Surely You’re Joking, Mr. Feynman

As director of this project, I would he making trips down to Aberdeen to get the firing tables. However, they already had some preliminary data. I noticed that for most of the higher altitudes where these airplanes would be flying, there wasn’t any data. So I called up to find out why there wasn’t any data and it turned out that the fuses they were going to use were not clock fuses, but powder-train fuses, which didn’t work at those altitudes—they fizzled out in the thin air.

I thought I only had to correct the air resistance at different altitudes. Instead, my job was to invent a machine that would make the shell explode at the right moment, when the fuse won’t burn!

I decided that was too hard for me and went back to Princeton.

Testing Bloodhounds

When I was at Los Alamos and would get a little time off, I would often go visit my wife, who was in a hospital in Albuquerque, a few hours away. One time I went to visit her and couldn’t go in right away so I went to the hospital library to read.

I read an article in Science about bloodhounds, and how they could smell so very well. The authors described the various experiments that they did—the bloodhounds could identify which items had been touched by people, and so on—and I began to think: It is very remarkable how good bloodhounds are at smelling, being able to follow trails of people, and so forth, but how good are we, actually?

When the time came that I could visit my wife, I went to see her, and I said, “We’re gonna do an experiment. Those Coke bottles over there (she had a six-pack of empty Coke bottles that she was saving to send out)—now you haven’t touched them in a couple of days, right?”

“That’s right.”

I took the six-pack over to her without touching the bottles, and said, “OK. Now I’ll go out, and you take out one of the bottles, handle it for about two minutes, and then put it back. Then I’ll come in, and try to tell which bottle it was.”

So I went out, and she took out one of the bottles and handled it for quite a while—lots of time, because I’m no bloodhound! According to the article, they could tell if you just touched it.

Then I came back, and it was absolutely obvious! I didn’t even have to smell the damn thing, because, of course, the temperature was different. And it was also obvious from the smell. As soon as you put it up near your face, you could smell it was dampish and warmer. So that experiment didn’t work because it was too obvious.

Then I looked at the bookshelf and said, “Those books you haven’t looked at for a while, right? This time, when I go out, take one book off the shelf, and just open it—that’s all—and close it again; then put it back.”

So I went out again, she took a book, opened it and closed it, and put it back. I came in—and nothing to it! It was easy. You just smell the books. It’s hard to explain, because we’re not used to saying things about it. You put each book up to your nose and sniff a few times, and you can tell. It’s very different. A book that’s been standing there a while has a dry uninteresting kind of smell. But when a hand has touched it, there’s a dampness and a smell that’s very distinct.

We did a few more experiments, and I discovered that while bloodhounds are indeed quite capable, humans are not as incapable as they think they are: it’s just that they carry their nose so high off the ground!

(I’ve noticed that my dog can correctly tell which way I’ve gone in the house, especially if I’m barefoot, by smelling my footprints. So I tried to do that: I crawled around the rug on my hands and knees, sniffing, to see if I could tell the difference between where I walked and where I didn’t, and I found it impossible. So the dog is much better than I am.)

Many years later, when I was first at Caltech, there was a party at Professor Bacher’s house, and there were a lot of people from Caltech. I don’t know how it came up, but I was telling them this story about smelling the bottles and the books. They didn’t believe a word, naturally because they always thought I was a faker. I had to demonstrate it.

We carefully took eight or nine books off the shelf without touching them directly with our hands, and then I went out. Three different people touched three different books: they picked one up, opened it, closed it, and put it back.

Then I came back, and smelled everybody’s hands, and smelled all the books—I don’t remember which I did first—and found all three books correctly; I got one person wrong.

They still didn’t believe me; they thought it was some sort of magic trick. They kept trying to figure out how I did it. There’s a famous trick of this kind, where you have a confederate in the group who gives you signals as to what it is, and they were trying to figure out who the confederate was. Since then I’ve often thought that it would be a good card trick to take a deck of cards and tell someone to pick a card and put it back, while you’re in the other room. You say, “Now I’m going to tell you which card it is, because I’m a bloodhound: I’m going to smell all these cards and tell you which card you picked.” Of course, with that kind of patter, people wouldn’t believe for a minute that that’s what you were actually doing!

