Supersymmetry

by David Walton

  “The last I saw, he was still alive. He’s smart and strong, Mom. He’ll find a way.” She tried to sound like she meant it, though all she could think of was the casual way Jean had killed her friends. Could he really survive against a varcolac?

  “What about you?” Angel asked. “How do you feel?”

  “Okay, I guess. My head is about to explode, but besides that . . .”

  “Not physically—I mean, about what just happened. You and your sister . . . I mean . . . you . . .”

  Alessandra shook her head. “I’m not thinking about that right now. I haven’t had time to process what it means.” She didn’t want to think too hard about it. Who was she now? What had she lost? She remembered not wanting this to happen, both as Alex and as Sandra, each of whom had feared they would lose their identities. Now that it had happened, now that she was just her, Alessandra, she wasn’t sure it was such a bad thing. But did that mean that it wasn’t? Would her prior selves have agreed? Or were they dead, leaving only her . . . whoever she was?

  She couldn’t think about it, not now.

  “What’s that thing in the middle of the room?” Angel said. He pointed to the 3D display of Ryan’s universe.

  Alessandra raised an eyebrow, wondering at the question. “It’s a photoionization microscopy display, used to visualize quantum n-dimensional data in an intuitive, three-dimensional arrangement.”

  His eyebrows went up. “Wow. It’s really true.”

  “What?”

  “Sandra didn’t know that. A few hours ago, she said she didn’t know what that thing was.”

  He was right. She could remember saying she didn’t know. She could even remember not knowing. But now she knew now exactly what it was and how it worked.

  “My father knew this would happen,” she said. “At least, he knew the probability field was weakening, making it more likely that . . . we . . . would come together.” She had started to say, “Alex and I,” or else, “Sandra and I,” but neither seemed right. Although, neither did referring to either of her previous selves as “she.” The pronouns were confusing.

  “And his data seemed to suggest that Oronzi’s work was the cause,” Angel said. “But how could that be? After all this time, what could have made a difference?”

  “I don’t know,” she said. “Maybe his work just shook things up.” It wasn’t an answer the physicist part of her was satisfied with, but at this point she really didn’t have a better one.

  Angel stroked his chin. “It must have been essentially the same technology that you used fifteen years ago, right? The wave didn’t resolve then. The technology was still there. But the varcolac wasn’t.”

  “What do you mean?”

  “According to your story, you split at exactly the same time that the varcolac was shut out of our universe. The standing probability wave was created at that moment.”

  “You’re saying the varcolac had something to do with it?”

  “I’m saying, what if it was your probability wave that kept the varcolac from returning? For years and years, you two are completely separate, and there’s no sign of the varcolac. Then as soon as the wave starts to lose strength, the varcolac starts interacting in the world again. It can’t be a coincidence. I’m wondering if one is the cause of the other.”

  “Or if both have the same cause,” she said. Then she sat up, ignoring the sudden throb of pain in her head. “That’s it!”

  “What’s it?”

  “You’re right. You must be. I always wondered why the varcolac was going after Alex and me. It seemed to have a specific vendetta, showing up wherever we were. I mean, why kill us? It was like it wanted revenge for shutting it out fifteen years ago. But what if you’re right, and it was our standing probability wave that it was trying to kill? Maybe the wave had been weakening, allowing it access, but it wasn’t completely gone. It was still preventing the varcolac from fully interacting with our world.

  “It makes sense of a lot of things. It explains why it wanted to kill us particularly. It also explains why it failed, despite its power—it’s not at its full strength. It’s only partially able to manipulate things in our universe. Not only that, but it explains why it wasn’t able to possess us directly, despite seeming to be able to possess anyone around us and use them to attack.”

  “What about your father? The varcolac attacked him first, not you.”

  “No, it didn’t. Remember, it killed him by sending a particle back in time.”

  “I don’t understand.”

  “My dad knew about the standing wave. If we’re right, he knew it was what was keeping the varcolac out. What if he figured out a way to delay its collapse or even strengthen it? It would have preserved us—me—as two different people, and it would have kept the varcolac away. But then, what if after he did so, the varcolac had to attack in a different way, by sending the Higgs singlet back in time to kill him before he figured it out in the first place?”

  Angel held her gaze intently. “Let’s say that’s right. What happened to the original timeline? In which your father defeated the varcolac and preserved you as two separate people?”

  Alessandra pressed her lips together and shook her head. “It was destroyed. Erased. A new history began with the stadium disaster.”

  “How do you know?”

  She shrugged. “I don’t entirely know. But the multiverse theories have always been a bit fanciful. It’s hard to believe that entirely new universes are being created all the time, whenever any particle’s probability wave collapses. The math certainly doesn’t require it. Remember Ryan’s illustration with the billiard balls? There’s only one timeline. The universe solves the equation so that causality is preserved.”

  “You’re saying that it creates a loop? That the changed event in the past causes a situation that results in the particle being sent back in time to change the past?”

  “Pretty much. Not in the same way, necessarily, but somehow a sequence of particles will cause that one to be created and sent back with the exact properties needed to cause this timeline. It sounds crazy, but the math works out. The solutions are possible, and the universe finds them.”

