Quantum Leap By LOUISA GILDER

Quantum Leap By LOUISA GILDER
September 13, 2009

THE STRANGEST MAN
The Hidden Life of Paul Dirac, Mystic of the Atom
By Graham Farmelo
Illustrated. 539 pp. Basic Books. $29.95

This biography is a gift. It is both wonderfully written (certainly not a given in the category Accessible Biographies of Mathematical Physicists) and a thought-provoking meditation on human achievement, limitations and the relations between the two. Here we find a man with an almost miraculous apprehension of the structure of the physical world, coupled with gentle incomprehension of that less logical, messier world, the world of other people.
At Cambridge University in 1930, Subrahmanyan Chandrasekhar took a class in quantum mechanics from the 28-year-old Paul Dirac. Three years later, Dirac would become the youngest theoretician to receive the Nobel Prize in Physics up to that time (50 years after that, Chandrasekhar would become one of the older ones). Chandrasekhar described Dirac as a “lean, meek, shy young ‘Fellow’ ” (i.e., of the Royal Society) “who goes slyly along the streets. He walks quite close to the walls (like a thief!), and is not at all healthy.” Dirac’s class — which Chandrasekhar took in its entirety four times, even though Dirac taught it by repeating material from his recently published textbook word for word — was “just like a piece of music you want to hear over and over again.”
Dirac is the main character of a thousand humorous tales told among physicists for his monosyllabic approach to conversation and his innocent, relentless application of logic to everything. Listening to a Dirac story is like slipping into an alternate universe: Dirac reads “Crime and Punishment” and reports it “nice” but notes that in one place the sun rises two times in a day; Dirac eats his dinner in silence until his companion asks, “Have you been to the theater or cinema this week?” and Dirac replies, “Why do you wish to know?”
His work was as sui generis as his social skills. “The great papers of the other quantum pioneers were more ragged, less perfectly formed than Dirac’s,” explained Freeman Dyson, who took Dirac’s course as a precocious 19-year-old. Dirac’s discoveries “were like exquisitely carved marble statues falling out of the sky, one after another. He seemed to be able to conjure laws of nature from pure thought.” (Most notably, Dirac predicted the existence of antimatter in 1928 because his just discovered relativistic electron equation required it.) “It was this purity that made him unique.”
In 1990, Helge Kragh wrote “Dirac: A Scientific Biography,” a useful resource comprising physics, a little history and a dessert of Dirac stories in a chapter entitled “The Purest Soul.” And indeed, what else besides quantum mechanics and amusing anecdotes did this great and single-minded physicist’s life hold?
“The purest soul” is a quotation about Dirac from Niels Bohr, as is Graham Farmelo’s title. (“Dirac is the strangest man,” Bohr said, “who ever visited my institute.”) But purity and strangeness were not the whole story. Kragh’s book offers a collage of a brilliant and peculiar man seen from the outside; Farmelo’s is a tapestry, and he provides glimpses of the inside.
A senior research fellow at the Science Museum in London, Farmelo gives us the texture of Dirac’s life, much of it spent outdoors — from long Sunday walks as a young man, looking like “the bridegroom in an Italian wedding photograph,” “dressed in the suit he wore all week, his hands joined behind his back, both feet pointing outwards as he made his way around the countryside in his metronomic stride”; to late-life canoeing trips with Leopold Halpern, a physicist even stranger than he, “through forests of sassafras and American beech trees, draped with Spanish moss. The alligators made scarcely a sound: the silence was broken only by the rhythmic sloshing of the paddles, the cry of a circling osprey, the occasional shuffling of wind passing through shoreline gaps in the forest.” (After lunch, they swam and paddled back, “scarcely exchanging a word.”)
We follow Dirac from his pinched and chilly childhood in Bristol (a few blocks away from the two-years-younger Archie Leach, a k a Cary Grant); through his discovery, visiting the Bohrs in Copenhagen, of what a happy family was like; his fiercely loyal friendship with Werner Heisenber; his joyful beach honeymoon, still in a three-piece suit; his careful fatherhood (constructing for his daughters’ cat a door wider than its whiskers); to his death in Florida — “a place where recreational walkers are regarded as perverse” — in 1984.
The science writing in “The Strangest Man” isn’t glib, but neither does it require problem-solving on the part of the reader. In most cases, Farmelo presents the technical matter clearly and efficiently, and in all cases — one of the great joys of the book — Dirac’s scientific insights are placed within the circumstances in which they were born: e.g., the “sweltering July” of 1926 when Dirac, sitting at his college desk, produced his paper on what became Fermi-Dirac statistics.
In a prologue, Farmelo describes a visit to the elderly Dirac paid by his biologist colleague Kurt Hofer. Through the eyes of Hofer, we see Dirac suddenly break out of monosyllables to talk for two hours with increasing vehemence about his monstrous father. This represents the author’s careful decision to keep the tale Dirac told about his childhood separate from — even as it overshadows — the rest of the book, and it ends with Hofer’s thoughts, not Dirac’s: “ ‘I simply could not conceive of any childhood as dreadful as Dirac’s.’ . . . Could it be that Dirac — usually as literal-minded as a computer — was exaggerating? Hofer could not help asking himself, over and again: ‘Why was Paul so bitter, so obsessed with his father?’ ”
The conflict between this prologue (which gives ample reason for Dirac to be bitter about his father) and the seemingly warm family life that emerges in the first chapter casts a tension over the rest of the book very similar to that felt when reading a mystery. And as in a mystery, the penultimate chapter sheds new light. There Farmelo delves into a sensitive exploration of the possibility that Dirac was autistic, and of the ways in which his lack of facility in reading the emotions of others affected their perceptions of him and his perceptions of them. The emphasis on Dirac’s childhood as a story — one Farmelo (along with me) believes to be true — usefully reinforces the importance of point of view.
In a memorable episode, Dirac and his wife visit their closest friends, Peter and Anna Kapitza, in Russia. In 1934, the long arm of the Soviet state had wrenched Kapitza, despite his devoted long-distance fellow-traveling, away from his lab at Cambridge under Ernest Rutherford and back into the Soviet Union. In 1937 the friends reunited at the Kapitzas’ summer house in the piney woods of Bolshevo, “with wild strawberries ripe for gathering and a fast-flowing river close by.” They arrived only “days before Stalin authorized the torture of suspected enemies of the people,” Farmelo writes. “On the roads around Bolshevo, some of the trucks marked ‘Meat’ and ‘Vegetables’ hid prisoners on their way to be shot and buried in the forests to the north of the city which Dirac admired through his binoculars.”
Farmelo handles such scenes with a refreshing, cleareyed understanding of how complicated the world actually is. Dirac did not — probably could not — know what the Soviet Union really was; he also could not know who his father really was, and his father could not really know him. These complexities and unresolvably cubist perspectives make, paradoxically, for the most satisfying and memorable biography I have read in years.

Louisa Gilder is the author of “The Age of Entanglement: When Quantum Physics Was Reborn,” which will be published in paperback in November.

http://www.nytimes.com/2009/09/13/books/review/Gilder-t.html?ref=books