- Basil J. Hiley
Standard quantum mechanics, in the hands of von Neumann, makes the assumption that the ► wave function, ψ(r, t), provides the most complete description of state of an evolving system. It then uses the Born probability postulate (► Born rule) and assumes that the probability of finding the system at position r at time t is given by P = |ψ(r, t)|2. This gives an essentially statistical theory, ► probability interpretation but a statistical theory unlike those found in classical situations where all the dynamical variables such as position, momentum, angular momentum etc., are well defined but unknown.
The dynamical variables of a quantum system are determined by the eigenvalues of operators called ► ‘observables’. Given a quantum state, not all the dynamical variables have simultaneous values. For example, if the position is sharply defined, then the momentum is undefined and vice-versa. In other words there exist sets of complementary variables such that if one set are well defined, the other set are completely undefined. This is the feature that underlies the ► Heisenberg uncertainty principle.
- Hidden Variables
- Book Title
- Compendium of Quantum Physics
- pp 284-287
- Print ISBN
- Online ISBN
- Springer Berlin Heidelberg
- Copyright Holder
- Springer-Verlag Berlin Heidelberg
- Additional Links
- Industry Sectors
- Editor Affiliations
- 1. Department of Physics, The City College of New York
- 2. Section for the History of Science & Technology, University of Stuttgart
- 3. Department of Social Sciences and Humanities, University of Bradford
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