We had done things like this on adding machines. Usually you go one step across yourself, doing everything. But this was different–where you go first to the adder, then we go to the multiplier, then you go to the adder, and so on. So, he designed this thing and ordered the machine from the IBM company, ’cause we realized it was a good way of solving our problems. We found that there was somebody in the Army that had IBM training. We needed a man to repair them, to keep them going and everything. And they were going to send this fellow, but it was delayed, always delayed. Now, we always were in a hurry. I have to explain that–everything we did, we tried to do as quickly as possible. In this particular case, we worked out all the numerical steps that we were supposed to, that the machines were supposed to do, multiply this, and then do this, and subtract that. And then we worked out the program, but we didn’t have any machine to test it on. So what we did, I arranged, was a room with girls in it, each one had a Marchant. But she was the multiplier and she was the adder, and this one cubed, and so we had cards, index cards, and all she did was cube this number and send it to the next one. She was imitating the multiplier, the next one was imitating the adder; we went through our cycle, we got all the bugs out. Well, we did it that way. And it turned out that the speed at which we were able to do it–we’d never done mass production calculating and everybody who’d ever calculated before, every single person, did all the steps. But Ford had a good idea, the damn thing works a hell of a lot faster the other way and we got speed with this system that was the predicted speed for the IBM machine, the same. The only difference is that the IBM machines didn’t get tired and could work three shifts. But the girls got tired after a while. So, anyway, we got the bugs out during that process and finally the machines arrived, but not the repairman. So, we went down to put them together. And they were one of the most complicated machines of the technology of those days, these computing machines, big things that came partially disassembled with lots of wires and blueprints of what to do. We went down, we put them together, Stan Frankle and I and another fellow, and we had our troubles. Most of the trouble was the big shots coming all the time and saying you’re going to break something, going to break something. We put them together and sometimes they would work, and sometimes they were put together wrong and they didn’t work. And so we fiddled around and got them to work. We didn’t get them all to work and I was last working on some multiplier, saw a bent part inside and I was afraid to straighten it because it might snap off. They were always telling us we were going to bust it irreversibly. And finally the man from the IBM company came, as a matter of fact, according to schedule, but he came and he fixed the rest that we hadn’t got ready, and we got the program going. But he had trouble with the one that I had had trouble with. So after three days he was still working on that last one. I went down, I said, “Oh, I noticed that was bent.” He said, “Oh, of course, that’s all there is to it!” (Snap)–It was all right. So that was it.
Well, Mr. Frankle started this program and began to suffer from a disease, the computer disease, that anybody who works with computers now knows about. It’s a very serious disease and it interferes completely with the work. It was a serious problem that we were trying to do. The disease with computers is you play with them. They are so wonderful. You have these x switches that determine, if it’s an even number you do this, if it’s an odd number you do that, and pretty soon you can do more and more elaborate things if you are clever enough, on one machine. And so after a while it turned out the whole system broke down. He wasn’t paying any attention; he wasn’t supervising anybody. The system was going very, very slowly. The real problem was that he was sitting in a room figuring out how to make one tabulator automatically print arc-tangent x, and then it would start and it would print columns and then bitsi, bitsi, bitsi and calculate the arc-tangents automatically by integrating as it went along and make a whole table in one operation. Absolutely useless. We had tables of arc-tangents. But if you’ve ever worked with computers you understand the disease. The delight to be able to see how much you can do. But he got the disease for the first time, the poor fellow who invented the thing got the disease.
And so, I was asked to stop working on the stuff I was doing in my group and go down and take over the IBM group. I noticed the disease and I tried to avoid it. And although they did three problems in nine months, I had a very good group. The first problem was that they had never told the fellows–they had selected from all over the country, a thing called Special Engineer Detachment. There were clever boys from high school, who had engineering ability, and the Army collected them together in the Special Engineer Detachment. They sent them up to Los Alamos. They put them in barracks and they would tell them nothing. Then they came to work and what they had to do was work on IBM machines, punching holes, numbers that they didn’t understand, nobody told them what it was. The thing was going very slowly. I said that the first thing there has to be is that the technical guys know what we’re doing. Oppenheimer went and talked to the security people and got special permission. So I had a nice lecture in which I told them what we were doing, and they were all excited. We’re fighting a war. We see what it is. They knew what the numbers meant. If the pressure came out higher, that meant there was more energy released and so on and so on. They knew what they were doing. Complete transformation! They began to invent ways of doing it better. They improved the scheme. They worked at night. They didn’t need supervising in the night. They didn’t need anything. They understood everything. They invented several of the programs that we used and so forth. So my boys really came through and all that had to be done was to tell them what it was, that’s all. It’s just, don’t tell them, they’re punching holes, please. As a result, although it took them nine months to do three problems before, we did nine problems in three months, which is about nearly ten times as fast. But one of the secret ways that we did our problems was this: The problems consisted of a bunch of cards which had to go through a cycle. First add, then multiply, and so it went through the cycle of machines in this room, slowly about as it went around and around. So we figured a way, by taking a different colored set of cards, to put them through a cycle too, but out of phase. We’d do two or three problems at a time. You see this was another problem. While this one was adding, it was multiplying on the other problem. And such managerial schemes, we got many more problems.
