Surely You're Joking, Mr. Feynman! (33 page)

At all these places everybody working in physics would tell me what they were doing and I’d discuss it with them. They would tell me the general problem they were working on, and would begin to write a bunch of equations.

“Wait a minute,” I would say. “Is there a particular example of this general problem?”

“Why yes; of course.”

“Good. Give me one example.” That was for me: I can’t understand anything in general unless I’m carrying along in my mind a specific example and watching it go. Some people think in the beginning that I’m kind of slow and I don’t understand the problem, because I ask a lot of these “dumb” questions: “Is a cathode plus or minus? Is an an-ion this way, or that way?”

But later, when the guy’s in the middle of a bunch of equations, he’ll say something and I’ll say, “Wait a minute! There’s an error! That can’t be right!”

The guy looks at his equations, and sure enough, after a while, he finds the mistake and wonders, “How the hell did this guy, who hardly understood at the beginning, find that mistake in the mess of all these equations?”

He thinks I’m following the steps mathematically, but that’s not what I’m doing. I have the specific, physical example of what he’s trying to analyze, and I know from instinct and experience the properties of the thing. So when the equation says it should behave so-and-so, and I know that’s the wrong way around, I jump up and say, “Wait! There’s a mistake!”

So in Japan I couldn’t understand or discuss anybody’s work unless they could give me a physical example, and most of them couldn’t find one. Of those who could, it was often a weak example, one which could be solved by a much simpler method of analysis.

Since I was perpetually asking _not_ for mathematical equations, but for physical circumstances of what they were trying to work out, my visit was summarized in a mimeographed paper circulated among the scientists (it was a modest but effective system of communication they had cooked up after the war) with the title, “Feynman’s Bombardments, and Our Reactions.”

After visiting a number of universities I spent some months at the Yukawa Institute in Kyoto. I really enjoyed working there. Everything was so nice: You’d come to work, take your shoes off, and someone would come and serve you tea in the morning when you felt like it. It was very pleasant.

While in Kyoto I tried to learn Japanese with a vengeance. I worked much harder at it, and got to a point where I could go around in taxis and do things. I took lessons from a Japanese man every day for an hour.

One day he was teaching me the word for “see.” “All right,” he said. “You want to say, ‘May I see your garden?’ What do you say?”

I made up a sentence with the word that I had just learned.

“No, no!” he said. “When you say to someone, ‘Would you like to see my garden? you use the first ’see.’ But when you want to see someone else’s garden, you must use another ’see,’ which is more polite.”

“Would you like to _glance at_ my lousy garden?” is essentially what you’re saying in the first case, but when you want to look at the other fella’s garden, you have to say something like, “May I _observe_ your gorgeous garden?” So there’s two different words you have to use.

Then he gave me another one: “You go to a temple, and you want to look at the gardens . . .”

I made up a sentence, this time with the polite “see.”

“No, no!” he said. “In the temple, the gardens are much more elegant. So you have to say something that would be equivalent to ‘May I _hang my eyes_ on your most exquisite gardens?’”

Three or four different words for one idea, because when _I’m_ doing it, it’s miserable; when _you’re_ doing it, it’s elegant.

I was learning Japanese mainly for technical things, so I decided to check if this same problem existed among the scientists.

At the institute the next day, I said to the guys in the office, “How would I say in Japanese, ‘I solve the Dirac Equation’?”

They said such-and-so.

“OK. Now I want to say, ‘Would _you_ solve the Dirac Equation?’–how do I say that?”

“Well, you have to use a different word for ’solve,’ “they say.

“Why?” I protested. “When _I_ solve it, I do the same damn thing as when _you_ solve it!”

“Well, yes, but it’s a different word–it’s more polite.”

I gave up. I decided that wasn’t the language for me, and stopped learning Japanese.

———————-
The 7 Percent Solution
———————-

The problem was to find the right laws of beta decay. There appeared to be two particles, which were called a tan and a theta. They seemed to have almost exactly the same mass, but one disintegrated into two pions, and the other into three pions. Not only did they seem to have the same mass, but they also had the same lifetime, which is a funny coincidence. So everybody was concerned about this.

