Supersymmetry

by David Walton

  “Yes. And if we keep on going?”

  “Um . . . faster still?”

  “Eventually the slope becomes vertical. At that point, the bird isn’t sliding toward the black hole; it arrives there instantly. What if we add even more mass?”

  Sandra shrugged. “You’re going to tell me, I bet.”

  “Space-time becomes so warped that the slope is backward: the only solution to the equation is negative. Now, instead of a black hole, we call it a wormhole. Unlike the wormhole that connects my baby universe to ours, this one connects our universe in the present to a point in the past. The eagle is sucked through the wormhole and arrives before it left. Of course, it’s been ripped apart into its constituent atoms, but besides that, it’s fine.”

  “What do you have against birds?” Alex asked.

  “The point is, the topography of space-time allows time travel. Not for eagles or humans—the process would completely destroy us. But for single particles, yes. The NJSC, in fact, has successfully demonstrated time travel for Higgs singlets.”

  “I know you’re a genius and all, so you probably know what you’re talking about,” Sandra said. “But there’s a paradox here, right? If something goes back in time, there’s always the possibility that it can interfere with its own creation. Like going back in time and killing my own grandfather. What if the Higgs singlets, traveling back in time, get in the way of the protons that were about to collide to create them? Or what if you use the singlets to send your past self a message, warning you not to perform the experiment in the first place?”

  Alex spoke up. “The universe won’t allow it.”

  “The universe?”

  “That’s right.” She looked at Ryan. “May I?”

  Ryan made a mock bow.

  “All right,” Alex said. “I think we’ve exhausted the eagle analogy. Let’s move on to billiard balls.”

  Sandra crossed her hands in her lap and looked up with an attentive expression, as if in class.

  “The problem you raise is called Polchinski’s paradox,” Alex said. “Say you roll a billiard ball through a wormhole, so that it goes five seconds back in time.”

  “Okay.”

  “Only, you roll it through the wormhole at such an angle that it hits its earlier self, thus preventing itself from rolling into the wormhole in first place.”

  “That’s what I’m saying. It’s a paradox.”

  “And that’s why it can’t actually happen,” Alex said.

  “Can’t happen? Who says? Is there a referee that cries foul and takes you out of the game?”

  “Not exactly. But the universe can’t contradict itself. There’s a natural law that says self-consistency is always conserved. If you roll the ball through the wormhole at its past self, then either it will miss entirely, or else it will deliver itself a glancing blow that will knock it into the wormhole at such an angle that it will give itself that glancing blow,” Alex said.

  “You’re kidding,” Sandra said. Then she made a connection in her mind, and without thinking, said, “It’s called the Novikov self-consistency principle, isn’t it?”

  Ryan’s surprise was obvious on his face. “You really did grow up with a physicist father, didn’t you?”

  Sandra shrugged, surprised herself. “I guess so.”

  “Well, you’re right,” he said. “It’s the only way the math works out. In fact, this specific case, with billiard balls, has been studied.”

  Sandra raised an eyebrow. “People have been sending billiard balls back in time?”

  “No, I mean mathematically. Echeverria and Klinkhammer set up a computer simulation with billions of variations. They showed empirically that, not only do most conditions have multiple solutions, but that there are no initial conditions for which no self-consistent solution exists. It’s actually where my work started.” Ryan’s excitement grew as he spoke. “The universe is a giant quantum computer, remember? It takes these complex consistency problems and solves them. It’s doing it all the time.”

  Sandra grew sober. “And the varcolac fits into that somehow, doesn’t it?”

  “It’s a sentient manifestation of that quantum computer,” Alex said. “It’s like an artificial intelligence, only on a vaster scale.”

  “You’re saying the varcolac is the universe?”

  “No. Or at least, I don’t think so. It’s an intelligence born out of the quantum complexity of the universe. We don’t even know if there are many of them, or only one. Or if that distinction even has meaning to a being like that.”

