KnowraWigner’s friendLinked fromLinked fromThe 8 pages that link to Wigner’s friend, each with the reason it gives.All 8Broader topic 5Related 3Quantum measurementRelated: It asks whether different observers can consistently assign outcomes and quantum states.Copenhagen interpretationBroader topic: It tests whether measurement outcomes can be definite for one observer but indefinite for another.Eugene WignerBroader topic: It probes tensions between quantum measurement and observer-independent descriptions.Measurement problemBroader topic: It probes whether different observers can assign incompatible accounts of a measurement outcome.Relational quantum mechanicsBroader topic: It exposes how different systems can assign different accounts to the same measurement interaction.Schrödinger’s catRelated: It extends the measurement puzzle to observers who disagree about whether an outcome is definite.Wave function collapseRelated: It exposes disagreement over whether collapse depends on an observer's perspective.Quantum BayesianismBroader topic: It tests how QBism handles distinct agents’ accounts of the same measurement event.