Finally, near the end of the war, just before we had to make a test in Alamogordo, the question was, how much energy would be released? We had been calculating the release from various designs but the specific design which was ultimately used we hadn’t computed. So Bob Christie came down and said, we would like the results for how this thing is going to work in one month, or some very short time, I don’t know, less than that, three weeks. I said, “It’s impossible.” He said, “Look, you’re putting out so and so many problems a week. It takes only two weeks per problem, or three weeks per problem.” I said, “I know, it takes much longer to do the problem, but we’re doing them in parallel As they go through it takes a long time and there’s no way to make it go around faster.” So he went out. I began to think–is there a way to make it go around faster? Well, if we did nothing else on the machine, so there was nothing else interfering, and so on and so on. I began to think. I put on the blackboard a challenge–CAN WE DO IT? to the boys. They all respond, yes, we’ll work double shifts, we’ll work overtime, all this kind of thing, we’ll try it. We’ll try it!! And so the rule was, all other problems out. Only one problem and just concentrate on this thing. So they started to work.
My wife died in Albuquerque and I had to go down. I borrowed Fuchs’ car; he was a friend of mine in the dormitory. He had an automobile. He was using the automobile to take the secrets away, you know, they went down to Santa Fe. He was the spy; I didn’t know that. I borrowed his car to go to Albuquerque. The damned thing got three flat tires on the way. I came back from there and I went into the room, because I was supposed to be supervising everyt
hing, but I couldn’t do it for three days. It was in this mess, this big rush to get the answer for the test that was going to be done in the desert. I go into the room and there are three different color cards. There’s white cards, there’s blue cards, there’s yellow cards and I start to say, “Well, you’re not supposed to do more than one problem–only one problem!” They said, “Get out, get out, get out. Wait, we’ll explain everything.” So I waited, and what happened was this. As they went through, sometimes the machine made a mistake or they put a wrong number in; that happened. What we used to have to do was to go back and do that over again. But they noticed this, that the deck represented positions and depth in the machine, in space or something. A mistake made here, in one cycle, only affects the nearby numbers, the next cycle affects the nearby numbers, and so on. It works its way through the pack of cards. If you have fifty cards and you make a mistake at card number 39, it affects 37, 38, and 39. The next card 36, 37, 38, 39, and 40. The next time it spreads like a disease. So they found an error, back a way, and they got an idea. They would only compute a small deck, of ten cards, around the error. And because ten cards could be put through the machine faster than the deck of fifty cards, they would go with this other deck rapidly through while they continued with the fifty cards with the disease spreading. But the other thing was computing faster and they would seal it all up and correct it. OK? Very clever. That was the way those guys worked, really hard, very clever, to get speed. There was no other way. If they had to stop to try to fix it, we’d have lost out time. We couldn’t have got it. That was what they were doing. Of course you know what happened while they were doing that. They found an error in the blue deck. And so they had a yellow deck with a little fewer cards; it was going around faster than the blue deck, you know. Just when they are going crazy, because after they get it straightened out they got to fix the white one, they got to take the other cards out and replace it by the right ones, and continue correctly, and it’s rather confusing–you know how those things always are. You don’t want to make a mistake. Just at the time when they’ve got these three decks going, they’re trying to seal everything up, the BOSS comes walking in. “Leave us alone,” they said, so I left them alone and everything came out; we solved the problem in time and that’s the way it was.
I would like to tell you just a few words about some of the people that I met. I was an underling at the beginning. I became a group leader, but I met some very great men–besides the men on the evaluation committee, the men that I met in Los Alamos. And there are so many of them that it’s one of my great experiences in life to have met all these wonderful physicists. Men that I had heard of, smaller and larger, but the greatest ones were there also. There was of course Fermi.* He came down once. The first time that he came was from Chicago to consult a little bit, to help us if we had some problems. We had a meeting with him and I had been doing some calculations and gotten some results. The calculations were so elaborate it was very difficult. Now, usually, I was the expert at this, I could always tell you what the answer was going to look like or when I got it I could explain why. But this thing was so complicated I couldn’t explain why it was like that. So I said to Fermi that I was doing this problem and I started to calculate–he said, wait, before you tell me the result, let me think. It’s going to come out like this (he was right), and it’s going to come out like this because of so and so. And there’s a perfectly obvious explanation. . . . So he was doing what I was supposed to be good at, ten times better. So that was quite a lesson to me.
Then there was Von Neumann, who was the great mathematician. He suggested, I won’t go into the things here, some very clever technical observations. We had some very interesting phenomena in the computing of the numbers. The problem looked as if it was unstable and he explained why and so forth. It was very good technical advice. But we used to go for walks often to get rest, like on Sunday or something. We’d walk in the canyons in the neighborhood and we’d often walk with Bethe, Von Neumann, and Bacher. It was a great pleasure. And the one thing that Von Neumann gave me was an idea that he had which was interesting. That you don’t have to be responsible for the world that you’re in, and so I have developed a very powerful sense of social irresponsibility as a result of Von Neumann’s advice. It’s made me a very happy man since. But it was Von Neumann who put the seed in which grew now into my active irresponsibility!
