Split second, p.14
Split Second, page 14
“Believe it or not,” said Blake, “I’ve actually read a story about Hawking’s conjecture. You jogged my memory. It was called The Chronology Protection Case, and it was in an anthology of detective stories. A physicist hires a detective after a fellow physicist dies in mysterious circumstances. Before too long they discover that a large group of physicists, who all collaborated on a paper, are dropping like flies, each dying in freakishly unlikely ways. Eventually, the detective comes to realize it’s the chronology projection conjecture in action. Seems the entire group was about to publish results on time travel, and the universe was acting to protect itself. The detective, himself, has two freak accidents that put him near death, and begins to realize the universe is nudging him to convince the last remaining physicist to lie about the work, and discredit it, to stay alive, ensuring time travel never happens.”
“Great idea for a story,” said Walsh. “Apparently, you do not want to piss off the universe,” he added with a broad grin.
Jenna smiled as well. She never thought she’d see the entire universe compared to a mob enforcer, protecting its interests. “Could this be why a half-second is the limit?” she said thoughtfully. “Because the universe is making sure we don’t have enough time to create a paradox?”
Walsh shook his head. “The half-second limit wouldn’t, necessarily, ensure that,” he said. “I’m sure you’ve heard the term Chaos Theory, often called the butterfly effect. This just means there are certain systems for which the slightest change in initial conditions can cause huge effects, huge uncertainty in the end result. Edward Lorenz was one of the early pioneers—by accident. He was modeling weather systems, and he wanted to repeat an analysis he had already done, entering interim results by hand. The computer he used calculated numbers to six decimal places, but to save time he truncated them to just three. Instead of entering .546124, he entered only .546. He never thought in a million years this minuscule change would matter in the least. Only it did. It had huge effects on the end results—changed everything.”
Jenna had never heard this story but was fascinated by it. “So you’re saying that the reverberations of going back less than a second and making even the smallest change aren’t predictable, and could be a lot more profound than we could guess?”
Walsh beamed, a proud professor delighted by a talented student. “I couldn’t have said it better myself,” he said. “Still, despite this, I believe you’re right. A half-second limit may well prevent major paradoxes, so the universe isn’t under threat. But even if there is no chronology protection, even if time travel is the Wild West and anything goes, Chaos Theory suggests you can’t control it. And you can’t know for sure what impact a change might have.”
Jenna was utterly spellbound by this discussion, and her body chose to demonstrate her enthusiasm by forcing a prolonged yawn, and then another. She shot Walsh an apologetic look as he continued.
“Just to finish the thought,” he said, “let me take an example from the iconic time travel movie, Back to The Future. I love this movie, but it revolves around human conception, which provides a perfect example of how you can never replicate history, never step in the same river twice.”
Walsh took another quick gulp of water and then continued. “Marty McFly changes the past and has to fix it. He has to be sure his parents still marry so he and his siblings can be conceived. But this is absurd. Even if Marty gets his parents together, they’ll fall in love in a slightly different way, with different timing. A billion tiny variables are changed, meaning the orgasm his father had that led to Marty’s conception can never happen the exact same way. Even if there were only a single change created, say the proverbial butterfly from Chaos Theory flying through the bedroom window when his parents were having sex, this might cause his father’s ejaculation to be delayed by Nathan’s forty-five microseconds. Even this minute change would mean that this time around, the sperm that has Marty’s name on it won’t outrace the other hundreds of millions of sperm to the goal. Some other sperm will penetrate the egg instead. Or maybe no sperm will make it and his parents will have to try again. So even if Marty gets his parents together, he can never put the genie back in the bottle.”
Jenna’s eyes swam out of focus and she shook her head vigorously in response. She rose and poured herself a third cup of coffee, wrinkling up her nose in disgust at the thought of forcing it down, but she was determined to remain alert until they had exhausted all possibilities.
“Nathan also mentioned something called a block universe,” said Blake. “What’s that?”
“Time isn’t my area of expertise,” said Walsh, “but I do know the rudiments. But rather than address the questions Nathan posed in his e-mail piecemeal, I think it would be better if I gave a crash course on the nature of time itself. That way you can both put everything into context.”
Jenna glanced at Aaron Blake, who nodded his assent.
“Lecture on,” she said, unable to fight off yet another yawn. “We’re all ears.”
22
“Sorry I couldn’t take your calls earlier, Jack,” said Edgar Knight, a three-dimensional view of his always-intense face hovering in the air above the phone Jack Rourk had purchased from a store at the foot of Palomar Mountain, fortunately open until nine. “I always seem to be fighting fires.”
“I understand completely,” said Rourk.
And he did understand, only too well. Which is why he couldn’t help but be pissed off at his boss, who had seen his calls come in repeatedly two hours earlier but had chosen to ignore them, deciding that whatever he was doing had to be more important than what Rourk might have to report.
Knight was very smart and had probably decided that for Rourk to escort his private eye down the mountain and to a secure location would be laborious and time-consuming, and would probably include having to knock the hostage unconscious for an extended period before reviving and interrogating him more fully. Knight had assumed Rourk’s earlier calls were to provide an interim update.
