The Nature of Time in Relativistic Operational Reality

Abstract

Abstract In their recent articles Gruber, Block and Montemayor (2022: Front. Psychol., 13, 718505) and Buonomano and Rovelli (2022: arXiv:2110.01976) discuss the differences between time in physics and psychology. With the aim of commenting on their views, we first outline a few general aspects of relativity theory, and some of the core elements of our approach, referring the reader to Aerts (1996: Found. Phys., 26, 1627–1644; 2018: Found. Sci., 23, 511–547), Aerts and Aerts (2004: in A. C. Elitzur, S. Dolev and N. Kolenda (Eds), Quo Vadis Quantum Mechanics? Possible Developments in Quantum Theory in the 21st Century, pp. 153–207) and Aerts and Sassoli de Bianchi (2023: arXiv:2307.04764) for more details. In our approach, the ability of the experimenter to freely choose to perform or not to perform an experiment is explicitly considered and applied to the typical twin-paradox situation. This leads to the definition of a four-dimensional spacetime reality for each observer, a personal block universe. This is compatible with the existence of a local contextual present for each observer, travelling on their worldline, from their personal past to their personal future. Global spacetime becomes, as a corollary, a structure full of measurement-induced bifurcations towards the future, thus fundamentally nondeterministic. We analyze and highlight how this nondeterministic global reality is the one that follows from an operational approach inspired by quantum foundations, opening a way for an integration of relativity and quantum.