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Wigner’s friend and relational objectivity

The ‘Wigner’s friend’ thought experiment illustrates the puzzling nature of quantum measurement. Časlav Brukner discusses how recent results suggest that in quantum theory the objectivity of measurement outcomes is relative to observation and observer.

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Fig. 1: Illustration of the two ‘bubbles’: the laboratory of Wigner’s friend and that of Wigner.


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Correspondence to Časlav Brukner.

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Brukner, Č. Wigner’s friend and relational objectivity. Nat Rev Phys 4, 628–630 (2022).

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