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!”
Meeeeeeeeeee!
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-and so”—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 be 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.