Richard Feynman was a brilliant, bongo-playing, lock-picking, eminently quotable physicist. His quips, on anything from the pleasure of findings things out to the key to science to how fire works are standard fare for science fans.

For synthetic biologists, it's a quotation he left on his last blackboard at Caltech before his death in 1988 that is most frequently quoted: "What I cannot create, I do not understand." This statement gives quotable form to the "drive to make" that happens when engineers start doing biology.

Feynman of course wasn't an engineer, he was a theoretical physicist--a field less often associated with creating stuff than with creating equations. But Feynman also liked to dabble in other fields, including a sabbatical year in Max Delbrück's biology lab at Caltech studying genetic mutations in viruses that infect bacteria. The chapter on this disciplinary dabbling in Feynman's autobiography, Surely You're Joking Mr. Feynman, is a fascinating look at what happens when a physicist starts doing biology.

I read Surely You're Joking during college, just as I was starting to work in a biology lab. I still vividly remember one tiny anecdote about the general applicability of a certain lab technique in everyday life, a technique I was just starting to get the hang of while I was reading the book:

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.

For Feynman, these little tricks of the trade--the tacit knowledge that biologists gain through experience--end up being the focus of his biological excursion more than any facts about bacteria, phage, and DNA. He concludes that:

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.

These stories of these lessons are told with Feynman's quirky mix of charming arrogance and humility, the strange combination of traits that gave him the confidence and the curiosity to jump into a new field. Feynman discusses giving a presentation to fellow students in a biology class at Princeton, the other students "laughing hysterically" at his mispronunciation of common biology terms. Later, the class urges him to move on after an especially long introduction of background facts saying, "We know all that!" He replied:

"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.

The chapter's title, "A Map of the Cat?", comes from a short anecdote that captures Feynman's humility and humor when confronted with too many new facts:

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 had not 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 a dumb biology student who was looking for "a map of the cat."

Rereading the chapter now after many years in biology labs, I'm particularly struck by they way Feynman describes experimental work, the early molecular biology tools and techniques that require "great care and a lot of tedious work." More than the facts or the jargon or the disciplinary conventions for writing papers, this is where the biggest differences appear between the practice of biology and the practice of theoretical physics. Feynman's legendary ability to think through problems in physics--his "problem-solving algorithm"--didn't help as much in the lab, leading him at one point to say, "It would have been a fantastic and vital discovery if I had been a good biologist. But I wasn't a good biologist."

Feynman's legendary curiosity also shows through when he talks about biology and the many questions that were wide open at the time. He mentions his first look through a 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.

One of the most exciting parts of interdisciplinary research and of art-science collaborations is the questions that smart and curious people ask when they're encountering a new field, the things that stick out when viewed from a different perspective. These kinds of questions might sometimes seem naive or even arrogant, but at their best they can point towards new directions where no one knows the answer and everyone ends up seeing something differently. Feynman's great talent was to show us the universe--and the wonder and tedium of life in the biology lab--through a physicist's eyes.