Split second, p.21
Split Second, page 21
He was right, thought Blake, his eyes wide. And from the expressions on the faces of his companions, this was blowing their minds as well. When Knight got no response to his question, he continued.
“The Earth rotates at roughly a thousand miles per hour. It revolves around the sun at sixty-seven thousand miles per hour. Our solar system whips around the center of our galaxy at four hundred and ninety thousand miles per hour. The galaxies in our neighborhood are also racing toward something called the Great Attractor, which has a mass one hundred quadrillion times greater than our sun, and is a hundred and fifty million light years from us.”
Knight paused. “So how do all these motions add up? In 1989 we launched the Cosmic Background Explorer satellite, which measures something called the cosmic background radiation. Because this radiation pervades the entire universe, but not uniformly, scientists were able to get an exact measure of the Earth’s speed and direction. Turns out we’re moving with respect to the cosmic background radiation at two hundred and forty-two miles per second. Per second,” he repeated.
Blake glanced at Dan Walsh, who nodded, confirming this figure.
“So I’ll confess,” continued Knight, “my time machine can only hit the first electron orbital, so to speak, the first landing platform Nathan spoke about, forty-five microseconds in the past. But in that amount of time the Earth has moved. I’ll spare you the math and just tell you: approximately fifty-eight feet. So I can put my phone in my time machine and press send. And while it does travel back through time to a split second before, it stays pinned in space. But a split second earlier, the Earth was fifty-eight feet away. So in this earlier time, there are now two identical cell phones, separated by this distance.”
Walsh left his seat and seized a pad of paper on the desk. He hastily scrawled on it and held it up for Blake to read. Wouldn’t it materialize in mid-air?
“Wouldn’t it materialize in mid-air?” asked Blake.
“Good question,” said Knight. “By rights it should. We’re not entirely clear on exactly how this works. Our best hypothesis is that while it doesn’t fully move in space, only time, gravity plays a role as well, that we haven’t fully characterized, such that it ends up fifty-eight feet away, but the same distance off the ground as when it started. We also shouldn’t be able to achieve any directionality. The Earth moves through the universe the way it moves, and we should have no control. But we do. By adjusting the polarity of the time travel field and the directionality of the field itself—which we can do by positioning the device in a certain orientation combined with a certain field dynamic—we can more or less point the effect.”
Walsh’s face wrinkled up in absolute confusion, and he looked at Blake as though Knight had just told them that two plus two was five. If the UCLA physicist was confused, what hope did Blake have?
“This makes no sense at all,” said Blake.
Knight actually smiled. “I don’t fully understand it either. We’ve figured this part out empirically. Guess-and-check, over many months. Time travel doesn’t seem to cut across the space-time axis, per se, which would be through the fourth dimension, but rather through a fifth dimension. Movement through this dimension translates in unexpected ways through our own, so we get results that aren’t intuitive, to say the least, and don’t even seem possible.”
“I’ll take your word for it,” said Blake, giving up.
“But you’ve actually done this?” said Jenna. “You’ve actually sent matter back through time?”
“Many, many times,” replied Knight. “It’s become routine.”
Blake looked at another scrawled question from Walsh and repeated it, even though he didn’t understand what Walsh was getting at. “And what if you decide after you’ve sent something back, not to send it back?”
Knight grinned in delight. “Outstanding, Mr. Blake. You have an excellent scientific mind. No wonder you’re a good detective. For Jenna’s benefit, who probably isn’t on the same page as you are, let’s pretend again we can send something back an hour, just because thinking in microseconds messes with one’s mind, and makes everything harder to understand.
“So Aaron’s question is this: Say I decide that in an hour from now, I’m going to send my phone back in time an hour. The hour passes and I press the button, as planned. Because I did this, an hour earlier, a cell phone magically appears in front of my earlier self. To make this as easy as possible to picture, imagine the phone appears right next to the earlier version of itself. Cool, the me in the past thinks when the phone appears. I must have sent it back from the future like I was planning. Now I have two phones.”
Knight arched an eyebrow. “But now, what if the me in the past changes his mind? What if he now decides not to send it back, after all? Now what happens? Does the second phone disappear the moment he makes this decision, like a photo of Marty McFly and his siblings? Or does it stick around? And what if the hour passes and I really don’t send my phone back? Do I still have two phones? And if so, how is this possible? After all, in this version of reality, I never sent it back, so how is it still there?”
“Which would be the single timeline theory of time travel,” said Jenna. “The one in which this type of paradox is possible. However, if a version of the chronology protection conjecture were operating, the phone would never appear in the past in the first place, as long as the universe knew you were going to change your mind and not send it. Or, if it did appear, you would send it back after an hour passed. Nothing could prevent you from doing this, including changing your mind.”
Knight shook his head in wonder. “I have to say your grasp of time travel theory is truly impressive.”
“So what’s the answer?” said Jenna, ignoring him. “What happens?”
