The Strangest Man: The Hidden Life of Paul Dirac by Graham Farmelo

He was certainly a genius. He was able, with the power of pure thought, to imagine how the infinitesimally small particles that make up the universe actually fit together. Dirac wrote a classic book on quantum mechanics; when Einstein was faced with a knotty problem, he would mutter, "Where's my Dirac?" It is possible, then, that when he was at his peak, in the 1920s, Dirac had the best scientific brain in the world. He knew other giants in the field of quantum mechanics, such as Werner Heisenberg and Erwin Schrödinger, and wrote beautiful equations effectively explaining their work to each other. One of his equations, describing the behaviour of electrons, was described by the physicist Frank Wilkzek as "achingly beautiful".

Among theoretical physicists, he was known as "the theorist's theorist".

But, my goodness, he was strange.

Dirac was the nerd's nerd. His colleagues, themselves the geekiest of geeks, joked about Dirac's lack of social communication. Among these brainboxes, the smallest use of language possible in a given situation was known as a "Dirac". His tendency was to answer questions in one of two ways — by saying either "yes" or "no". Sometimes he simply remained silent. One story about Dirac was that, after he'd given a talk, a member of the audience said they didn't understand something he had written on the blackboard. Dirac said nothing..

When asked for a reply, he said, "That was not a question, it was a comment." Graham Farmelo, who has done a terrific job with this biography, tells us about Dirac's origins. He was the son of a Swiss schoolteacher, Charles Dirac, who settled in Bristol. Charles was intense and peculiar. At dinner, he sat alone with the young Dirac, while his two other children sat separately with their mother. Dirac's father insisted on speaking French, and "would refuse him permission to leave the table if he had made a linguistic error". The young Dirac had problems with his digestion; he was often forced, as Farmelo tells us, "to sit at the table and vomit". Later, his brother, Felix, committed suicide.

Theoretical physics was Dirac's escape. Incredibly precocious, he began his degree in Bristol at the age of 16; by his early twenties he was a research student at Cambridge, and already a towering figure in his subject. He spent a lot of his time thinking, often on long country walks. He predicted the existence of anti-matter, an astonishing mental feat. He might have been autistic.

Amazingly, he fell in love with a Hungarian woman, Manci Balazs, and they had four children. But you should see one of his love letters, reproduced here; it is, mostly, a list of precise questions and answers.

If you're interested in crunchy scientific problems, and how the best human brains tackle them, this is a wonderful book. Dirac thought, with penetrating rigour, about subatomic particles, and tried to express them in terms of mathematical equations. But when the maths didn't add up, he did not give up. His genius was to assume, not that his maths was wrong, but that maths itself was wrong — in other words, the universe was weirder than people thought.

At least, that's what I think he did. And one of the good things about this book is that I'll be thinking about it for a while yet..

Synopsis by Foyles.co.uk

Paul Dirac was one of the leading pioneers of the greatest revolution in 20th-century science: quantum mechanics. One of the youngest theoreticians ever to win the Nobel Prize for Physics, he was also pathologically reticent, strangely literal-minded and legendarily unable to communicate or empathize. Through his greatest period of productivity, his postcards home contained only remarks about the weather. Based on a previously undiscovered archive of family papers, Graham Farmelo celebrates Dirac's massive scientific achievement while drawing a compassionate portrait of his life and work. Farmelo shows a man who, while hopelessly socially inept, could manage to love and sustain close friendship. 'The Strangest Man' is an extraordinary and moving human story, as well as a study of one of the most exciting times in scientific history.