Noise-induced reduction of wave packets and faster-than-light influences

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.46.6860· OSTI ID:7174113

Stapp, H P ^[1]

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1. Theoretical Physics Group, Physics Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

A simple proof is given of a recent claim [P. Pearle, Phys. Rev. A 39, 2277 (1989)] that appropriately coupled classical white noise reduces wave packets of macroscopic objects. Three difficulties with the classical mechanism are noted. All three are resolved by passing to the quantum analog. The 2.7-K microwave background is effective in some cases. Quantum noise reduces the density matrix of observables, not the wave function itself. The relative merits and liabilities of these two kinds of reduction, called von Neumann reduction and Heisenberg reduction, respectively, are discussed. In this connection a new type of correlation experiment, devised by Hardy [Phys. Rev. Lett. 68, 2981 (1992)] is used to prove a theorem that says, essentially, that any ontological solution of the quantum measurement problem must admit either parallel worlds of the Everett kind or faster-than-light influences of some kind.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7174113
• Journal Information: Physical Review A. General Physics; (United States), Journal Name: Physical Review A. General Physics; (United States) Vol. 46:11; ISSN PLRAAN; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

665400* -- Quantum Physics Aspects of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BACKGROUND RADIATION
DENSITY MATRIX
FLUCTUATIONS
HEISENBERG PICTURE
INHIBITION
MATHEMATICS
MATRICES
MEASURE THEORY
MECHANICS
QUANTUM MECHANICS
RADIATIONS
SIZE
VARIATIONS
WAVE PACKETS