In the Dark

Since getting rid of my telly a few weeks ago I’ve reverted to a previous incarnation as a bookworm, and have been tackling the backlog of unread volumes sitting on my coffee table at home. Over the last couple of days I’ve spent the evenings reading The Strangest Man by Graham Farmelo, a biography of the great theoretical physicist Paul Dirac.

I’m actually quite ashamed that it has taken me so long to get around to reading this. I’ve had it for two years or more and really should have found time to do it before now. Dirac has long been one of my intellectual heroes, for his unique combination of imagination and mathematical rigour; the Dirac equation is one of the topics I most enjoy lecturing about to physics students. I am also immensely flattered to be one of his academic descendants: Paul Dirac was the PhD supervisor of Dennis Sciama, who supervised my supervisor John Barrow, making me (in a sense) his great-grandson. Not that I’ll ever achieve anything of the magnitude he did.

The book is pretty long, and I suppose one of the factors putting me off reading it was that I thought it might be heavy going. That turned out to be far from the case. It’s wonderfully well written, never getting bogged down in details, and cleverly interweaving Dirac’s life and scientific career together against a vivid historical backdrop dominated by the rise of Nazism in Germany and the tragedy of World War 2. It also beautifully conveys the breathless sense of excitement as the new theory of quantum mechanics gradually fell into place. Altogether it’s a gripping story that had me hooked from the start, and I devoured the 400+ pages in just a couple of evenings (which is quick by my standards). I’ve never read a scientific biography so pacey and engaging before, so it’s definitely hats off to Graham Farmelo!

Among the book’s highlights for me were the little thumbnail sketches of famous physicists I knew beforehand mostly only as names. Niels Bohr comes across as a splendidly warm and avuncular fellow, Werner Heisenberg as a very slippery customer of questionable political allegiance (likewise Erwin Schrödinger), Ernest Rutherford as blunt and irascible. I was already aware of the reputation of Wolfgang Pauli had for being an absolute git; this book does nothing to dispel that opinion. We tend to forget that the names we came to know through their association with physics also belonged to real people, with all that entails.

I was also interested to learn that Dirac and his wife Manci spent their honeymoon in 1937, as the clouds of war gathered on the horizon, in Brighton, which Farmelo describes as

..a peculiarly raffish town., famous for its two Victorian piers jutting imperiously out to sea, for the pale green domes of its faux-oriential pavilions, its future-robot and a host of other tacky attractions.

So in most respects it hasn’t changed much, although one of the two piers  has since gone for a Burton.

So what of Dirac himself? Most of what you’re likely to hear about him concerns his apparently cold and notoriously uncommunicative nature. I never met Dirac. He died in 1984. I was an undergraduate at Cambridge at the time, but he had moved to Florida many years before that. I have, however, over the years had occasion to talk to quite a few people who knew Dirac personally, including Dennis Sciama. All of them told me that he wasn’t really anything like the caricature that is usually drawn of him. While it’s true that he had no time for small talk and was deeply uncomfortable in many social settings, especially formal college occasions and the like, he very much enjoyed the company of people more extrovert than himself and was more than willing to talk if he felt he had anything to contribute. He got on rather well with Richard Feynman, for example, although they couldn’t have had more different personalities. This gives me the excuse to include this wonderful picture of Dirac and Feynman together, taken in 1962 – the body language tells you everything there is to know about these two remarkable characters:

Feynman is also an intellectual hero of mine, because he was outrageously gifted not only at doing science but also at communicating it. On the other hand, I suspect (although I’ll obviously never know) that I might not have liked him very much at a personal level. He strikes me as the sort of chap who’s a lot of fun in small doses, but by all accounts he could be prickly and wearingly egotistical.

On the other hand, the more I read The Strangest Man the more I came to think that I would have liked Dirac. He may have been taciturn, but at least that meant he was free from guile and artifice. It’s not true that he lacked empathy for other people, either. Perhaps he didn’t show it outwardly very much, but he held a great many people in very deep affection. It’s also clear from the quotations peppered throughout the book that people who worked closely with him didn’t just admire him for his scientific work; they also loved him as a person. A strange person, perhaps, but also a rather wonderful one.

In the last Chapter, Farmelo touches on the question of whether Dirac may have displayed the symptoms of autism. I don’t know enough about autism to comment usefully on this possibility. I don’t even know whether the term autistic is defined with sufficient precision to be useful. There is such a wide and multidimensional spectrum of human personality that it’s inevitable that there will be some individuals who appear to be extreme in some aspect or other. Must everyone who is a bit different from the norm be labelled as having some form of disorder?

The book opens with the following quote from John Stuart Mill’s On Liberty, which says it all.

Eccentricity has always abounded when and where strength of character has abounded; and the amount of eccentricity in a society has generally been proportional to the amount of genius, mental vigor, and courage which it contained. That so few now dare to be eccentric, marks the chief danger of the time.

Another thought occurred to me after I’d finished reading the book. Dirac’s heyday as a theoretical physicist was the period 1928-1932 or thereabouts. Comparatively speaking, his productivity declined significantly in later years; he produced fewer original results and became increasingly isolated from the mainstream. Eddington’s career followed a similar pattern: he did brilliant work when young, but subsequently retreated into the cul-de-sac of his Fundamental Theory. Fred Hoyle is another example – touched by greatness early in his career, but cantankerous and blinded by his own dogma later on. Even Albert Einstein, genius-of-geniuses, spent his later scientific life chasing shadows.

I think there’s a tragic inevitability about the mid-life decline of these geniuses of theoretical physics, because the very same determination and intellectual courage that allowed them to break new ground also rendered them unwilling to be deflected by subsequent innovations elsewhere. And break new ground Dirac certainly did. The word genius is perhaps over-used, but it certainly applies to Paul Dirac. We need more like him.