Beautiful coincidences

I like coincidences. Two days ago a friend recommended to me a BBC Four documentary (‘I never thought I’d say I had a good night in watching BBC Four,’ was his selling line). ‘Beautiful Equations’ does exactly what it says – it takes a look at the role beauty plays in maths. Art critic and artist Matt Collings is an engaging presenter as he investigates Newton and Einstein, quizzes Stephen Hawking on his black hole equations and gets scientists to explain what all those squiggles and numbers are all about. (It's for the general viewer rather than those who know their electrons from their positrons.)

My favourite squiggles were those of the so-called English Einstein, a Bristol-born physicist called Paul Dirac. Working in the first half of the 20th century, and using his own symbolic language, Dirac predicated anti-matter, and was one of the founding father of quantum mechanics. The reason he appeared in this programme was his underlying belief that the pursuit of beautiful equations would reveal the laws of nature. Beauty would be, in the words of Keats, truth, truth beauty. Nowhere was this more obvious than in the 'Dirac Equation' describing wave motions of electrons.

I was intrigued, although baffled by the mathematics. Anonymity was another of Dirac's desires (he had an incredibly literal mind that made social interaction a minefield), but biographer Graham Farmelo has written an acclaimed volume on his life. Time for a quick trip to the shops. I found a copy, and headed to the counter, where a girl in a festive green sparkly dress served me. When she saw what I was buying, her face lit up. 'Dirac. He's my hero!' Slightly surprised, given that I hadn't heard his name until the day before, we got chatting. It turned out that she was a physics student and artist, hence the love of Dirac. But there was another surprise to come.

'The programme talked a lot about the beauty of his mathematics,' I added. The reply: 'Yes, I've got his equation tattooed on my arm!'