Quantum mechanics stands in conflict with local realism only in its treatment of separated systems. A modification of quantum mechanics that changes the handling of separated systems is suggested that can reconcile quantum mechanics with local realism. An apparent obstacle to this program is the experimental evidence, but I argue that the experiments have been misinterpreted. By way of example, I describe a local realistic account of one important EPRB experiment that is claimed to demonstrate nonlocal entanglement. The local model can be calibrated into both quantum and classical domains via adjustment of parameters of the apparatus. Weihs incorrectly dismisses these parameters as uncritical, whereas we show that device calibration is crucial. When properly interpreted, the experiments show that nonlocal entanglement is an error. The rest of quantum mechanics remains intact, and remains highly valued as a powerful probability calculus for observables. Quantum mechanics and local realism can be reconciled, and they each can offer useful paradigms for describing systems.
Quantum mechanics stands in conflict with local realism only in its treatment of separated systems. A modification of quantum mechanics that changes the handling of separated systems is suggested that can reconcile quantum mechanics with local realism. An apparent obstacle to this program is the experimental evidence, but I argue that the experiments have been misinterpreted. By way of example, I describe a local realistic account of one important EPRB experiment that is claimed to demonstrate nonlocal entanglement. The local model can be calibrated into both quantum and classical domains via adjustment of parameters of the apparatus. Weihs incorrectly dismisses these parameters as uncritical, whereas we show that device calibration is crucial. When properly interpreted, the experiments show that nonlocal entanglement is an error. The rest of quantum mechanics remains intact, and remains highly valued as a powerful probability calculus for observables. Quantum mechanics and local realism can be reconciled, and they each can offer useful paradigms for describing systems.
Accepting nonlocal quantum correlations requires us to reject special relativity and/or probability theory. We can retain both by revising our interpretation of quantum mechanics regarding the handling of separated systems, as quantum mechanics conflicts with local realism only in its treatment of separated systems. We cannot use the joint probability formula for cases of separated measurements. We use the marginals (partial traces) together with whatever priors we have from an understanding of the system. This program can reconcile quantum mechanics with local realism. An apparent obstacle to this program is the experimental evidence, but we argue that the experiments have been misinterpreted, and that when correctly interpreted they confirm local realism. We describe a local realistic account of one important Einstein-Poldosky-Rosen-Bohm (EPRB) experiment (Weihs et al6) that claims to demonstrate nonlocal entanglement. We present a local realistic system (experiment) that can be calibrated into both quantum and classical correlation domains via adjustment of parameters (‘hidden variables’) of the apparatus. Weihs incorrectly dismisses these parameters as uncritical. Nonlocal entanglement is seen to be an error. The rest of quantum mechanics remains intact, and remains highly valued as a powerful probability calculus for observables. Freed from the incoherent idea of nonlocal entanglement, we can leverage powerful classical ideas, such as semiclassical radiation theory, stochastic dynamics, classical noncommutativity/contextuality, measurement effects on state, etc., to augment or complement quantum mechanics. When properly interpreted and applied, quantum mechanics lives in peaceful harmony with the local realist conception, and both perspectives offer useful paradigms for describing systems.
Despite its remarkable success in describing microscopic phenomena, quantum mechanics continues to pose unresolved foundational questions concerning measurement, nonlocality, wavefunction collapse, and the nature of physical reality. These issues were highlighted by the EPR paradox1-2, in which Einstein and his co-authors examined the measurement of entangled particles in space-like separation. Quantum mechanics predicts that measuring one particle’s observable instantaneously determines the state of the other, seemingly violating special relativity’s prohibition of faster-than-light influences and suggesting an incomplete description of physical reality. However, Bell’s theorem3-5, along with the Bell-Kochen-Specker theorem6-10 and subsequent experiments, has largely ruled out local hidden variable theories. In this work, I apply the quantum decoherence framework11-13, pioneered by Zeh, Zurek, Joos and Leggett et al. to analyze an EPR-like system using system-environment interactions as a measurement model. I demonstrate that measurement on one entangled particle does not instantaneously collapse the system's wavefunction. Instead, the local wavefunctions of the measured particle and its environment evolve dynamically, while the remote particle’s wavefunction remains unchanged. Environment-induced decoherence selects pointer states and rapidly suppresses quantum correlations through local interactions, giving rise to the appearance of wavefunction collapse. These findings suggest that quantum mechanics can be reconciled with local realism if the wavefunction is treated as an ontic entity, offering a potential path toward a locally realistic quantum theory in alignment with Einstein’s vision.