People’s hands smell very different—that’s why dogs can identify people; you have to try it! All hands have a sort of moist smell, and a person who smokes has a very different smell on his hands from a person who doesn’t; ladies often have different kinds of perfumes, and so on. If somebody happened to have some coins in his pocket and happened to be handling them, you can smell that.

Los Alamos from Below [1]

When I say “Los Alamos from below,” I mean that. Although in my field at the present time I’m a slightly famous man, at that time I was not anybody famous at all. I didn’t even have a degree when I started to work with the Manhattan Project. Many of the other people who tell you about Los Alamos—people in higher echelons—worried about some big decisions. I worried about no big decisions. I was always flittering about underneath.

I was working in my room at Princeton one day when Bob Wilson came in and said that he had been funded to do a job that was a secret, and he wasn’t supposed to tell anybody but he was going to tell me because he knew that as soon as I knew what he was going to do, I’d see that I had to go along with it. So he told me about the problem of separating different isotopes of uranium to ultimately make a bomb. He had a process for separating the isotopes of uranium (different from the one which was ultimately used) that he wanted to try to develop. He told me about it, and he said, “There’s a meeting..

I said I didn’t want to do it.

He said, “All right, there’s a meeting at three o’clock. I’ll see you there.”

I said, “It’s all right that you told me the secret because I’m not going to tell anybody but I’m not going to do it.”

So I went back to work on my thesis—for about three minutes. Then I began to pace the floor and think about this thing. The Germans had Hitler and the possibility of developing an atomic bomb was obvious, and the possibility that they would develop it before we did was very much of a fright. So I decided to go to the meeting at three o’clock.

By four o’clock I already had a desk in a room and was trying to calculate whether this particular method was limited by the total amount of current that you get in an ion beam, and so on. I won’t go into the details. But I had a desk, and I had paper, and I was working as hard as I could and as fast as I could, so the fellas who were building the apparatus could do the experiment right there.

It was like those moving pictures where you see a piece of equipment go bruuuuup, bruuuuup, bruuuuup. Every time I’d look up, the thing was getting bigger. What was happening, of course, was that all the boys had decided to work on this and to stop their research in science. All science stopped during the war except the little bit that was done at Los Alamos. And that was not much science; it was mostly engineering.

All the equipment from different research projects was being put together to make the new apparatus to do the experiment—to try to separate the isotopes of uranium. I stopped my own work for the same reason, though I did take a six-week vacation after a while and finished writing my thesis. And I did get my degree just before I got to Los Alamos—so I wasn’t quite as far down the scale as I led you to believe.

One of the first interesting experiences I had in this project at Princeton was meeting great men. I had never met very many great men before. But there was an evaluation committee that had to try to help us along, and help us ultimately decide which way we were going to separate the uranium. This committee had men like Compton and Tolman and Smyth and Urey and Rabi and Oppenheimer on it. I would sit in because I understood the theory of how our process of separating isotopes worked, and so they’d ask me questions and talk about it. In these discussions one man would make a point. Then Compton, for example, would explain a different point of view. He would say it should be this way, and he was perfectly right. Another guy would say, well, maybe, but there’s this other possibility we have to consider against it.

So everybody is disagreeing, all around the table. I am surprised and disturbed that Compton doesn’t repeat and emphasize his point. Finally at the end, Tolman, who’s the chairman, would say, “Well, having heard all these arguments, I guess it’s true that Compton’s argument is the best of all, and now we have to go ahead.”

It was such a shock to me to see that a committee of men could present a whole lot of ideas, each one thinking of a new facet, while remembering what the other fella said, so that, at the end, the decision is made as to which idea was the best—summing it all up—without having to say it three times. These were very great men indeed.

