Foundations of Quantum Theory and Complementarity

Abstract

Complementarity denotes the logical relation between concepts which are mutually exclusive, and which therefore cannot be considered at the same time because that would lead to logical mistakes, but which nevertheless must both be used in order to give a complete description of the situation. The conception of complementarity as an extension of concepts of natural phenomena is discussed. It is pointed out that atomic structures may be described in terms of macroscopic concepts by describing the atomic system in terms of the motions of its parts, or by describing such quantities as volume, pressure, temperatare, and entropy, which are related to the laws of thermodynamics. Between these two modes of description there is a relation of complementarity. The author postulates that this complementarity can be formulated in a more general and precise way in a wide-going analogy with the case of quantum mechanics by setting up reciprocal relations between the statistical fluctuations affecting macroscopic quantities. It is pointed out that the reciprocal limitation of the dynamical and thermodynamical modes of description has nothing to do with the quantum of action, and the similarity of the two cases is on the logical level only, since physically they are completely independent.more » The atomistic view of the world involves in its description two stages of complementarity. The first and most fundamental occurs in the account of the properties of individual atomic systems, and the second when the behavior of systems of large numbers of atoms are described. (C.H.)« less