Surely You're Joking, Mr. Feynman! (8 page)

I learned a lot of different things from different schools. MIT is a _very_ good place; I’m not trying to put it down. I was just in love with it. It has developed for itself a spirit, so that every member of the whole place thinks that it’s the most wonderful place in the world–it’s the _center_, somehow, of scientific and technological development in the United States, if not the world. It’s like a New Yorker’s view of New York: they forget the rest of the country. And while you don’t get a good sense of proportion there, you do get an excellent sense of being _with_ it and _in_ it, and having motivation and desire to keep on–that you’re specially chosen, and lucky to be there.

So MIT was good, hut Slater was right to warn me to go to another school for my graduate work. And I often advise my students the same way. Learn what the rest of the world is like. The variety is worthwhile.

I once did an experiment in the cyclotron laboratory at Princeton that had some startling results. There was a problem in a hydrodynamics book that was being discussed by all the physics students. The problem is this: You have an S-shaped lawn sprinkler–an S-shaped pipe on a pivot–and the water squirts out at right angles to the axis and makes it spin in a certain direction. Everybody knows which way it goes around; it backs away from the outgoing water. Now the question is this: If you had a lake, or swimming pool–a big supply of water–and you put the sprinkler completely under water, and sucked the water in, instead of squirting it out, which way would it turn? Would it turn the same way as it does when you squirt water out into the air, or would it turn the other way?

The answer is perfectly clear at first sight. The trouble was, some guy would think it was perfectly clear one way, and another guy would think it was perfectly clear the other way. So everybody was discussing it. I remember at one particular seminar, or tea, somebody went nip to Prof John Wheeler and said, “Which way do _you_ think it goes around?”

Wheeler said, “Yesterday, Feynman convinced me that it went backwards. Today, he’s convinced me equally well that it goes around the other way. I don’t know _what_ he’ll convince me of tomorrow!”

I’ll tell you an argument that will make you think it’s one way, and another argument that will make you think it’s the other way, OK?

One argument is that when you’re sucking water in, you’re sort of pulling the water with the nozzle, so it will go forward, towards the incoming water.

But then another guy comes along and says, “Suppose we hold it still and ask what kind of a torque we need to hold it still. In the case of the water going out, we all know you have to hold it on the outside of the curve, because of the centrifugal force of the water going around the curve, Now, when the water goes around the same curve the _other_ way, it still makes the same centrifugal force toward the outside of the curve. Therefore the two cases are the same, and the sprinkler will go around the same way, whether you’re squirting water out or sucking it in.”

After some thought, I finally made up my mind what the answer was, and in order to demonstrate it, I wanted to do an experiment.

In the Princeton cyclotron lab they had a big carboy–a monster bottle of water. I thought this was just great for the experiment. I got a piece of copper tubing and bent it into an S-shape. Then in the middle I drilled a hole, stuck in a piece of rubber hose, and led it up through a hole in a cork I had put in the top of the bottle. The cork had another hole, into which I put another piece of rubber hose, and connected it to the air pressure supply of the lab. By blowing air into the bottle, I could force water into the copper tubing exactly as if I were sucking it in. Now, the S-shaped tubing wouldn’t turn around, but it would twist (because of the flexible rubber hose), and I was going to measure the speed of the water flow by measuring how far it squirted out of the top of the bottle.

I got it all set up, turned on the air supply, and it went “_Puup!_” The air pressure blew the cork out of the bottle. I wired it in very well, so it wouldn’t jump out. Now the experiment was going pretty good. The water was coming out, and the hose was twisting, so I put a little more pressure on it, because with a higher speed, the measurements would be more accurate. I measured the angle very carefully, and measured the distance, and increased the pressure again, and suddenly the whole thing just blew glass and water in all directions throughout the laboratory. A guy who had come to watch got all wet and had to go home and change his clothes (it’s a miracle he didn’t get cut by the glass), and lots of cloud chamber pictures that had been taken patiently using the cyclotron were all wet, but for some reason I was far enough away, or in some such position that I didn’t get very wet. But I’ll always remember how the great Professor Del Sasso, who was in charge of the cyclotron, came over to me and said sternly, “The freshman experiments should be done in the freshman laboratory!”

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Meeeeeeeeeee!
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On Wednesdays at the Princeton Graduate College, various people would come in to give talks. The speakers were often interesting, and in the discussions after the talks we used to have a lot of fun. For instance, one guy in our school was very strongly anti-Catholic, so he passed out questions in advance for people to ask a religious speaker, and we gave the speaker a hard time.

