Retroactive Event Determination and the Interpretation of Macroscopic Quantum Superposition States in Consistent Histories and Relational Quantum Mechanics

Abstract

The concept of “objective reality” is addressed, and an ontological model is suggested, in which correlations of events in the configuration space of the wave function are considered invariant with respect to changes of observer. It is suggested that these statements make the best sense when considered from within a fifth-dimensional framework, extrapolated from the four dimensions of spacetime in a direct way. A pair of postulates is then suggested which strengthens two current models of quantum theory into a broader picture, giving a physical interpretation of Macroscopic Quantum Superposition (MQS) states. Relational Quantum Mechanics (RQM) from Rovelli and Consistent Histories (“CH”) from Griffiths are discussed and related to the postulates. By dropping the assumption that unobserved macroscopic events are “in a definite state” determined independently of an observer, a surprising but consistent theory of quantum macroscopic reality is arrived at (with fewer fundamental assumptions about everyday reality) that does not contradict experiment or everyday experience. As a result, a concept herein termed “retroactive event determination” is extended from a quantum principle (in CH) to a macroscopic principle. Macroscopic events that have not been observed by a particular observer are free to be retroactively determined. The feasibility of applying the physics of quantum operators to macro systems is analyzed using the concept of “macro projectors.” Various concerns with this model are addressed, such as solipsism and decoherence of the wave function for macro objects. A discussion is also made of the philosophical context of the ideas suggested. Some experimental ideas are offered.

Keywords: Macroscopic quantum superposition—MQS—consistent histories—relational quantum mechanics—time—spacetime—retrocausation—framework—single-framework rule—macro pointers—synchronicity—meaningful coincidence—positivism—observer effect—measurement problem—delayed choice experiment—retroactive event determination—existential behavior—Many-Worlds model