Surely You’re Joking, Mr. Feynman

My first day on the job the pantry lady explained that she usually made a ham sandwich, or something, for the guy who was on the late shift. I said that I liked desserts, so if there was a dessert left over from supper, I’d like that. The next night I was on the late shift till 2:00 A.M. with these guys playing poker. I was sitting around with nothing to do, getting bored, when suddenly I remembered there was a dessert to eat. I went over to the icebox and opened it up, and there she’d left six desserts! There was a chocolate pudding, a piece of cake, some peach slices, some rice pudding, some jello—there was everything! So I sat there and ate the six desserts—it was sensational!

The next day she said to me, “I left a dessert for you.

“It was wonderful,” I said, “absolutely wonderful!”

“But I left you six desserts because I didn’t know which one you liked the best.”

So from that time on she left six desserts. They weren’t always different, but there were always six desserts.

One time when I was desk clerk a girl left a book by the telephone at the desk while she went to eat dinner, so I looked at. it. It was The Life of Leonardo, and I couldn’t resist: The girl let me borrow it and I read the whole thing.

I slept in a little room in the back of the hotel, and there was some stew about turning out the lights when you leave your room, which I couldn’t ever remember to do. Inspired by the Leonardo book, I made this gadget which consisted of a system of strings and weights—Coke bottles full of water—that would operate when I’d open the door, lighting the pull-chain light inside. You open the door, and things would go, and light the light; then you close the door behind you, and the light would go out. But my real accomplishment came later.

I used to cut vegetables in the kitchen. String beans had to be cut into one-inch pieces. The way you were supposed to do it was: You hold two beans in one hand, the knife in the other, and you press the knife against the beans and your thumb, almost cutting yourself. It was a slow process. So I put my mind to it, and I got a pretty good idea. I sat down at the wooden table outside the kitchen, put a bowl in my lap, and stuck a very sharp knife into the table at a forty-five-degree angle away from me. Then I put a pile of the string beans on each side, and I’d pick out a bean, one in each hand, and bring it towards me with enough speed that it would slice, and the pieces would slide into the bowl that was in my lap.

So I’m slicing beans one after the other—chig, chig, chig, chig, chig—and everybody’s giving me the beans, and I’m going like sixty when the boss comes by and says, “What are you doing?”

I say, “Look at the way I have of cutting beans!”—and just at that moment I put a finger through instead of a bean. Blood came out and went on the beans, and there was a big excitement: “Look at how many beans you spoiled! What a stupid way to do things!” and so on. So I was never able to make any improvement, which would have been easy—with a guard, or something—but no, there was no chance for improvement.

I had another invention, which had a similar difficulty. We had to slice potatoes after they’d been cooked, for some kind of potato salad. They were sticky and wet, and difficult to handle. I thought of a whole lot of knives, parallel in a rack, coming down and slicing the whole thing. I thought about this a long time, and finally I got the idea of wires in a rack,

So I went to the five-and-ten to buy some knives or wires, and saw exactly the gadget I wanted: it was for slicing eggs. The next time the potatoes came out I got my little egg-slicer out and sliced all the potatoes in no time, and sent them back to the chef. The chef was a German, a great big guy who was King of the Kitchen, and he came storming out, blood vessels sticking out of his neck, livid red. “What’s the matter with the potatoes?” he says. “They’re not sliced!”

I had them sliced, but they were all stuck together. He says, “How can I separate them?”

“Stick ‘em in water,” I suggest.

“IN WATER? EAGHHHHHHHHHHH!!!”

Another time I had a really good idea. When I was desk clerk I had to answer the telephone. When a call came in, something buzzed, and a flap came down on the switchboard so you could tell which line it was. Sometimes, when I was helping the women with the bridge tables or sitting on the front porch in the middle of the afternoon (when there were very few calls), I’d be some distance from the switchboard when suddenly it would go. I’d come running to catch it, but the way the desk was made, in order to get to the switchboard you had to go quite a distance further down, then around, in behind, and then back up to see where the call was coming from—it took extra time.