It was ultimately decided that this project was not to be the one they were going to use to separate uranium. We were told then that we were going to stop, because in Los Alamos, New Mexico, they would be starting the project that would actually make the bomb. We would all go out there to make it. There would be experiments that we would have to do, and theoretical work to do. I was in the theoretical work. All the rest of the fellas were in experimental work.

The question was—What to do now? Los Alamos wasn’t ready yet. Bob Wilson tried to make use of this time by among other things, sending me to Chicago to find out all that we could find out about the bomb and the problems. Then, in our laboratories, we could start to build equipment, counters of various kinds, and so on, that would be useful when we got to Los Alamos. So no time was wasted.

I was sent to Chicago with the instructions to go to each group, tell them I was going to work with them, and have them tell me about a problem in enough detail that I could actually sit down and start to work on it. As soon as I got that far, I was to go to another guy and ask for another problem. That way I would understand the details of everything.

It was a very good idea, but my conscience bothered me a little bit because they would all work so hard to explain things to me, and I’d go away without helping them. But I was very lucky. When one of the guys was explaining a problem, I said, “Why don’t you do it by differentiating under the integral sign?” In half an hour he had it solved, and they’d been working on it for three months. So, I did something, using my “different box of tools.” Then I came back from Chicago, and I described the situation—how much energy was released, what the bomb was going to be like, and so forth.

I remember a friend of mine who worked with me, Paul Olum, a mathematician, came up to me afterwards and said, “When they make a moving picture about this, they’ll have the guy coming back from Chicago to make his report to the Princeton men about the bomb. He’ll be wearing a suit and carrying a briefcase and so on—and here you’re in dirty shirtsleeves and just telling us all about it, in spite of its being such a serious and dramatic thing.”

There still seemed to be a delay and Wilson went to Los Alamos to find out what was holding things up. When he got there, he found that the construction company was working very hard and had finished the theater, and a few other buildings that they understood, but they hadn’t gotten instructions clear on how to build a laboratory—how many pipes for gas, how much for water. So Wilson simply stood around and decided, then and there, how much water, how much gas, and so on, and told them to start building the laboratories.

When he came back to us, we were all ready to go and we were getting impatient. So they all got together and decided we’d go out there anyway even though it wasn’t ready.

We were recruited, by the way by Oppenheimer and other people, and he was very patient. He paid attention to everybody’s problems. He worried about my wife, who had TB, and whether there would he a hospital out there, and everything. It was the first time I met him in such a personal way; he was a wonderful man.

We were told to be very careful—not to buy our train ticket in Princeton, for example, because Princeton was a very small station, and if everybody bought train tickets to Albuquerque, New Mexico, in Princeton, there would be some suspicions that something was up. And so everybody bought their tickets somewhere else, except me, because I figured if everybody bought their tickets somewhere else..

So when I went to the train station and said, “I want to go to Albuquerque, New Mexico,” the man says, “Oh, so all this stuff is for you!” We had been shipping out crates full of counters for weeks and expecting that they didn’t notice the address was Albuquerque. So at least I explained why it was that we were shipping all those crates; I was going out to Albuquerque.

Well, when we arrived, the houses and dormitories and things like that were not ready. In fact, even the laboratories weren’t quite ready. We were pushing them by coming down ahead of time. So they just went crazy and rented ranch houses all around the neighborhood. We stayed at first in a ranch house and would drive in in the morning. The first morning I drove in was tremendously impressive. The beauty of the scenery, for a person from the East who didn’t travel much, was sensational. There are the great cliffs that you’ve probably seen in pictures. You’d come up from below and be very surprised to see this high mesa. The most impressive thing to me was that, as I was going up, I said that maybe there had been Indians living here, and the guy who was driving stopped the car and walked around the corner and pointed out some Indian caves that you could inspect. It was very exciting.

When I got to the site the first time, I saw there was a technical area that was supposed to have a fence around it ultimately but it was still open. Then there was supposed to be a town, and then a big fence further out, around the town. But they were still building, and my friend Paul Olum, who was my assistant, was standing at the gate with a clipboard, checking the trucks coming in and out and telling them which way to go to deliver the materials in different places.

