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A Map of the Cat?

   In the Graduate College dining room at Princeton everybody used to sit with his own group. I sat with the physicists, but after a bit I thought: It would be nice to see what the rest of the world is doing, so I’ll sit for a week or two in each of the other groups.
   When I sat with the philosophers I listened to them discuss very seriously a book called Process and Reality by Whitehead. They were using words in a funny way, and I couldn’t quite understand what they were saying. Now I didn’t want to interrupt them in their own conversation and keep asking them to explain something, and on the few occasions that I did, they’d try to explain it to me, but I still didn’t get it. Finally they invited me to come to their seminar.
   They had a seminar that was like, a class. It had been meeting once a week to discuss a new chapter out of Process and Reality–some guy would give a report on it and then there would be a discussion. I went to this seminar promising myself to keep my mouth shut, reminding myself that I didn’t know anything about the subject, and I was going there just to watch.
   What happened there was typical—so typical that it was unbelievable, but true. First of all, I sat there without saying anything, which is almost unbelievable, but also true. A student gave a report on the chapter to be studied that week. In it Whitehead kept using the words “essential object” in a particular technical way that presumably he had defined, but that I didn’t understand.
   After some discussion as to what “essential object” meant, the professor leading the seminar said something meant to clarify things and drew something that looked like lightning bolts on the blackboard. “Mr. Feynman,” he said, “would you say an electron is an ‘essential object’?”
   Well, now I was in trouble. I admitted that I hadn’t read the book, so I had no idea of what Whitehead meant by the phrase; I had only come to watch. “But,” I said, “I’ll try to answer the professor’s question if you will first answer a question from me, so I can have a better idea of what ‘essential object’ means. Is a brick an essential object?”
   What I had intended to do was to find out whether they thought theoretical constructs were essential objects. The electron is a theory that we use; it is so useful in understanding the way nature works that we can almost call it real. I wanted to make the idea of a theory clear by analogy. In the case of the brick, my next question was going to be, “What about the inside of the brick?”—and I would then point out that no one has ever seen the inside of a brick. Every time you break the brick, you only see the surface. That the brick has an inside is a simple theory which helps us understand things better. The theory of electrons is analogous. So I began by asking, “Is a brick an essential object?”
   Then the answers came out. One man stood up and said, “A brick as an individual, specific brick. That is what Whitehead means by an essential object.”
   Another man said, “No, it isn’t the individual brick that is an essential object; it’s the general character that all bricks have in common—their ‘brickiness’—that is the essential object.”
   Another guy got up and said, “No, it’s not in the bricks themselves. ‘Essential object’ means the idea in the mind that you get when you think of bricks.”
   Another guy got up, and another, and I tell you I have never heard such ingenious different ways of looking at a brick before. And, just like it should in all stories about philosophers, it ended up in complete chaos. In all their previous discussions they hadn’t even asked themselves whether such a simple object as a brick, much less an electron, is an “essential object.”
   After that I went around to the biology table at dinner time. I had always had some interest in biology, and the guys talked about very interesting things. Some of them invited me to come to a course they were going to have in cell physiology. I knew something about biology, but this was a graduate course. “Do you think I can handle it? Will the professor let me in?” I asked.
   They asked the instructor, E. Newton Harvey, who had done a lot of research on light-producing bacteria. Harvey said I could join this special, advanced course provided one thing—that I would do all the work, and report on papers just like everybody else.
   Before the first class meeting, the guys who had invited me to take the course wanted to show me some things under the microscope. They had some plant cells in there, and you could see some little green spots called chloroplasts (they make sugar when light shines on them) circulating around. I looked at them and then looked up: “How do they circulate? What pushes them around?” I asked.
   Nobody knew. It turned out that it was not understood at that time. So right away I found out something about biology: it was very easy to find a question that was very interesting, and that nobody knew the answer to. In physics you had to go a little deeper before you could find an interesting question that people didn’t know.
   When the course began, Harvey started out by drawing a great, big picture of a cell on the blackboard and labeling all the things that are in a cell. He then talked about them, and I understood most of what he said.
   After the lecture, the guy who had invited me said, “Well, how did you like it?”
   “Just fine,” I said. “The only part I didn’t understand was the part about lecithin. What is lecithin?”
   The guy begins to explain in a monotonous voice: “All living creatures, both plant and animal, are made of little bricklike objects called ‘cells’.
   “Listen,” I said, impatiently, “I know all that; otherwise I wouldn’t be in the course. What is lecithin?”
   “I don’t know.”
   I had to report on papers along with everyone else, and the first one I was assigned was on the effect of pressure on cells—Harvey chose that topic for me because it had something that had to do with physics. Although I understood what I was doing, I mispronounced everything when I read my paper, and the class was always laughing hysterically when I’d talk about “blastospheres” instead of “blastomeres,” or some other such thing.
   The next paper selected for me was by Adrian and Bronk. They demonstrated that nerve impulses were sharp, single-pulse phenomena. They had done experiments with cats in which they had measured voltages on nerves.
   I began to read the paper. It kept talking about extensors and flexors, the gastrocnemius muscle, and so on. This and that muscle were named, but I hadn’t the foggiest idea of where they were located in relation to the nerves or to the cat. So I went to the librarian in the biology section and asked her if she could find me a map of the cat.
   “A map of the cat, sir?” she asked, horrified. “You mean a zoological chart!” From then on there were rumors about some dumb biology graduate student who was looking for a “map of the cat.”
   When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.
   The other students in the class interrupt me: “We know all that!”
   “Oh,” I say, “you do? Then no wonder I can catch up with you so fast after you’ve had four years of biology.” They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes.
   After the war, every summer I would go traveling by car somewhere in the United States. One year, after I was at Caltech, I thought, “This summer, instead of going to a different place, I’ll go to a different field.”
   It was right after Watson and Crick’s discovery of the DNA spiral. There were some very good biologists at Caltech because Delbrьck had his lab there, and Watson came to Caltech to give some lectures on the coding systems of DNA. I went to his lectures and to seminars in the biology department and got full of enthusiasm. It was a very exciting time in biology, and Caltech was a wonderful place to be.
   I didn’t think I was up to doing actual research in biology, so for my summer visit to the field of biology I thought I would just hang around the biology lab and “wash dishes,” while I watched what they were doing. I went over to the biology lab to tell them my desire, and Bob Edgar, a young post-doc who was sort of in charge there, said he wouldn’t let me do that. He said, “You’ll have to really do some research, just like a graduate student, and we’ll give you a problem to work on.” That suited me fine.
   I took a phage course, which told us how to do research with bacteriophages (a phage is a virus that contains DNA and attacks bacteria). Right away I found that I was saved a lot of trouble because I knew some physics and mathematics. I knew how atoms worked in liquids, so there was nothing mysterious about how the centrifuge worked. I knew enough statistics to understand the statistical errors in counting little spots in a dish. So while all the biology guys were trying to understand these “new” things, I could spend my time learning the biology part.
