Doubts and Hopes in Quantum-Electrodynamics

Abstract

When I have to sum up the results of our conference on quantum-electrodynamics I feel this is an especially difficult task, because here the situation is still worse than in the case of superconductivity. In superconductivity at least the foundations of the theory are safe because we know that the problem is finally to solve the Schrödinger equation for electrons in a cristal. In quantum-electrodynamics however even the foundations are quite uncertain. When I remember the many discussions on electrodynamics there were in the old times with Lorentz, Ehrenfest and Kramers, I feel that it is difficult to keep up with this tradition, and I am almost tempted to quote a sentence by E h r e n f e s t which was not meant too seriously. He emphasized how difficult it always is to explain a subject to an audience, so that the audience can really understand it and he added: “but if one has not understood the probblem oneself then to explain it to the audience in such a way that the audience can understand it — that is really difficult”. This being now more or less the case, I will start with the optimictic side of the problem and later on come to the difficulties and finally I will try to say what hopes one may have in the present situation.

Summarizing address in the final session of the Conference at Leiden, June 26th, 1953, taken from the recording magnetophone tape.