  “What would happen if we sent a particle back in time to smash into the varcolac’s particle, and we stopped it from destroying the stadium and killing your father?” Angel asked.

  Alessandra gave a rueful smile. “We would all die.”

  “What? What do you mean?”

  “This timeline, in which you are I are living, would be erased. We would cease to exist—to have ever existed. Time would be recreated from that point forward. The stadium would never have been destroyed. My father would live, perhaps long enough to defeat the varcolac, but you and I would never know it.”

  “What do you mean? We would still be alive, too.”

  “No. Other very similar people named Angel and Sandra and Alex would still be alive. But they wouldn’t be us. They wouldn’t have our memories or experiences. They would be as different from us as Sandra and Alex were from each other. Different options, different choices, different people.”

  Angel’s forehead wrinkled at the thought. “I see what you’re saying,” he said. “I wouldn’t have thought of it that way, but then, I haven’t lived side by side with an alternate me for the last fifteen years.”

  “Sandra!” her mother called. Alessandra thought about correcting the name, but she heard the concern in her mother’s voice. Her mother had been sitting in a corner of the lab, reading something on her phone.

  “What is it?” Alessandra asked.

  “You’d better look at this,” her mother said.

  She held up the phone. The news headlines read: NUCLEAR BLAST DESTROYS KRAKOW. WAR DECLARED.

  Angel caught her eye. We have to do something, he seemed to say. He was looking to her for a solution. But what could she possibly do?

  CHAPTER 27

  Over the course of the next three hours, nuclear blasts destroyed the cities of Berlin, Frankfurt, an
d Istanbul. The president of Turkey went on the air to urge restraint, claiming that his country had not fired any of the weapons. He asked the surviving leaders of Poland, Germany, and the United States to consider a summit to discuss peace accords. Poland and Germany refused. The United States remained silent.

  Then Russia, which had so far remained neutral in the conflict, inexplicably fired high-yield nuclear missiles on China’s three largest cities. Shanghai, Beijing, and Guangzhou disappeared before the sun had risen in New Jersey, and a hundred million people died. The Russian premier, looking genuinely horrified, mirrored the Turkish president’s claim that the weapons had not been fired by his government, but it was too late. Ancient globe-spanning hatreds and mistrusts were reignited around the world. Militaries were put on high alert, fleets were launched, and world leaders were evacuated to secure locations.

  “It’s the right thing to do,” Angel said. “If it’s at all feasible to send that particle back and change the past, we should. We’re going to die anyway. Humanity itself as a species might not survive. If there’s any possible chance to reverse that, it’s our moral obligation to do it.”

  “Think about what you’re saying,” Alessandra said. “Even if it were possible—which, let me tell you, I sincerely doubt—you’re talking about annihilating everyone. Murdering everyone currently alive and replacing them with different versions of themselves, in a brand new timeline. Nuclear weapons can kill millions, but what you’re suggesting would kill everyone.”

  “It’s not like that. Except for any children born in the last few weeks, those people would be alive. All the people dying in those cities right now would be alive again. It’s not killing them; it’s saving them.”

  “Think of it like a river,” Alessandra said. “We’re floating along downstream. What you’re suggesting would be like damming the river and sending it floating off in a different direction. There would be a different timeline—different people, different events—but it wouldn’t be us. Our whole universe from that point onward would disappear. We would be dead, replaced by a different version of ourselves, living in a similar but different universe.”

  “I agree with Angel,” her mother said.

  Alessandra turned on her, feeling hurt, but her mother put a hand on her face, momentarily stopping any angry outburst. “You’re wrong. Don’t you feel it? Sandra and Alex haven’t died. They were always the same. They were always you, and they still are. Different careers, different friends; those things were peripheral. It was always you. My daughter. My Alessandra.” She stroked her cheek. “To do this, it won’t be killing anyone. A different version is still the same person.”

  Alessandra shook her head. “It isn’t right,” she whispered. “It’s what Jean tried to do. She didn’t like the daughter that genetics had served up for her, so she tried to reshape her. To kill the present version of her daughter in favor of another. How can we make that choice for everyone?”

  “The varcolac won’t stop,” her mother said. “You and I were both there. Remember? Kidnapped and trapped by that monster? It won’t stop. It will track down every last human being until there are none left. Preserving the lives of people as they are now isn’t an option on the table.”

  “Besides,” Angel said. “Not doing it is choosing for them, too. How many people in big cities right now do you think would prefer we do nothing? Russia has thousands of nukes; the United States nearly as many. If the varcolac can control them, it’ll be a long time before it stops.”

  “We could chase it,” Alessandra said. “We could track it down and fight it. Stop it from killing anyone else.”

  “Could we?”

  Alessandra thought about it. “No,” she said. “But then, I don’t think we can send a Higgs singlet back in time, either, not with that kind of control. It’s never been done. It’s never even been attempted.”

  “I believe in you,” her mother said.

  Alessandra threw up her hands. “I’m no genius like Ryan.”