At a meeting I went to, it was reported that when these two particles were produced in a cyclotron at different angles and different energies, they were always produced in the same proportions–so many taus compared to so many thetas.

Now, one possibility, of course, was that it was the same particle, which sometimes decayed into two pions, and sometimes into three pions. But nobody would allow that, because there is a law called the parity rule, which is based on the assumption that all the laws of physics are mirror-imagesymmetrical, and says that a thing that can go into two pions can’t also go into three pions.

At that particular time I was not really quite up to things: I was always a little behind. Everybody seemed to be smart, and I didn’t feel I was keeping up. Anyway, I was sharing a room with a guy named Martin Block, an experimenter. And one evening he said to me, “Why are you guys so insistent on this parity rule? Maybe the tau and theta are the same particle. What would be the consequences if the parity rule were wrong?”

I thought a minute and said, “It would mean that nature’s laws are different for the right hand and the left hand, that there’s a way to define the right hand by physical phenomena. I don’t know that that’s so terrible, though there must be some bad consequences of that, but I don’t know. Why don’t you ask the experts tomorrow?” , -

He said, “No, they won’t listen to me. _You_ ask.”

So the next day, at the meeting, when we were discussing the tau-theta puzzle, Oppenheimer said, “We need to hear some new, wilder ideas about this problem.”

So I got up and said, “I’m asking this question for Martin Block: What would be the consequences if the parity rule was wrong?”

Murray Gell-Mann often teased me about this, saying I didn’t have the nerve to ask the question for myself. But that’s not the reason. I thought it might very well be an important idea.

Lee, of Lee and Yang, answered something complicated, and as usual I didn’t understand very well. At the end of the meeting, Block asked nie what he said, and I said I didn’t know, but as far as I could tell, it was still open–there was still a possibility. I didn’t think it was likely, but I thought it was possible.

Norm Ramsey asked me if I thought he should do an experiment looking for parity law violation, and I replied, “The best way to explain it is, I’ll bet you only fifty to one you don’t find anything.”

He said, “That’s good enough for me.” But he never did the experiment.

Anyway, the discovery of parity law violation was made, experimentally, by Wu, and this opened up a whole bunch of new possibilities for beta decay theory, It also unleashed a whole host of experiments immediately after that. Some showed electrons coming out of the nuclei spun to the left, and some to the right, and there were all kinds of experiments, all kinds of interesting discoveries about parity. But the data were so confusing that nobody could put things together.

At one point there was a meeting in Rochester–the yearly Rochester Conference. I was still always behind, and Lee was giving his paper on the violation of parity. He and Yang had come to the conclusion that parity was violated, and flow he was giving the theory for it.

During the conference I was staying with my sister in Syracuse. I brought the paper home and said to her, “I can’t understand these things that Lee and Yang are saying. It’s all so complicated.”

“No,” she said, “what you mean is _not_ that you can’t understand it, but that you didn’t _invent_ it. You didn’t figure it out your _own_ way, from hearing the clue. What you should do is imagine you’re a student again, and take this paper upstairs, read every line of it, and check the equations. Then you’ll understand it very easily.”

I took her advice, and checked through the whole thing, and found it to be very obvious and simple. I had been afraid to read it, thinking it was too difficult.

It reminded me of something I had done a long time ago with left and right unsymmetrical equations, Now it became kind of clear, when I looked at Lee’s formulas, that the solution to it all was much simpler: Everything comes out coupled to the left. For the electron and the muon, my predictions were the same as Lee’s, except I changed some signs around. I didn’t realize it at the time, but Lee had taken only the simplest example of muon coupling, and hadn’t proved that all muons would be full to the right, whereas according to my theory, all muons would have to be full automatically. Therefore, I had, in fact, a prediction on top of what he had. I had different signs, but I didn’t realize that I also had this quantity right.