   There was one useful lab technique I learned in that course which I still use today. They taught us how to hold a test tube and take its cap off with one hand (you use your middle and index fingers), while leaving the other hand free to do something else (like hold a pipette that you’re sucking cyanide up into). Now, I can hold my toothbrush in one hand, and with the other hand, hold the tube of toothpaste, twist the cap off, and put it back on.
   It had been discovered that phages could have mutations which would affect their ability to attack bacteria, and we were supposed to study those mutations. There were also some phages that would have a second mutation which would reconstitute their ability to attack bacteria. Some phages which mutated back were exactly the same as they were before. Others were not: There was a slight difference in their effect on bacteria—they would act faster or slower than normal, and the bacteria would grow slower or faster than normal. In other words, there were “back mutations, but they weren’t always perfect; sometimes the phage would recover only part of the ability it had lost.
   Bob Edgar suggested that I do an experiment which would try to find out if the back mutations occurred in the same place on the DNA spiral. With great care and a lot of tedious work I was able to find three examples of back mutations which had occurred very close together—closer than anything they had ever seen so far—and which partially restored the phage’s ability to function. It was a slow job. It was sort of accidental: You had to wait around until von got a double mutation, which was very rare.
   I kept trying to think of ways to make a phage mutate more often and how to detect mutations more quickly, but before I could come up with a good technique the summer was over, and I didn’t feel like continuing on that problem.
   However, my sabbatical year was coming up, so I decided to work in the same biology lab but on a different subject. I worked with Matt Meselson to some extent, and then with a nice fella from England named J. D. Smith. The problem had to do with ribosomes, the “machinery” in the cell that makes protein from what we now call messenger RNA. Using radioactive substances, we demonstrated that the RNA could come out of ribosomes and could be put back in.
   I did a very careful job in measuring and trying to control everything, but it took me eight months to realize that there was one step that was sloppy. In preparing the bacteria, to get the ribosomes out, in those days you ground it up with alumina in a mortar. Everything else was chemical and all under control, but you could never repeat the way you pushed the pestle around when you were grinding the bacteria. So nothing ever came of the experiment.
   Then I guess I have to tell about the time I tried with Hildegarde Lamfrom to discover whether peas could use the same ribosomes as bacteria. The question was whether the ribosomes of bacteria can manufacture the proteins of humans or other organisms, She had just developed a scheme for getting the ribosomes out of peas and giving them messenger RNA so that they would make pea proteins. We realized that a very dramatic and important question was whether ribosomes from bacteria, when given the peas’ messenger RNA, would make pea protein or bacteria protein. It was to be a very dramatic and fundamental experiment.
   Hildegarde said, “I’ll need a lot of ribosomes from bacteria.”
   Meselson and I had extracted enormous quantities of ribosomes from E. coli for some other experiment. I said, “Hell, I’ll just give you the ribosomes we’ve got. We have plenty of them in my refrigerator at the lab.”
   It would have been a fantastic and vital discovery if I had been a good biologist. But I wasn’t a good biologist. We had a good idea, a good experiment, the right equipment, but I screwed it up: I gave her infected ribosomes—the grossest possible error that you could make in an experiment like that. My ribosomes had been in the refrigerator for almost a month, and had become contaminated with some other living things. Had I prepared those ribosomes promptly over again and given them to her in a serious and careful way, with everything under control, that experiment would have worked,. and we would have been the first to demonstrate the uniformity of life: the machinery of making proteins, the ribosomes, is the same in every creature. We were there at the right place, we were doing the right things, but I was doing things as an amateur—stupid and sloppy.
   You know what it reminds me of? The husband of Madame Bovary in Flaubert’s book, a dull country doctor who had some idea of how to fix club feet, and all he did was screw people up. I was similar to that unpracticed surgeon.
   The other work on the phage I never wrote up—Edgar kept asking me to write it up, but I never got around to it. That’s the trouble with not being in your own field: You don’t take it seriously.
   I did write something informally on it. I sent it to Edgar, who laughed when he read it. It wasn’t in the standard form that biologists use—first, procedures, and so forth. I spent a lot of time explaining things that all the biologists knew. Edgar made a shortened version, but I couldn’t understand it. I don’t think they ever published it. I never published it directly.
   Watson thought the stuff I had done with phages was of some interest, so he invited me to go to Harvard. I gave a talk to the biology department about the double mutations which occurred so close together. I told them my guess was that one mutation made a change in the protein, such as changing the pH of an amino acid, while the other mutation made the opposite change on a different amino acid in the same protein, so that it partially balanced the first imitation—not perfectly, but enough to let the phage operate again. I thought they were two changes in the same protein, which chemically compensated each other.
   That turned out not to be the case. It was found out a few years later by people who undoubtedly developed a technique for producing and detecting the mutations faster, that what happened was, the first mutation was a mutation in which an entire DNA base was missing. Now the “code” was shifted and could not be read any more. The second mutation was either one in which an extra base was put back in, or two more were taken out. Now the code could be read again. The closer the second mutation occurred to the first, the less message would he altered by the double mutation, and the more completely the phage would recover its lost abilities. The fact that there are three “letters” to code each amino acid was thus demonstrated.
   While I was at Harvard that week, Watson suggested something and we did an experiment together for a few days. It was an incomplete experiment, but I learned some new lab techniques from one of the best men in the field.
   But that was my big moment: I gave a seminar in the biology department of Harvard! I always do that, get into something and see how far I can go.
   I learned a lot of things in biology, and I gained a lot of experience. I got better at pronouncing the words, knowing what not to include in a paper or a seminar, and detecting a weak technique in an experiment. But I love physics, and I love to go back to it.
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Monster Minds

   While I was still a graduate student at Princeton, I worked as a research assistant under John Wheeler. He gave me a problem to work on, and it got hard, and I wasn’t getting anywhere. So I went back to an idea that I had had earlier, at MIT. The idea was that electrons don’t act on themselves, they only act on other electrons.
   There was this problem: When you shake an electron, it radiates energy and so there’s a loss. That means there must he a force on it. And there must he a different force when it’s charged than when it’s not charged. (If the force were exactly the same when it was charged and not charged, in one case it would lose energy, and in the other it wouldn’t. You can’t have two different answers to the same problem.)
   The standard theory was that it was the electron acting on itself that made that force (called the force of radiation reaction), and I had only electrons acting on other electrons. So I was in some difficulty, I realized, by that time. (When I was at MIT, I got the idea without noticing the problem, but by the time I got to Princeton, I knew that problem.)
   What I thought was: I’ll shake this electron. It will make some nearby electron shake, and the effect back from the nearby electron would be the origin of the force of radiation reaction. So I did some calculations and took them to Wheeler.
   Wheeler, right away said, “Well, that isn’t right because it varies inversely as the square of the distance of the other electrons, whereas it should not depend on any of these variables at all. It’ll also depend inversely upon the mass of the other electron; it’ll be proportional to the charge on the other electron.”