  “That’s probably a good thing,” Angel said. “Look, just explain the principle to me. I won’t understand it, but it’ll help you think through the problem. Between the NJSC and the High Energy Lab, we have the best equipment in the world available to us. You’ll think of something.”

  “I’m not so sure.”

  “Just start talking. If someone could do such a thing, how would they go about doing it?”

  “Gravity,” she said with a sigh. “They would need an immense gravitational pull.” She repeated for Angel the same illustration that Ryan had used with the golden eagle on Hawk Mountain. How the eagle’s possible locations—limited by the speed of light—were shifted by the gravity of a massive nearby object.

  Using a shared eyejack space, she started drawing in the air with her finger, making lines that the three of them could see. She drew a simple pair of axes on the board, marking the horizontal axis x and the vertical one t. “Okay. The x axis is for movement in space; the t axis is for movement through time. So, if I draw a V, like this”—she switched to a red color and drew a V shape with its point at the origin—“that represents the area the eagle can theoretically fly, right?”

  “As time advances, it can range farther in space,” Angel said.

  “Right.” She almost smiled, but then the news feed in the corner of her vision reported that Tokyo and its fifty million people had been erased from the map by a pair of American nukes. It was hard to process. It was so horrible, so far beyond horrible, that her mind was rejecting it. “This is stupid,” she said. “What are we doing? This won’t accomplish anything.”

  “Please. Keep talking.”

  She sighed. She couldn’t shake the idea that she should be doing something, either fighting the varcolac, or at least finding somewhere far from cities to hide.

  “Okay. Let’s say I was standing near a black hole when I turned my light on. The black hole’s gravity would deform space-time toward itself. It would change the cone like this.” She drew a new V, only now it was tilted toward one side.

  “The photon could travel farther if it traveled toward the black hole than if it traveled away from it, since the black hole’s gravity is, in effect, pulling it in.”

  “Why is it tilted toward the right side?” Angel asked.

  “It doesn’t matter which side. It’s just showing that the eagle’s possible travel locations are skewed toward the black hole.”

  Her news feed reported the destruction of Karachi and Jakarta. The numbers of dead were becoming inconceivable, meaningless. She stopped talking and just watched as Mumbai was added to the list, then Moscow, and then São Paolo. Images from weather satellites showed mushroom clouds surging with radiant heat.

  “He’s going in order,” Angel said. He was watching the same feed.

  “What?”

  “Ryan has a list of the populations of major world cities. Tokyo was the biggest. Then the three Chinese cities, then Karachi, then Jakarta. After the first few, he just started working his way down the list, killing the largest possible number of people with each blast.”

  The sheer coldness of that put a chill down her back. He was a sick, evil man. She couldn’t believe she had talked to him, had ridden in his car. She had put her arms around him when she thought he had come to rescue them. Could the nervous, phobia-driven man she had briefly known really be systematically killing off the world’s population? What she said was, “Where’s New York City on the list?”

  “It’s down to number thirty-five. American population growth has been dropping compared to the rest of the world. But New York is seventy-five miles away; we should be safe enough. I mean, we might get an unhealthy dose of radiation, but we’re well outside the blast range.”

  Alessandra shook her head. “It’s the EMP I’m worried about. Depending on how high it actually detonates, it could knock out electronics as far as Chicago.”

  “This is a high-security government lab. Wouldn’t it be shielded?” her mother asked.
r />   Kinshasa, the news feed reported.

  “Maybe,” Alessandra said. “But it’s not the lab that’s the problem. The super collider has thirty miles of electromagnets with associated infrastructure that relies on above-ground power sources. It wouldn’t survive.”

  Angel moved his eyes up and down, scrolling through a list. “We don’t have much time, then. He’s been taking out a city every few minutes.”

  Alessandra stood up taller and spoke with a stronger voice. “All right, then. Let’s get moving.” She pointed at the light cone again. “This cone is how we define causality. Since nothing can travel faster than the speed of light, only things located inside the cone in space and time could possibly be affected by anything that occurred at the origin of the graph. Anything outside that cone is causally independent.”

  “So you’re just telling me that what the varcolac did was impossible,” Angel said.

  Mexico City.

  Alessandra glanced at the news feed and started talking faster. “An object in orbit around the black hole would travel straight down the middle of this cone. From its own perspective, it would be in free fall—not moving, just staying on its local t axis. But to an outside observer, it’s moving in space, falling into the black hole.”

  “I sense the moment coming where you totally lose me,” Angel said.

  Delhi, the feed said. They were coming faster. The satellite images scrolling by left no doubt as to the reality of the disasters. Alessandra swallowed back tears and tried to keep talking. “What we need to do is turn the cone backward,” she said. “We need to warp the fabric of space and time so radically that the light cone looks like this.” She drew a new V, this one tilting so far that its edge reached into negative time.

  “This would mean the span of possible travel for our particle includes points down here”—she tapped the graph—“earlier in time than where it started.”

  Shenzhen.

  “I don’t understand,” her mother said. “What are we talking about?”

  “Gravity,” Alessandra said. “Like I said, an immense amount of gravity. We need to create a black hole.”