Complementarity Principle

CORE DEFINITION

In quantum mechanics, the complementarity principle (English: Complementarity principle) is a fundamental principle proposed by Niels Bohr in 1927, and is a cornerstone of the Copenhagen interpretation. In different academic fields, the complementarity principle is often used to explain very different phenomena. For these uses, the meaning implied by the complementarity principle is quite different, and the operational mechanisms on which it is based are also completely different. Conceptually, microscopic objects have wave or particle properties, sometimes exhibiting wave properties and sometimes particle properties. Wave properties refer to the fact that the wavelength and frequency of a wave imply that it has extension in both space and time. Particle properties refer to the property that a particle can always be observed to have a definite position and momentum at a certain time and space. When describing the quantum behavior of microscopic objects, both wave and particle properties must be considered. The complementarity principle clarifies that a single concept cannot completely describe the overall quantum phenomenon; to completely describe the overall quantum phenomenon, concepts describing wave and particle properties must be included. These two concepts can be seen as two sides of the same coin. According to Bohr, the wave and particle properties of microscopic objects are complementary.