   What bothered me was, I thought he must have done the calculation. I only realized later that a man like Wheeler could immediately see all that stuff when you give him the problem. I had to calculate, but he could see.
   Then he said, “And it’ll be delayed—the wave returns late—so all you’ve described is reflected light.”
   “Oh! Of course,” I said.
   “But wait,” he said. “Let’s suppose it returns by advanced waves—reactions backward in time—so it comes back at the right time. We saw the effect varied inversely as the square of the distance, but suppose there are a lot of electrons, all over space: the number is proportional to the square of the distance. So maybe we can make it all compensate.”
   We found out we could do that. It came out very nicely, and fit very well. It was a classical theory that could be right, even though it differed from Maxwell’s standard, or Lorentz’s standard theory. It didn’t have any trouble with the infinity of self-action, and it was ingenious. It had actions and delays, forwards and backwards in time—we called it “half-advanced and half-retarded potentials.”
   Wheeler and I thought the next problem was to turn to the quantum theory of electrodynamics, which had difficulties (I thought) with the self-action of the electron. We figured if we could get rid of the difficulty first in classical physics, and then make a quantum theory out of that, we could straighten out the quantum theory as well.
   Now that we had got the classical theory right, Wheeler said, “Feynman, you’re a young fella—you should give a seminar on this. You need experience in giving talks. Meanwhile, I’ll work out the quantum theory part and give a seminar on that later.”
   So it was to be my first technical talk, and Wheeler made arrangements with Eugene Wigner to put it on the regular seminar schedule.
   A day or two before the talk I saw Wigner in the hail. “Feynman,” he said, “I think that work you’re doing with Wheeler is very interesting, so I’ve invited Russell to the seminar.” Henry Norris Russell, the famous, great astronomer of the day, was coming to the lecture!
   Wigner went on. “I think Professor von Neumann would also he interested.” Johnny von Neumann was the greatest mathematician around. “And Professor Pauli is visiting from Switzerland, it so happens, so I’ve invited Professor Pauli to come”—Pauli was a very famous physicist—and by this time, I’m turning yellow. Finally, Wigner said, “Professor Einstein only rarely comes to our weekly seminars, but your work is so interesting that I’ve invited him specially, so he’s coming, too.”
   By this time I must have turned green, because Wigner said, “No, no! Don’t worry! I’ll just warn you, though: If Professor Russell falls asleep—and he will undoubtedly fall asleep—it doesn’t mean that the seminar is bad; he falls asleep in all the seminars. On the other hand, if Professor Pauli is nodding all the time, and seems to be in agreement as the seminar goes along, pay no attention. Professor Pauli has palsy.”
   I went back to Wheeler and named all the big, famous people who were coming to the talk he got me to give, and told him I was uneasy about it.
   “It’s all right,” he said. “Don’t worry. I’ll answer all the questions.”
   So I prepared the talk, and when the day came, I went in and did something that young men who have had no experience in giving talks often do—I put too many equations up on the blackboard. You see, a young fella doesn’t know how to say, “Of course, that varies inversely, and this goes this way … because everybody listening already knows; they can see it. But he doesn’t know. He can only make it come out by actually doing the algebra—and therefore the reams of equations.
   As I was writing these equations all over the blackboard ahead of time, Einstein came in and said pleasantly, “Hello, I’m coming to your seminar. But first, where is the tea?”
   I told him, and continued writing the equations.
   Then the time came to give the talk, and here are these monster minds in front of me, waiting! My first technical talk—and I have this audience! I mean they would put me through the wringer! I remember very clearly seeing my hands shaking as they were pulling out my notes from a brown envelope.
   But then a miracle occurred, as it has occurred again and again in my life, and it’s very lucky for me: the moment I start to think about the physics, and have to concentrate on what I’m explaining, nothing else occupies my mind—I’m completely immune to being nervous. So after I started to go, I just didn’t know who was in the room. I was only explaining this idea, that’s all.
   But then the end of the seminar came, and it was time for questions. First off, Pauli, who was sitting next to Einstein, gets up and says, “I do not sink dis teory can be right, because of dis, and dis, and dis,” and he turns to Einstein and says, “Don’t you agree, Professor Einstein?”
   Einstein says, “Nooooooooooooo,” a nice, German sounding “No, “—very polite. “I find only that it would be very difficult to make a corresponding theory for gravitational interaction.” He meant for the general theory of relativity, which was his baby. He continued: “Since we have at this time not a great deal of experimental evidence, I am not absolutely sure of the correct gravitational theory.” Einstein appreciated that things might he different from what his theory stated; he was very tolerant of other ideas.
   I wish I had remembered what Pauli said, because I discovered years later that the theory was not satisfactory when it came to making the quantum theory. It’s possible that that great man noticed the difficulty immediately and explained it to me in the question, but I was so relieved at not having to answer the questions that I didn’t really listen to them carefully. I do remember walking up the steps of Palmer Library with Pauli, who said to me, “What is Wheeler going to say about the quantum theory when he gives his talk?”
   I said, “I don’t know. He hasn’t told me. He’s working it out himself.”
   “Oh?” he said. “The man works and doesn’t tell his assistant what he’s doing ‘on the quantum theory?” He came closer to me and said in a low, secretive voice, “Wheeler will never give that seminar.”
   And it’s true. Wheeler didn’t give the seminar. He thought it would he easy to work out the quantum part; he thought he had it, almost. But he didn’t. And by the time the seminar came around, he realized he didn’t know how to do it, and therefore didn’t have anything to say.
   I never solved it, either—a quantum theory of half-advanced, half-retarded potentials—and I worked on it for years.
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Mixing Paints

   The reason why I say I’m “uncultured” or “anti-intellectual” probably goes all the way back to the time when I was in high school. I was always worried about being a sissy; I didn’t want to be too delicate. To me, no real man ever paid any attention to poetry and such things. How poetry ever got written–that never struck me! So I developed a negative attitude toward the guy who studies French literature, or studies too much music or poetry—all those “fancy” things. I admired better the steel-worker, the welder, or the machine shop man. I always thought the guy who worked in the machine shop and could make things, now he was a real guy! That was my attitude. To be a practical man was, to me, always somehow a positive virtue, and to be “cultured” or “intellectual” was not. The first was right, of course, but the second was crazy.
   I still had this feeling when I was doing my graduate study at Princeton, as you’ll see. I used to eat often in a nice little restaurant called Papa’s Place. One day while I was eating there, a painter in his painting clothes came down from an upstairs room he’d been painting, and sat near me. Somehow we struck up a conversation and he started talking about how you’ve got to learn a lot to be in the painting business. “For example,” he said, “in this restaurant, what colors would you use to paint the walls, if you had the job to do?”
   I said I didn’t know, and he said, “You have a dark band up to such-and-such a height, because, you see, people who sit at the tables rub their elbows against the walls, so you don’t want a nice, white wall there. It gets dirty too easily. But above that, you do want it white to give a feeling of cleanliness to the restaurant.”
