Quantum Theory and Gravitation [1966a]

Abstract

The incorporation of gravitation into a general quantum theory of fields is an open problem, because the necessary empirical clues for deciding the question of the quantization of the gravitational field are missing. It is not so much a matter here of the mathematical problem of how one should develop a quantum formalism for gravitation, but rather of the purely empirical question, whether the gravitational field — and thus also the metric — evidences quantum-like features. In the absence of relevant observations, we can only attempt to shed light on such a question from the epistemological side; and we cannot hope thereby to reach any sort of final conclusions, since epistemological considerations can indeed help in investigating the logical structure of a given theory, but not its conformity to phenomena.

A talk at the Einstein Symposium of November 2–5, 1965, in Berlin.