22 Jul 07 Can Quantum-Mechanical Description of Physical Reality be Considered Complete? (2)
- N. Bohr
- Institute for Theoretical Physics, University, Copenhagen
Received 13 July 1935
It is shown that a certain “criterion of physical reality” formulated in a recent article with the above title by A. Einstein, B. Podolsky and N. Rosen contains an essential ambiguity when it is applied to quantum phenomena. In this connection a viewpoint termed “complementarity” is explained from which quantum-mechanical description of physical phenomena would seem to fulfill, within its scope, all rational demands of completeness.
©1935 The American Physical Society
19 Jul 07 Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?
- A. Einstein, B. Podolsky, and N. Rosen
- Institute for Advanced Study, Princeton, New Jersey
Received 25 March 1935
In a complete theory there is an element corresponding to each element of reality. A sufficient condition for the reality of a physical quantity is the possibility of predicting it with certainty, without disturbing the system. In quantum mechanics in the case of two physical quantities described by non-commuting operators, the knowledge of one precludes the knowledge of the other. Then either (1) the description of reality given by the wave function in quantum mechanics is not complete or (2) these two quantities cannot have simultaneous reality. Consideration of the problem of making predictions concerning a system on the basis of measurements made on another system that had previously interacted with it leads to the result that if (1) is false then (2) is also false. One is thus led to conclude that the description of reality as given by a wave function is not complete.
©1935 The American Physical Society