   The guy seemed to know what he was doing, and I was sitting there, hanging on his words, when he said, “And you also have to know about colors—how to get different colors when you mix the paint. For example, what colors would you mix to get yellow?”
   I didn’t know how to get yellow by mixing paints. If it’s light, you mix green and red, but I knew he was talking paints. So I said, “I don’t know how you get yellow without using yellow.”
   “Well,” he said, “if you mix red and white, you’ll get yellow.”
   “Are you sure you don’t mean pink?”
   “No,” he said, “you’ll get yellow”—and I believed that he got yellow, because he was a professional painter, and I always admired guys like that. But I still wondered how he did it.
   I got an idea. “It must be some kind of chemical change. Were you using some special kind of pigments that make a chemical change?”
   “No,” he said, “any old pigments will work. You go down to the five-and-ten and get some paint—just a regular can of red paint and a regular can of white paint—and I’ll mix ‘em, and I’ll show how you get yellow.”
   At this juncture I was thinking, “Something is crazy. I know enough about paints to know you won’t get yellow, but he must know that you do get yellow, and therefore something interesting happens. I’ve got to see what it is!”
   So I said, “OK, I’ll get the paints.”
   The painter went back upstairs to finish his painting job, and the restaurant owner came over and said to me, “What’s the idea of arguing with that man? The man is a painter; he’s been a painter all his life, and he says he gets yellow. So why argue with him?”
   I felt embarrassed. I didn’t know what to say. Finally I said, “All my life, I’ve been studying light. And I think that with red and white you can’t get yellow—you can only get pink.”
   So I went to the five-and-ten and got the paint, and brought it back to the restaurant. The painter came down from upstairs, and the restaurant owner was there too. I put the cans of paint on an old chair, and the painter began to mix the paint. He put a little more red, he put a little more white—it still looked pink to me—and he mixed some more. Then he mumbled something like, “I used to have a little tube of yellow here to sharpen it up a bit—then this’ll be yellow.”
   “Oh!” I said. “Of course! You add yellow, and you can get yellow, but you couldn’t do it without the yellow.”
   The painter went back upstairs to paint.
   The restaurant owner said, “That guy has his nerve, arguing with a guy who’s studied light all his life!”
   But that shows you how much I trusted these “real guys.” The painter had told me so much stuff that was reasonable that I was ready to give a certain chance that there was an odd phenomenon I didn’t know. I was expecting pink, but my set of thoughts were, “The only way to get yellow will be something new and interesting, and I’ve got to see this.”
   I’ve very often made mistakes in my physics by thinking the theory isn’t as good as it really is, thinking that there are lots of complications that are going to spoil it—an attitude that anything can happen, in spite of what you’re pretty sure should happen.
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A Different Box of Tools

   At the Princeton graduate school, the physics department and the math department shared a common lounge, and every day at four o’clock we would have tea. It was a way of relaxing in the afternoon, in addition to imitating an English college. People would sit around playing Go, or discussing theorems. In those days topology was the big thing.
   I still remember a guy sitting on the couch, thinking very hard, and another guy standing in front of him, saying, “And therefore such-and-such is true.”
   “Why is that?” the guy on the couch asks.
   “It’s trivial! It’s trivial!” the standing guy says, and he rapidly reels off a series of logical steps: “First you assume thus-and-so, then we have Kerchoff’s this-and-that; then there’s Waffenstoffer’s Theorem, and we substitute this and construct that. Now you put the vector which goes around here and then thus-and-so …” The guy on the couch is struggling to understand all this stuff, which goes on at high speed for about fifteen minutes!
   Finally the standing guy comes out the other end, and the guy on the couch says, “Yeah, yeah. It’s trivial.”
   We physicists were laughing, trying to figure them out. We decided that “trivial” means “proved.” So we joked with the mathematicians: “We have a new theorem—that mathematicians can prove only trivial theorems, because every theorem that’s proved is trivial.”
   The mathematicians didn’t like that theorem, and I teased them about it. I said there are never any surprises—that the mathematicians only prove things that are obvious.
   Topology was not at all obvious to the mathematicians. There were all kinds of weird possibilities that were “counterintuitive.” Then I got an idea. I challenged them: “I bet there isn’t a single theorem that you can tell me—what the assumptions are and what the theorem is in terms I can understand—where I can’t tell you right away whether it’s true or false.”
   It often went like this: They would explain to me, “You’ve got an orange, OK? Now you cut the orange into a finite number of pieces, put it back together, and it’s as big as the sun. True or false?”
   “No holes?”
   “No holes.”
   “Impossible! There ain’t no such a thing.”
   “Ha! We got him! Everybody gather around! It’s So-and-so’s theorem of immeasurable measure!”
   Just when they think they’ve got me, I remind them, “But you said an orange! You can’t cut the orange peel any thinner than the atoms.”
   “But we have the condition of continuity: We can keep on cutting!”
   “No, you said an orange, so I assumed that you meant a real orange.”
   So I always won. If I guessed it right, great. If I guessed it wrong, there was always something I could find in their simplification that they left out.
   Actually, there was a certain amount of genuine quality to my guesses. I had a scheme, which I still use today when somebody is explaining something that I’m trying to understand: I keep making up examples. For instance, the mathematicians would come in with a terrific theorem, and they’re all excited. As they’re telling me the conditions of the theorem, I construct something which fits all the conditions. You know, you have a set (one ball)—disjoint (two halls). Then the balls turn colors, grow hairs, or whatever, in my head as they put more conditions on. Finally they state the theorem, which is some dumb thing about the ball which isn’t true for my hairy green ball thing, so I say, “False!”
   If it’s true, they get all excited, and I let them go on for a while. Then I point out my counterexample.
   “Oh. We forgot to tell you that it’s Class 2 Hausdorff homomorphic.”
   “Well, then,” I say, “It’s trivial! It’s trivial!” By that time I know which way it goes, even though I don’t know what Hausdorff homomorphic means.
   I guessed right most of the time because although the mathematicians thought their topology theorems were counterintuitive, they weren’t really as difficult as they looked. You can get used to the funny properties of this ultra-fine cutting business and do a pretty good job of guessing how it will come out.
   Although I gave the mathematicians a lot of trouble, they were always very kind to me. They were a happy hunch of boys who were developing things, and they were terrifically excited about it. They would discuss their “trivial” theorems, and always try to explain something to you if you asked a simple question.
   Paul Olum and I shared a bathroom. We got to be good friends, and he tried to teach me mathematics. He got me up to homotopy groups, and at that point I gave up. But the things below that I understood fairly well.
   One thing I never did learn was contour integration. I had learned to do integrals by various methods shown in a book that my high school physics teacher Mr. Bader had given me.
   One day he told me to stay after class. “Feynman,” he said, “you talk too much and you make too much noise. I know why. You’re bored. So I’m going to give you a book. You go up there in the back, in the corner, and study this book, and when you know everything that’s in this book, you can talk again.”
