For more than five years, former physicist Graham Farmelo devoted himself to unlocking the secrets of one of the most important and curious figures of 20th century science, Paul Dirac. He was born in 1902 and died in 1984, and though lionized by his peers for his fundamental work in quantum mechanics (among other things, he predicted the existence of antimatter and won a Nobel Prize when he was only 31), Dirac’s legacy has fared poorly among the general public. During his research, Farmelo found that most residents of the “famous” physicist’s hometown of Bristol didn’t even know who Dirac was. Unquestionably, this is due to Dirac’s reclusive and taciturn behavior; his social quiescence was so extreme that it inspired his fellow physicists to invent an unofficial unit of measure for the minimal number of words a person could speak in polite company: a “Dirac,” roughly one utterance per hour.
But as Farmelo delved deeper into Dirac’s life for his new biography, The Strangest Man, he discovered surprising complexity and contradiction that gives new appreciation to the physicist’s character: Despite what many perceived as a lack of empathy, Dirac married, raised children, and forged several close lifelong friendships. Despite his professed distaste for unscientific reasoning, in his later life he became increasingly obsessed with philosophical, even religious, questions. And despite his love for the rarefied subject of theoretical physics, Dirac also had a passion for “lowbrow” cartoons and comic books.
Farmelo spoke with Seed’s Lee Billings about the process of researching the book and his astonishing hypothesis that could explain, once and for all, Dirac’s enigmatic behavior.
Seed: What motivated you to spend five years writing a book about Paul Dirac?
Graham Farmelo: I used to be a theoretical physicist, and I can say that everyone in that profession is interested in Dirac. He’s often said to be “the first really modern theoretician” or “the theorist’s theorist.” I remember as an undergraduate coming across my first taste of Dirac’s physics, something called Fermi-Dirac statistics, which governs the transistors and electron flow in your computer. I was blown away, a bit like a young music student listening to Beethoven’s “Moonlight Sonata.” Dirac’s first papers on quantum mechanics still look modern, more than those of any of his fellow pioneers. The mathematical imagination and beauty of those articles is amazing. I wanted to write a biography of him to try to communicate the power and scope of his work to non-specialists who are nevertheless curious about science, and to try to understand his remarkable personality.
In my time in physics, I met quite a few “Dirac fanatics,” people who are obsessive about him. I’m speaking to you from the Institute for Advanced Study in Princeton, and I’ve spent several lunchtimes recounting to the physicists here some new “Dirac stories.”
Seed: “Dirac stories?” Can you give me some examples?
GF: Certainly. At the end of a lecture, Dirac agreed to answer questions. Someone in the audience piped up: “I didn’t understand the equation on the top right of the blackboard, professor.” Dirac was silent for more than a minute. When the moderator asked him if he’d like to answer the question, Dirac shook his head and said, “That wasn’t a question. It was a comment.”
Here’s another: Over dinner one evening at Saint John’s College, Cambridge, an American visitor who was desperate to meet the formidable Dirac steeled himself to ask, “Are you going on vacation this summer, professor?” Silence. About 20 minutes later, Dirac turned to the visitor and said, “Why do you ask?”
Seed: He sounds like quite a deep, literal thinker. Did Dirac have any interests outside physics?
GF: Yes, a lot, but he just didn’t talk about them. He read widely, from Tolstoy to John le Carré. Among artists, he loved Rembrandt and Salvador Dali. Like Einstein, Dirac’s taste in music was mainly classical, but in later life he had a thing about Cher. To settle a dispute with his wife, he bought a second television so that he could watch a Cher special while she watched the Oscars.
Seed: The book includes several revelatory passages documenting Dirac’s personal life. How did you research and verify that material?
GF: I devoted a lot of time tracking down Dirac’s surviving friends, people who knew him very well. The most important one I found was his last great friend, Leopold Halpern, an expert on relativity who slept in the open air, refused to wash with soap, and liked to slice open baked potatoes with a karate chop. A few years ago, when Halpern was at death’s door with prostate cancer, he flew across the country to Florida, where Dirac spent the latter part of his life, just so he could row me up Wakulla Springs. He and Dirac used to go rowing every weekend. That was a special trip for me: Even now I’m looking at my arm and there are goose bumps. He showed me places where they talked, even where they went skinny dipping. Two and a half months later, Halpern died.
