Timothy Zahn - Time Bomb And Zahndry Others

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."

Almost unwillingly, Davidson reached out to touch what was left of the cigarette. "Why you?" he asked. "If your time machine is built, then everything in the world ought to be equally fair game. So why don't things disintegrate in my hands, too?"

"Again, I don't know for sure. I suspect the probability shifts cluster around me because I'm the only one who knows how to make the machine." Garwood seemed to brace himself. "But you're right. If the machine is actually made, then it's all out of my hands... and I can't see any reason why the effect wouldn't then mushroom into something worldwide."

A brief mental image flashed through Davidson's mind: a black vision of the whole of advanced technology falling to pieces, rapidly followed by society itself. If a superpower war of suspicion didn't end things even quicker... "My God," he murmured. "You can't let that happen, Doctor."

Garwood locked eyes with him. "I agree. At the moment, though, you have more power over that than I do."

For a long minute Davidson returned the other's gaze, torn by indecision. He could do it—he could simply let Garwood walk. It would mean his career, possibly, but the stakes here made such considerations trivial. Another possibility occurred briefly to him... "Why did you need the computer?" he asked Garwood. "What were you trying to do?"

"Find a solution to my equations that would allow for a safer form of time travel," Garwood said. "Something that would allow us to observe events, perhaps, without interacting with them."

"Did you have any luck?"

"No. But I'm not ready to give up the search, either. If you let me go, I'll keep at it."

Davidson clenched his jaw tightly enough to hurt. "I know that, Doctor," he said quietly. "But you'll have to continue your search at Backdrop."

Garwood sighed. "I should have known you wouldn't buck your orders," he said bitterly.

"And leave you out here, threatening a community of innocent bystanders?" Davidson retorted, feeling oddly stung by the accusation. "I have a working conscience, Doctor, but I also have a working brain. Backdrop is still the safest place for you to be, and you're going back there. End of argument." Abruptly, he got to his feet. "Come on. I'll have some of my people pack up your stuff and bring it to Backdrop behind us."

Reluctantly, Garwood also stood up. "Can I at least ask a favor?"

"Shoot."

"Can we drive instead of flying? I'm still afraid of what influence I might have on a plane's engines."

"If you can sit this close to that terminal without killing it, the engines should be perfectly safe," Davidson told him.

"Under the circumstances, 'should' is hardly adequate—"

"You're arguing in circles," Davidson pointed out. "If you get killed in a plane crash, how is anyone going to use your equations to build a time machine?"

Garwood blinked, then frowned. "Well... maybe I wouldn't actually die in the wreck."

"All right, fine," Davidson snapped, suddenly tired of the whole debate. "We'll put an impact bomb under your seat to make sure you'll die if we crash. Okay?"

Garwood's face reddened, and for a second Davidson thought he would explode with anger of his own. But he didn't. "I see," he said stiffly. "Very well, then, let's find a phone booth and see what Saunders says. You will accept suggestions from Saunders, won't you?"

Davidson gritted his teeth. "Never mind. You want to sit in a car for fourteen hours, fine. Let's go; we'll radio Chanute from the car and have them call in the change of schedule to Backdrop. And arrange for a quiet escort."

V

"I hope you realize," Garwood said heavily, "that by bringing me back you're putting everyone in Backdrop at risk."

Saunders raised polite eyebrows. Polite, stupidly unconcerned eyebrows. "Perhaps," he said. "But at least here we understand what's going on and can take the appropriate precautions. Unlike the nation at large, I may add, which you've just spent nearly four months putting at similar risk. Under the circumstances, I'm sure you'd agree that one of our concerns now has to be to keep you as isolated from the rest of the country as possible." He shrugged. "And as long as you have to be here anyway, you might as well keep busy."