  “And it can travel in time?”

  “I can travel in time,” Ryan said. “At roughly the rate of one minute every minute.”

  Sandra made a face. “At some other rate than the usual,” she clarified.

  “No. Not travel, exactly, not like you’re thinking. It wouldn’t be able to send its intelligence back to a point in the past; that would be like rewinding the particle interactions of the universe. But could it send a Higgs singlet back in time on exactly the right trajectory to cause a chain reaction that destroys a baseball stadium? Yes. I think it might very well be able to do exactly that.”

  Sandra felt suddenly tired and sad, overwhelmed by the conversation. It wasn’t just a distracting intellectual exercise anymore. She spoke quietly. “Why? Why would it do such a thing?”

  “I don’t know,” Oronzi said. “Maybe your father would have found a way to stop it, and it could see that somehow.”

  Alex stood up and stretched. “This is all a possible explanation, but how do we test it? How can we know if that’s really what happened, or if it’s just a wild fantasy?”

  “We go back to the lab,” Oronzi said. “We pore through the logs, double-check the math, look for anomalies. See if we can find when such a thing might have happened.”

  Sandra shook her head. “You two go. I need to be alone for a while.”

  “Are you okay?” Alex asked.

  Sandra smiled wanly. “Not exactly.” In truth, she wasn’t okay at all. Her father was dead, and she had hardly even paused to let that truth sink in. Her mother was all alone, and instead of helping her when she needed them the most, they were worrying about murder charges and time-traveling quantum creatures. “Has anyone even told Claire? Or Sean?”

  “I’m sure Mom called them.”

  “There’s going to have to be a funeral, you know. They’ll arrest you, if they see you there.”

  Alex shrugged. “That’s all right. I don’t need to go.”

  “We could switch. We’ll wear the same dress. I’ll go into the bathroom with a GPS, then I can teleport out, and you—”

  “No.” Alex took Sandra’s shoulders. “You go. I don’t want to see him like that.”

  Sandra nodded. “All right.”

  “I need to get back to the lab,” Ryan said. “If we’re right about the varcolac changing the past, we need to understand how it works.”

  “I’ll come, too,” Alex said.

  “Okay,” Sandra said. “I’ll see you later then.”

  “What are you going to do?”

  “I’m going to walk down the mountain. I just need some time to think. Then I’ll go find Mom.”

  “Later, then.”

  “Later. And Alex?”

  Alex turned. “Yes?”

  “It’s not your fault.”

  Alex made a tiny shrug, noncommittal, and frowned. “Thanks.”

  Ryan and Alex made eye contact and then teleported away, leaving Sandra alone on the mountain. Sandra took the trail leading from the peak back down to the road. She was still wearing her police uniform, which attracted looks from the other hikers, but the slope was an easy one, and the walk pleasant. She soon settled into a comfortable pace. The pretty, wooded surroundings and the sound of birdsong increased her melancholy.

  In truth, it was more than just her father’s death that was bothering her. She was certain, quite certain, that she had never heard of the Novikov self-consistency principle, a
nd yet she had come up with the name in an instant. She wanted to tell herself that she must have heard of it a long time ago, when she was a child, and it just came bubbling to the surface of her memory at that moment. But she knew that wasn’t true.

  It was Alex’s memory. Her sister knew very well what the Novikov self-consistency principle was, and Sandra had accessed that knowledge as if it were her own. It was what had happened fifteen years ago to her father, shortly before he resolved into a single person, after having been split in two for months. It made her afraid that their probability wave, after all this time, was in danger of collapsing. Maybe the reason they had remained two individuals for so many years was because the varcolac was gone. Now that it was back, maybe they would resolve into one person again.

  And what if they did? Who would Alessandra Kelley be? She and Alex were such different people now, with different skill sets, different desires, different relationships, different lives. Would either of them survive in any meaningful sense? Or would one personality dominate, and the other, for all practical purposes, die? Sandra was afraid that if it came down to strength of personality, there wouldn’t be very much of her personality left.

