Max Karl Ernst Ludwig Planck, 1858-1947

Abstract

Almost half a century has elapsed since Max Planck’s discovery of the quantum of action, a time sufficiently long to estimate its importance for science and, more generally, for the development of human thought. There is no doubt that it was an event of the first order, comparable with the scientific revolutions brought about by Galileo and Newton, Faraday and Maxwell. Like these it has changed the whole aspect of physics and deeply influenced all neighbouring sciences, from chemistry to biology. Its philosophical implications reach far beyond the epistemology of science itself into the deepest roots of metaphysics. What kind of man was he who initiated this great movement? Apart from his numerous works, papers and books, we have a short Scientific Autobiography which is a great help in the understanding of his motives and his reactions. There are, furthermore, a series of articles published in Naturwissenschaften on the occasion of Planck’s sixtieth birthday, amongst them an excellent biographical one by Sommerfeld. All this valuable material will be used and quoted in the following attempt to give a picture of Planck’s personality. Yet my best help must be the memory of years of personal contact and friendship, which have left an unforgettable impression.