So I got a good idea. I tied threads to the flaps on the switchboard, and strung them over the top of the desk and then down, and at the end of each thread I tied a little piece of paper. Then I put the telephone talking piece up on top of the desk, so I could reach it from the front. Now, when a call came, I could tell which flap was down by which piece of paper was up, so I could answer the phone appropriately, from the front, to save time. Of course I still had to go around back to switch it in, but at least I was answering it. I’d say, “Just a moment,” and then go around to switch it in.

I thought that was perfect, but the boss came by one day, and she wanted to answer the phone, and she couldn’t figure it out—too complicated. “What are all these papers doing? Why is the telephone on this side? Why don’t you … raaaaaaaa!”

I tried to explain—it was my own aunt—that there was no reason not to do that, but you can’t say that to anybody who’s smart, who runsa hotel! I learned there that innovation is a very difficult thing in the real world.

Who Stole the Door?

At MIT the different fraternities all had “smokers” where they tried to get the new freshmen to be their pledges, and the summer before I went to MIT I was invited to a meeting in New York of Phi Beta Delta, a Jewish fraternity. In those days, if you were Jewish or brought up in a Jewish family, you didn’t have a chance in any other fraternity. Nobody else would look at you. I wasn’t particularly looking to be with other Jews, and the guys from the Phi Beta Delta fraternity didn’t care how Jewish I was—in fact, I didn’t believe anything about that stuff, and was certainly not in any way religious. Anyway, some guys from the fraternity asked me some questions and gave me a little bit of advice—that I ought to take the first-year calculus exam so I wouldn’t have to take the course-which turned out to be good advice. I liked the fellas who came down to New York from the fraternity, and the two guys who talked me into it, I later became their roommate.

There was another Jewish fraternity at MIT, called “SAM,” and their idea was to give me a ride up to Boston and I could stay with them. I accepted the ride, and stayed upstairs in one of the rooms that first night.

The next morning I looked out the window and saw the two guys from the other fraternity (that I met in New York) walking up the steps. Some guys from the Sigma Alpha Mu ran out to talk to them and there was a big discussion.

I yelled out the window, “Hey, I’m supposed to be with those guys!” and I rushed out of the fraternity without realizing that they were all operating, competing for my pledge. I didn’t have any feelings of gratitude for the ride, or anything.

The Phi Beta Delta fraternity had almost collapsed the year before, because there were two different cliques that had split the fraternity in half. There was a group of socialite characters, who liked to have dances and fool around in their cars afterwards, and so on, and there was a group of guys who did nothing but study, and never went to the dances.

Just before I came to the fraternity they had had a big meeting and had made an important compromise. They were going to get together and help each other out. Everyone had to have a grade level of at least such-and-such. If they were sliding behind, the guys who studied all the time would teach them and help them do their work. On the other side, everybody had to go to every dance. If a guy didn’t know how to get a date, the other guys would get him a date. If the guy didn’t know how to dance, they’d teach him to dance. One group was teaching the other how to think, while the other guys were teaching them how to be social.

That was just right for me, because I was not very good socially. I was so timid that when I had to take the mail out and walk past some seniors sitting on the steps with some girls, I was petrified: I didn’t know how to walk past them! And it didn’t help any when a girl would say, “Oh, he’s cute!”

It was only a little while after that the sophomores brought their girlfriends and their girlfriends’ friends over to teach us to dance. Much later, one of the guys taught me how to drive his car. They worked very hard to get us intellectual characters to socialize and be more relaxed, and vice versa. It was a good balancing out.

I had some difficulty understanding what exactly it meant to be “social.” Soon after these social guys had taught me how to meet girls, I saw a nice waitress in a restaurant where I was eating by myself one day. With great effort I finally got up enough nerve to ask her to be my date at the next fraternity dance, and she said yes.

Back at the fraternity, when we were talking about the dates for the next dance, I told the guys I didn’t need a date this time—I had found one on my own. I was very proud of myself.

