Wednesday, March 4, 2009

Classical and Quantum Genius?

P.A.M. Dirac was the Calvin Coolidge of physicists. Unlike Calvin Coolidge, he was also a genius -- though the title of his new biography, The Strangest Man: The Hidden Life of Paul Dirac, Quantum Genius, is cringe-inducing. (Is a quantum genius someone who's both a genius and not a genius at the same time?)

Anyway, here's Dirac having a nice Coolidgesque moment (Jeremy Bernstein, LRB Letters):
While it is certainly true that Dirac was a man of relatively few words, as David Kaiser makes clear, it is easy to exaggerate his reluctance to speak (LRB, 26 February). During the 1958-59 academic year at the Institute for Advanced Study at Princeton he frequently had dinner in the cafeteria with young people like myself. He entered into our conversations, sometimes with quite unexpected comments. On one occasion I had asked a colleague what Hans Bethe – a very successful consultant and a well-paid professor at Cornell who even so lived quite modestly – did with his money. My colleague said he thought that Bethe invested it. ‘Maybe he loses it,’ Dirac commented.


oz_tomoki said...

Another interesting story about Dirac

Jeremy said...

A few I found:

Attending a meeting in a castle, a fellow guest warned Dirac that a certain room was haunted by a ghost that always appeared at midnight. "Is that midnight Greenwich time, or daylight-saving time?" Dirac asked.

Classicist John Crook tried making small talk with Dirac in the Hall of St John's College, Cambridge. Crook said, "Cold, isn't it?" After long thought, Dirac replied, "How cold?"

Dirac was often invited to summer garden parties at Buckingham Palace, but found them a chore. When a colleague was invited he asked Dirac how to make the most of the event. "Get a large piece of cake and sit by the lake" was the reply.

Dirac often dozed during other people's lectures, occasionally waking to make a sharp remark. An unfortunate speaker once paused in confusion: "Here is a minus where there should be a plus. I seem to have made an error of sign." Dirac opened one eye and said: "Or an odd number of errors."

When Dirac first visited Niels Bohr's institute in Copenhagen, his utterances consisted almost entirely of three phrases: "Yes", "No" and "I don't mind". Later, he became more flexible. When astrophysicist Subrahmanyan Chandrasekhar expounded his views, Dirac repeatedly interjected with "Yes", Hebut explained later, "When I say Yes, it does not mean that I agree; it means only that you should go on."

In 1929, Dirac sailed from America to Japan with Werner Heisenberg. During the trip, Heisenberg spent the evenings dancing while Dirac looked on, puzzled. Eventually Dirac asked his friend why he danced. Heisenberg replied, "Well, when there are nice girls it is a pleasure to dance." After thinking for 5 minutes, Dirac said: "But how do you know beforehand that the girls are nice?"