C.P. Snow had an unusually wide range of interests and many different talents, but he probably was at his best in crisply summing up people and situations. I recall from my own experience the occasions when he used to visit the universities during the war, with his friend and assistant William Cooper, to decide the fate of students about to graduate in science. Each student had to be assigned to some branch of the armed services, or to a research project of military importance, or perhaps to further research training. On the strength of the paper record and a two-minute interview, he would give a thumbnail sketch of the personality and ability of the student, which usually could not be improved upon the teachers who had known the student for years.
The same power of characterizing real people, a talent which is quite distinct from the ability to make fictional characters come alive, showed up in his biographical essays, for example about Einstein, or about the mathematician G.H. Hardy. But he did not, as far as I am aware, produce a book of such portraits.
When he died in 1980 he had been working on a book that would describe a half-century of physics and some of the leading characters in it. He was able to complete only a first draft, which has now been published. We are not given the name of an editor, but from remarks in the introduction by William Cooper it appears that he was responsible for arranging the text for publication.
The drama of twentieth-century physics, which Snow presents, comes in several acts. Up to the end of the nineteenth century physicists had not regarded the structure of matter as their problem. One knew there were atoms, but their nature was the chemist’s problem, if anybody’s. The beginning of the new attitude came with the discovery of the electron, and the realization that the laws of mechanics could be applied to its behavior within the atom. From then on atoms and what went on in them became the physicists’ main preoccupation. With improved tools experimental discoveries led to a rapidly growing body of information about the atom, one of the crucial steps, which Snow describes at the start of the book, being Rutherford’s discovery of the atomic nucleus as the center of the atom, with the electrons orbiting around it.
But the new-found knowledge did not fit in with the laws of physics as they had developed since the time of Isaac Newton, and the resolution of these contradictions required the acceptance of revolutionary new concepts. These came through Einstein’s theory of relativity, and through the quantum theory of Max Planck (whom Snow barely mentions), Einstein, and Niels Bohr. At first the quantum theory was a makeshift affair, grafting ad hoc rules on to the old mechanics, and it was only in the late Twenties that a drastic revision of the most fundamental concepts about space and motion led …