Emergence of Objective Reality in an Irreversible Friend thought Experiment

Abstract

Background: Recently some photon models of a Wigner's friend experiment have led investigators to suggest objective reality does not exist, and to publish non-academic articles with such claims. The public is not equipped to evaluate the severe limitations of these experiments. The separation of Wigner from the experiment and use of only reversible coherent processes for the friend allow operations that are not possible in ordinary reality according to the latest quantum research. Methods: We suggest directly testing the implied claim that objective reality, including incoherent objects with irreversible non-destructive memory, can be held in superposition. We suspect it will fail, but provide for a graduated approach that may discover something about the conditions for superposition collapse. To this end we design a thought experiment to model the objective world, investigating under what conditions experimenters in the same world (ensemble member) will be able to record a result and find it does not appear to change. An observer has a viewing apparatus and a memory apparatus. A second uncorrelated viewer of the same recorded result is employed to obtain objectivity. By hypothesis the uncorrelated second viewer obtains the same view of the measurement record as the first observer. There are not two measurements. This is not an investigation of hidden variables. Results: To model the objective world, incoherent and irreversible processes must be included. To test for superposition, coherence has to be established. These seem to present a contradiction. Conclusions: The thought experiment has suggested new places to look other than size for the origin of objective reality from the quantum world, casts doubt on the Many-Worlds interpretation, and provides a method of testing it.

Making Mistakes Saves the Single Observer’s World of the Extended Wigner’s Friend Experiment

“…The legitimacy of the EWF procedure has been questioned [14] [15], respectively under a nonunitary account of quantum state reduction, and decoherence. Indeed, the measurement problem is the only source of contradictions in Bell-type experiments.…”

“…The reader may be tempted at this point to question the validity of Equations ( 14) and (15). If the first qubit is measured (by Alice) it retains its state and instead of ( 14) and ( 15) we would have respectively |h〉|0〉 or ( )…”

“…Although the author considers such an assumption as unrealistic, it is a priori assumed to be correct. However, in this setup Alice's action must be taken into account, as Bob's lab cannot be described by the state (13), which leads us to Equations ( 14), (15), and the 3 rd version of the EWF.…”

“…In order to affect the unitary evolution of such two different quantum registers to bring them both to the entangled state |ψ〉 AB (8), that would be the same regardless of the initial state |ψ〉 h0 (14) or |ψ〉 t01 (15), Alice must use two different variants of some suitable 4 × 4 unitary matrices.…”

“…But what if Alice makes a mistake and applies a "wrong" transformation RA h0 or RA t01 , respectively to the quantum register |ψ〉 t01 (15) or |ψ〉 h0 ( 14)? Assume, for example, that there is no agent (no Alice) performing the "actual" measurement of the first qubit (1) in Alice's isolated lab but just some mechanism applying randomly with a probability p matrix transformation RA h0 and with the probability (1 − p) matrix transformation RA t01 to the initial separable state |ψ〉 h0 or |ψ〉 t01 .…”