This was fascinating on Paul Dirac (by Richard Gunderman for the Conversation based on Graham Farmelo’s biography, The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom)…

…Born in Bristol, England, in 1902, Dirac became, after Einstein, the second most important theoretical physicist of the 20th century. He studied at Cambridge, where he wrote the first-ever dissertation on quantum mechanics. Shortly thereafter he produced one of physics’ most famous theories, the Dirac equation, which correctly predicted the existence of antimatter. Dirac did more than any other scientist to reconcile Einstein’s general theory of relativity to quantum mechanics. In 1933 he received the Nobel Prize in Physics, the youngest theoretical physicist ever to do so.

At the time Dirac received the Nobel Prize, he was leading a remarkably drab and, to most eyes, unappealing existence….

….Dirac was socially awkward and showed no interest in the opposite sex. Some of his colleagues suspected that he might be utterly devoid of such feelings. Once, Farmelo recounts, Dirac found himself on a two-week cruise from California to Japan with the eminent physicist Werner Heisenberg. The gregarious Heisenberg made the most of the trip’s opportunities for fraternization with the opposite sex, dancing with the flapper girls. Dirac found Heisenberg’s conduct perplexing, asking him, “Why do you dance?” Heisenberg replied, “When there are nice girls, it is always a pleasure to dance.” Dirac pondered this for some minutes before responding, “But Heisenberg, how do you know beforehand that the girls are nice?”

Love finds the professor

Then one day, something remarkable entered Dirac’s life. Her name was Margit Wigner, the sister of a Hungarian physicist and recently divorced mother of two. She was visiting her brother at the Institute for Advanced Study in Princeton, New Jersey, where Dirac had just arrived.

Known to friends and family as “Manci,” one day she was dining with her brother when she observed a frail, lost-looking young man walk into the restaurant. “Who is that?” she asked. “Why that is Paul Dirac, one of last year’s Nobel laureates,” replied her brother. To which she replied, “Why don’t you ask him to join us?”

Thus began an acquaintance that eventually transformed Dirac’s life. Writes Farmelo:

His personality could scarcely have contrasted more with hers: to the same extent that he was reticent, measured, objective, and cold, she was talkative, impulsive, subjective, and passionate.“

A self-described "scientific zero,” Manci embodied many things that were missing in Dirac’s life. After their first meeting, the two dined together occasionally, but Dirac, whose office was two doors down from Einstein, remained largely focused on his work.

After Manci returned to Europe, they maintained a lopsided correspondence. Manci wrote letters that ran to multiple pages every few days, to which Dirac responded with a few sentences every few weeks. But Manci was far more attuned than Dirac to a “universally acknowledged truth” best expressed by Jane Austen: “A single man in possession of a good fortune must be in want of a wife.”

She persisted despite stern warnings from Dirac:

I am afraid I cannot write such nice letters to you – perhaps because my feelings are so weak and my life is mainly concerned with facts and not feelings.

When she complained that many of her queries about his daily life and feelings were going unanswered, Dirac drew up a table, placing her questions in the left column, paired with his responses on the right. To her question, “Whom else should I love?” Dirac responded, “You should not expect me to answer this question. You would say I was cruel if I tried.” To her question, “Are there any feelings for me?” Dirac answered only, “Yes, some.”

Realizing that Dirac lacked the insight to see that many of her questions were rhetorical, she informed him that “most of them were not meant to be answered.” Eventually, exasperated by Dirac’s lack of feeling, Manci wrote to him that he should “get a second Nobel Prize in cruelty.” Dirac wrote back:

You should know that I am not in love with you. It would be wrong for me to pretend that I am, as I have never been in love I cannot understand fine feelings.

Yet with time, Dirac’s outlook began to change. After returning from a visit with her in Budapest, Dirac wrote, “I felt very sad leaving you and still feel that I miss you very much. I do not understand why this should be, as I do not usually miss people when I leave them.” The man whose mathematical brilliance had unlocked new truths about the fundamental nature of the universe was, through his relationship with Manci, discovering truths about human life that he had never before recognized.

Soon thereafter, when she returned for a visit, he asked her to marry him, and she accepted immediately. The couple went on two honeymoons little more than month apart. Later he wrote to her:

Manci, my darling, you are very dear to me. You have made a wonderful alteration in my life. You have made me human… I feel that life for me is worth living if I just make you happy and do nothing else.

Full essay here.