I don't know what sort of reaction I had expected. I got three different ones—four, if you count the flic, who looked worried. Larry looked despondent. The other Larry and the two FBI people looked opaque: the poker face was a Tau trait, I had discovered, probably because it was not a time when you wanted other people to know what you were thinking very often. And the two Dominics looked interested. I took a swallow of my cooling coffee-I hadn't even touched the solid food yet—and tried to explain:
"There's a tension between the worlds. Call it a skin. Once it's punctured anywhere, it is weakened everywhere: It's a little like that heat-sealed plastic wrapping that the meat comes in in supermarkets, you know?" They didn't. "Like the stuff your eggs were wrapped in," I said. "It's in a state of tension. When we puncture it anywhere it takes a lot of power, but then the skin is weaker— thinner—in other places. It's hard to predict just where the other places will be, because the geometry is fractal—well, never mind that; it's just hard. But it thins. At first radiation is all that gets through; then gases. Then—more than gases." I looked at our own Larry. "Since you, uh, left," I told him, "we've come across some bad ones. Large areas open, causing violent storms. And—well, there was one that killed a lot of people. Time Eta had built apartments over an abandoned railroad right-of-way. Two diesels and four or five flatcars came through at eighty kilometers an hour, right into the lobby of a building, before it closed again."
Nicky put his hand up. "Doc? There were some stories about loud noises around a little airfield—could they have been that? From a time where they had rocketships, like this one?"
I started to tell him that a pulseur wasn't a rocketship but a jet, but caught myself in time. "I'd say probably yes," I agreed. "And we don't seem to be able to prevent it. At first we thought it was because of leakage of energy from our portal generators, and if we could control them better we could eliminate the ballistic recoil. But now we think it's really recoil, and there's a conservation law involved. If x amount of energy or matter goes from my time to yours, then x amount has to come back out of it again. Not necessarily back to mine. It may go to a third time entirely. It may go in fractions to several different ones.
"And we can't stop it."
"Jesus," said Nyla Christophe contemptuously. "You guys are playing with dynamite. Talk about irresponsible!"
Senator Dom cut in. His tone was less accusing, but a long way from really friendly. "Wouldn't it be a good idea to stop all this until you learn how to control it?" he asked.
"A damn good idea," I said fervently. "Only it got out of our hands when Larry got captured in Gamma. We could stop. But we couldn't both stop and keep an eye on them—not to mention the other times that were getting close, like yours, or that looked as though they'd be dangerous if they ever did get anywhere, like Ms. Christophe's."
The senator said temperately, "I'm in no position to blame you for anything, Dom. If we'd moved a little faster, my time might've been the first to break through, and I don't have any reason to believe we'd have done better. But—it scares me, Dom. I wish we'd thought a little more about the consequences before we got started. Those are big risks to take, just for the sake of developing a new weapon."
I lost my temper. Not at him. At myself, mostly, because of course he was saying nothing I hadn't said to myself a good many times over the past months. "You can't stop scientific research because there might be some danger somewhere!" I snapped. "Anyway, who said anything about a weapon?"
He looked surprised. "I only thought that it was obvious—"
"Maybe to savages the military application was obvious! Do you have any idea at all of what paratime means to research in general? Especially in the sciences that can't perform experiments?"
"I don't know exactly what you mean." He frowned.
"Think about it! Sociology, for instance. You can't isolate societies and perform experiments on them. But here we have an infinite number of societies, as like to our own or as different as we could want: we can develop a science of comparative sociology! Or economics, or poli-sci, or any of the social sciences at all. And not just the soft sciences! We had a meteorologist who came in as a research fellow. He went out of his mind when he discovered that your paratime, Nicky, hasn't had an Atlantic hurricane sweep up the coast in thirty years. We've been having them one or two a year and the damage is terrible. Now they think it has something to do with industrialization and urban sprawl; if we know that, maybe we can do something to stop it. And—trade."
The Tau Larry Douglas pricked up his ears. "I don't get what you're saying, DeSota," he said. "What kind of trade between two sets of the same people?"
"Two sets with slightly different histories. Slightly different fads, for one thing—there's a twenty-million-dollar business in hula hoops that came out of our peeping a year ago."
For once there was unanimity among my guests. All looked blank at once. "What's a hula hoop?" asked Larry Tau.
"A kind of a toy, that's all. But I'm not just talking about toys, I'm talking about a lot more valuable things. Think of it this way. If each paratime spends, oh, call it a billion dollars a year, on research and development—and if you can skim the cream of the R and D for fifty different paratimes—then, even with all the duplication, you're bound to find you still multiply your R and D results by a bunch!"
Silence for a moment while they digested that. Then Nicky said slowly, "I guess I can see what you're saying, Dom. You can't find out things unless you try them, so there's a risk in any kind of science; all right. And I guess getting other people's research to add to your own would be a big help, all right. But still—honestly, Dom, I don't really see how you expected this thing to do much for the ordinary slob in the street. Like me."
"It could save millions of lives, for one thing," I said.
"Come on! You mean by defeating an enemy before he defeats you, something like that?"
"No, not that. Maybe that would be true sometimes, but it's not what I'm talking about. Do you know what nuclear winter is? The death of everything because nuclear war throws so much dust into the air that it hides the sun, long enough to kill off nearly all the vegetation and most of the large animals—including human beings?"
They hadn't; but they understood it quickly enough. "Is that what you mean by a benefit?" Christophe said with a sneer. "Killing everybody?"
"Of course I don't. But there are times where it has happened. There are times we have reached where there are no mammals larger than a rat still alive—because the war did happen, five, ten, or more years ago, and the human race simply exterminated itself."
"Lovely!"
I kept a grip on my temper. Not easily. The woman got under my skin—was having the same effect, or some even more penetrating effect, on the senator, because he was looking at her with an expression I can only describe as fascinated. "No," I said tightly, "it isn't lovely at all. It's just a fact. Some time-lines have a virgin planet. The land is there, even the cities are sometimes there, though they're damaged. But there aren't any people to live in them.
"And then there are other times, our own included, where there are people dying and starving for lack of homes and land. Our Africa has been in a drought condition for most of the last decade. Parts of Asia are almost as bad. In other times Latin America has its own famines.
"Suppose we took those starving people without land, and let them emigrate to the empty planets without people?"