The Biography of A Strange Man

This is a review of the The Strangest Man by Graham Farmelo. It is the biography of Paul Dirac, one of the pioneers of quantum physics, the youngest ever theoretical physicist to win the Nobel prize (at 31 years of age), and according to Stephen Hawking, the greatest English physicist since Newton (I would place Maxwell and Faraday as close competitors for the accolade).

The book is deeply researched and well written and has won several prizes, including the L.A. Times Book Prize for Science and Technology. It is a substantial (~540 pages) treatment of the life of the man who was famous both for his intellectual achievements as well as his eccentricities (stories about him abound; some of them will be recounted below). The title of the book derives from a quote by the famous physicist Bohr, who was one of Dirac's mentors.

Rather than follow the chronological presentation of the book, I will describe the major themes around which the author writes:

1. Dirac's relationship with his father: His father was domineering and disciplinarian. Dirac famously became taciturn because his father would only allow him to speak French at home, with penalties for every mistake Dirac made. His father was not affectionate and did not allow Dirac visitors. His father's relationship with his mother was volatile and made home a toxic place for Dirac.

   
   

   Later, Dirac thought better of his father as he received financial support for his academic career from him. But even later, it became clear that the money had come from elsewhere, and that Dirac's father had simply taken the credit for supplying it.

   
   

   Dirac spoke little, was socially awkward, and did not prefer to collaborate professionally. A famous example, included in the book: At a talk he was giving, someone from the audience said he had not understood such-and-such point. Dirac remained silent. After some prodding from the host to answer the question, Dirac responded that it was a statement, not a question.

   
   

   Because he was also very logical, Dirac's brevity of speech produced entertaining stories, some probably apocryphal. One that I did not find in the book (or missed): He was traveling via train with a friend who looked out into the English countryside and observed that the sheep seemed to have been sheared. "At least on this side," replied Dirac.

   
   

2. Dirac's insistence on mathematical beauty: Dirac famously insisted that in physics truth was to be found by searching for equations that were beautiful, rather than by trying to model experiments. Even approximate theories he said, can, and should, have mathematical beauty. There has been a lot of discussion about these assertions and even entire books refuting them.

   
   

   The biography returns time and again to this theme, starting, as far back as the curricular influences of the Aesthetic Movement in England in the 1850s. It goes on to describe the role played by mathematical aesthetics in Dirac's thinking as he cut his teeth on his initial training, then performed his groundbreaking work in the face of competition from European colleagues, and was finally superseded by advances made by younger, largely American, physicists.

3. Dirac's theoretical brilliance: Dirac's theoretical brilliance manifested itself clearly in high school. He digested both special and general relativity by himself as an engineering undergraduate. In his professional career, by employing pure thought, he managed to make astonishingly deep advances in physics.

   
   

   There are extensive descriptions in the book of his interactions with major scientists in Cambridge and elsewhere (Rutherford, Bohr, Einstein, Schrodinger, Heisenberg, Pauli...and of course Fowler, his thesis advisor) and the great regard in which they held him.

   
   

An undesirable side effect of his academic brilliance was his discord with his brother,

who was not as bright, felt overshadowed, and eventually committed suicide.

4. Dirac's connection to communism: Dirac was greatly interested in the Soviet Union, visited it, and had a particularly close friendship with his Russian colleague at Cambridge, Pyotr Kapitza.

   
   

   The book covers this aspect with wartime and postwar Europe as the background. As a result of his Soviet connections, Dirac was initially refused a visa by the United States. This resulted in a visit to India.

   
   

   Perhaps it would be relevant to mention in this section that Dirac was also quite atheistic. He was vocal about his (lack of) belief and this led Pauli to famously and sarcastically say (as reported in the book) that there is no God and Dirac is his prophet.

   
   

   Dirac's antireligiosity led to some difficulty in securing a gravestone at the Westminster Abbey, an honor accorded only to the greatest of British subjects. Persistent lobbying by the physics community finally succeeded in getting him admitted (at least 10 years have to pass after death for the honor to be considered) in 1995: today his stone decorates the Abbey floor, inscribed with his famous equation (I visited it in 2022). Dirac himself lies buried in Florida.

Summary

Overall, the book rings true and deserves all the accolades it has received. It is good to finally have a substantial biography of one of the great figures of 20th century science. The technical matter has been conveyed very well and should be largely accessible to a layperson.

Although Dirac's presence is still substantial in the physics lore, I still learnt some things from the book that I did not know: Dirac's text was Einstein's preferred book on quantum mechanics; Dirac had a sense of humor which extended to mailing a baby alligator (while he was working in Florida) to the physicist Gamow; Dirac liked entertainment and art, including Mickey Mouse and Cher, Sherlock Holmes and Dali.

Perhaps the most moving episode in the book is a remarkable conversation with the physicist Pierre Ramond in which Dirac claimed his life had been a failure, since modern quantum theories, though they matched experiment, were not elegant enough for his taste.