Einstein is dead. To say that he was a genius is commonplace. To compare him with other great scientists is not a great help, for there are so few of the right stature. To assess the importance of his achievements is an impossible task, for only a meagre fifty years have passed since he burst like a volcano on the scientific world; the echoes of that revolution reverberate still. In science, in physics, there has never been anything quite like that year of 1905. It was a time of confusion. For twenty years people had been collecting evidence that the old classical scheme of things had to go. The world was not as simple as the great Victorian physicists, the Maxwells and the Rayleighs, said it was. For Thomson at Cambridge had made electrons; Lorentz in Holland had found it necessary to introduce into the theory of electricity assumptions that were quite unwarrantable then; and Planck, in Germany, had made a revolutionary postulate in his theory of the way in which heat was radiated from hot bodies that gave the right answer for no reason that was apparent. Yet the new generation of scientists was undismayed; it was a time of great adventure; but a time that needed a guiding hand, a unifying imagination. This was Einstein╒s task and achievement. His theory of relativity, for example, made Lorentz╒s assumptions intelligible in terms of much simpler ideas which carried their own conviction. But he did more than make sense out of confusion; he provided the tools, the instructions and the ideas that have guided physicists ever since.
Einstein has often been analysed in one way or another ╤ among scientists the occupation is as common as Shakespearian criticism is elsewhere. Some have sought the sources of his work in Ernst Mach╒s famous book; others have searched his manuscripts for statements that appeared contradictory (and have found surprisingly few); still more have interpreted his work in different ways, making his theories suitable for one application or another. This will go on for many years. Yet he was more than a scientist; he was a humanitarian. His horror of war was born of the delight in human relationships that those who met him remember. This and his conviction that scientific discoveries could be used for the profit of all mankind were so strong that he overcame his distaste for public affairs and became an unofficial elder statesman. He was a pacifist and a Jew and got into trouble with the Kaiser and with Hitler. He was as frank in
his condemnation of certain Russian restrictions on individual freedom as he was when the United States fell sadly short of its liberal traditions. He believed in the international control of atomic energy and continually urged the United States Administration and international bodies of scientists to work towards this end. (There is every reason to suppose that he could not have found a job with the Atomic Energy Commission!) Yet his statements on policy were not characterised by that pontifical smugness that often comes from laboratories. He was a reasonable man and could state his case in reasonable terms. No doubt this quality was as effective as his scientific work in making him so revered wherever science is done. There is a handful of scientists in England who have met him, and a few more who have worked alongside his pupils. Yet all workers everywhere in this vast field have benefited from the awareness that in Princeton there has been this great figure brooding over the progress of science and looking after its place in human affairs. When H. G. Wells died young people recognised that one of their prophets had gone. It will be the same for scientists now.