   So every physics class, I paid no attention to what was going on with Pascal’s Law, or whatever they were doing. I was up in the back with this book: Advanced Calculus, by Woods. Bader knew I had studied Calculus for the Practical Man a little bit, so he gave me the real works—it was for a junior or senior course in college. It had Fourier series, Bessel functions, determinants, elliptic functions—all kinds of wonderful stuff that I didn’t know anything about.
   That book also showed how to differentiate parameters under the integral sign—it’s a certain operation. It turns out that’s not taught very much in the universities; they don’t emphasize it. But I caught on how to use that method, and I used that one damn tool again and again. So because I was self-taught using that book, I had peculiar methods of doing integrals.
   The result was, when guys at MIT or Princeton had trouble doing a certain integral, it was because they couldn’t do it with the standard methods they had learned in school. If it was contour integration, they would have found it; if it was a simple series expansion, they would have found it. Then I come along and try differentiating under the integral sign, and often it worked. So I got a great reputation for doing integrals, only because my box of tools was different from everybody else’s, and they had tried all their tools on it before giving the problem to me.
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Mindreaders

   My father was always interested in magic and carnival tricks, and wanting to see how they worked. One of the things he knew about was mindreaders. When he was a little boy growing up in a small town called Patchogue, in the middle of Long Island, it was announced on advertisements posted all over that a mindreader was coming next Wednesday. The posters said that some respected citizens—the mayor, a judge, a banker—should take a five-dollar bill and hide it somewhere, and when the mindreader came to town, he would find it.
   When he came, the people gathered around to watch him do his work. He takes the hands of the banker and the judge, who had hidden the five-dollar bill, and starts to walk down the street. He gets to an intersection, turns the corner, walks down another street, then another, to the correct house. He goes with them, always holding their hands, into the house, up to the second floor, into the right room, walks up to a bureau, lets go of their hands, opens the correct drawer, and there’s the five-dollar bill. Very dramatic!
   In those days it was difficult to get a good education, so the mindreader was hired as a tutor for my father. Well, my father, after one of his lessons, asked the mindreader how he was able to find the money without anyone telling him where it was.
   The mindreader explained that you hold onto their hands, loosely and as you move, you jiggle a little bit. You come to an intersection, where you can go forward, to the left, or to the right. You jiggle a little bit to the left, and if it’s incorrect, you feel a certain amount of resistance, because they don’t expect you to move that way. But when you move in the right direction, because they think you might he able to do it, they give way more easily and there’s no resistance. So you must always be jiggling a little bit, testing out which seems to be the easiest way.
   My father told me the story and said he thought it would still take a lot of practice. He never tried it himself.
   Later, when I was doing graduate work at Princeton, I decided to try it on a fellow named Bill Woodward. I suddenly announced that I was a mindreader, and could read his mind. I told him to go into the “laboratory”—a big room with rows of tables covered with equipment of various kinds, with electric circuits, tools, and junk all over the place—pick out a certain object, somewhere, and come out. I explained, “Now I’ll read your mind and take you right up to the object.”
   He went into the lab, noted a particular object, and came out. I took his hand and started jiggling. We went down this aisle, then that one, right to the object. We tried it three times. One time I got the object right on—and it was in the middle of a whole bunch of stuff. Another time I went to the right place but missed the object by a few inches—wrong object. The third time, something went wrong. But it worked better than I thought. It was very easy.
   Some time after that, when I was about twenty-six or so, my father and I went to Atlantic City where they had various carnival things going on outdoors. While my father was doing some business, I went to see a mindreader. He was seated on the stage with his back to the audience, dressed in robes and wearing a great big turban. He had an assistant, a little guy who was running around through the audience, saying things like, “Oh, Great Master, what is the color of this pocketbook?”
   “Blue!” says the master.
   “And oh, Illustrious Sir, what is the name of this woman?”
   “Marie!”
   Some guy gets up: “What’s my name?”
   “Henry.”
   I get up and say, “What’s my name?”
   He doesn’t answer. The other guy was obviously a confederate, but I couldn’t figure out how the mindreader did the other tricks, like telling the color of the pocketbook. Did he wear earphones underneath the turban?
   When I met up with my father, I told him about it. He said, “They have a code worked out, but I don’t know what it is. Let’s go back and find out.”
   We went back to the place, and my father said to me, “Here’s fifty cents. Go get your fortune read in the booth back there, and I’ll see you in half an hour.”
   I knew what he was doing. He was going to tell the man a story, and it would go smoother if his son wasn’t there going, “Ooh, ooh!” all the time. He had to get me out of the way.
   When he came back he told me the whole code: “Blue is ‘Oh, Great Master,’ Green is ‘Oh, Most Knowledgeable One,’” and so forth. He explained, “I went up to him, afterwards, and told him I used to do a show in Patchogue, and we had a code, but it couldn’t do many numbers, and the range of colors was shorter. I asked him, ‘How do you carry so much information?’”
   The mindreader was so proud of his code that he sat down and explained the whole works to my father. My father was a salesman. He could set up a situation like that. I can’t do stuff like that.
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The Amateur Scientist

   When I was a kid I had a “lab.” It wasn’t a laboratory in the sense that I would measure, or do important experiments.
   Instead, I would play: I’d make a motor, I’d make a gadget that would go off when something passed a photocell. I’d play around with selenium; I was piddling around all the time. I did calculate a little bit for the lamp bank, a series of switches and bulbs I used as resistors to control voltages. But all that was for application. I never did any laboratory kind of experiments.
   I also had a microscope and loved to watch things under the microscope.It took patience: I would get something under the microscope and I would watch it interminably. I saw many interesting things, like everybody sees—a diatom slowly making its way across the slide, and so on.
   One day I was watching a paramecium and I saw something that was not described in the books I got in school—in college, even. These books always simplify things so the world will be more like they want it to be: When they’re talking about the behavior of animals, they always start out with, “The paramecium is extremely simple; it has a simple behavior. It turns as its slipper shape moves through the water until it hits something, at which time it recoils, turns through an angle, and then starts out again.”
   It isn’t really right. First of all, as everybody knows, the paramecia, from time to time, conjugate with each other—they meet and exchange nuclei. How do they decide when it’s time to do that? (Never mind; that’s not my observation.)
   I watched these paramecia hit something, recoil, turn through an angle, and go again. The idea that it’s mechanical, like a computer program—it doesn’t look that way. They go different distances, they recoil different distances, they turn through angles that are different in various cases; they don’t always turn to the right; they’re very irregular. It looks random, because you don’t know what they’re hitting; you don’t know all the chemicals they’re smelling, or what.
   One of the things I wanted to watch was what happens to the paramecium when the water that it’s in dries up. It was claimed that the paramecium can dry up into a sort of hardened seed. I had a drop of water on the slide under my microscope, and in the drop of water was a paramecium and some “grass”—at the scale of the paramecium, it looked like a network of jackstraws. As the drop of water evaporated, over a time of fifteen or twenty minutes, the paramecium got into a tighter and tighter situation: there was more and more of this back-and-forth until it could hardly move. It was stuck between these “sticks,” almost jammed.
