Friday, 16 March 2012

Dirac story

"[Pierre] Ramond had met Dirac twice before, but had not been able to draw him into anything resembling a normal conversation. 'I had heard that the only way to persuade Dirac to talk was to ask him a non-trivial question that required a direct answer,' Ramond recalls. So he asked Dirac directly whether it would be a good idea to explore high-dimensional field theories, like the ones he had presented in his lecture.

Ramond braced himself for a long pause, but Dirac shot back with an emphatic 'No!' and stared anxiously into the distance. Neither man moved, neither sought eye contact; they both froze in a silent stand-off. It lasted several minutes. Dirac broke it when he volunteered a concession: 'It might be useful to study higher dimensions if we're led to them by beautiful mathematics.' Encouraged, Ramond saw an opportunity: doing his best to sound understanding, he invited Dirac to give a talk on his ideas at Gainesville any time he liked, adding that he would be glad •to drive him there and back. Dirac responded instantly: 'No! I have nothing to talk about. My life has been a failure!'

Ramond would have been less stunned if Dirac had smashed him over the head with a baseball bat. Dirac explained himself without emotion: quantum mechanics, once so promising to him, had ended up unable even to give a proper account of something as simple as an electron interacting with a photon - the calculations ended up with meaningless results, full of infinities. Apparently on autopilot, he continued with the same polemic against renormalisation he had been delivering for some forty years. Ramond was too shocked to listen with any concentration. He waited until Dirac had finished and gone quiet before pointing out that there already existed crude versions of theories that appeared to be free of infinities. But Dirac was not interested: disillusion had crushed his pride and spirit.

Dirac said goodbye and walked off, looking impassive, but Ramond was shattered. He took the elevator to the ground floor and walked alone in the fading light of the afternoon back to his car. Twenty-five years later, he could still recall how upset he was: 'I could hardly believe that such a great man could look back on his life as a failure. What did that say about the rest of us?'"

"The Strangest Man - The Hidden Life of Paul Dirac Quantum Genius"
by Graham Farmelo pages 408-409



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