The Complementary Nature of the Quantum Theory

Abstract

PROF. BOHR has kindly informed me that in the last chapter of my recently published book on quantum mechanics, the reference to his work on the complementary nature of the quantum theory (described in the supplement to NATURE of April 14, pp. 579–590) may perhaps give rise to misunderstanding. When I was last in Copenhagen, in September of the past year, Prof. Bohr was away at the congress in Como, and the views which had been recently developed by Heisenberg and himself were elucidated to me at the Institute for the purpose of this last chapter. In the discussions, use was frequently made of a mode of probability calculation similar to that used in earlier work on the statistical formulation of quantum mechanics, but which appeared to me to be more simple and direct. Prof. Bohr points out that the wording of the chapter may create the impression that these calculations were primarily developed in connexion with the new ideas, whereas they may be said to be characteristic of the whole recent development of the quantum theory. When Prof. Bohr was in Cambridge in November, I happened to have neither the manuscript (then in the press) nor the proof of this chapter (then not yet printed), otherwise this impression would doubtless have been noticed and removed.