When the upperclassmen found out my date was a waitress, they were horrified. They told me that was not possible; they would get me a “proper” date. They made me feel as though I had strayed, that I was amiss. They decided to take over the situation. They went to the restaurant, found the waitress, talked her out of it, and got me another girl. They were trying to educate their “wayward son,” so to speak, but they were wrong, I think. I was only a freshman then, and I didn’t have enough confidence yet to stop them from breaking my date.

When I became a pledge they had various ways of hazing. One of the things they did was to take us, blindfolded, far out into the countryside in the dead of winter and leave us by a frozen lake about a hundred feet apart. We were in the middle of absolutely nowhere—no houses, no nothing—and we were supposed to find our way back to the fraternity. We were a little bit scared, because we were young, and we didn’t say much—except for one guy, whose name was Maurice Meyer: you couldn’t stop him from joking around, making dumb puns, and having this happy-go-lucky attitude of “Ha, ha, there’s nothing to worry about. Isn’t this fun!”

We were getting mad at Maurice. He was always walking a little bit behind and laughing at the whole situation, while the rest of us didn’t know how we were ever going to get out of this.

We came to an intersection not far from the lake—there were still no houses or anything—and the rest of us were discussing whether we should go this way or that way, when Maurice caught up to us and said, “Go this way.”

“What the hell do you know, Maurice?” we said, frustrated. “You’re always making these jokes. Why should we go this way?”

“Simple: Look at the telephone lines. Where there’s more wires, it’s going toward the central station.”

This guy, who looked like he wasn’t paying attention to anything, had come up with a terrific idea! We walked straight into town without making an error.

On the following day there was going to be a schoolwide freshman versus sophomore mudeo (various forms of wrestling and tug of wars that take place in the mud). Late in the evening, into our fraternity comes a whole bunch of sophomores—some from our fraternity and some from outside—and they kidnap us: they want us to be tired the next day so they can win.

The sophomores tied up all the freshmen relatively easily—except me. I didn’t want the guys in the fraternity to find out that I was a “sissy.” (I was never any good in sports. I was always terrified if a tennis ball would come over the fence and land near me, because I never could get it over the fence-it usually went about a radian off of where it was supposed to go.) I figured this was a new situation, a new world, and I could make a new reputation. So in order that I wouldn’t look like I didn’t know how to fight, I fought like a son of a gun as best I could (not knowing what I was doing), and it took three or four guys many tries before they were finally able to tie me up. The sophomores took us to a house, far away in the woods, and tied us all down to a wooden floor with big U tacks.

I tried all sorts of ways to escape, but there were sophomores guarding us, and none of my tricks worked. I remember distinctly one young man they were afraid to tie down because he was so terrified: his face was pale yellow-green and he was shaking. I found out later he was from Europe-this was in the early thirties—and he didn’t realize that these guys all tied down to the floor was some kind of a joke; he knew what kinds of things were going on in Europe. The guy was frightening to look at, he was so scared.

By the time the night was over, there were only three sophomores guarding twenty of us freshmen, but we didn’t know that. The sophomores had driven their cars in and out a few times to make it sound as if there was a lot of activity, and we didn’t notice it was always the same cars and the same people. So we didn’t win that one.

My father and mother happened to come up that morning to see how their son was doing in Boston, and the fraternity kept putting them off until we came back from being kidnapped. I was so bedraggled and dirty from struggling so hard to escape and from lack of sleep that they were really horrified to discover what their son looked like at MIT!

I had also gotten a stiff neck, and I remember standing in line for inspection that afternoon at ROTC, not being able to look straight forward. The commander grabbed my head and turned it, shouting, “Straighten up!”

I winced, as my shoulders went at an angle: “I can’t help it, sir!

“Oh, excuse me!” he said, apologetically.

Anyway, the fact that I fought so long and hard not to be tied up gave me a terrific reputation, and I never had to worry about that sissy business again—a tremendous relief.

I often listened to my roommates—they were both seniors—studying for their theoretical physics course. One day they were working pretty hard on something that seemed pretty clear to me, so I said, “Why don’t you use the Baronallai’s equation?”

“What’s that!” they exclaimed. “What are you talking about!”

