"I still don't see the hitch. Rocks are cheap."
"Use your head, Danny. With a rocket ship you can aim the kinkin' thing. But which direction is last week? Point to it. Just try. You haven't the slightest idea which mass is going back and which one is going forward. There's no way to orient the equipment."
I shut up. It would be embarrassing to a general to expect a division of fresh shock troops and get nothing but a pile of gravel. No wonder the ex-prof never made brigadier. But Chuck was still talking:
"You treat the two masses like the plates of a condenser, bringing them up to the same temporal potential. Then you discharge them on a damping curve that is effectively vertical. Smacko!-one of them heads for the middle of next year, the other one is history. But you never know which one. But that's not the worst of it; you can't come back."
"Look, what use is it for research if you can't come back? Or for commerce? Either way you jump, your money is no good and you can't possibly get in touch with where you started. No equipment-and believe me it takes equipment and power. We took power from the Arco reactors. Expensive... that's another drawback."
"You could get back," I pointed out, "with cold sleep."
"Huh? If you went to the past. You might go the other way; you never know. If you went a short enough time back so that they had cold sleep... no farther back than the war. But what's the point of that? You want to know something about 1980, say, you ask somebody or you look it up in old newspapers. Now if there was some way to photograph the Crucifixion...but there isn't. Not possible. Not only couldn't you get back, but there isn't that much power on the globe. There's an inverse-square law tied up in it too."
"Nevertheless, some people would try it just for the hell of it. Didn't anybody ever ride it?"
Chuck glanced around again. "I've talked too much already."
"A little more won't hurt."
"I think three people tried it. I think. One of them was an instructor. I was in the lab when Twitch and this bird, Leo Vincent, came in; Twitch told me I could go home. I hung around outside. After a while Twitch came Out and Vincent didn't. So far as I know, he's still in there. He certainly Wasn't teaching at Boulder after that."
"How about the other two?"
"Students. They all three went in together; only Twitch came Out. But one of them was in class the next day, whereas the other one was missing for a week. Figure it out yourself."
"Weren't you ever tempted?"
"Me? Does my head look fiat? Twitch suggested that it was almost my duty, in the interests of science, to volunteer. I said no, thanks; I'd take a short beer instead... but that I would gladly throw the switch for him. He didn't take me up on it."
"I'd take a chance on it. I could check up on what's worrying me... and then come back again by cold sleep. It would be worth it."
Chuck sighed deeply. "No more beer for you, my friend; you're drunk. You didn't listen to me. One,"-he started making tallies on the table top-"you have no way of knowing that you'd go back; you might go forward instead."
"I'd risk that. I like now a lot better than I liked then; I might like thirty years from now still better."
"Okay, so take the Long Sleep again; it's safer. Or just sit tight and wait for it to roll around; that's what I'm going to do. But quit interrupting me. Two, even if you did go back, you might miss 1970 by quite a margin. So far as I know, Twitch was shooting in the dark; I don't think he had it calibrated. But of course I was just the flunky. Three, that lab was in a stand of pine trees and it was built in 1980. Suppose you come out ten years before it was built in the middle of a western yellow pine? Ought to make quite an explosion, about like a cobalt bomb, huh? Only you wouldn't know it."
"But- As a matter of fact, I don't see why you would come out anywhere near the lab. Why not to the spot in outer space corresponding to where the lab used to be-I mean where it was.
or rather--"
"You don't mean anything. You stay on the world line you were on. Don't worry about the math; just remember what that guinea pig did. But if you go back before the lab was built, maybe you wind up in a tree. Four, how could you get back to now even with cold sleep, even if you did go the right way, arrive at the right time, and live through it?"
"Huh? I did once, why not twice?"
"Sure. But what are you going to use for money?"
I opened my mouth and closed it. That one made me feel foolish. I had had the money once; I had it no longer. Even what I had saved (not nearly enough) I could not take with me-shucks, even if I robbed a bank (an art I knew nothing about) and took a million of the best back with me, I couldn't spend it in 1970. I'd simply wind up in jail for trying to shove funny money. They had even changed the shape, not to mention serial numbers, dates, colors, and designs. "Maybe I'd just have to save it up."
"Good boy. And while you were saving it, you'd probably wind up here and now again without half trying... but minus your hair and your teeth."
"Okay, okay. But let's go back to that last point. Was there ever a big explosion on that spot? Where the lab was?"
"No, I don't think so."
"Then I wouldn't wind up in a tree-because I didn't. Follow me?"
"I'm three jumps ahead of you. The old time paradox again, only I won't buy it. I've thought about theory of time, too, maybe more than you have. You've got it just backward. There wasn't any explosion and you aren't going to wind up in a tree... because you aren't ever going to make the jump. Do you follow me?"
"But suppose I did?"
"You won't. Because of my fifth point. It's the killer, so listen closely. You ain't about to make any such jump because the whole thing is classified and you can't. They won't let you. So let's forget it, Danny. It's been a very interesting intellectual evening and the FBI will be looking for me in the morning. So let's have one more round and Monday morning if I'm still out of jail I'll phone the chief engineer over at Aladdin and find out the first name of this other `D. B. Davis' character and who he was or is. He might even be working there and, if so, we'll have lunch with him and talk shop. I want you to meet Springer, the chief over at Aladdin, anyway; he's a good boy. And forget this time-travel nonsense; they'll never get the bugs out of it. I should never have mentioned it, and if you ever say I did I'll look you square in the eye and call you a liar. I might need my classified status again someday."
So we had another beer. By the time I was home and had taken a shower and had washed some of the beer out of my system I knew he was right. Time travel was about as practical a solution to my difficulties as cutting your throat to cure a headache. More important, Chuck would find out what I wanted to know from Mr. Springer just over chips and a salad, no sweat, no expense, no risk. And I liked the year I was living in.
When I climbed into bed I reached out and got the week's stack of papers. The Times came to me by tube each morning, now that I was a solid citizen. I didn't read it very much, because whenever I got my head soaked full of some engineering problem, which was usually, the daily fripperies you find in the news merely annoyed me, either by boring me or, worse still, by being interesting enough to distract my mind from its proper work.
Nevertheless, I never threw out a newspaper until I had at least glanced at the headlines and checked the vital-statistics column, the latter not for births, deaths, and marriages, but simply for "withdrawals," people coming out of cold sleep. I had a notion that someday I would see the name of someone I had known back then, and then I would go around and say hello, bid him welcome, and see if I could give him a hand. The chances were against it, of course, but I kept on doing it and it always gave me a feeling of satisfaction.