“Surely You’re Joking, Mr. Feynman”: Adventures of a Curious Character

A few moments later Mrs. Eisenhart’s daughter and a schoolmate came over, and we were introduced to each other. The whole idea of this “heh-heh-heh” was: Mrs. Eisenhart didn’t want to talk to me, she wanted me over there getting tea when her daughter and friend came over, so they would have someone to talk to. That’s the way it worked. By that time I knew what to do when I heard “Heh-heh-heh-heh- heh.” I didn’t say, “What do you mean, ‘Heh-heh-heh-heh-heh’?”; I knew the “heh-heh-heh” meant “error,” and I’d better get it straightened out.

Every night we wore academic gowns to dinner. The first night it scared the life out of me, because I didn’t like formality. But I soon realized that the gowns were a great advantage. Guys who were out playing tennis could rush into their room, grab their academic gown, and put it on. They didn’t have to take time off to change their clothes or take a shower. So underneath the gowns there were bare arms, T-shirts, everything. Furthermore, there was a rule that you never cleaned the gown, so you could tell a first-year man from a second-year man, from a third-year man, from a pig! You never cleaned the gown and you never repaired it, so the first-year men had very nice, relatively clean gowns, but by the time you got to the third year or so, it was nothing but some kind of cardboard thing on your shoulders with tatters hanging down from it.

So when I got to Princeton, I went to that tea on Sunday afternoon and had dinner that evening in an academic gown at the “College.” But on Monday, the first thing I wanted to do was to see the cyclotron.

MIT had built a new cyclotron while I was a student there, and it was just beautiful! The cyclotron itself was in one room, with the controls in another room. It was beautifully engineered. The wires ran from the control room to the cyclotron underneath in conduits, and there was a whole console of buttons and meters. It was what I would call a gold-plated cyclotron.

Now I had read a lot of papers on cyclotron experiments, and there weren’t many from MIT. Maybe they were just starting. But there were lots of results from places like Cornell, and Berkeley, and above all, Princeton. Therefore what I really wanted to see, what I was looking forward to, was the PRINCETON CYCLOTRON. That must be something!

So first thing on Monday, I go into the physics building and ask, “Where is the cyclotron—which building?”

“It’s downstairs, in the basement—at the end of the hall.”

In the basement? It was an old building. There was no room in the basement for a cyclotron. I walked down to the end of the hall, went through the door, and in ten seconds I learned why Princeton was right for me—the best place for me to go to school. In this room there were wires strung all over the place! Switches were hanging from the wires, cooling water was dripping from the valves, the room was full of stuff, all out in the open. Tables piled with tools were everywhere; it was the most godawful mess you ever saw. The whole cyclotron was there in one room, and it was complete, absolute chaos!

It reminded me of my lab at home. Nothing at MIT had ever reminded me of my lab at home. I suddenly realized why Princeton was getting results. They were working with the instrument. They built the instrument; they knew where everything was, they knew how everything worked, there was no engineer involved, except maybe he was working there too. It was much smaller than the cyclotron at MIT, and “gold-plated”?—it was the exact opposite. When they wanted to fix a vacuum, they’d drip glyptal on it, so there were drops of glyptal on the floor. It was wonderful! Because they worked with it. They didn’t have to sit in another room and push buttons! (Incidentally, they had a fire in that room, because of all the chaotic mess that they had—too many wires—and it destroyed the cyclotron. But I’d better not tell about that!)

(When I got to Cornell I went to look at the cyclotron there. This cyclotron hardly required a room: It was about a yard across—the diameter of the whole thing. It was the world’s smallest cyclotron, but they had got fantastic results. They had all kinds of special techniques and tricks. If they wanted to change something in the “D’s”—the D-shaped half circles that the particles go around—they’d take a screwdriver, and remove the D’s by hand, fix them, and put them back. At Princeton it was a lot harder, and at MIT you had to take a crane that came rolling across the ceiling, lower the hooks, and it was a hellllll of a job.)

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, but 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