I explained to them what I meant and how it worked in this case, and it solved the problem. It turned out it was Bernoulli’s equation that I meant, but I had read all this stuff in the encyclopedia without talking to anybody about it, so I didn’t know how to pronounce anything.

But my roommates were very excited, and from then on they discussed their physics problems with me—I wasn’t so lucky with many of them—and the next year, when I took the course, I advanced rapidly. That was a very good way to get educated, working on the senior problems and learning how to pronounce things.

I liked to go to a place called the Raymor and Playmore Ballroom—two ballrooms that were connected together—on Tuesday nights. My fraternity brothers didn’t go to these “open” dances; they preferred their own dances, where the girls they brought were upper crust ones they had met “properly.” I didn’t care, when I met somebody, where they were from, or what their background was, so I would go to these dances—even though my fraternity brothers disapproved (I was a junior by this time, and they couldn’t stop me)—and I had a very good time.

One time I danced with a certain girl a few times, and didn’t say much. Finally, she said to me, “Who hants vewwy nice-ee.”

I couldn’t quite make it out—she had some difficulty in speech—but I thought she said, “You dance very nicely.”

“Thank you,” I said. “It’s been an honor.”

We went over to a table where a friend of hers had found a boy she was dancing with and we sat, the four of us, together. One girl was very hard of hearing, and the other girl was nearly deaf.

When the two girls conversed they would do a large amount of signaling very rapidly back and forth, and grunt a little bit. It didn’t bother me; the girl danced well, and she was a nice person.

After a few more dances, we’re sitting at the table again, and there’s a large amount of signaling back and forth, back and forth, back and forth, until finally she says something to me which I gathered means, she’d like us to take them to some hotel.

I ask the other guy if he wants to go.

“What do they want us to go to this hotel for?” he asks.

“Hell, I don’t know. We didn’t talk well enough!” But I don’t have to know. It’s just fun, seeing what’s going to happen; it’s an adventure!

The other guy’s afraid, so he says no. So I take the two girls in a taxi to the hotel, and discover that there’s a dance organized by the deaf and dumb, believe it or not. They all belonged to a club. It turns out many of them can feel the rhythm enough to dance to the music and applaud the band at the end of each number.

It was very, very interesting! I felt as if I was in a foreign country and couldn’t speak the language: I could speak, but nobody could hear me. Everybody was talking with signs to everybody else, and I couldn’t understand anything! I asked my girl to teach me some signs and I learned a few, like you learn a foreign language, just for fun.

Everyone was so happy and relaxed with each other, making jokes and smiling all the time; they didn’t seem to have any real difficulty of any kind communicating with each other. It was the same as with any other language, except for one thing: as they’re making signs to each other, their heads were always turning from one side to the other. I realized what that was. When someone wants to make a side remark or interrupt you, he can’t yell, “Hey, Jack!” He can only make a signal, which you won’t catch unless you’re in the habit of looking around all the time.

They were completely comfortable with each other. It was my problem to be comfortable. It was a wonderful experience.

The dance went on for a long time, and when it closed down we went to a cafeteria. They were all ordering things by pointing to them. I remember somebody asking in signs, “Where-are-you-from?” and my girl spelling out “N-e-w Y-o-r-k.” I still remember a guy signing to me “Good sport!”—he holds his thumb up, and then touches an imaginary lapel, for “sport.” It’s a nice system.

Everybody was sitting around, making jokes, and getting me into their world very nicely. I wanted to buy a bottle of milk, so I went up to the guy at the counter and mouthed the word “milk” without saying anything.

The guy didn’t understand.

I made the symbol for “milk,” which is two fists moving as if you’re milking a cow, and he didn’t catch that either.

I tried to point to the sign that showed the price of milk, but he still didn’t catch on.

Finally, some stranger nearby ordered milk, and I pointed to it.

“Oh! Milk!” he said, as I nodded my head yes.

He handed me the bottle, and I said, “Thank you very much!”

“You SON of a GUN!” he said, smiling.

