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

on that problem.

However, my sabbatical year was coming up, so I decided to work in the same biology lab but on a different subject. I worked with Matt Meselson to some extent, and then with a nice fella from England named J. D. Smith. The problem had to do with ribosomes, the “machinery” in the cell that makes protein from what we now call messenger RNA. Using radioactive substances, we demonstrated that the RNA could come out of ribosomes and could be put back in.

I did a very careful job in measuring and trying to control everything, but it took me eight months to realize that there was one step that was sloppy. In preparing the bacteria, to get the ribosomes out, in those days you ground it up with alumina in a mortar. Everything else was chemical and all under control, but you could never repeat the way you pushed the pestle around when you were grinding the bacteria. So nothing ever came of the experiment.

Then I guess I have to tell about the time I tried with Hildegarde Lamfrom to discover whether peas could use the same ribosomes as bacteria. The question was whether the ribosomes of bacteria can manufacture the proteins of humans or other organisms, She had just developed a scheme for getting the ribosomes out of peas and giving them messenger RNA so that they would make pea proteins. We realized that a very dramatic and important question was whether ribosomes from bacteria, when given the peas’ messenger RNA, would make pea protein or bacteria protein. It was to be a very dramatic and fundamental experiment.

Hildegarde said, “I’ll need a lot of ribosomes from bacteria.”

Meselson and I had extracted enormous quantities of ribosomes from E. coli for some other experiment. I said, “Hell, I’ll just give you the ribosomes we’ve got. We have plenty of them in my refrigerator at the lab.”

It would have been a fantastic and vital discovery if I had been a good biologist. But I wasn’t a good biologist. We had a good idea, a good experiment, the right equipment, but I screwed it up: I gave her infected ribosomes—the grossest possible error that you could make in an experiment like that. My ribosomes had been in the refrigerator for almost a month, and had become contaminated with some other living things. Had I prepared those ribosomes promptly over again and given them to her in a serious and careful way, with everything under control, that experiment would have worked, and we would have been the first to demonstrate the uniformity of life: the machinery of making proteins, the ribosomes, is the same in every creature. We were there at the right place, we were doing the right things, but I was doing things as an amateur—stupid and sloppy.

You know what it reminds me of? The husband of Madame Bovary in Flaubert’s book, a dull country doctor who had some idea of how to fix club feet, and all he did was screw people up. I was similar to that unpracticed surgeon.

The other work on the phage I never wrote up—Edgar kept asking me to write it up, but I never got around to it. That’s the trouble with not being in your own field: You don’t take it seriously.

I did write something informally on it. I sent it to Edgar, who laughed when he read it. It wasn’t in the standard form that biologists use—first, procedures, and so forth. I spent a lot of time explaining things that all the biologists knew. Edgar made a shortened version, but I couldn’t understand it. I don’t think they ever published it. I never published it directly.

Watson thought the stuff I had done with phages was of some interest, so he invited me to go to Harvard. I gave a talk to the biology department about the double mutations which occurred so close together. I told them my guess was that one mutation made a change in the protein, such as changing the pH of an amino acid, while the other mutation made the opposite change on a different amino acid in the same protein, so that it partially balanced the first imitation—not perfectly, but enough to let the phage operate again. I thought they were two changes in the same protein, which chemically compensated each other.

That turned out not to be the case. It was found out a few years later by people who undoubtedly developed a technique for producing and detecting the mutations faster, that what happened was, the first mutation was a mutation in which an entire DNA base was missing. Now the “code” was shifted and could not be read any more. The second mutation was either one in which an extra base was put back in, or two more were taken out. Now the code could be read again. The closer the second mutation occurred to the first, the less message would be altered by the double mutation, and the more completely the phage would recover its lost abilities. The fact that there are three “letters” to code each amino acid was thus demonstrated.

While I was at Harvard that week, Watson suggested something and we did an experiment together for a few days. It was an incomplete experiment, but I learned some new lab techniques from one of the best men in the field.

But that was my big moment: I gave a seminar in the biology department of Harvard! I always do that, get into something and see how far I can go.

I learned a lot of things in biology, and I gained a lot of experience. I got better at pronouncing the words, knowing what not to include in a paper or a seminar, and detecting a weak technique in an experiment. But I love physics, and I love to go back to it.

Monster Minds

While I was still a graduate student at Princeton, I worked as a research assistant under John Wheeler. He gave me a problem to work on, and it got hard, and I wasn’t getting anywhere. So I went back to an idea that I had had earlier, at MIT. The idea was that electrons don’t act on themselves, they only act on other electrons.

There was this problem: When you shake an electron, it radiates energy and so there’s a loss. That means there must be a force on it. And there must be a different force when it’s charged than when it’s not charged. (If the force were exactly the same when it was charged and not charged, in one case it would lose energy, and in the other it wouldn’t. You can’t have two different answers to the same problem.)

The standard theory was that it was the electron acting on itself that made that force (called the force of radiation reaction), and I had only electrons acting on other electrons. So I was in some difficulty, I realized, by that time. (When I was at MIT, I got the idea without noticing the problem, but by the time I got to Princeton, I knew that problem.)

What I thought was: I’ll shake this electron. It will make some nearby electron shake, and the effect back from the nearby electron would be the origin of the force of radiation reaction. So I did some calculations and took them to Wheeler.

Wheeler, right away said, “Well, that isn’t right because it varies inversely as the square of the distance of the other electrons, whereas it should not depend on any of these variables at all. It’ll also depend inversely upon the mass of the other electron; it’ll be proportional to the charge on the other electron.”

What bothered me was, I thought he must have done the calculation. I only realized later that a man like Wheeler could immediately see all that stuff when you give him the problem. I had to calculate, but he could see.

Then he said, “And it’ll be delayed—the wave returns late—so all you’ve described is reflected light.”

“Oh! Of course,” I said.

“But wait,” he said. “Let’s suppose it returns by advanced waves—reactions backward in time—so it comes back at the right time. We saw the effect varied inversely as the square of the distance, but suppose there are a lot of electrons, all over space: the number is proportional to the square of the distance. So maybe we can make it all compensate.”

We found out we could do that. It came out very nicely, and fit very well. It was a classical theory that could be right, even though it differed from Maxwell’s standard, or Lorentz’s standard theory. It didn’t have any trouble with the infinity of self-action, and it was ingenious. It had actions and delays, forwards and backwards in time— we called it “half-advanced and half-retarded potentials.”

Wheeler and I thought the next problem was to turn to the quantum theory of electrodynamics, which had difficulties (I thought) with the self-action of the electron. We figured if we could get rid of the difficulty first in classical physics, and then make a quantum theory out of that, we could straighten out the quantum theory as well.