Paul Dirac (left) and Richard Feynman. From The Strangest Man. Photograph by A. John Coleman, courtesy AIP Emilio Segre Visual Archives, Physics Today collection.
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.
