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

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.”

After that I went around to the biology table at dinner time. I had always had some interest in biology, and the guys talked about very interesting things. Some of them invited me to come to a course they were going to have in cell physiology. I knew something about biology, but this was a graduate course. “Do you think I can handle it? Will the professor let me in?” I asked.

They asked the instructor, E. Newton Harvey, who had done a lot of research on light-producing bacteria. Harvey said I could join this special, advanced course provided one thing—that I would do all the work, and report on papers just like everybody else.

Before the first class meeting, the guys who had invited me to take the course wanted to show me some things under the microscope. They had some plant cells in there, and you could see some little green spots called chloroplasts (they make sugar when light shines on them) circulating around. I looked at them and then looked up: “How do they circulate? What pushes them around?” I asked.

Nobody knew. It turned out that it was not understood at that time. So right away I found out something about biology: it was very easy to find a question that was very interesting, and that nobody knew the answer to. In physics you had to go a little deeper before you could find an interesting question that people didn’t know.

When the course began, Harvey started out by drawing a great, big picture of a cell on the blackboard and labeling all the things that are in a cell. He then talked about them, and I understood most of what he said.

After the lecture, the guy who had invited me said, “Well, how did you like it?”

“Just fine,” I said. “The only part I didn’t understand was the part about lecithin. What is lecithin?”

The guy begins to explain in a monotonous voice: “All living creatures, both plant and animal, are made of little bricklike objects called ‘cells’.”

“Listen,” I said, impatiently, “I know all that; otherwise I wouldn’t be in the course. What is lecithin?”

“I don’t know.”

I had to report on papers along with everyone else, and the first one I was assigned was on the effect of pressure on cells—Harvey chose that topic for me because it had something that had to do with physics. Although I understood what I was doing, I mispronounced everything when I read my paper, and the class was always laughing hysterically when I’d talk about “blastospheres” instead of “blastomeres,” or some other such thing.

The next paper selected for me was by Adrian and Bronk. They demonstrated that nerve impulses were sharp, single-pulse phenomena. They had done experiments with cats in which they had measured voltages on nerves.

I began to read the paper. It kept talking about extensors and flexors, the gastrocnemius muscle, and so on. This and that muscle were named, but I hadn’t the foggiest idea of where they were located in relation to the nerves or to the cat. So I went to the librarian in the biology section and asked her if she could find me a map of the cat.

“A map of the cat, sir?” she asked, horrified. “You mean a zoological chart!” From then on there were rumors about some dumb biology graduate student who was looking for a “map of the cat.”

When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.

The other students in the class interrupt me: “We know all that!”

“Oh,” I say, “you do? Then no wonder I can catch up with you so fast after you’ve had four years of biology.” They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes.

After the war, every summer I would go traveling by car somewhere in the United States. One year, after I was at Caltech, I thought, “This summer, instead of going to a different place, I’ll go to a different field.”

It was right after Watson and Crick’s discovery of the DNA spiral. There were some very good biologists at Caltech because Delbruck had his lab there, and Watson came to Caltech to give some lectures on the coding systems of DNA. I went to his lectures and to seminars in the biology department and got full of enthusiasm. It was a very exciting time in biology, and Caltech was a wonderful place to be.

I didn’t think I was up to doing actual research in biology, so for my summer visit to the field of biology I thought I would just hang around the biology lab and “wash dishes,” while I watched what they were doing. I went over to the biology lab to tell them my desire, and Bob Edgar, a young post-doc who was sort of in charge there, said he wouldn’t let me do that. He said, “You’ll have to really do some research, just like a graduate student, and we’ll give you a problem to work on.” That suited me fine.

I took a phage course, which told us how to do research with bacteriophages (a phage is a virus that contains DNA and attacks bacteria). Right away I found that I was saved a lot of trouble because I knew some physics and mathematics. I knew how atoms worked in liquids, so there was nothing mysterious about how the centrifuge worked. I knew enough statistics to understand the statistical errors in counting little spots in a dish. So while all the biology guys were trying to understand these “new” things, I could spend my time learning the biology part.

There was one useful lab technique I learned in that course which I still use today. They taught us how to hold a test tube and take its cap off with one hand (you use your middle and index fingers), while leaving the other hand free to do something else (like hold a pipette that you’re sucking cyanide up into). Now, I can hold my toothbrush in one hand, and with the other hand, hold the tube of toothpaste, twist the cap off, and put it back on.

It had been discovered that phages could have mutations which would affect their ability to attack bacteria, and we were supposed to study those mutations. There were also some phages that would have a second mutation which would reconstitute their ability to attack bacteria. Some phages which mutated back were exactly the same as they were before. Others were not: There was a slight difference in their effect on bacteria—they would act faster or slower than normal, and the bacteria would grow slower or faster than normal. In other words, there were “back mutations, but they weren’t always perfect; sometimes the phage would recover only part of the ability it had lost.

Bob Edgar suggested that I do an experiment which would try to find out if the back mutations occurred in the same place on the DNA spiral. With great care and a lot of tedious work I was able to find three examples of back mutations which had occurred very close together—closer than anything they had ever seen so far—and which partially restored the phage’s ability to function. It was a slow job. It was sort of accidental: You had to wait around until von got a double mutation, which was very rare.

I kept trying to think of ways to make a phage mutate more often and how to detect mutations more quickly, but before I could come up with a good technique the summer was over, and I didn’t feel like continuing