“What happens is that you can change your mind,” said Knight. “And the second phone remains anyway, even if you never send it back.”
“Which proves that timelines branch,” said Jenna.
“Yes and no,” replied Knight. “I see how you would think this is the only alternative left. That this is the answer to more than a century of time travel speculation. The instant you change the past, time branches into two separate and distinct realities. The you on the original timeline always sends the phone back. The you on the new timeline has two phones, forever, and can decide to send a phone back, or not, without affecting this.”
“But you’re saying this isn’t really how it works either?” said Jenna.
“That’s right. Turns out to be a combination of the two theories. I won’t describe the experiments that led us to this conclusion. Just suffice it to say that when you change the past, you get a new timeline. But the old timeline no longer exists. No branching occurs. You reset the universe from the point of the change onward.”
“You are planning to walk through an example of this, right?” said Blake.
“Yes. So you press the button and send your phone back an hour. Now, in the past, you have two phones. But whatever had happened before in the upcoming hour is wiped out. The universe is reset to where it was an hour earlier and then proceeds forward again. The original timeline is erased. And there is no branching.”
“Which gets us back to your original question,” said Jenna. “If this original timeline is erased, and you decide not to send the phone back this time, how do you have two phones?”
“Yep,” said Knight. “It’s a head-scratcher. Nonetheless, the second phone remains, and the universe just moves on from there, as if you’ve always had two phones, not caring about paradox. The universe would rather live with paradox than infinite timelines, I guess. Which may explain why there is a half-second limit. So it doesn’t have to reset too far back, and have to wipe out too much forward history. But the bottom line is this, once a timeline affects its own past, even though it erases itself in the process, the effect it had still remains.”
“So if you go back in time and kill your mother,” said Jenna, “history is rewritten from the moment of her death forward. Your own history as you knew it no longer exists, and never existed. You are never born. But the universe doesn’t care that you shouldn’t exist, and couldn’t have killed her. It just accepts the reality of a universe in which you exist anyway and she is dead. It ignores the paradox and continues forward from that point.”
“Outstanding,” said Knight, beaming. “There are world-class physicists who couldn’t catch on this quickly.”
Jenna just sneered at the television screen as he continued. “I hate to keep treating the universe like it is a living being, but the way I think of it is that the universe wants to deal with changes in time in the most efficient way possible. And it wants to maintain a single timeline, as infinite timelines aren’t very efficient.”
“And no doubt give the universe as much of a headache as they give me,” said Blake wryly.
Knight smiled. “Exactly. Another way to think of it, which removes some time travel confusion from the analogy, is this: Say you’re writing a novel, and you can only publish one version of it. You finish the novel and realize that you gave two characters names that are too similar: John Doe and John Dode. Too confusing. So you decide to go back in your novel and change John Doe’s name to Steve Smith. So you tell your word processor to find every instance of John Doe in the novel and change this to Steve Smith. You hit the button and instantly, wherever you had John Doe, you now have Steve Smith.”
He paused to give his listeners a chance to imagine this scenario.
“Now you want to save the file for publication,” he continued. “First, to be efficient, the computer doesn’t bother resaving the entire novel, since the vast majority is the same. It only saves the new name wherever it appears. Second, once this new version is saved and published, it’s as though the original version never existed. Steve Smith is just Steve Smith. There is no record of him ever being John Doe. A reader would have no idea what had led to the name Steve Smith having been chosen, could never tell that this was due to a different version of the story that no longer existed.”
Jenna nodded thoughtfully. “So in this analogy,” she said, “the writer is God, and the novel is the universe.”
“Yes. Or perhaps the universe is both the writer and the novel. Either way. I admit the analogy is tortured and incomplete, but hopefully also a little helpful.”
Blake thought that it was, although he also decided he would never fully grasp how this worked. That no one ever would.
He glanced at Walsh and he could tell the physicist was ecstatic. He was receiving the kind of answers to fundamental questions of physics the likes of which might be revealed only once in a generation, if that.
“All of this may be fascinating,” continued Knight. “But also a potential problem for us. Because when you alter the timeline, the universe makes as few changes as possible. You have two phones, but everything else remains unchanged.”
“Right,” said Blake. “You just change a name, the rest of the novel is untouched and unfolds exactly as before.”
“Yes. A tiny ripple is created exactly where you changed history, but the rest of the mighty river rages on, unchanged. Just because a split second of history is wiped out when I send my phone back, everything else in the universe, not directly influenced by this event, goes forward the same way it did.”
“So you send your phone back a split second,” said Jenna, “and the universe starts over from this point. But if a man had an orgasm during the forty-five microsecond period that got erased, when the universe goes forward again, he’ll have the exact same orgasm, and the exact same sperm will outcompete all the others in a race to the egg.”