I also met Niels Bohr.* That was interesting. He came down, his name was Nicholas Baker in those days and he came with Jim Baker, his son, whose name is really Aage†. They came from Denmark and they came to visit, and they were very famous physicists, as you all know. All the big shot guys, to them, he was even a great god; they were listening to him and so on. And he would talk about things. We were at a meeting and everybody wanted to see the great Bohr. So there were a lot of people and I was back in a corner somewhere and we talked about, discussed, the problems of the bomb. That was the first time. He came and he went away and all I could see of him was from between somebody’s heads, from the corner. Next time he’s due to come, in the morning of the day he’s due I get a telephone call. “Hello, Feynman?” “Yes.” “This is Jim Baker”; it’s his son. “My father and I would like to speak to you.” “Me? I’m Feynman, I’m just a . . .” “That’s right. OK.” So, eight o’clock in the morning, before anybody’s awake, I go down to the place. We go into an office in the technical area and he says, “We have been thinking how we could make the bomb more efficient and we think of the following idea.” I say, “No, it’s not going to work, it’s not efficient, blah, blah, blah.” So he says, “How about so and so?” I said, “That sounds a little bit better, but it’s got this damn fool idea in it.” So forth, back and forth. I was always dumb about one thing, I never knew who I was talking to. I was always worried about the physics; if the idea looked lousy, I said it looked lousy. If it looked good, I said it looked good. Simple proposition, I’ve always lived that way. It’s nice, it’s pleasant, if you can do it. I’m lucky. Just as lucky as I am with that blueprint, I’m lucky in my life that I can do that. So this went on for about two hours of going back and forth over lots of ideas, and then tearing back and forth, arguing. The great Niels always lighting his pipe; perpetually, it always went out. And he talked in a way that was un-understandable. He said, “Mumble, mumble,” hard to understand, but his son I could understand better. Finally he said, “Well,” he says, lighting his pipe, “I guess we can call in the big shots now” So then they called all the other guys and had a discussion with them. And then the son told me what had happened was–the last time he was there he said to his son–“Remember the name of that little fellow in the back over there? He’s the only guy who’s not afraid of me, and will say when I’ve got a crazy idea. So next time when we want to discuss ideas, we’re not going to be able to do it with these guys who say everything is yes, yes, Dr. Bohr. Get that guy first, we’ll talk with him first.”
The next thing that happened was, of course, the test after we’d made the calculations. We had to make the test. I was actually at home on a short vacation at that time, I guess because my wife died, and so I got a message from Los Alamos that said, “The baby will be born, is expected on such and such a day.” So I flew back, and I just arrived on the site while the buses were leaving; I couldn’t even get into my room. At Alamogordo we waited out there in the distance; we were 20 miles away. And we had a radio and they were supposed to tell us when the thing was going to go off and so forth. The radio wouldn’t work, and we never knew what was happening. But just a few minutes before it was supposed to go off, the radio started to work and they told us there was 20 seconds or something to go. For people who were far away like we were–others were closer, six miles away–they gave out dark glasses that you could watch it with. Dark glasses!! Twenty miles away from the damn thing, you get dark glasses–you couldn’t see a damn thing through dark glasses. So then I figured the only thing that could really hurt your eyes–bright light can never hurt y
our eyes–it’s ultraviolet light that does. So I got behind a truck windshield, so the ultraviolet can’t go through glass, so that would be safe, and so I could see the damn thing. Other people were never going to see the damn thing. OK. Time comes, and this trememdous flash out there, so bright I quickly see this purple splotch on the floor of the truck. I said, “That ain’t it. That’s an after-image.” So I turn back up and I see this white light changing into yellow and then into orange. The clouds form and then they disappear again, the compression and the expansion forms and makes clouds disappear. Then finally, a big ball of orange, the center that was so bright, became a ball of orange that started to rise and billow a little bit and get a little black around the edges and then you see it’s a big ball of smoke with flashes on the inside of the fire going out, the heat. I saw all that and all this that I just described in just a moment; took about one minute. It was a series from bright to dark and I had seen it. I am about the only guy that actually looked at the damn thing, the first Trinity Test. Everybody else had dark glasses. The people at six miles couldn’t see it because they were all told to lie on the floor with their eyes covered, so nobody saw it. The guys up where I was all had dark glasses. I’m the only guy who saw it with the human eye. Finally, after about a minute and a half, there’s suddenly a tremendous noise, BANG, and then rumble, like thunder, and that’s what convinced me. Nobody had said a word during this whole minute, we were all just watching quietly, but this sound released everybody, released me particularly because the solidity of the sound at that distance meant that it had really worked. The man who was standing next to me said, when the sound went off, “What’s that?” I said, “That was the bomb.” The man was William Laurence of the New York Times, who had come. He was going to write an article that was going to describe the whole situation. I had been the one who was supposed to have taken him around. It was found that it was too technnical for him.
The Pleasure of Finding Things Out Page 9
