But that thick circular line leading to the Calabi-Yau—

  “Dr. Capelo.”

  —shapes suggested a connection to something else. And the line extended to—

  “Dr. Capelo.”

  —extended to—

  “Dr. Capelo.”

  He gave up and turned his face to the side. “Who the hell are you?”

  “General Victoria Liu, Military Intelligence.”

  Two stars on the shoulder. Of course; there would have to be someone like this somewhere, a SADA line officer whom Kaufman would have to report to on his unorthodox project. But where had she come from? Capelo didn’t care.

  “Leave me alone.”

  “I will. As soon as I inform you of a few crucial points. It won’t take long.”

  Now that he had been jabbed away from Calabi-Yau dimensions and the thick circular line of the Faller’s drawing, Capelo took in his surroundings. Not his tiny cabin, not the brig, not the Faller’s cell. He lay on a bunk in a room fitted with desk, chair, paper, pencils, and access terminal. Through a half-opened door he glimpsed a bathroom. The other door had two e-locks.

  “Am I under arrest?”

  “Yes.” No hesitation at all. “But as I’m sure you understand, you’re a civilian. When we reach Mars, you will be turned over to a civilian court, if the prosecutor deems there to be sufficient charges.”

  “Or if you tell him there are.”

  She didn’t answer.

  “All right, we understand each other. What do you want?”

  “The same thing you do. The model and equations for the artifact’s functioning. Our aims are identical, Dr. Capelo, and without adversarial intent. You want to understand the artifact because you’re a scientist. You’re also a patriot, and you know we need that scientific breakthrough to win this war. There is no conflict between us.”

  “Then why am I under arrest?” Capelo asked.

  “Your methods so far have been irregular enough to warrant close supervision. I think you can’t disagree with that.”

  “Very logical, aren’t you? Reasonable and agreeable. Are you a scientist, General?”

  “I am not.”

  “What makes you think I can create a ‘model and equations’?”

  “Colonel Kaufman said you had some sort of breakthrough about the artifact physics just before we penetrated the scene.”

  “He did? Maybe Lyle can’t tell a breakthrough from a breakdown. I had been swaddled in unwelcome tanglefoam, remember. Twice.”

  “I remember.”

  “Where are my kids?”

  “With their nurse, as always. They haven’t been told you’re under arrest.”

  “And I won’t see them until I cooperate, right?”

  “Wrong. You can see them any time you wish.”

  “What if I just want to see them and the hell with the ‘artifact physics,’ as you so simplistically and incorrectly label it?”

  “That’s your privilege.”

  “But when we get to Mars, I’m in jail until I produce, or until the Big Crunch, whichever comes first.”

  She leaned forward earnestly. “Dr. Capelo, why would you even hesitate to create those equations? Hesitate to help your race when the enemy just wiped out ten million humans on Viridian?”

  “I didn’t say I wouldn’t ‘create the equations.’ But I don’t like being coerced.”

  “You did flirt with treason, Doctor. And I think you know it.”

  “All right, you made your point. Now get out.” She rose. Capelo sat up on the bunk. “No, wait a minute. Where are Lyle Kaufman and Marbet Grant?”

  “Under arrest.”

  “For more than a flirtation with treason. They bedded the old girl down and fucked her hard.”

  “You have a colorful turn of phrase, Doctor. If you need anything at all, there’s a comlink in the desk drawer. Preset for certain types of ship access only.”

  “Including my kids?”

  “Of course.”

  After she left, Capelo said to the computer, “On. Day and time.”

  It said, “Wednesday, four hundred sixteen hours.”

  He’d been unconscious about six hours. Undoubtedly they’d needed that much time to decide how to proceed with him, Kaufman, and Marbet. Kaufman was useless to Capelo. But he might need Marbet again, to help him check results with the Faller.

