Copenhagen

Having annoyingly missed the first showing on BBC4, I was determined to catch the adaptation of Michael Frayn’s play Copenhagen tonight. Well worth the time – it’s a crying shame it’s not already as famous as the seminal Life Story dramatisation of the discovery of the structure of DNA, since it’s clearly in the same league.

Without doing a whole heap of research, I’m not sure sure what to make of the central premise. The play is based around a meeting between Neils Bohr and Werner Heisenberg – two of the prime movers behind quantum theory, and colleagues before war divided them – in Copenhagen, in 1941. Heisenberg was running the German nuclear programme, and he visited his old mentor… why?

Frayn reaches not so much a conclusion as an observation. Had the two of them fallen into their old ways, he posits, they’d have realised that the then-common assumption about the quantity of uranium-235 needed to make a critical mass was false. Had Heisenberg worked out that only about fifty kilogrammes of fissile material was needed, we may now discuss ‘London’ and ‘Paris’ rather than ‘Hiroshima’ and ‘Nagasaki.’ There are, of course, a whole bundle of suppositions in there, but nevertheless it’s a chillingly fascinating thought experiment.

Meanwhile, I’m reminded how much I miss doodling with quantum mechanics. All those Schrödinger equation squiggles, Hermitian operators, psi-squared probability functions. It’s glorious, insane, beautiful, incomprehensible, tantalising stuff, as a model of the world – still the best model we have – flits across the page, always slightly out of reach.

It’s a good thing my copy of Gasiorowicz is 200 miles away, else I’d be flicking through it and reminding myself just how much I’ve forgotten in the last decade.