When I went into the laboratory, I would meet men I had heard of by seeing their papers in the Physical Review and so on. I had never met them before. “This is John Williams,” they’d say. Then a guy stands up from a desk that is covered with blueprints, his sleeves all rolled up, and he’s calling out the windows, ordering trucks and things going in different directions with building material. In other words, the experimental physicists had nothing to do until their buildings and apparatus were ready, so they just built the buildings—or assisted in building the buildings.

The theoretical physicists, on the other hand, could start working right away so it was decided that they wouldn’t live in the ranch houses, but would live up at the site. We started working immediately. There were no blackboards except for one on wheels, and we’d roll it around and Robert Serber would explain to us all the things that they’d thought of in Berkeley about the atomic bomb, and nuclear physics, and all these things. I didn’t know very much about it; I had been doing other kinds of things. So I had to do an awful lot of work.

Every day I would study and read, study and read. It was a very hectic time. But I had some luck. All the big shots except for Hans Bethe happened to be away at the time, and what Bethe needed was someone to talk to, to push his ideas against. Well, he comes in to this little squirt in an office and starts to argue, explaining his idea. I say “No, no, you’re crazy. It’ll go like this.” And he says, “Just a moment,” and explains how he’s not crazy, I’m crazy. And we keep on going like this. You see, when I hear about physics, I just think about physics, and I don’t know who I’m talking to, so I say dopey things like “no, no, you’re wrong,” or “you’re crazy.” But it turned out that’s exactly what he needed. I got a notch up on account of that, and I ended up as a group leader under Bethe with four guys under me.

Well, when I was first there, as I said, the dormitories weren’t ready. But the theoretical physicists had to stay up there anyway. The first place they put us was in an old school building—a boys’ school that had been there previously. 1 lived in a thing called the Mechanics’ Lodge. We were all jammed in there in bunk beds, and it wasn’t organized very well because Bob Christy and his wife had to go to the bathroom through our bedroom. So that was very uncomfortable.

At last the dormitory was built. I went down to the place where rooms were assigned, and they said, you can pick your room now. You know what I did? I looked to see where the girls’ dormitory was, and then I picked a room that looked right across—though later I discovered a big tree was growing right in front of the window of that room.

They told me there would be two people in a room, but that would only be temporary. Every two rooms would share a bathroom, and there would be double-decker bunks in each room. But I didn’t want two people in the room.

The night I got there, nobody else was there, and I decided to try to keep my room to myself. My wife was sick with TB in Albuquerque, but I had some boxes of stuff of hers. So I took out a little nightgown, opened the top bed, and threw the nightgown carelessly on it. I took out some slippers, and I threw some powder on the floor in the bathroom. I just made it look like somebody else was there. So, what happened? Well, it’s supposed to be a men’s dormitory see? So I came home that night, and my pajamas are folded nicely and put under the pillow at the bottom, and my slippers put nicely at the bottom of the bed. The lady’s nightgown is nicely folded under the pillow, the bed is all fixed up and made, and the slippers are put down nicely. The powder is cleaned from the bathroom and nobody is sleeping in the upper bed.

Next night, the same thing. When I wake up, I rumple up the top bed, I throw the nightgown on it sloppily and scatter the powder in the bathroom and so on. I went on like this for four nights until everybody was settled and there was no more danger that they would put a second person in the room. Each night, everything was set out very neatly even though it was a men’s dormitory.

I didn’t know it then, but this little ruse got me involved in politics. There were all kinds of factions there, of course—the housewives’ faction, the mechanics’ faction, the technical peoples’ faction, and so on. Well, the bachelors and bachelor girls who lived in the dormitory felt they had to have a faction too, because a new rule had been promulgated: No Women in the Men’s Dorm. Well, this is absolutely ridiculous! After all, we are grown people! What kind of nonsense is this? We had to have political action. So we debated this stuff, and I was elected to represent the dormitory people in the town council.

