Where is my Dirac?

There was a time when I talked about Paul Dirac all the time. My wife had quite enough of it and our neighbor Vera, who heard some of my monologues, said she was sick of listening about Dirac too. It was after I read his biography The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom by Graham Farmelo.

I like this book very much. And I love Dirac. I actually wanted to name this text: "I love Dirac."

But Vera heavily protested. "What kind of a title is this?"

So I named it: "Where is my Dirac?"

Where is my Dirac? That’s what Einstein always said when he was looking for The principles of Quantum Mechanics, a book by Paul Dirac which became a classic immediately after it was published in 1930. Note that Dirac, born in 1902, had been a legendary physicist long before he turned thirty.

But why do I like Dirac so much? After all, he was known for his literal-mindedness and for being totally unsociable and even unemotional. For example, his friends coined the term "a dirac," which was the smallest number of words it’s possible to say in an hour while still taking part in a conversation.

But is this true? Was he really such a strange man?

You know, some people actually think being literal-minded and unemotional are common traits of mathematicians and physicists.

"But they are!" said Vera. "Look at yourself, young boy!"

"I am not literal-minded, Vera!"

"Of course you are, you don’t understand jokes at all."

"I just don’t understand your jokes."

"You don’t understand any kind of jokes!"

But after reading Farmelo’s book it seems to me Dirac was actually a warm person. Not always and to everybody, but he surely was warm to his close friends. For example, he spent months on the campaign to free Peter Kapitza from his detention in the Soviet Union.

It just seems to me that he was heavily burdened by his childhood. He didn’t have an easy relationship with his father. For example, Paul was forced to eat dinner alone with his father and was required to converse in flawless French. Mistakes were not tolerated.

Observing photographs, I got the impression Dirac had actually become happier through the years. There is an unreserved, contagious smile on some photos of him when he was old. I didn’t see such a smile on photos from his youth. There is an interesting anecdote from the last years of his life: Dirac and Leopold Halpern, a general relativity specialist, spent many weekends canoeing in near wilderness on the Wakulla River in Florida. Once, Behram Kurşunoğlu, another physicist (who could stay silent for hours – a quality perhaps required to be a friend of Dirac), joined them. He was in a three-piece suit and at some point, he stood up in the canoe to admire the scenery. At that moment Dirac pushed him in the river just for fun. And burst into laughter. I can’t imagine Dirac doing something like this when he was twenty or thirty. And I guess it was truly great fun as the river is famous for alligators and snakes.

This might be about happiness, but on the other hand there is Farmelo’s observation on two portraits of Dirac – one from 1933 and one from 1978. Farmelo says that it’s clear from the two photographs how much Dirac’s confidence had drained away in forty-five years. And I actually agree with this observation. That’s sad. That’s really sad.

But it’s almost a rule that physicists do their best work before they are thirty. Just think of Dirac, Bohr, Heisenberg, Pauli. Einstein had his annus mirabilis in 1905 when he was twenty-six, but it’s true that he developed general relativity in his thirties. Schrödinger was another exception; he published his best work when he was nearing his forties. I don’t know about today’s physicists though.

But now to lighter themes. The true reason I am writing about Dirac again is because my brother-in-law insisted that I should write more about love affairs.

"That’s what people like to read, you know!"

So, yeah. Dirac might have turned out to be a warm person, but he was unusual, nevertheless. Also in love affairs. Most friends were convinced he would stay a bachelor as he seemed to be interesting only in physics. But in his thirties, when he finally met the right woman (the renowned physicist Eugene Wigner’s sister), their story was incredibly romantic.

"Don’t fool around!" said my brother-in-law.

You know, when Margit Wigner complained that he hadn’t answered many of her queries about his daily life and feelings, Dirac drew up a table, placing her questions in the left column and his responses on the right. It looked something like:

Letter number	Question	Answer
5	You know that I would like to see you very much?	Yes, but I cannot help it.
6	Do you know how I feel like?	Not very well. You change so quickly.
6	Were there any feelings for me?	Yes, some.

You can’t deny this is terribly romantic.

"Don’t fool around!" said my brother-in-law. And Vera agreed.

I told these stories to my wife too. And now whenever I am overly romantic, like propose to do some reading together instead of going to a concert or the theater, my wife always says: "Where is my Dirac!"