I predicted a few things that nobody had experiments for yet, but when it came to the neutron and proton, I couldn’t make it fit well with what was then known about neutron and proton coupling: it was kind of messy.

The next day, when I went back to the meeting, a very kind man named Ken Case, who was going to give a paper on something, gave me five minutes of his allotted time to present my idea. I said I was convinced that everything was coupled to the left, and that the signs for the electron and muon are reversed, but I was struggling with the neutron. Later the experimenters asked me some questions about my predictions, and then I went to Brazil for the summer.

When I came back to the United States, I wanted to know what the situation was with beta decay. I went to Professor Wu’s laboratory at Columbia, and she wasn’t there, but another lady was there who showed me all kinds of data, all kinds of chaotic numbers that didn’t fit with anything. The electrons, which in my model would have all come out spinning to the left in the beta decay, came out on the right in some cases. Nothing fit anything.

When I got back to Caltech, I asked some of the experimenters what the situation was with beta decay. I remember three guys, Hans Jensen, Aaldert Wapstra, and Felix Boehm, sitting me down on a little stool, and starting to tell me all these facts: experimental results from other parts of the country, and their own experimental results. Since I knew those guys, and how careful they were, I paid more attention to their results than to the others. Their results, alone, were not so inconsistent; it was all the others _plus_ theirs.

Finally they get all this stuff into me, and they say, “The situation is so mixed up that even some of the things they’ve established for _years_ are being questioned–such as the beta decay of the neutron is S and T. It’s so messed up. Murray says it might even be V and A.”

I jump up from the stool and say, “Then I understand EVVVVVERYTHING!”

They thought I was joking. But the thing that I had trouble with at the Rochester meeting–the neutron and proton disintegration: everything fit _but_ that, and if it was V and A instead of S and T, _that_ would fit too. Therefore I had the whole theory!

That night I calculated all kinds of things with this theory. The first thing I calculated was the rate of disintegration of the muon and the neutron. They should be connected together, if this theory was right, by a certain relationship, and it was right to 9 percent. That’s pretty close, 9 percent. It should have been more perfect than that, hut it was close enough.

I went on and checked some other things, which fit, and new things fit, new things fit, and I was very excited. It was the first time, and the only time, in my career that I knew a law of nature that nobody else knew. (Of course it wasn’t true, but finding out later that at least Murray Gell-Mann–and also Sudarshan and Marshak–had worked out the same theory didn’t spoil my fun.)

The other things I had done before were to take somebody else’s theory and improve the method of calculating, or take an equation, such as the Schrodinger Equation, to explain a phenomenon, such as helium. We know the equation, and we know the phenomenon, but how does it work?

I thought about Dirac, who had his equation for a while–a new equation which told how an electron behaved– and I had this new equation for beta decay, which wasn’t as vital as the Dirac Equation, but it was good. It’s the only time I ever discovered a new law.

I called up my sister in New York to thank her for getting me to sit down and work through that paper by Lee and Yang at the Rochester Conference. After feeling uncomfortable and behind, now I was _in_; I had made a discovery, just from what she suggested. I was able to enter physics again, so to speak, and I wanted to thank her for that. I told her that everything fit, except for the 9 percent.

I was very excited, and kept on calculating, and things that fit kept on tumbling out: they fit automatically, without a strain. I had begun to forget about the 9 percent by now, because everything else was coming out right.

I worked very hard into the night, sitting at a small table in the kitchen next to a window. It was getting later and later–about 2:00 or 3:00 AM. I’m working hard, getting all these calculations packed solid with things that fit, and I’m thinking, and concentrating, and it’s dark, and it’s quiet . . . when suddenly there’s a TAC-TAC-TAC-TAC–loud, on the window. I look, and there’s this _white face_, right at the window, only inches away, and I _scream_ with shock and surprise!

It was a lady I knew who was angry at me because I had come back from vacation and didn’t immediately call her up to tell her I was back. I let her in, and tried to explain that I was just now very busy, that I had just discovered something, and it was very important. I said, “Please go out and let me finish it.”