  Sudden nausea spilled through him. A Faller, one of the bastards who killed Karen … Capelo had actually “talked” to that filthy thing, exchanged ideas with it. And forgotten what it was while he did so. That was the part that sickened him. He’d actually forgotten it was a Faller, thought only about that thick black line, as if it could outweigh Karen, outweigh Viridian, outweigh everything … Loathing for himself filled Capelo. That thick circular line …

  That thick circular line.

  The marker board with the Faller’s last drawing sat propped against the desk. Carefully, as if the floor were a minefield, Capelo got off the bunk. He sat at the access terminal and picked up the marker board. The room disappeared.

  * * *

  He started all over again, from the beginning, as if he had not already worked out anything. The marker board sat propped in front of him. “Sit down before a fact as a little child,” Thomas Henry Huxley had famously said, “be prepared to give up every preconceived notion, follow humbly to whatever abysses nature leads.”

  Capelo the Great Crusading Lone Physicist tried to become a child.

  A particle stream approaches a ship equipped with the disrupter shield, which is prime setting two on the artifact. Call it a proton beam, although it could just as well be photons focused into a laser, or a half-dozen other possibilities. Call it a proton beam. What happens next?

  The beam is actually a stream of tiny oscillating threads. It is also, essentially, a moving smear of probabilities, as are all fundamental particles. The beam passes through the 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. But a proton is a heavy particle, compared to most of this frantic activity, so it speeds on its way without much interruption.

  Unless a heavier particle hits it. All right, look again at that quantum
agitation. A storm of known and unknown particles: virtual particles existing for a brief moment as well as more stable electrons, gravitons, photons, on and on. And, insists Capelo the Great Crusading Lone Physicist but no one else, also probons. Ubiquitous probons, woven into the very fabric of spacetime as thoroughly as are gravitons, so that gravity operates everywhere. As does probability.

  Make the probon heavy, heavier even than Capelo the Great Crusading Lone Physicist had originally thought. Make it heavy because that’s why no particle accelerator anywhere in the Solar System can yet reach the energy levels needed to detect it, which explains why we haven’t. And make it heavy because the circling line on the Faller’s diagram was very heavy in relation to the line on an earlier drawing representing photons.

  Each probon, like all fundamental particles, is made of tiny vibrating threads, and each is a smear of probabilities.

  The probon is a messenger particle, just as gravitons are messenger particles for gravity and gluons are messenger particles for the strong force. The message it carries, the force it transmits, is probability. In the universe as we know it, probability decrees that the path an object takes will be the average of all paths, the path resulting from wave function amplitudes squared, the path that gravity-warped-by-mass makes into the path of least resistance. Mass tells space how to curve; space tells mass how to move.

  The proton beam should therefore hit the ship.

  But we know, have known for two hundred years, that a particle actually takes all possible paths. That proton beam has traveled directly to the ship, has traveled obliquely to the ship, has reached the ship by detouring first to the Andromeda Galaxy. All possible paths. Including through the six curled-up dimensions of spacetime, the Calabi-Yau spaces. That proton beam traveled through the Calabi-Yau dimensions countless times because the dimensions are so tiny, returning each time to its starting place. But, ultimately, the average of all these circuitous journeys is the least-resistance sum-over-paths integral, because that’s the force probons carry and it operates everywhere, just as gravitons make gravity operate everywhere.

  Large masses warp gravity, sometimes to extremes, which is why you have black holes. What warps probons? The artifact? How?

  By changing the beam’s probable path. But no detection equipment anywhere had detected the proton beam the Alan B. Shepard fired at the artifact. The beam hadn’t merely been deflected, it had disappeared. To where? You can’t just lose all that energy; the law of conservation of energy didn’t allow it.

  He looked again at the Faller’s diagram, although it was burned into his brain. From the moment he’d seen the sketch, he’d known. But Capelo stayed with it, worked it out, saw it all as the collection of floating intuitive perceptions that physics had been to him since the age of nine. A child.