  She thought of her father, and his brief split before death. How awful for her mother, to have him home, to think him safe, and then to have him so suddenly gone. She ought to visit her. Sandra checked her phone and found the GPS log. She had made calls when in her old bedroom, and the data was still there. No one would be in her room.

  On her eyejack system, she brought up the menu of quantum functions that Alex had copied for her. There was a professional-looking menu with a military feel and a tiny Lockheed Martin logo. The options were tagged with unfamiliar icons and words like State Spin, Diffract, Tunnel, Attraction, and Probable Split. The only one she was familiar with was Teleport, and it didn’t seem very safe to experiment with the others. She accessed the teleport function, and her bedroom materialized around her.

  She grinned. It was such a rush, doing that. She barely understood how it was possible. She didn’t even have as much as a battery on her to provide the power. There was so much energy bound up in the basic structure of the universe. Technology like this would make primitive techniques like burning fuel a thing of the past. If they could learn how to tap it without calling murderous alien creatures out of the space between the atoms, that is.

  Sandra heard talking from her parents’ bedroom; it sounded like a comedy show on the stream. She didn’t want to startle her mother by walking in on her, so she sneaked downstairs and out the front door, and then rang the doorbell. A few minutes passed before her mother opened the door. Her normally pale face was leached of color, except for the skin around her eyes, which was red and raw. She wrapped her arms around Sandra without a word and buried her face in Sandra’s hair. Sandra remembered her mother as such a strong presence in her life, but her thin body felt fragile in Sandra’s arms.

  They went inside. Her mother went through the mechanical actions of pouring Sandra a cup of coffee. The forensics crew must have been through, looking for evidence to support the claim that her father had been here after the explosion, but the kitchen had since been cleaned to an antiseptic shine. Sandra had last seen her father right there, sitting at that table, poring over the data she had given him.

  “Is Claire here yet?” Sandra asked. She knew without asking that Claire would take care of the arrangements for the funeral. Claire was the planner in the family, the organizer of all details, and always had been. Even from California, Sandra had no doubt she was already making calls and writing lists of what needed to be done.

  “Her flight doesn’t come in until nine-thirty.”

  “And Sean?”

  “He called.” Her mother’s voice sounded dead, devoid of emotion. “You know the military.”

  “Will they let him come home?”

  “You mean, was it his choice or theirs for him to stay in Poland? I don’t know. He said something about a special mission.”

  Considering the current friction with Turkey, talk of a special mission was a frightening thing. Turkey’s influence had been spreading across the Balkans for years, and now Greece, Bulgaria, Romania, Serbia, Croatia, Hungary, and Slovenia had all been quietly assimilated, either through military threat or economic pressure. Allied with an increasingly powerful Iran, Turkey maintained a strong source of oil and a secure southern border. The growing Turkish navy now dominated the Mediterranean. Worse, they had apparently recovered a stockpile of Soviet nuclear warheads left over in Romania from the Cold War. The Romanian government had previously declared the weapons disassembled, but Turkey now claimed they were operational.

  American politicians were anxious to restore balance in the region before Turkey grew into a world power, so they were pouring troops and money into Poland and Germany. War seemed inevitable. As a Force Recon marine, Sean wasn’t trained for a back-row seat. Sandra didn’t know how her mother would survive if the next funeral was his.

  “I’m sure he’ll be okay,” Sandra said.

  Her mother forced a smile and squeezed her hand. They sat there for a while, their hands clasped across the table, not talking about war, or her father, or varcolacs, or what the future might hold. Memories flashed through Sandra’s mind, cued by this so-familiar kitchen. The memories that came from both before her split with Alex and those that came after merged seamlessly together in her mind. It was as if at fourteen years old, she had suddenly gained a twin sister. It felt to her like Alex was the new one, and she the daughter who had always been there. Of course, it would have felt just the same to Alex.