Another time somebody gave a talk about poetry. He talked about the structure of the poem and the emotions that come with it; he divided everything up into certain kinds of classes. In the discussion that came afterwards, he said, “Isn’t that the same as in mathematics, Dr. Eisenhart?”

Dr. Eisenhart was the dean of the graduate school and a great professor of mathematics. He was also very clever. He said, “I’d like to know what Dick Feynman thinks about it in reference to theoretical physics.” He was always putting me on in this kind of situation.

I got up and said, “Yes, it’s very closely related. In theoretical physics, the analog of the word is the mathematical formula, the analog of the structure of the poem is the interrelationship of the theoretical bling-bling with the so-andso”–and I went through the whole thing, making a perfect analogy. The speaker’s eyes were _beaming_ with happiness.

Then I said, “It seems to me that no matter _what_ you say about poetry, I could find a way of making up an analog with _any_ subject, just as I did for theoretical physics. I don’t consider such analogs meaningful.”

In the great big dining hall with stained-glass windows, where we always ate, in our steadily deteriorating academic gowns, Dean Eisenhart would begin each dinner by saying grace in Latin. After dinner he would often get up and make some announcements. One night Dr. Eisenhart got up and said, “Two weeks from now, a professor of psychology is coming to give a talk about hypnosis. Now, this professor thought it would be much better if we had a real demonstration of hypnosis instead of just talking about it. Therefore he would like some people to volunteer to be hypnotized.

I get all excited: There’s no question but that I’ve got to find out about hypnosis. This is going to he terrific!

Dean Eisenhart went on to say that it would be good if three or four people would volunteer so that the hypnotist could try them out first to see which ones would be able to be hypnotized, so he’d like to urge very much that we apply for this. (_He’s wasting all this time_, for God’s sake!)

Eisenhart was down at one end of the hall, and I was way down at the other end, in the back. There were hundreds of guys there. I knew that everybody was going to want to do this, and I was terrified that he wouldn’t see me because I was so far back. I just had to get in on this demonstration!

Finally Eisenhart said, “And so I would like to ask if there are going to be any volunteers . . .”

I raised my hand and shot out of my seat, screaming as loud as I could, to make sure that he would hear me: “MEEEEEEEEEEE!”

He heard me all right, because there wasn’t another soul. My voice reverberated throughout the hall–it was very embarrassing. Eisenhart’s immediate reaction was, “Yes, of course, I knew _you_ would volunteer, Mr. Feynman, but I was wondering if there would be anybody _else_.”

Finally a few other guys volunteered, and a week before the demonstration the man came to practice on us, to see if any of us would be good for hypnosis. I knew about the phenomenon, but I didn’t know what it was like to be hypnotized.

He started to work on me and soon I got into a position where he said, “You can’t open your eyes.”

I said to myself, “I bet I _could_ open my eyes, but I don’t want to disturb the situation: Let’s see how much further it goes.” It was an interesting situation: You’re only slightly fogged out, and although you’ve lost a little bit, you’re pretty sure you could open your eyes. But of course, you’re not opening your eyes, so in a sense you can’t do it.

He went through a lot of stuff and decided that I was pretty good.

When the real demonstration came he had us walk on stage, and he hypnotized us in front of the whole Princeton Graduate College. This time the effect was stronger; I guess I had learned how to become hypnotized. The hypnotist made various demonstrations, having me do things that I couldn’t normally do, and at the end he said that after I came out of hypnosis, instead of returning to my seat directly, which was the natural way to go, I would walk all the way around the room and go to my seat from the back.

All through the demonstration I was vaguely aware of what was going on, and cooperating with the things the hypnotist said, but this time I decided, “Damn it, enough is enough! I’m gonna go straight to my seat.”

When it was time to get up and go off the stage, I started to walk straight to my seat. But then an annoying feeling came over me: I felt so uncomfortable that I couldn’t continue. I walked all the way around the hall.

I was hypnotized in another situation some time later by a woman. While I was hypnotized she said, “I’m going to light a match, blow it out, and immediately touch the back of your hand with it. You will feel no pain.”

I thought, “Baloney!” She took a match, lit it, blew it out, and touched it to the back of my hand. It felt slightly warm. My eyes were closed throughout all of this, but I was thinking, “That’s easy. She lit one match, but touched a different match to my hand. There’s nothin’ to _that_; it’s a fake!”

When I came out of the hypnosis and looked at the back of my hand, I got the biggest surprise: There was a burn on the back of my hand. Soon a blister grew, and it never hurt at all, even when it broke.

So I found hypnosis to be a very interesting experience. All the time you’re saying to yourself, “I could do that, but I won’t”–which is just another way of saying that you can’t.

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A Map of the Cat?
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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.”