   Then I saw something I had never seen or heard of: the paramecium lost its shape. It could flex itself, like an amoeba. It began to push itself against one of the sticks, and began dividing into two prongs until the division was about halfway up the paramecium, at which time it decided that wasn’t a very good idea, and backed away.
   So my impression of these animals is that their behavior is much too simplified in the books. It is not so utterly mechanical or one-dimensional as they say. They should describe the behavior of these simple animals correctly. Until we see how many dimensions of behavior even a one-celled animal has, we won’t be able to fully understand the behavior of more complicated animals.
   I also enjoyed watching hugs. I had an insect book when I was about thirteen. It said that dragonflies are not harmful; they don’t sting. In our neighborhood it was well known that “darning needles,” as we called them, were very dangerous when they’d sting. So if we were outside somewhere playing baseball, or something, and one of these things would fly around, everybody would run for cover, waving their arms, yelling, “A darning needle! A darning needle!”
   So one day I was on the beach, and I’d just read this book that said dragonflies don’t sting. A darning needle came along, and everybody was screaming and running around, and I just sat there. “Don’t worry!” I said. “Darning needles don’t sting!”
   The thing landed on my foot. Everybody was yelling and it was a big mess, because this darning needle was sitting on my foot, And there I was, this scientific wonder, saying it wasn’t going to sting me.
   You’re sure this is a story that’s going to come out that it stings me—but it didn’t. The book was right. But I did sweat a bit.
   I also had a little hand microscope. It was a toy microscope, and I pulled the magnification piece out of it, and would hold it in my hand like a magnifying glass, even though it was a microscope of forty or fifty power. With care you could hold the focus. So I could go around and look at things right out in the street.
   So when I was in graduate school at Princeton, I once took it out of my pocket to look at some ants that were crawling around on some ivy. I had to exclaim out loud, I was so excited. What I saw was an ant and an aphid, which ants take care of—they carry them from plant to plant if the plant they’re on is dying. In return the ants get partially digested aphid juice, called “honeydew.” I knew that; my father had told me about it, but I had never seen it.
   So here was this aphid and sure enough, an ant came along, and patted it with its feet—all around the aphid, pat, pat, pat, pat, pat. This was terribly exciting! Then the juice came out of the back of the aphid. And because it was magnified, it looked like a big, beautiful, glistening ball, like a balloon, because of the surface tension. Because the microscope wasn’t very good, the drop was colored a little bit from chromatic aberration in the lens—it was a gorgeous thing!
   The ant took this ball in its two front feet, lifted it off the aphid, and held it. The world is so different at that scale that you can pick up water and hold it! The ants probably have a fatty or greasy material on their legs that doesn’t break the surface tension of the water when they hold it up. Then the ant broke the surface of the drop with its mouth, and the surface tension collapsed the drop right into his gut. It was very interesting to see this whole thing happen!
   In my room at Princeton I had a bay window with a U-shaped windowsill. One day some ants came out on the windowsill and wandered around a little bit. I got curious as to how they found things. I wondered, how do they know where to go? Can they tell each other where food is, like bees can? Do they have any sense of geometry?
   This is all amateurish; everybody knows the answer, but I didn’t know the answer, so the first thing I did was to stretch some string across the U of the bay window and hang a piece of folded cardboard with sugar on it from the string. The idea of this was to isolate the sugar from the ants, so they wouldn’t find it accidentally. I wanted to have everything under control.
   Next I made a lot of little strips of paper and put a fold in them, so I could pick up ants and ferry them from one place to another. I put the folded strips of paper in two places:
   Some were by the sugar (hanging from the string), and the others were near the ants in a particular location. I sat there all afternoon, reading and watching, until an ant happened to walk onto one of my little paper ferries. Then I took him over to the sugar. After a few ants had been ferried over to the sugar, one of them accidentally walked onto one of the ferries nearby, and I carried him back.
   I wanted to see how long it would take the other ants to get the message to go to the “ferry terminal.” It started slowly but rapidly increased until I was going mad ferrying the ants back and forth.
   But suddenly, when everything was going strong, I began to deliver the ants from the sugar to a different spot. The question now was, does the ant learn to go back to where it just came from, or does it go where it went the time before?
   After a while there were practically no ants going to the first place (which would take them to the sugar), whereas there were many ants at the second place, milling around, trying to find the sugar. So I figured out so far that they went where they just came from.
   In another experiment, I laid out a lot of glass microscope slides, and got the ants to walk on them, back and forth, to some sugar I put on the windowsill. Then, by replacing an old slide with a new one, or by rearranging the slides, I could demonstrate that the ants had no sense of geometry: they couldn’t figure out where something was. If they went to the sugar one way and there was a shorter way back, they would never figure out the short way.
   It was also pretty clear from rearranging the glass slides that the ants left some sort of trail. So then came a lot of easy experiments to find out how long it takes a trail to dry up, whether it can be easily wiped off, and so on. I also found out the trail wasn’t directional. If I’d pick up an ant on a piece of paper, turn him around and around, and then put him back onto the trail, he wouldn’t know that he was going the wrong way until he met another ant. (Later, in Brazil, I noticed some leaf-cutting ants and tried the same experiment on them. They could tell, within a few steps, whether they were going toward the food or away from it—presumably from the trail, which might be a series of smells in a pattern: A, B, space, A, B, space, and so on.)
   I tried at one point to make the ants go around in a circle, but I didn’t have enough patience to set it up. I could see no reason, other than lack of patience, why it couldn’t be done.
   One thing that made experimenting difficult was that breathing on the ants made them scurry. It must be an instinctive thing against some animal that eats them or disturbs them. I don’t know if it was the warmth, the moisture, or the smell of my breath that bothered them, but I always had to hold my breath and kind of look to one side so as not to confuse the experiment while I was ferrying the ants.
   One question that I wondered about was why the ant trails look so straight and nice. The ants look as if they know what they’re doing, as if they have a good sense of geometry. Yet the experiments that I did to try to demonstrate their sense of geometry didn’t work.
   Many years later, when I was at Caltech and lived in a little house on Alameda Street, some ants came out around the bathtub. I thought, “This is a great opportunity.” I put some sugar on the other end of the bathtub, and sat there the whole afternoon until an ant finally found the sugar. It’s only a question of patience.
   The moment the ant found the sugar, I picked up a colored pencil that I had ready (I had previously done experiments indicating that the ants don’t give a damn about pencil marks—they walk right over them—so I knew I wasn’t disturbing anything), and behind where the ant went I drew a line so I could tell where his trail was. The ant wandered a little bit wrong to get back to the hole, so the line was quite wiggly unlike a typical ant trail.
   When the next ant to find the sugar began to go back, I marked his trail with another color. (By the way he followed the first ant’s return trail back, rather than his own incoming trail. My theory is that when an ant has found some food, he leaves a much stronger trail than when he’s just wandering around.)