But this wasn’t the reason for the calls at all. Knight could never have guessed that Rourk had found the winning lottery ticket. Had he known, no power on Earth would have prevented him from taking his calls immediately.
Fighting fires, my ass, thought Rourk, barely managing to keep from scowling.
“So what do you have to report?” said Knight impatiently. He leaned in closer, as though examining Rourk’s image on his own screen more closely. “What’s wrong with your arm?” he asked.
“The private eye that I had in my sights was better than I thought. He shot me.”
Knight’s lip curled up in anger and disgust. “So what are you saying?” he barked. “You lost him! The perfect link to the girl!”
“I didn’t lose him,” replied Rourk. “I let him get away. And only because I have great news that makes the search for Jenna Morrison irrelevant.”
And thanks for asking if I’m okay after being shot, he thought. I managed a field dressing, and it’s heavily bandaged, but I’ll be good as new.
“What are you talking about?” demanded Knight, as though ready to choke the life out of the holographic image in front of him.
“I have the flash drive,” announced Rourk triumphantly. “Jenna Morrison gave it to this guy for safekeeping, and I was able to get it. I had the choice of either retrieving the drive or going after the PI.”
Knight’s hostile expression transformed into a broad smile immediately. “Outstanding work, Jack,” he said in delight. “Apologies for doubting you. You made the right choice.” He pursed his lips. “Can I assume the drive is undamaged?”
“It is. It’s password protected, as you already know, but in perfect condition.”
“Bring it in. As soon as you can. Get a few hours sleep and then get it here by eight in the morning.”
“I should be able to make that,” said Rourk. “But I can’t guarantee it. I need to ditch this car and get new transportation, since I have no doubt my ex-comrades are searching for me by now.”
“I understand. I guess you won’t be getting any sleep, after all. Don’t steal a car. We don’t want any more heat on you. Find a car rental place that’s still open. If there isn’t one around you, I know the ones at the San Diego airport are open until eleven or midnight, so drive there if you have to. I assume you have alternate ID you can use for the rental?”
“Yes.”
“Good. So get a car and get your ass, and that flash drive, over here. And be sure to drive at the speed limit. Got it?”
“Understood.”
“Great. And Jack . . . fantastic work.”
Knight was about to end the connection when he noticed Rourk’s arm once again. “Oh, and Jack, try not to lose too much blood. I need you to make it here. I’ll be sure to have a doctor standing by to patch up your arm when you arrive.”
“That would be helpful,” said Rourk, not exactly overwhelmed by Knight’s concern for his health.
23
“Time is a nightmare,” began Dan Walsh simply. “No subject is so utterly intuitive, and also counter-intuitive, at the same time. It’s a subject that really messes with your head. And the more you know about it, the more this is true. The intuitive perception of time for most of us is that we are trapped in an instant of time, but one that seems to be moving. This moment, the precise instant I’m telling you about this, is now. But this now becomes the past an instant later, before I’ve even finished my next word. We’re the needle on a record player. We stay in an infinitesimally thin band we call now, while the past and future are continually unreachable on either side. At least until the future decides to intersect with our infinitesimally thin needle and play a note.”
Blake blew out a breath. “Wow. You just started, and I’m already getting a headache.”
Walsh laughed. “Don’t worry, it will get much worse.”
He gathered his thoughts and continued. “As far back as five centuries before the birth of Christ, a Greek philosopher named Zeno was already assembling a host of thought experiments to try to understand time. My favorite that addresses the meaning of the ever-frozen, but ever-moving, now, is called the arrow.
“Imagine two arrows, one shot from a powerful bow, and one held horizontally and dropped straight down from above. Now imagine a time when the dropped arrow is precisely above the shot arrow. Take a snapshot of just this instant, frozen in time.”
Walsh paused for a moment to let Jenna and Blake visualize this in their minds. “Okay, your photograph will show two arrows, perfectly still, one above the other. And they will look identical in every way. In this precise instant of time, they are identical in every way. So how do they get to the next instant of time? And how does one arrow know to move toward the target in the next frame, and one arrow know to begin falling straight down? If time really is divided into infinitesimal moments, infinitesimal nows, and in each one the arrow shot from the bow isn’t moving at all, what is it about the passage of time that informs the arrow where to be at the next moment?”
Jenna groaned. “Please tell me you don’t want us to really try to answer that,” she said.
“No. I’m just trying to give you a sense of some of the questions that have been asked throughout history. To ease you into the subject,” he added with a smile.
“But if we forget about Zeno for a moment,” continued Walsh, “time is the most intuitive concept there is. Right? At least if we don’t think too hard about it. Who doesn’t know what time is? We get it. Einstein once quipped that time’s only purpose was to make sure that everything didn’t happen at once.
“But when you really think about it, time is also the least intuitive concept there is. How fast does time travel? And does time travel? Or do you travel through time? And if you do travel through time, at what rate are you moving?”
The physicist shrugged. “After all, speed is about how far we move in a given time. You drive your car at sixty miles . . . per hour. You walk to the store at two feet . . . per second. But how fast does time itself move?” asked Walsh, throwing out his hands in a gesture of helplessness. “At one second per second?”
