Niels Bohr’s Times, In Physics, Philosophy, and Polity
As Abraham Pais makes clear in his careful study, many of the scientists who encountered Niels Bohr even briefly came away with a remarkable impression. My own took place in 1958, when new elementary particles were appearing, in a bewildering profusion, from both cosmic rays and accelerator experiments. These were pre-quark days, so there was no theoretical model within which to fit this unexpected data. Things were so desperate that J. Robert Oppenheimer—I think he was kidding—suggested that a Nobel-like prize be given to an experimental physicist who did not discover a new particle.
In the confusion, a rumor arrived at The Institute for Advanced Study in Princeton, where I was then working, that Werner Heisenberg and Wolfgang Pauli had discovered a Theory of Everything. Each generation of theoretical physicists thinks it has discovered a Theory of Everything. By this time, Heisenberg’s physics were thought to be a bit over the hill, but Pauli, who died in 1958, was still considered one of the most brilliant and skeptical theoretical physicists who had ever lived. When Pauli said, as he occasionally did, that a paper was so bad that it was not even wrong, it generally sank without a trace. That Pauli had taken part in such an enterprise gave people pause.
Pauli was invited to lecture on his work with Heisenberg at Columbia University in late January 1958. A group of us came to New York from Princeton to hear him. I recall sitting next to Freeman Dyson during the lecture. Not long after the talk began, Dyson said to me, “It is like watching the death of a noble animal.” He had seen at once that the new theory was hopeless. What none of us then knew was that Pauli was to die of cancer a few months later. Before his death he turned against the theory and was circulating a cartoon, of his own devising, which showed only a blank canvas and a caption, in Heisenberg’s voice, which read, “I can paint like Titian—only a few details are missing.”
Niels Bohr was also at the lecture, a big man who reminded me of a Saint Bernard, dressed in an elegant dark suit with a vest. After Pauli had finished his lecture, Bohr was called upon to comment. I believe it was Pauli who remarked, perhaps in jest, that the theory may, at first, look “somewhat crazy.” Bohr then replied that the problem was that it was not crazy enough. Unlike quantum mechanics, say, it did not have the divine madness of great physics. At this point, Pauli and Bohr began stalking each other around the large demonstration table in front of the lecture hall. When Pauli appeared in front of the table he would say to the audience that the theory was sufficiently crazy, and when it was Bohr’s turn to stand in front of the table, he would say it wasn’t. The encounter of two of the giants of modern …