   This second ant was in a great hurry and followed, pretty much, the original trail. But because he was going so fast he would go straight out, as if he were coasting, when the trail was wiggly. Often, as the ant was “coasting,” he would find the trail again. Already it was apparent that the second ant’s return was slightly straighter. With successive ants the same “improvement” of the trail by hurriedly and carelessly “following” it occurred.
   I followed eight or ten ants with my pencil until their trails became a neat line right along the bathtub. It’s something like sketching: You draw a lousy line at first; then you go over it a few times and it makes a nice line after a while.
   I remember that when I was a kid my father would tell me how wonderful ants are, and how they cooperate. I would watch very carefully three or four ants carrying a little piece of chocolate back to their nest. At first glance it looks like efficient, marvelous, brilliant cooperation. But if you look at it carefully you’ll see that it’s nothing of the kind: They’re all behaving as if the chocolate is held up by something else. They pull at it one way or the other way. An ant may crawl over it while it’s being pulled at by the others. It wobbles, it wiggles, the directions are all confused. The chocolate doesn’t move in a nice way toward the nest.
   The Brazilian leaf-cutting ants, which are otherwise so marvelous, have a very interesting stupidity associated with them that I’m surprised hasn’t evolved out. It takes considerable work for the ant to cut the circular arc in order to get a piece of leaf. When the cutting is done, there’s a fifty-fifty chance that the ant will pull on the wrong side, letting the piece he just cut fall to the ground. Half the time, the ant will yank and pull and yank and pull on the wrong part of the leaf, until it gives up and starts to cut another piece. There is no attempt to pick up a piece that it, or any other ant, has already cut. So it’s quite obvious, if you watch very carefully that it’s not a brilliant business of cutting leaves and carrying them away; they go to a leaf, cut an arc, and pick the wrong side half the time while the right piece falls down.
   In Princeton the ants found my larder, where I had jelly and bread and stuff, which was quite a distance from the window. A long line of ants marched along the floor across the living room. It was during the time I was doing these experiments on the ants, so I thought to myself, “What can I do to stop them from coming to my larder without killing any ants? No poison; you gotta be humane to the ants!”
   What I did was this: In preparation, I put a bit of sugar about six or eight inches from their entry point into the room, that they didn’t know about. Then I made those ferry things again, and whenever an ant returning with food walked onto my little ferry I’d carry him over and put him on the sugar. Any ant coming toward the larder that walked onto a ferry I also carried over to the sugar. Eventually the ants found their way from the sugar to their hole, so this new trail was being doubly reinforced, while the old trail was being used less and less. I knew that after half an hour or so the old trail would dry up, and in an hour they were out of my larder. I didn’t wash the floor; I didn’t do anything but ferry ants
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Part 3.
Feynman, the Bomb, and the Military

Fizzled Fuses

   When the war began in Europe but had not yet been declared in the United States, there was a lot of talk about getting ready and being patriotic. The newspapers had big articles on businessmen volunteering to go to Plattsburg, New York, to do military training, and so on.
   I began to think I ought to make some kind of contribution, too. After I finished up at MIT, a friend of mine from the fraternity, Maurice Meyer, who was in the Army Signal Corps, took me to see a colonel at the Signal Corps offices in New York.
   “I’d like to aid my country sir, and since I’m technically minded, maybe there’s a way I could help.”
   “Well, you’d better just go up to Plattsburg to boot camp and go through basic training. Then we’ll be able to use you,” the colonel said.
   “But isn’t there some way to use my talent more directly?”
   “No; this is the way the army is organized. Go through the regular way.”
   I went outside and sat in the park to think about it. I thought and thought: Maybe the best way to make a contribution is to go along with their way. But fortunately I thought a little more, and said, “To hell with it! I’ll wait awhile. Maybe something will happen where they can use me more effectively”
   I went to Princeton to do graduate work, and in the spring I went once again to the Bell Labs in New York to apply for a summer job. I loved to tour the Bell Labs. Bill Shockley the guy who invented transistors, would show me around. I remember somebody’s room where they had marked a window: The George Washington Bridge was being built, and these guys in the lab were watching its progress. They had plotted the original curve when the main cable was first put up, and they could measure the small differences as the bridge was being suspended from it, as the curve turned into a parabola. It was just the kind of thing I would like to be able to think of doing. I admired those guys; I was always hoping I could work with them one day.
   Some guys from the lab took me out to this seafood restaurant for lunch, and they were all pleased that they were going to have oysters. I lived by the ocean and I couldn’t look at this stuff; I couldn’t eat fish, let alone oysters.
   I thought to myself, “I’ve gotta be brave. I’ve gotta eat an oyster.”
   I took an oyster, and it was absolutely terrible. But I said to myself, “That doesn’t really prove you’re a man. You didn’t know how terrible it was gonna be. It was easy enough when it was uncertain.”
   The others kept talking about how good the oysters were, so I had another oyster, and that was really harder than the first one.
   This time, which must have been my fourth or fifth time touring the Bell Labs, they accepted me. I was very happy. In those days it was hard to find a job where you could be with other scientists.
   But then there was a big excitement at Princeton. General Trichel from the army came around and spoke to us: “We’ve got to have physicists! Physicists are very important to us in the army! We need three physicists!”
   You have to understand that, in those days, people hardly knew what a physicist was. Einstein was known as a mathematician, for instance—so it was rare that anybody needed physicists. I thought, “This is my opportunity to make a contribution,” and I volunteered to work for the army.
   I asked the Bell Labs if they would let me work for the army that summer, and they said they had war work, too, if that was what I wanted. But I was caught up in a patriotic fever and lost a good opportunity. It would have been much smarter to work in the Bell Labs. But one gets a little silly during those times.
   I went to the Frankfort Arsenal, in Philadelphia, and worked on a dinosaur: a mechanical computer for directing artillery. When airplanes flew by the gunners would watch them in a telescope, and this mechanical computer, with gears and cams and so forth, would try to predict where the plane was going to he. It was a most beautifully designed and built machine, and one of the important ideas in it was non-circular gears—gears that weren’t circular, but would mesh anyway. Because of the changing radii of the gears, one shaft would turn as a function of the other. However, this machine was at the end of the line. Very soon afterwards, electronic computers came in.
   After saying all this stuff about how physicists were so important to the army the first thing they had me doing was checking gear drawings to see if the numbers were right. This went on for quite a while. Then, gradually the guy in charge of the department began to see I was useful for other things, and as the summer went on, he would spend more time discussing things with me.
   One mechanical engineer at Frankfort was always trying to design things and could never get everything right. One time he designed a box full of gears, one of which was a big, eight-inch-diameter gear wheel that had six spokes. The fella says excitedly “Well, boss, how is it? How is it?”
   “Just fine!” the boss replies. “All you have to do is specify a shaft passer on each of the spokes, so the gear wheel can turn!” The guy had designed a shaft that went right between the spokes!
