Foundations of Physics

, Volume 18, Issue 9, pp 939–952 | Cite as

Experimental approaches to the quantum measurement paradox

  • A. J. Leggett
Part III. Invited Papers Dedicated To David Bohm


I examine the question of how far experiments that look for the effects of superposition of macroscopically distinct states are relevant to the classic measurement paradox of quantum mechanics. Existing experiments on superconducting devices confirm the predictions of the quantum formalism extrapolated to the macroscopic level, and to that extent provide strong circumstantial evidence for its validity at this level, but do not directly test the principle of superposition of macrostates. A more ambitious experiment, not obviously infeasible with current technology, could provide a direct test between quantum mechanics and a whole class of theories embodying the postulate of realism at the macroscopic level.


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Copyright information

© Plenum Publishing Corporation 1988

Authors and Affiliations

  • A. J. Leggett
    • 1
  1. 1.Department of PhysicsUniversity of Illinois at Urbana-ChampaignUrbana

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