  The line on the Faller sketch went into one of the six Calabi-Yau spaces. And then the line continued on to a different Calabi-Yau space, with a different configuration. Only it wasn’t a different space. That’s why the Faller had drawn two “flowers,” not six. The “flowers” weren’t two different Galabi-Yau spaces. They were the same one, transformed.

  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 is 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 into a curled-up dimension.

  And stayed there.

  Why?

  Because the energy it brought into the 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 flop transition might look something like this:

  As the Calabi-Yau space evolves through the tear, what’s affected are the precise values of the masses of the individual particles—the energies in their threads. The tiny vibrating threads that made up the protons, always smears of probability, now vibrate at a different resonance. It has ceased to be a proton, and has become a different, unknown particle. After all, matter itself, at the deepest level, was itself a manifestation of probabilities. The probabilities had been changed:

  He had never seen it. For ten years he hadn’t seen it, Capelo the Great Crusading Lone Physicist. The mathematics of flop-transitions were well established, had been established for a hundred and fifty years. He started to calculate, using the enormous power of the ship’s computer.

  Hours later, it all balanced, the elegant mathematics, and Capelo felt humbled by the hidden, ineffably beautiful structure he had uncovered.

  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.

  The probon was real. Now he had its mass, its spin, its thread constant, its neutral charge. Probability could take its rightful place as the fifth force in the universe. Electromagnetism, strong force, weak force, gravity, probability. No, that wasn’t right … probability had always had an equal place in the universe. It was just that humans hadn’t seen it.

  Had Fallers? Did their physics start at a different place, perhaps even at probability, and come to the same elegant structure by a different path? There were an infinite number of paths: for particles, for physics, for discovery.

  When he finally stood up from the chair, he was shaky from lack of food, lack of motion, uncharacteristic lack of pride. Capelo the Great Crusading Lone Physicist. Not so Lone, after all. He sat down again and looked down at his printed flimsies, at the beating mathematical heart of his theory.

  His critics might say it wasn’t even a theory, but a patchwork of intuitions and guesses and borrowed maths. But Capelo knew in his bones, in his testicles that had given life to Amanda and Sudie, that the theory was true, that it did describe reality, even though many details remained to be worked out. Details of theory, solutions to some of his equations, the role of quantum entanglement. And, of course, the entire mass of engineering details that would take this from mathematics to hardware, which the Fallers had already done.

  Or had they? A sudden thought occurred to Capelo, but he shoved it aside. Irrelevant to the last major step: the remaining Faller drawing to which its line led: a nine-planet star system, the third planet with one moon, the fourth with two, the sixth with rings … the Solar System, with two artifacts drawn within it and a thick circular line canceling the whole thing.

  Was it some warlike statement: “We will obliterate you with our artifact and take yours”? Bellicose bragging from a helpless prisoner of war? Capelo didn’t think so.

  He set about applying his new equations not to the tiny, curled-up dimensions of Calabi-Yau space, but to the large, three-extended-dimensions universe. He already had a few specific numbers to work with, including one for the energy that had fried all of the World star system, except World itself. He worked for more unnoticed hours. Once, when he lay down a flimsy, it encountered a tray of food
he hadn’t noticed anyone bring in. He made himself gulp down something, he had no idea what, and went on working.

  When he finally finished, he sat staring at the results for a long time.

  The probability energy focused by two artifacts was huge. It was enough to do 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 sphere extending fifteen billion lightyears 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 c. And every living thing in it—humans and Fallers, bacteria and grasses, glow-worms and genetically recreated tigers, would die.

  That was why the enemy Faller had been so desperate to give humans the physics it knew. Because it knew from Marbet that humans had an artifact, too, and it knew what would happen if the two artifacts were set off as close together as within the same star system.

  He had to tell somebody. Some military brass who would understand, somebody not stupid enough to either disbelieve him or to take the artifact to the Faller’s home system, where theirs probably already was. Tell somebody … Grafton … no, not Grafton rigid stupid weapon-pusher … Kaufman, then … tell somebody …

  He stood up too quickly, felt the blood rush to his head, and fainted.