   The boss went on to tell us that there was such a thing as a shaft passer (I thought he must have been joking). It was invented by the Germans during the war to keep the British minesweepers from catching the cables that held the German mines floating under water at a certain depth. With these shaft passers, the German cables could allow the British cables to pass through as if they were going through a revolving door. So it was possible to put shaft passers on all the spokes, but the boss didn’t mean that the machinists should go to all that trouble; the guy should instead just redesign it and put the shaft somewhere else.
   Every once in a while the army sent down a lieutenant to check on how things were going. Our boss told us that since we were a civilian section, the lieutenant was higher in rank than any of us. “Don’t tell the lieutenant anything,” he said. “Once he begins to think he knows what we’re doing, he’ll be giving us all kinds of orders and screwing everything up.
   By that time I was designing some things, but when the lieutenant came by I pretended I didn’t know what I was doing, that I was only following orders.
   “What are you doing here, Mr. Feynman?”
   “Well, I draw a sequence of lines at successive angles, and then I’m supposed to measure out from the center different distances according to this table, and lay it out.
   “Well, what is it?”
   “I think it’s a cam.” I had actually designed the thing, but I acted as if somebody had just told me exactly what to do.
   The lieutenant couldn’t get any information from anybody and we went happily along, working on this mechanical computer, without any interference.
   One day the lieutenant came by and asked us a simple question: “Suppose that the observer is not at the same location as the gunner—how do you handle that?”
   We got a terrible shock. We had designed the whole business using polar coordinates, using angles and the radius distance. With X and Y coordinates, it’s easy to correct for a displaced observer. It’s simply a matter of addition or subtraction. But with polar coordinates, it’s a terrible mess!
   So it turned out that this lieutenant whom we were trying to keep from telling us anything ended up telling us something very important that we had forgotten in the design of this device: the possibility that the gun and the observing station are not at the same place! It was a big mess to fix it.
   Near the end of the summer I was given my first real design job: a machine that would make a continuous curve out of a set of points—one point coming in every fifteen seconds—from a new invention developed in England for tracking airplanes, called “radar.” It was the first time I had ever done any mechanical designing, so I was a little bit frightened.
   I went over to one of the other guys and said, “You’re a mechanical engineer; I don’t know how to do any mechanical engineering, and I just got this job
   “There’s nothin’ to it,” he said. “Look, I’ll show you. There’s two rules you need to know to design these machines. First, the friction in every bearing is so-and-so much, and in every gear junction, so-and-so much. From that, you can figure out how much force you need to drive the thing. Second, when you have a gear ratio, say 2 to 1, and you are wondering whether you should make it 10 to 5 or 24 to 12 or 48 to 24, here’s how to decide: You look in the Boston Gear Catalogue, and select those gears that are in the middle of the list. The ones at the high end have so many teeth they’re hard to make. If they could make gears with even finer teeth, they’d have made the list go even higher. The gears at the low end of the list have so few teeth they break easy. So the best design uses gears from the middle of the list.”
   I had a lot of fun designing that machine. By simply selecting the gears from the middle of the list and adding up the little torques with the two numbers he gave me, I could be a mechanical engineer!
   The army didn’t want me to go back to Princeton to work on my degree after that summer. They kept giving me this patriotic stuff, and offered a whole project that I could run, if I would stay.
   The problem was to design a machine like the other one—what they called a director—but this time I thought the problem was easier, because the gunner would be following behind in another airplane at the same altitude. The gunner would set into my machine his altitude and an estimate of his distance behind the other airplane. My machine would automatically tilt the gun up at the correct angle and set the fuse.
   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.
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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.
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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 …
 
 
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Zodijak Gemini
Pol Muškarac
Poruke Odustao od brojanja
Zastava 44°49′N - 20°29′E
mob
Apple iPhone 6s
   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.
   As a result of all these experiences with the censor, I knew exactly what could get through and what could not get through. Nobody else knew as well as I. And so I made a little money out of all of this by making bets.
   One day I discovered that the workmen who lived further out and wanted to come in were too lazy to go around through the gate, and so they had cut themselves a hole in the fence. So I went out the gate, went over to the hole and came in, went out again, and so on, until the sergeant at the gate began to wonder what was happening. How come this guy is always going out and never coming in? And, of course, his natural reaction was to call the lieutenant and try to put me in jail for doing this. I explained that there was a hole.
   You see, I was always trying to straighten people out. And so I made a bet with somebody that I could tell about the hole in the fence in a letter, and mail it out. And sure enough, I did. And the way I did it was I said, You should see the way they administer this place (that’s what we were allowed to say). There’s a hole in the fence seventy-one feet away from such-and-such a place, that’s this size and that size, that you can walk through.
   Now, what can they do? They can’t say to me that there is no such hole. I mean, what are they going to do? It’s their own hard luck that there’s such a hole. They should fix the hole. So I got that one through.
   I also got through a letter that told about how one of the boys who worked in one of my groups, John Kemeny had been wakened up in the middle of the night and grilled with lights in front of him by some idiots in the army there because they found out something about his father, who was supposed to be a communist or something. Kemeny is a famous man now.
   There were other things. Like the hole in the fence, I was always trying to point these things out in a non-direct manner. And one of the things I wanted to point out was this—that at the very beginning we had terribly important secrets; we’d worked out lots of stuff about bombs and uranium and how it worked, and so on; and all this stuff was in documents that were in wooden filing cabinets that had little, ordinary common padlocks on them. Of course, there were various things made by the shop, like a rod that would go down and then a padlock to hold it, but it was always just a padlock. Furthermore, you could get the stuff out without even opening the padlock. You just tilt the cabinet over backwards. The bottom drawer has a little rod that’s supposed to hold the papers together, and there’s a long wide hole in the wood underneath. You can pull the papers out from below.
   So I used to pick the locks all the time and point out that it was very easy to do. And every time we had a meeting of everybody together, I would get up and say that we have important secrets and we shouldn’t keep them in such things; we need better locks. One day Teller got up at the meeting, and he said to me, “I don’t keep my most important secrets in my filing cabinet; I keep them in my desk drawer. Isn’t that better?”
   I said, “I don’t know. I haven’t seen your desk drawer.” He was sitting near the front of the meeting, and I’m sitting further back. So the meeting continues, and I sneak out and go down to see his desk drawer.
   I don’t even have to pick the lock on the desk drawer. It turns out that if you put your hand in the back, underneath, you can pull out the paper like those toilet paper dispensers. You pull out one, it pulls another, it pulls another … I emptied the whole damn drawer, put everything away to one side, and went back upstairs.
   The meeting was just ending, and everybody was coming out, and I joined the crew and ran to catch up with Teller, and I said, “Oh, by the way let me see your desk drawer.”
   “Certainly,” he said, and he showed me the desk.
   I looked at it and said, “That looks pretty good to me. Let’s see what you have in there.”
   “I’ll be very glad to show it to you,” he said, putting in the key and opening the drawer. “If,” he said, “you hadn’t already seen it yourself.”
   The trouble with playing a trick on a highly intelligent man like Mr. Teller is that the time it takes him to figure out from the moment that he sees there is something wrong till he understands exactly what happened is too damn small to give you any pleasure!

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