Quantum measurements with, and yet without an Observer

Abstract

It is argued that Feynman's rules for evaluating probabilities, combined with von Neumann's principle of psycho-physical parallelism, help avoid inconsistencies, often associated with quantum theory. The former allows one to assign probabilities to entire sequences of hypothetical Observers' experiences, without mentioning the problem of wave function collapse.The latter limits the Observer's (e.g., Wigner's friend's) participation in a measurement to the changes produced in material objects,thus leaving his/her consciousness outside the picture.

References in corpus (3)

• Respecting One's Fellow: QBism's Analysis of Wigner's Friend
• Wigner Friend scenarios with non-invasive weak measurements
• Wigner's friend, Feynman's paths and material records

Cited by in corpus (4)

• Extended Wigner's friend problem and the internal consistency of standard quantum mechanics
• Speakable and unspeakable in quantum measurements
• Wigner's friends, tunnelling times and Feynman's "only mystery of quantum mechanics"
• Unitary evolution and elements of reality in consecutive quantum measurements