I often liked to play tricks on people when I was at MIT. One time, in mechanical drawing class, some joker picked up a French curve (a piece of plastic for drawing smooth curves—a curly, funny-looking thing) and said, “I wonder if the curves on this thing have some special formula?”

I thought for a moment and said, “Sure they do. The curves are very special curves. Lemme show ya,” and I picked up my French curve and began to turn it slowly. “The French curve is made so that at the lowest point on each curve, no matter how you turn it, the tangent is horizontal.”

All the guys in the class were holding their French curve up at different angles, holding their pencil up to it at the lowest point and laying it along, and discovering that, sure enough, the tangent is horizontal. They were all excited by this “discovery”—even though they had already gone through a certain amount of calculus and had already “learned” that the derivative (tangent) of the minimum (lowest point) of any curve is zero (horizontal). They didn’t put two and two together. They didn’t even know what they “knew.”

I don’t know what’s the matter with people: they don’t learn by understanding; they learn by some other way—by rote, or something. Their knowledge is so fragile!

I did the same kind of trick four years later at Princeton when I was talking with an experienced character, an assistant of Einstein, who was surely working with gravity all the time. I gave him a problem: You blast off in a rocket which has a clock on board, and there’s a clock on the ground. The idea is that you have to be back when the clock on the ground says one hour has passed. Now you want it so that when you come back, your clock is as far ahead as possible. According to Einstein, if you go very high, your clock will go faster, because the higher something is in a gravitational field, the faster its clock goes. But if you try to go too high, since you’ve only got an hour, you have to go so fast to get there that the speed slows your clock down. So you can’t go too high. The question is, exactly what program of speed and height should you make so that you get the maximum time on your clock?

This assistant of Einstein worked on it for quite a bit before he realized that the answer is the real motion of matter. If you shoot something up in a normal way, so that the time it takes the shell to go up and come down is an hour, that’s the correct motion. It’s the fundamental principle of Einstein’s gravity—that is, what’s called the “proper time” is at a maximum for the actual curve. But when I put it to him, about a rocket with a clock, he didn’t recognize it. It was just like the guys in mechanical drawing class, but this time it wasn’t dumb freshmen. So this kind of fragility is, in fact, fairly common, even with more learned people.

When I was a junior or senior I used to eat at a certain restaurant in Boston. I went there by myself, often on successive evenings. People got to know me, and I had the same waitress all the time.

I noticed that they were always in a hurry, rushing around, so one day, just for fun, I left my tip, which was usually ten cents (normal for those days), in two nickels, under two glasses: I filled each glass to the very top, dropped a nickel in, and with a card over it, turned it over so it was upside down on the table. Then I slipped out the card (no water leaks out because no air can come in—the rim is too close to the table for that).

I put the tip under two glasses because I knew they were always in a hurry. If the tip was a dime in one glass, the waitress, in her haste to get the table ready for the next customer, would pick up the glass, the water would spill out, and that would be the end of it. But after she does that with the first glass, what the hell is she going to do with the second one? She can’t just have the nerve to lift it up now!

On the way out I said to my waitress, “Be careful, Sue. There’s something funny about the glasses you gave me—they’re filled in on the top, and there’s a hole on the bottom!”

The next day I came back, and I had a new waitress. My regular waitress wouldn’t have anything to do with me. “Sue’s very angry at you,” my new waitress said. “After she picked up the first glass and water went all over the place, she called the boss out. They studied it a little bit, but they couldn’t spend all day figuring out what to do, so they finally picked up the other one, and water went out again, all over the floor. It was a terrible mess; Sue slipped later in the water. They’re all mad at you.”

I laughed.

She said, “It’s not funny! How would you like it if someone did that to you—what would you do?”

“I’d get a soup plate and then slide the glass very carefully over to the edge of the table, and let the water run into the soup plate—it doesn’t have to run onto the floor. Then I’d take the nickel out.”

“Oh, that’s a goood idea,” she said.

That evening I left my tip under a coffee cup, which I left upside down on the table.

The next night I came and I had the same new waitress.

“What’s the idea of leaving the cup upside down last time?”

