Friday, August 10, 2007

"Atom", BBC4, part 3 of 3

The final part of “Atom” was shown last night on BBC4, presented by the estimable Professor Jim Al-Khalili of Surrey University. We started in the 1920s with Paul Dirac’s relativistic theory of the electron, which predicted antimatter (or at least the anti-electron, the positron), which led to Feynman’s and Schwinger’s quantum electrodynamics, the first fully-fledged quantum field theory.

This was extended by Murray Gell-Mann’s theory of quarks, leading to the hyper-accurate Standard Model of quantum mechanics. We briefly digressed to the quantum vacuum and its validation by experimental measurement of the Casimir force (recently in the news again as researchers at St. Andrews University propose to use it for repulsion - in a theoretical study).

Professor Al-Khalili then took us right up to the ‘measurement problem’: what exactly is quantum mechanics telling us about how the universe really is? We heard from David Deutsch (many worlds), Roger Penrose and a representative of the Copenhagen interpretation (impossible to know ... just be happy the calculations turn out right and predict the results of experiments). Jim turned out to be a closet realist, like most of us.

This was, I think, the best programme of the three. The script-writers had more confidence they could leverage the first two programmes so although still super-oversimplified, the programme definitely gave a flavour of the real issues. Congrats to the team.

Just before “Atom” I caught the last hour of “Copenhagen”, the play-turned-into-a-film about the wartime meeting between Werner Heisenberg (of the uncertainty principle), then head of the Nazi atomic research programme, and Niels Bohr, Godfather of quantum physics.

What was the point of the meeting, what were the motives of the two men, what actually took place at all? The programme spiralled around these questions, shaving layers of deception and self-deception. The metaphors of quantum mechanics - superposition, uncertainty - were deployed sensitively, intelligently and appropriately.

Truly a superior piece of work and one which did not talk down to the audience (such a rarity for science-based material on TV).