If he let his beard grow out, he would be the only professor on campus so adorned. “Why doesn’t anyone wear a beard?” he asked Martha.
She touched the scar on her cheek. “Nobody could tell your rank.”
“Maybe I could get away with it. Not having any real rank other than ‘professor from the past.’ ”
She reached up demurely and rubbed the stubble on his chin. “Maybe. It looks nice.”
When they stepped into the anteroom of the dean’s office, he smelled coffee for the first time since he’d left the past. He tried not to salivate.
Martha took a seat there, and the dean’s secretary, a beautiful woman with long black hair and no mark of academic rank, escorted him in.
It was a corner office, flooded with light. The walls that weren’t windows were crowded with paintings, some religious, but mostly portraits of deans, ending with Dean Eagan. Not a book in sight.
The dean was an old man, but vigorous. He came around the desk with a sure stride, helped slightly by an ebony cane, and shook Matt’s hand. When they sat down, the secretary brought over a tray with an elegant silver coffee service and delicate porcelain cups. The sugar was in irregular brown lumps, and the cream was thick and real.
She left after pouring the coffee, and the dean studied Matt for an uncomfortable moment. His eyes sparkled with intelligence.
“Matthew … Fuller. Is there a foolproof way for you to convince me that you are what you say you are?”
“A traveler from the past.”
He nodded. “From this Institute, when it was … before Theosophy.”
Matt clumsily sorted through his robe to the jeans underneath, and pulled out his wallet. His MIT ID was five years old, but it did still resemble him. And it was three-dimensional, a white-light hologram.
The dean looked at it and tried to stick his finger into the holo. He looked on the back, shook it, tapped it on his desk, then handed it back. “These were common then?”
“Every student and employee had one.” Matt had three, in fact, with different names, which he had done just to prove he could hack the system. “I was just a graduate assistant. ” The dean’s eyebrows went up. “It meant something different then, a kind of apprenticeship. I think like scholars, now.”
He took a sip of coffee and tried not to make a face. It was acrid and flat.
“All the way from Georgia,” the dean said. Matt decided to hold out for Colombian.
“So how did you do this, traveling through time?”
“There was a machine,” he said, not lying, “in the Green Building. That used to be near where the dining areas are now.”
“They did natural philosophy there?”
“Yes, physics. I used to work there, in the Center for Theoretical Physics.”
“Before Theosophy.”
“The term didn’t exist then. To the best of my knowledge. ”
“To teach here, though, you can learn Theosophy. It’s not as if you weren’t a Christian—a Methodist, I believe?—so you’re halfway there.”
“That’s right,” he said slowly. They’d talked to Moses. “I can learn quickly. My graduate assistant, Martha, said I wouldn’t be teaching until next year.”
He nodded, a faraway look in his eyes. “What was it like, traveling through time? Did you see the future going by?”
“I wish I had. It was all just a gray blur, which seemed to last only a minute or so.”
“You were in a car?”
“That seemed sensible. We didn’t know where I might end up.”
“We sent a team out to Arlington, to tow it in.” It took a moment for the meaning of “team” to sink in. Horses. “Do you think you could get it to work?”
“I don’t know. Can you generate electricity and store it in a fuel cell?”
“You’ll have to ask the people in mechanical studies. I’ve seen them make sparks with electricity that they carried in a box.”
“That would be a start.” He choked down some more coffee to be polite. “If it’s something like a chemical battery,in theory it could work.” Though it might take months to get enough charge to go a few miles, he wouldn’t mind having a getaway vehicle that was also a Faraday cage.
“Can you travel back? Go back to the … earlier MIT?”
“Some say yes, and some say no. If I were back in my own time, maybe I could build a machine that went the other direction. People were working on it when I left. But you can see the logical problem in going backward.”
The dean’s brow furrowed. “You would meet yourself? Be in two places at the same time?”
“That’s one manifestation of it. But the larger philosophical problem is that it blows apart cause and effect. You could use the time machine to go back and murder the person who invented the time machine.”
“But … that would be a sin.”
“I don’t mean you would actually do it.”
“No, of course. Theoretical possibility.” He laughed. “Sorry. I used to be a Father. So you would be using the machine to make the machine not exist in the first place.”
“Exactly.”
“But then …” He rubbed his chin and concentrated. “There doesn’t have to be a paradox. Time just starts over, and goes on as if the machine had never existed. Assuming the time traveler would have to disappear once his time machine stopped existing.”
Pretty damned good. “That’s right, sir. And the ‘loop,’ as we call it, of time and space when and where the machine existed—that loop itself ceases to exist.”
“So where does it go?”
Matt shrugged. “Limbo? Nobody can say.”
“Interesting.” He poured himself some more coffee, and Matt declined a refill. “How could one tell … how can you tell that you aren’t in one of those closed-off loops? Suppose you do invent a reverse time machine, and you go back and smash the machine that sent you here. The fact that you obviously exist—does that mean you didn’t do it? Aren’t going to do it? If you were in one of those closed-off loops, doomed to Limbo, how could you tell?”
“Well, you could jump forward again, and”—a thread of ice water down his spine—“you’d wind up in a future where your time machine had never been invented.”
Dean Eagan put his fingers together in a steeple and smiled. “Like this one.”
After the interview, Matt went for a walk to clear his head. Could he be in a Gödelian strange loop? It wouldn’t have to be he himself who went back and destroyed the time machine. Anyone capable of traveling into the past could do it, and deposit him in this odd future. A future where he was an anomaly, because the time machine had never been invented and Professor Marsh never stole the Nobel Prize from him.
But thinking about interference from the future made him wonder about the machine’s infuriating singularity. Thousands of copies had been made, and none of them worked; in essence, none of them had the vital, untraceable mistake that turned a graviton/photon calibrator into a time machine.
What if it hadn’t been anything Matt did? What if somebody from the future had come back and modified the machine, so as to make his own present possible? And then someone else from his present—or future—came back and destroyed the machine, because his own history required that it not exist? There could be an infinity of closed strange loops like this one.
Or the straightforward explanation could be true. Occam’s Razor. There was a conservative Christian revolution, and when they got into power, they systematically destroyed history in order to rewrite it. The Chinese had done that in ancient times, he remembered from an undergraduate history class—they defeated the kingdom that would become Vietnam in a war, and made the possession of historical documents a crime punishable by death.