Paul Dirac was arguably the greatest British physicist since Newton. Holder of the same chair as Newton (and Stephen Hawking) at Cambridge, he took an unwaveringly mathematical approach to physics despite his engineering background, always stressing the beauty of the equations as paramount. He tends to be remembered for having predicted anti-matter and specifically the positron, but his role in the development of quantum mechanics was much more significant than this alone.
That Dirac is almost unheard of (and seemingly hardly remembered in his home city of Bristol) is very sad – yet in some ways not surprising, given the unremitting lack of communication that seemed to typify his existence. Graham Farmelo’s book is full of examples of Dirac failing to communicate, whether with the general public or with other scientists – even those as great as Richard Feynman – though he does seem to have delivered some effective public lectures.
This is a big, beefy biography, running to 438 pages before you reach the extensive notes. There is plenty of opportunity to get immersed in the Dirac home life in what seems to have been a highly dysfunctional family. Despite his many years of marriage, Dirac never seems to have come to terms with the realities of family life. But family and friends inevitably come second to the man’s science – and Graham Farmelo manages well the difficult task of leading us through the mental minefields of the development of quantum theory, his excursions into relativity and cosmology, and his unremitting distaste for the the need to dispose of infinities in Quantum Electrodynamics, a field where theory managed irritatingly to predict reality more accurately than any other. If anything real opens a view on Dirac, it was his insistence that this match to reality was less important than the ugliness of the approach.
I do have two minor concerns about this book. One is the sheer length. It is too long. I’ve been taken to task before for complaining about fat books, but popular science should not require such sticking power to get the results. The reason for the length seems to be a case of I’ve-got-access-to-the-archives-itis. I know what this feels like. You get fascinated by all the little details in the primary material – and the result is putting much too much detail into the finished book. At least a third of the content could have been cut out with no loss of understanding.
The other slightly unnerving aspect is the way that Farmelo holds off until chapter 30 of 31 before speculating that Dirac could well have been on the autistic spectrum. This is such an obvious deduction that the reader is from early on wondering why it’s not mentioned. Of course we can never be 100 per cent certain looking back at a historical character, but I don’t think I’ve ever seen better indications, and it’s something that should have been more woven into the main text.
These remain small issues, though. This book should be cherished as one of the better scientific biographies -certainly the best of 2009 so far – and gives us an insight into what was the most secretive scientific life of the twentieth century.