When Richard Feynman was notified in October 1965 that he was to share that year’s Nobel Prize in Physics, the telegram stated simply that the award was ‘for fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles’. A reporter asked Feynman to tell him in just two sentences what he had actually done. ‘If I could tell you in two sentences,’ Feynman replied, ‘I wouldn’t have won the Nobel Prize.’

Despite being a pioneer in the field, Feynman later admitted, ‘I think I can safely say that nobody understands quantum mechanics.’ In the fifty or so years since, very little has changed, for at the centre of quantum mechanics is the vexed question of what sort of reality