Knight’s mouth dropped open. “That’s right,” he said. “Great example to really drive the concept home. Although I must say it isn’t exactly the first one most people think of,” he added in a way that made it clear this was an understatement. “But unless the phone I sent back smacks the man in the head when he’s about to . . . ejaculate . . . his ejaculation, and everything else in the universe, would unfold the same way.”
“So why is this a potential problem for you?” asked Blake.
“I’ll have to explain with more examples. Say it’s eleven a.m., and I program my device to send my phone back an hour in time, exactly when the clock strikes noon. Noon arrives and the device sends it back to eleven. So the me at eleven now has two phones, and the universe does a restart from there. The old future no longer exists. But . . .” he paused once again for effect, “because the rest of the universe unfolds as before, my original phone is still in the chamber, and the device is still programmed to send it back at noon. That hasn’t changed. So even though I now have two phones, if I do nothing, the computer will send the original phone back again.”
“But once you see you already have two phones,” said Blake, “you can just cancel these instructions.”
“Easy to do when you have an hour to play with,” said Knight. “But in forty-five microseconds you don’t have time to cancel your instructions. So boom, you have two cell phones, and in the new reality you continue to have two, no matter what else happens. But the time machine exists in this new reality, cocked and ready to go. So you move forward forty-five millionths of a second and, boom, the button is triggered again, and an instant earlier you now have three phones. And these three are here to stay on the new timeline, no matter what happens. But then, boom, the machine is triggered again and an instant earlier, now you have four.”
There was a long, stunned silence in the motel room.
Knight waited patiently for his audience to wrap their minds around this.
“So it isn’t just a duplication machine,” said Blake finally. “It’s a duplication machine that makes infinite copies.”
“Yes, in theory. Fortunately, in practice, here is what happens: The original phone sent back ends up fifty-eight feet away from itself, on its own private real estate. But the second time the original phone is sent back, the second time it runs through the loop, the phone arrives at the precise location in space as the first time it was sent back. While this could result in the mother of all explosions, as Jenna suggested, it doesn’t. Nuclear repulsion prevents this. Matter exerts such a strong repulsive force that other matter trying to occupy the exact same space is deflected away to a more receptive location. Like forcing two opposing magnets together. The instant you let go, they will push each other away. The third time through the loop, the new incoming phone has to be deflected even farther away, since it has to bypass two phones. And so on.
“Eventually, the phone has to be deflected such a great distance from its arrival coordinates that time travel stops working. The system doesn’t have the energy to send something through time that has to be deflected so far away. Which is why your phone can’t materialize in a wall or a mountain. For a wall, it will take the path of least resistance and appear just beside the wall, in open space. For a mountain, assuming no open space is near enough, time travel just won’t work.”
“So eventually the endless loop stops,” said Jenna, “but how many phones do you end up with before this happens?”
Knight shrugged. “I’d have to do the math, but basically you can fill a space about eighty times the size of your time machine. So I can send whatever fits inside my—call it a large suitcase-sized device—and fill a space about eighty times this much volume with phones before time travel fails.”
“So there isn’t a way to just make a single copy?” asked Blake.
“No, there is. You can make as many as you’d like. Humans can’t operate at the microsecond level, but computers can. So I have the computer send the phone back forty-five microseconds. From a location I would call the sending station. At the receiving station the phone appears in the past. Now there are two phones, fifty-eight feet apart. The receiver is rigged so that the instant a sensor records the phone has appeared, it signals the sending station, fifty-eight feet distant, to abort sending the original phone back. So what happens in practice is you send the phone back, get two phones, and then turn the system off.”
Blake shook his head. “How can any of this even be possible?” he asked. “How can the universe work this way?”
“How can anything be possible?” replied Knight. “How did our universe of more than a hundred billion galaxies, each with hundreds of billions of stars, arise from a single point smaller than an atom?”
“This has been fascinating . . . Edgar,” said Jenna. “Truly. But no more time travel theory. Let’s get to the part where Nathan comes in. Why is he dead? Why have we been hunted?”
Knight sighed. “I understand your impatience, Jenna, I really do. But I promise you, I’m almost there.”
38
Blake had studied Edgar Knight ever since his video image had appeared on the Best Border Inn’s television, trying to employ what he had learned about reading body language while taking specialized courses at Fort Benning. This was not an exact science, in the best of times, and it was made harder by the fact that his mind kept either getting blown by the utterly fantastic nature of Knight’s revelations, or getting fried as he tried to understand concepts out of his depth, which required a diagram, at minimum, to truly understand.
Even so, he believed that much of what the man was saying was the truth. He seemed genuine. He didn’t come across as hiding an evil or sadistic streak. At least not in a way that was obvious. But innate human nature could be hidden, and truth skillfully adhered to yet distorted at the same time. So the jury was very much out on the man.
As for Jenna, she had stab wounds to her psyche that couldn’t be more raw, and Blake could tell she was desperate to uncover Knight as a villain, as someone against whom she could target her venom, extract her revenge.
