In reply to the reciprocal question, Beard said he was a theoretical physicist. It always sounded like a lie. The sculptor paused, perhaps to rehearse mentally his English, then asked a surprising question. Señor Beard was to excuse an uneducated man’s naïvety and ignorance, but was the strange reality described by quantum mechanics a description of the actual world, or was it simply a system that happened to work? Infected by the Mallorcan’s courtly style, Beard complimented him on the question. He could not have phrased it better himself, for there was no better interrogation of quantum theory than this. It was a matter that had dominated years of Einstein’s life and led him to insist that the theory was correct but incomplete. Intuitively, he just could not accept that there was no reality without an observer, or that this reality was defined by the observer, as Bohr and the rest seemed to be saying. In Einstein’s memorable phrase, there was out there a ‘real factual situation’. ‘When a mouse observes,’ he had once asked, ‘does that change the state of the universe?’ Quantum mechanics seemed to imply that a measurement of the state of one particle could instantaneously determine the state of another, even if it was far away. But this was ‘spiritualistic’ in Einstein’s view, it was ‘spooky action at a distance’, for nothing could move faster than the speed of light. Beard the realist was sympathetic to Einstein’s extended, failing battle with the brilliant coterie of quantum pioneers, but it had to be faced: the experimental proof suggested that there really could be long-range spooky correlations, and that the texture of reality at the small and large scale really did defy common sense. Einstein was also convinced that the mathematics needed to describe the universe would ultimately be shown to be elegant and relatively simple. But even in his lifetime, two new fundamental forces had been found, and ever since, the view had been complicated by a messy array of new particles and antiparticles, as well as various imaginary dimensions and all kinds of untidy accommodations. But Beard still clung to the hope that as yet more was revealed, a genius would arise to propose an overarching theory binding all in a formulation of astounding beauty. After many years (this was his little joke as he placed a confiding hand on Jesus’s frail arm), he had finally given up hopes of being the mortal chosen to find this grail.
Ian McEwan, Solar.