Wigner's friend (English, name)
expansion: Wigner's friend
Senses:
topics: human-sciences
natural-sciences
philosophy
physical-sciences
physics
sciences
glosses: The hypothetical observer in a thought experiment in which Wigner, absent when his friend observes the state of a particle (in some versions, Schrödinger's cat) as it collapses from quantum superposition, concludes that both the particle and his friend remain in quantum superposition until Wigner himself learns the result of the observation.
Forms: