Wigner's friend

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Named after Hungarian-American physicist Eugene Wigner.


Wigner's friend ‎(plural not attested)

  1. A hypothetical person who performs the Schrödinger's cat thought experiment after Wigner leaves the laboratory, so that Wigner only learns the result from his friend; intended to illustrate the idea that consciousness is necessary to the quantum mechanical measurement process.


Q is for Quantum: Particle Physics from A to Z (1998) by John Gribbin