Wigner’s friend thought experiment
E98263
foundational quantum mechanics scenario
interpretation-of-quantum-mechanics problem
philosophy of physics concept
thought experiment
Wigner’s friend thought experiment is a foundational quantum mechanics scenario that explores the role of observers and consciousness in measurement by considering how different observers can assign conflicting quantum states to the same system.
Aliases (2)
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
foundational quantum mechanics scenario
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interpretation-of-quantum-mechanics problem → philosophy of physics concept → thought experiment → |
| addresses |
objectivity of measurement outcomes
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observer relativity of quantum states → quantum measurement problem → |
| coreIdea |
different observers can assign different quantum states to the same physical system
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friend observes a definite outcome while Wigner may still assign a superposed state → tension between unitary evolution and collapse postulate → |
| field |
foundations of quantum mechanics
→
philosophy of physics → quantum mechanics → |
| hasAuthor |
Eugene Wigner
NERFINISHED
→
|
| hasInterpretationImplicationsFor |
collapse theories
→
hidden-variable theories → objective collapse models → subjective Bayesian interpretations → |
| historicalPeriod |
20th century
→
|
| involvesConcept |
conscious observer
→
measurement outcome → observer-relative state assignment → superposition → unitary evolution → wave function collapse → |
| involvesEntity |
Wigner
NERFINISHED
→
Wigner’s friend NERFINISHED → laboratory isolated from Wigner → quantum system in a superposition → |
| mainTheme |
consciousness and quantum measurement
→
measurement problem in quantum mechanics → observer-dependent quantum states → role of observers in quantum measurement → |
| namedAfter |
Eugene Wigner
NERFINISHED
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|
| proposes |
consciousness may play a role in wave function collapse
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|
| questionRaised |
whether all observers must agree on a single set of facts
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whether consciousness is necessary to define measurement outcomes → whether quantum mechanics is universally valid for observers themselves → |
| relatedTo |
Copenhagen interpretation
NERFINISHED
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Everett many-worlds interpretation NERFINISHED → Frauchiger–Renner paradox NERFINISHED → QBism NERFINISHED → Schrödinger’s cat NERFINISHED → relational quantum mechanics → |
| usedInDebatesOn |
consistency of quantum theory for multiple observers
→
objectivity vs subjectivity of quantum states → role of consciousness in physics → status of the wave function → |
Referenced by (3)
| Subject (surface form when different) | Predicate |
|---|---|
|
Eugene Wigner
→
|
knownFor |
|
Eugene Wigner
("Wigner’s friend paradox")
→
|
notableIdea |
|
Erwin Schrödinger
("Schrödinger's cat")
→
|
notableWork |