After I’d been in it for about a year and a half, I was talking to Hans Bethe about something. He was on the big governing council all this time, and I told him about this trick with my wife’s nightgown and bedroom slippers. He started to laugh. “So that’s how you got on the town council,” he said.

It turned out that what happened was this. The woman who cleans the rooms in the dormitory opens this door, and all of a sudden there is trouble: somebody is sleeping with one of the guys! She reports to the chief charwoman, the chief charwoman reports to the lieutenant, the lieutenant reports to the major. It goes all the way up through the generals to the governing board.

What are they going to do? They’re going to think about it, that’s what! But, in the meantime, what instructions go down through the captains, down through the majors, through the lieutenants, through the chars’ chief, through the charwoman? “Just put things back the way they are, clean ‘em up, and see what happens.” Next day same report. For four days, they worried up there about what they were going to do. Finally they promulgated a rule: No Women in the Men’s Dormitory! And that caused such a stink down below that they had to elect somebody to represent the …

I would like to tell you something about the censorship that we had there. They decided to do something utterly illegal and censor the mail of people inside the United States—which they have no right to do. So it had to be set up very delicately as a voluntary thing. We would all volunteer not to seal the envelopes of the letters we sent out, and it would he all right for them to open letters coming in to us; that was voluntarily accepted by us. We would leave our letters open; and they would seal them if they were OK. If they weren’t OK in their opinion, they would send the letter back to us with a note that there was a violation of such and such a paragraph of our “understanding.”

So, very delicately amongst all these liberal-minded scientific guys, we finally got the censorship set up, with many rules. We were allowed to comment on the character of the administration if we wanted to, so we could write our senator and tell him we didn’t like the way things were run, and things like that. They said they would notify us if there were any difficulties.

So it was all set up, and here comes the first day for censorship: Telephone! Briiing!

Me: “What?”

“Please come down.” I come down.

“What’s this?”

“It’s a letter from my father.”

“Well, what is it?”

There’s lined paper, and there’s these lines going out with dots—four dots under, one dot above, two dots under, one dot above, dot under dot …

“What’s that?”

I said, “It’s a code.”

They said, “Yeah, it’s a code, but what does it say?”

I said, “I don’t know what it says.”

They said, “Well, what’s the key to the code? How do you decipher it?”

I said, “Well, I don’t know.”

Then they said, “What’s this?”

I said, “It’s a letter from my wife—it says TJXYWZ TW1X3.”

“What’s that?”

I said, “Another code.”

“What’s the key to it?”

“I don’t know.”

They said, “You’re receiving codes, and you don’t know the key?”

I said, “Precisely. I have a game. I challenge them to send me a code that I can’t decipher, see? So they’re making up codes at the other end, and they’re sending them in, and they’re not going to tell me what the key is.”

Now one of the rules of the censorship was that they aren’t going to disturb anything that you would ordinarily send in the mail. So they said, “Well, you’re going to have to tell them please to send the key in with the code.”

I said, “I don’t want to see the key!”

They said, “Well, all right, we’ll take the key out.”

So we had that arrangement. OK? All right. Next day I get a letter from my wife that says, “It’s very difficult writing because I feel that the—is looking over my shoulder.” And where the word was there is a splotch made with ink eradicator.

So I went down to the bureau, and I said, “You’re not supposed to touch the incoming mail if you don’t like it. You can look at it, but you’re not supposed to take anything out.”

They said, “Don’t be ridiculous. Do you think that’s the way censors work—with ink eradicator? They cut things out with scissors.”

I said OK. So I wrote a letter back to my wife and said,. “Did you use ink eradicator in your letter?” She writes back, “No, I didn’t use ink eradicator in my letter, it must have been the—“—and there’s a hole cut out of the paper.

So I went back to the major who was supposed to be in charge of all this and complained. You know, this took a little time, but I felt I was sort of the representative to get the thing straightened out. The major tried to explain to me that these people who were the censors had been taught how to do it, but they didn’t understand this new way that we had to be so delicate about.