He rolled his eyes. “That’s like saying you’re walking at a mile per mile. It’s absolutely an absurd and useless concept.”
“Well, take the Einstein quote,” said Jenna, proud that she could still channel semi-coherent thoughts in her state of weariness. “The one you just cited. He said time exists to prevent everything from happening at once. Which implies that time is change. A car moves forward. The hand of a clock ticks. And time elapses, moves on.”
“Excellent. This is called the relational theory of time. People who believe this believe time can only be gauged with respect to change. It’s an absolute requirement. Without change, time can’t exist. With change you have befores and afters. First you weren’t watching TV. Now you are.” Walsh smiled. “If you believe this theory, then you believe time could not exist before there was a universe.”
Blake thought about this for a few seconds and shook his head. “I get why this would be,” he said. “But my gut feel is that time still passed, even before the birth of the universe.”
“I would tend to agree with the relational theory,” said Jenna. “Without a universe, there can be no change. Without change, no time.”
“There are those on both sides of this issue,” said Walsh. “But already you can see how tricky time can be. And it seems fairly clear to me that change is also a requirement for humans to perceive the passage of time. We lay down memory. Our memory changes, and we know that time has passed. Even if we’re just thinking with our eyes closed, we have certain thoughts that didn’t used to be there, but are now. Before and after. Imagine you were given drugs to knock you out for an eight-hour surgery. No dreaming, no thinking, no observing. Did you experience time during these eight hours? If I told you I gave you the wrong dose of anesthetic and you were really only out for eight minutes, would you know I was lying?”
“I doubt it,” said Blake. “You make a very interesting point.”
“Newton thought time was an absolute,” continued Walsh. “Dependable. But Einstein turned this on its ear. He realized that space and time could not be separated. They form the fabric of what he called space-time. Not three dimensions, but four. Newton thought you and your friend would always—always—agree on the timing of an event, agree on when something happened. But Einstein proved this was wrong. You might see event A happen before event B, while I might see the exact opposite, depending on our velocities and positions. The faster something moves through space, the slower it moves through time. If you were traveling at the speed of light, time would stop altogether.”
Jenna nodded. “Nathan explained to me that this has been proven over and over. That Einstein’s theory is used to correct the timing of GPS satellites, or they wouldn’t work correctly. And particles that decay very quickly take much longer to decay when they’re traveling near the speed of light, the precise delay predicted by Einstein’s equations.”
“Exactly,” said Walsh enthusiastically. “It turns out that while objects can move through space and time at different rates, they all move through space-time at exactly the same rate: the speed of light. Always.”
“I’m not following,” said Blake. “You can’t mean to say that right now, sitting at this table, we’re all moving at the speed of light.”
“Through space-time, yes, that’s exactly what I’m saying. When you’re not moving at all in space, you’re moving at the speed of light, so to speak, through time—the fastest the universe allows you to do so. When you’re moving at the speed of light through space, you stop moving through time. It stops completely. It turns out that your speed through space, combined with your speed through time, always adds up to the speed of light.”
“You’ve lost me,” said Blake. “How do you add your speed through time, which I thought we decided wasn’t even measurable, to your speed through space?”
“Good question. It’s a bit complicated, and not important at the moment. What is important is what this theory says about the nature of time. It suggests that just like all of space is laid out at once, so is all of time. This is called the block universe, which you had asked about, Aaron. In the theorized block universe, everything that has happened, or will happen, is already set in stone. And no particular ‘now’ is privileged.”
“What does that mean?” said Jenna.
“It means that when you’re here and your friend is in New York, you believe that both places are equally real, right? Both exist, and neither location has a better claim to being real than the other.”
Jenna and Blake both nodded.
“The same should be true of time. Why is this instant, this now, privileged? Why is it any more real than the instant you experienced years ago, or will experience years in the future? It’s all there, all of time, already laid out in its entirety, our consciousness just isn’t designed to see it. Einstein wrote that for physicists like himself, the distinction between past, present, and future was only a stubborn illusion. And we’re talking about the entire life of the universe. From the big bang to the universe’s death, it’s all laid out. Every point in time existing in a block with every other point, simultaneously. All equally real, and all with an equal claim to the designation of now.”
Blake shook his head, as though not wanting to believe this could be true. “So what does that say about free will?” he asked.
“Great question. Doesn’t bode well, does it?”
“I used to tape football games on occasion for later viewing,” said Blake. “I’d watch knowing that whatever I was about to see happen, had already happened. I just didn’t know what that was. I could gradually watch it unfold, and it would be a surprise to me, but it was already set in stone, like you said.”
He tilted his head, remembering. “Once I watched a replay of a game after someone accidentally told me the Saints had won. So I’m watching, and with nine minutes left in the game the Saints are down twenty-three points. So even though I know how it ends, it seems impossible to me that this could be right. Surely there’s been some kind of glitch in reality. Surely the universe will now correct for this. But, of course, it didn’t. The Saints scored a quick touchdown, followed that up with a pick six, recovered an onside kick, and so on. They kicked a winning field goal with one second left in the game.”
