Consistent Histories and Quantum Measurements

AUG 01, 1999

The traditional Copenhagen orthodoxy saddles quantum theory with embarrassments like Schrödinger’s cat and the claim that properties don’t exist until you measure them. The consistent‐histories approach seeks a sensible remedy.

DOI: 10.1063/1.882775

Robert B. Griffiths

Roland Omnès

Students of quantum theory always find it a very difficult subject. To begin with, it involves unfamiliar mathematics: partial differential equations, functional analysis, and probability theory. But the main difficulty, both for students and their teachers, is relating the mathematical structure of the theory to physical reality. What is it in the laboratory that corresponds to a wavefunction, or to an angular momentum operator? Or, to use the picturesque term introduced by John Bell, what are the “beables” (pronounced BE‐uh‐bulls) of quantum theory—that is to say, the physical referents of the mathematical terms?

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References

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More about the Authors

Robert B. Griffiths. Carnegie‐Mellon University, Pittsburgh, Pennsylvania.

Roland Omnès. University of Paris XI, Orsay, France.