I spent several months consulting the Dirac archive at Florida State University in Tallahassee, which was virtually untouched. Dirac was an FSU professor for the last 14 years of his life. I found amazing things, not just letters from great physicists like Heisenberg and Schrödinger but also an amazing cache of weekly letters from Dirac’s mother, spanning almost 20 years. Many historians would’ve probably turned their noses up at these, but I found in them a dramatic story that illuminates Dirac’s home life and upbringing. I was also blessed with beginner’s luck when I happened to meet Dirac’s younger daughter at a centenary celebration of his birth. We hit it off well, and one day in her kitchen while I was visiting her, she showed me something like 120 private letters between Dirac and his first serious girlfriend, later his wife. Keep in mind, this man hardly spoke a word, and here he was opening up, writing whole pages—epics for him. I couldn’t believe my luck. Here was Dirac talking about his father with whom he didn’t get along at all, and about what it felt like to be someone conscious, that he was unlike most other people, unable to empathize with them. This is just my opinion here, but I believe he demonstrated many symptoms of what we now call autism, though that condition had not been identified at the time.
Seed: You think Dirac had undiagnosed autism?
GF: I did not go into this book project thinking Dirac was autistic in any way. When I started researching him all those years ago, I barely even knew what the term “autism” meant, and certainly didn’t apply it to Dirac. But as I researched, I encountered rumors about Dirac being autistic, about Einstein being autistic, and speculations that autism was more prevalent in scientists and mathematicians. So during one of my stays at Cambridge, I went to see Simon Baron-Cohen, who is arguably Britain’s leading expert on autism. He knew nothing about Dirac, but, to my amazement, he began describing patterns of behavior that exactly correspond to Dirac’s. Let me stress that this is just a hypothesis, and that I’m personally very skeptical of attempts to psychoanalyze people who are dead. This isn’t theoretical physics; I can’t do a slam-dunk experiment to prove it.
Seed: What were some of the behavioral indicators?
GF: There are many of them: inability to empathize, extreme taciturnity and literal-mindedness, a passion for a routine, narrow interests, a lack of physical coordination, dislike of sudden loud noises, and so on. Many of the “Dirac stories” told by physicists are, in my opinion, actually autism stories. When people are laughing at these things, they forget what they’re actually doing is mocking.
Seed: Do you think those traits might have helped him in his work or given him a unique perspective?
GF: Well, he was certainly as focused as a laser and as logical as a computer. He also had a fascinating way of looking at mathematics. He had a phrase, “My equation is smarter than I am.” He really did think that a good equation could be more intelligent than its creator. There’s a kind of mysticism in that. In the last 15 or 20 years of his life, he became obsessed with the philosophy that, for a piece of mathematics to be useful in fundamental physics, it must be beautiful. For instance, he thought the theory of photon and electron interactions—what we call quantum electrodynamics—was ugly, so he wouldn’t accept it. He had this extremely rigorous sense of beauty, and saw each successive revolution in physics progressing through increasingly beautiful mathematics.
Dirac, to his dying breath, pursued this quest for mathematical beauty. For him, everything apart from that principle was just details. The job of the fundamental theorist was to look for mathematically beautiful laws. That’s why the string theorists are on the right track, even though there aren’t experiments to bear them out at the moment.
Seed: So Dirac would be a fan of string theory, you think?
GF: Well, when people get old, they tend to basically think that everything’s gone to the dogs, and there was an element to that in Dirac, who took virtually no interest in the latest findings in his field. But if you apply his idea about sticking to mathematically beautiful generalizations of past theories and to hell with experiments in the short term, then this philosophy should embolden string theorists, yes.
Source: http://seedmagazine.com/content/article/studying_the_strangest_man/
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