Beyond Wavefunctions: A Time-Symmetric Nonlocal Ontology for Quantum Mechanics

Joseph Agassi has won eminence in many branches of philosophy, among them philosophy of physics. He has authored several insightful works on relativity, quantum mechanics and thermodynamics. To his merit is the open-mindedness he exercises in these works. Unlike his illustrious master, Popper, who has dogmatically asserted his semi-classical “propensities theory” (Popper 1983) as a solution to QM’s riddles, Agassi humbly and gracefully pleads ignorance with respect to the latter. His writings are erudite, curious and thought-provoking. In short, he is a true philosopher and teacher. One of us (AE) had the privilege of being his student. Of the two pictures describing quantum mechanics, due to Heisenberg and Schrödinger, it was the latter, based on wave mechanics, which was preferred over the former, which addressed particles and time-dependent operators rather than wave-functions. We revisit Heisenberg’s formalism and show that it has several philosophical advantages over Schrödinger’s. Furthermore, we embed the former within a time-symmetric framework, granting quantum mechanics with a richer underlying structure. Interference and many quantum oddities of the localized particle are accounted for by regarding its nonlocal properties, such as its modular momentum.