He looked up, to find Garwood frowning at him with surprise. Surprise, and a suddenly nervous indecision... "No, don't try it, Doctor," Davidson told him. "Running won't help; I have men covering all the exits. Sit down, please."
Slowly, Garwood stepped forward to sink into the chair across from Davidson. "What do you want?" he asked carefully, resting his hands in front of him on the table.
"I want you to tell me what's going on," Davidson said bluntly. He glanced down at the table, noting both the equation-filled papers and the loose cigarettes scattered about. "I want to know what Backdrop's purpose is, why you left it—" he raised his eyes again—"and how this voodoo effect of yours works."
Garwood licked his lips, a quick slash of the tongue tip. "Major... if you had the proper clearance—"
"Then Saunders would have told me everything?" Davidson shrugged. "Maybe. But he's had three weeks, and I'm not sure he's ever going to."
"So why should I?"
Davidson let his face harden just a bit. "Because if Backdrop is a danger to my country, I want to know about it."
Garwood matched his gaze for a second, then dropped his eyes to the table, his fingers interlacing themselves into a tight double fist there. Then he took a deep breath. "You don't play fair, Major," he sighed. "But I suppose it doesn't really matter anymore. Besides, what's Saunders going to do?—lock me up? He plans to do that anyway."
"So what is it you know that has them so nervous?" Davidson prompted.
Garwood visibly braced himself. "I know how to make a time machine."
—
For a long moment the only sound in the room was the hum of the terminal in the corner... and the hazy buzzing of Garwood's words spinning over and over in Davidson's brain. "You what?" he whispered at last.
Garwood's shoulders heaved fractionally. "Sounds impossible, doesn't it? But it's true. And it's because of that..." he broke off, reached over to flick one of the loose cigarettes a few inches further away from him.
"Dr. Garwood—" Davidson licked dry lips, tried again. "Doctor, that doesn't make any sense. Why should a... a time machine—?" He faltered, his tongue balking at even suggesting such a ridiculous thing.
"Make things disintegrate?" Garwood sighed. "Saunders didn't believe it, either, not even after I explained what my paper really said."
The shock was slowly fading from Davidson's brain. "So what did it say?" he demanded.
"That the uncertainty factor in quantum mechanics didn't necessarily arise from the observer/universe interaction," Garwood said. "At least not in the usual sense. What I found was a set of self-consistent equations that showed the same effect would arise from the universe allowing for the possibility of time travel."
"And these equations of yours are the ones you recited to me when you wrecked my car and gun?"
Garwood shook his head. "No, those came later. Those were the equations that actually show how time travel is possible." His fingers moved restlessly, worrying at another of the cigarettes. "You know, Major, it would be almost funny if it weren't so deadly serious. Even after Backdrop started to fall apart around us Saunders refused to admit the possibility that it was our research that was causing it. That trying to build a time travel from my equations was by its very nature a self-defeating exercise."
"A long time ago," Davidson said slowly, "on that car ride from Springfield, you called it subconscious democracy. That cigarettes disintegrated in your hand because some people didn't like smoking."
Garwood nodded. "It happens to cigarettes, plastics—"
"How? How can peoples' opinions affect the universe that way?"
Garwood sighed. "Look. Quantum mechanics says that everything around us is made up of atoms, each of which is a sort of cloudy particle with a very high mathematical probability of staying where it's supposed to. In particular, it's the atom's electron cloud that shows the most mathematical fuzziness; and it's the electron clouds that interact with each other to form molecules."
Davidson nodded; that much he remembered from college physics.
"Okay. Now, you told me once that you hated being hooked by cigarettes, right? Suppose you had the chance—right now—to wipe out the tobacco industry and force yourself out of that addiction? Would you do it?"
"With North Carolina's economy on the line?" Davidson retorted. "Of course not."
Garwood lips compressed. "You're more ethical than most," he acknowledged. "A lot of the 'not-me' generation wouldn't even bother to consider that particular consequence. Of course, it's a moot question anyway—we both know the industry is too well established for anyone to get rid of it now.
"But what if you could wipe it out in, say, 1750?"
Davidson opened his mouth... closed it again. Slowly, it was starting to become clear... "All right," he said at last. "Let's say I'd like to do that. What then?"
Garwood picked up one of the cigarettes. "Remember what I said about atoms—the atoms in this cigarette are only probably there. Think of it as a given atom being in its proper place ninety-nine point nine nine nine nine percent of the time and somewhere else the rest of it. Of course, it's never gone long enough to really affect the atomic bonds, which is why the whole cigarette normally holds together.
"But now I know how to make a time machine; and you want to eliminate the tobacco industry in 1750. If I build my machine, and if you get hold of it, and if you succeed in stamping out smoking, then this cigarette would never have been made and all of its atoms would be somewhere else."
Davidson's mouth seemed abnormally dry. "That's a lot of ifs," he managed.
"True, and that's probably why the cigarette doesn't simply disappear. But if enough of the electron clouds are affected—if they start being gone long enough to strain their bonds with the other atoms—then eventually the cigarette will fall apart." He held out his palm toward Davidson.
Davidson looked at the cigarette, kept his hands where they were. "I've seen the demo before, thanks."
Garwood nodded soberly. "It's scary, isn't it?"
"Yeah," Davidson admitted. "And all because I don't like smoking?"
"Oh, it's not just you," Garwood sighed. He turned his hand over, dropping the cigarette onto the table, where it burst into a little puddle of powder. "You could be president of Philip Morris and the same thing would happen. Remember that if a time machine is built from my equations, literally everyone from now until the end of time has access to the 1750 tobacco crop. And to the start of the computer age; and the inception of the credit card; and the invention of plastic." He rubbed his forehead wearily. "This list goes on and on. Maybe forever."
Davidson nodded, his stomach feeling strangely hollow. A walking time bomb, he'd called Garwood. A time bomb. No wonder everyone at Backdrop had been so quick to latch onto that particular epithet. "What about my car?" he asked. "Surely no one seriously wants to go back to the horse and buggy."
"Probably not," Garwood shook his head. "But the internal combustion engine is both more complicated and less efficient than several alternatives that were stamped out early in the century. If you could go back and nurture the steam engine, for instance—"
"Which is why the engine seemed to be trying to flow into a new shape, instead of just falling apart?" Davidson frowned. "It was starting to change into a steam engine?"
Garwood shrugged. "Possibly. I really don't know for sure why engines behave the way they do."