So, anyway he said, “What’s the matter, don’t you think I have good will?”

I said, “Yes, you have perfectly good will but I don’t think you have power.” Because, you see, he had already been on the job three or four days.

He said, “We’ll see about that!” He grabs the telephone, and everything is straightened out. No more is the letter cut.

However, there were a number of other difficulties. For example, one day I got a letter from my wife and a note from the censor that said, “There was a code enclosed without the key and so we removed it.”

So when I went to see my wife in Albuquerque that day, she said, “Well, where’s all the stuff?”

I said, “What stuff?”

She said, “Litharge, glycerine, hot dogs, laundry.”

I said, “Wait a minute—that was a list?”

She said, “Yes.”

“That was a code,” I said. “They thought it was a code—litharge, glycerine, etc.” (She wanted litharge and glycerine to make a cement to fix an onyx box.)

All this went on in the first few weeks before we got everything straightened out. An way, one day I’m piddling around with the computing machine, and I notice something very peculiar. If you take 1 divided by 243 you get.004115226337

It’s quite cute: It goes a little cockeyed after 559 when you’re carrying but it soon straightens itself out and repeats itself nicely. I thought it was kind of amusing.

Well, I put that in the mail, and it comes back to me. It doesn’t go through, and there’s a little note: “Look at Paragraph 17B.” I look at Paragraph 17B. It says, “Letters are to be written only in English, Russian, Spanish, Portuguese, Latin, German, and so forth. Permission to use any other language must be obtained in writing.” And then it said, “No codes.”

So I wrote back to the censor a little note included in my letter which said that I feel that of course this cannot be a code, because if you actually do divide 1 by 243, you do, in fact, get all that, and therefore there’s no more information in the number.004115226337 … than there is in the number 243—which is hardly any information at all. And so forth. I therefore asked for permission to use Arabic numerals in my letters. So I got that through all right.

There was always some kind of difficulty with the letters going back and forth. For example, my wife kept mentioning the fact that she felt uncomfortable writing with the feeling that the censor is looking over her shoulder. Now, as a rule, we aren’t supposed to mention censorship. We aren’t, but how can they tell her? So they keep sending me a note: “Your wife mentioned censorship.” Certainly my wife mentioned censorship. So finally they sent me a note that said, “Please inform your wife not to mention censorship in her letters.” So I start my letter: “I have been instructed to inform you not to mention censorship in your letters.” Phoom, phoooom, it comes right back! So I write, “I have been instructed to inform my wife not to mention censorship. How in the heck am I going to do it? Furthermore, why do I have to instruct her not to mention censorship? You keeping something from me?”

It is very interesting that the censor himself has to tell me to tell my wife not to tell me that she’s … But they had an answer. They said, yes, that they are worried about mail being intercepted on the way from Albuquerque, and that someone might find out that there was censorship if they looked in the mail, and would she please act much more normal.

So I went down the next time to Albuquerque, and I talked to her and I said, “Now, look, let’s not mention censorship.” But we had had so much trouble that we at last worked out a code, something illegal. If I would put a dot at the end of my signature, it meant I had had trouble again, and she would move on to the next of the moves that she had concocted. She would sit there all day long, because she was ill, and she would think of things to do. The last thing she did was to send me an advertisement which she found perfectly legitimately. It said, “Send your boyfriend a letter on a jigsaw puzzle. We sell you the blank, you write the letter on it, take it all apart, put it in a little sack, and mail it.” I received that one with a note saying, “We do not have time to play games. Please instruct your wife to confine herself to ordinary letters.”

Well, we were ready with the one more dot, but they straightened out just in time and we didn’t have to use it. The thing we had ready for the next one was that the letter would start, “I hope you remembered to open this letter carefully because I have included the Pepto-Bismol powder for your stomach as we arranged.” It would be a letter full of powder. In the office we expected they would open it quickly the powder would go all over the floor, and they would get all upset because you are not supposed to upset anything. They’d have to gather up all this Pepto-Bismol … But we didn’t have to use that one.