  Sandra wanted to share some of these memories with her mother. They were good memories, on the whole. Her father had loved them all, though imperfectly, and they had loved him. He had been a father who was present in their home, for whom family, rather than work or friends or other ambitions, was the highest priority. She said none of these things to her mother. There would be time for such remembrances. For now, she just held her hand.

  A ping told Sandra that someone was trying to contact her. She checked her phone, and saw that it was Angel Gutierrez. “Hello?” she said.

  “Sandra. It’s me. Do you have some time to talk?”

  “Yeah, sure.”

  “I mean, in person? I don’t think this should be going over the airwaves.”

  “Sure. Where are you?”

  “At the robotics lab at U-Penn.”

  Sandra turned to her mother. “I need to go meet someone.”

  “Go ahead,” her mother said. “I’ll be okay. I’ll have to pick up Claire from the airport soon anyway.”

  Sandra left the house and closed the door behind her, then spoke into her phone again. “Is there anyone else there at the lab with you?”

  “No. Why?” Angel said.

  “Send me the GPS data from your phone.”

  “Um, okay. Done.” She could hear the confusion in his voice. “Does that mean you’re coming?”

  “Yeah. One more thing. Can you clear away anything within about five meters of where you’re standing?”

  “Um, it’s pretty clear already.”

  “Pretty clear?”

  “Nothing but a folding chair, which I just slid out of the way.”

  “Great. Now walk five meters away yourself, and don’t move.”

  “This is really weird, Sandra. Are you watching me or something?”

  “Did you do it?”

  “Yes. How long do I have to stand here?”

  Sandra smiled. “Not long at all.”

  CHAPTER 14

  Sandra materialized in the University of Pennsylvania robotics lab. Angel, standing five meters away, leaped back with a shriek and crashed to the floor, knocking over a folding chair with a clatter. Sandra shrugged. “Sorry,” she said. “Did I startle you?”

  He looked up at her from the ground with an expression of utter astonishment. “Where did you come from?”

  “My parents’ house. It’s about
twenty miles west of here, in Media.”

  “No, I mean, just now. Were you hiding in here?” He looked up, examining the ceiling tiles above her.

  She laughed. “Nope. I just teleported right in. That’s why I needed the coordinates. And why I asked you to stand aside.”

  “You . . .”

  “Teleported.” Sandra was enjoying this, despite the seriousness of the situation—or maybe even because of it. “I’ll tell you all about it. But you wanted to tell me something, too, right? Which should we do first?”

  Angel stood shakily to his feet. “I think we’d better start with you explaining how you just did black magic in my science lab.”

  The lab’s interior was two stories high, and most of the space was taken up by a central cage, no more than a wooden framework wrapped with tightly stretched mosquito netting. The inside of the cage was entirely empty, except for a series of cameras and motion sensors affixed at regular intervals. Outside of the cage, the room was cluttered with metal folding chairs, ladders, scraps of wood and piping, tablets, wiring, and card tables piled with random electronics. Sandra saw a few surprising items as well: hula-hoops, brightly colored beach balls, and marching-band batons.

  “Okay, fine. Watch. This is the technology my sister was working on.” It was supposed to be super-classified, Sandra knew, but she wasn’t a government employee. No one had sworn her to secrecy. If she wanted to show off for Angel and tell him all about it, she’d do as she pleased. Sandra looked inside the wood-and-mesh cage and estimated the distance. Teleporting this close, she wasn’t too worried about making a mistake. She disappeared and reappeared in the middle of the empty cage. To her, it seemed as though the entire room had suddenly shifted. Angel was still staring at the spot she had been standing a moment earlier. “Hey,” she said. “Over here.”

  Angel turned and saw her, his face incredulous and a little frightened. “Is this really happening?”

  “There’s more. Soldiers with this technology can walk through walls, dodge bullets, even rip an enemy’s gun out of his hands from across a field. They’ll be practically invincible.”