“Well, I thought that even though you were in a hurry, you’d have to go back into the kitchen and get a soup plate; then you’d have to sloooowly and carefully slide the cup over to the edge of the table …”

“I did that,” she complained, “but there was no water in it!”

My masterpiece of mischief happened at the fraternity. One morning I woke up very early, about five o’clock, and couldn’t go back to sleep, so I went downstairs from the sleeping rooms and discovered some signs hanging on strings which said things like “DOOR! DOOR! WHO STOLE THE DOOR?” I saw that someone had taken a door off its hinges, and in its place they hung a sign that said, “PLEASE CLOSE THE DOOR!”—the sign that used to be on the door that was missing.

I immediately figured out what the idea was. In that room a guy named Pete Bernays and a couple of other guys liked to work very hard, and always wanted it quiet. If you wandered into their room looking for something, or to ask them how they did problem such and such, when you would leave you would always hear these guys scream, “Please close the door!”

Somebody had gotten tired of this, no doubt, and had taken the door off. Now this room, it so happened, had two doors, the way it was built, so I got an idea: I took the other door off its hinges, carried it downstairs, and hid it in the basement behind the oil tank. Then I quietly went back upstairs and went to bed.

Later in the morning I made believe I woke up and came downstairs a little late. The other guys were milling around, and Pete and his friends were all upset: The doors to their room were missing, and they had to study, blah, blah, blah, blah. I was coming down the stairs and they said, “Feynman! Did you take the doors?”

“Oh, yeah!” I said. “I took the door. You can see the scratches on my knuckles here, that I got when my hands scraped against the wall as I was carrying it down into the basement.”

They weren’t satisfied with my answer; in fact, they didn’t believe me.

The guys who took the first door had left so many clues—the handwriting on the signs, for instance—that they were soon found out. My idea was that when it was found out who stole the first door, everybody would think they also stole the other door. It worked perfectly: The guys who took the first door were pummeled and tortured and worked on by everybody, until finally, with much pain and difficulty, they convinced their tormentors that they had only taken one door, unbelievable as it might be.

I listened to all this, and I was happy.

The other door stayed missing for a whole week, and it became more and more important to the guys who were trying to study in that room that the other door be found.

Finally, in order to solve the problem, the president of the fraternity says at the dinner table, “We have to solve this problem of the other door. I haven’t been able to solve the problem myself, so I would like suggestions from the rest of you as to how to straighten this out, because Pete and the others are trying to study.”

Somebody makes a suggestion, then someone else.

After a little while, I get up and make a suggestion. “All right,” I say in a sarcastic voice, “whoever you are who stole the door, we know you’re wonderful. You’re so clever! We can’t figure out who you are, so you must be some sort of super-genius. You don’t have to tell us who you are; all we want to know is where the door is. So if you will leave a note somewhere, telling us where the door is, we will honor you and admit forever that you are a super-marvel, that you are so smart that you could take the other door without our being able to figure out who you are. But for God’s sake, just leave the note somewhere, and we will be forever grateful to you for it.”

The next guy makes his suggestion: “I have another idea,” he says. “I think that you, as president, should ask each man on his word of honor towards the fraternity to say whether he took the door or not.”

The president says, “That’s a very good idea. On the fraternity word of honor!” So he goes around the table, and asks each guy, one by one: “Jack, did you take the door?”

“No, sir, I did not take the door.”

“Tim: Did you take the door?”

“No, sir! I did not take the door!”

“Maurice. Did you take the door?”

“No, I did not take the door, sir.”

“Feynman, did you take the door?”

“Yeah, I took the door.”

“Cut it out, Feynman; this is serious! Sam! Did you take the door …”—it went all the way around. Everyone was shocked. There must be some real rat in the fraternity who didn’t respect the fraternity word of honor!

That night I left a note with a little picture of the oil tank and the door next to it, and the next day they found the door and put it back.

Sometime later I finally admitted to taking the other door, and I was accused by everybody of lying. They couldn’t remember what I had said. All they could remember was their conclusion after the president of the fraternity had gone around the table and asked everybody, that nobody admitted taking the door. The idea they remembered, but not the words.