Experimental measurements of entangled photons have enabled effective probing of foundational principles of physical law, Quantum Mechanics (QM) in particular. When it was noted that QM is non-local and precludes certain real properties, change in the description of basic phenomena was required. Bell's Inequality work clarified this conflict with Local-Realistic descriptions but left open whether locality, realism, or both should be abandoned. More recent investigations consider models that maintain forms of non-local realism as alternatives to QM. Problems with those are illustrated here, and support a non-local QM description of entangled photons having non-determinate properties.
An open letter to Bellians and the Annals of Physics' Editors re -- it's a proven scientific fact: a violation of local realism has been demonstrated theoretically and experimentally -- after AoP (2016:67). EPR (1935) famously argue that additional variables will bring locality and causality to QM's completion; we show that they are right. Even more famously, Bell (1964) cried ‘impossible' against such variables; we give the shortest possible refutation of his claims. With EPR-based variables (and without QM), an old thought-experiment delivers a commonsensical locally-causal account of EPRB and GHZ in 3-space. We then name the flaw in Bell's theorem – Bell's error -- Bell's 1964:(14a) ≠ Bell's 1964:(14b) under EPRB. Thus, given Bell's (1988:88) gloss on a snippet of von Neumann's work, ‘There's nothing to Bell's theorem -- nor variants like CHSH (1969), Mermin (1990), Peres (1995) -- it's not just flawed, it's silly; not merely false but foolish.' In short, we show that the whole Bellian canon -- with its no-name brand of local realism -- is all of those, and misleading too. Under EPR, mixing common-sense with undergrad math/physics in the classical way so favored by Einstein, we interpret QM locally and realistically. We thus define a new brand of local realism -- CLR, commonsense local realism -- the union of local-causality (no causal influence propagates superluminally) and physical-realism (some physical properties change interactively). Long may EPR rule OK we say.
Eschewing naive realism, we define true (classical/quantum) realism:= some existents (ie, some Bell-beables) may change interactively. We then show that Bell's mathematical ideas re local causality—from his 1964:(1)-(2) to his 1990a:(6.9.3)—are valid under true realism. But we refute Bell's analyses (and his ‘local realism’), as we resolve his consequent ‘action-at-a-distance’ dilemma in favor of true locality:= no influence propagates superluminally. In short: defining beables by properties and values—and allowing that locally-causal interactions may yield new beables—we predict the probabilities of such interaction outcomes via equivalence-classes that are weaker (hence more general) than the corresponding classes in EPR/Bell. In this way delivering the same results as quantum theory and experiment—using EPRB, CHSH, GHZ and 3-space—we also advance QM's reconstruction in spacetime with a new vector-product for geometric algebra. True local realism thus supports local causality, resolves Bell's dilemma, negates nonlocality, demystifies QM, rejects naive realism, eliminates the quantum/classical divide (since observables are clearly beables; being or not being, prior to an interaction, but certainly existing thereafter), etc: all at the level of undergraduate math and logic, and all contra the analyses and impossibility-claims of Bell and many others. We also show that Bayes' Law and Malus' Law hold, undiminished, under true local realism and the quantum.
Bell's theorem, and inequalities that stem from it, address the conflict between the explanation of key experimental observations by quantum mechanics (QM) and by models expressing Locally Realistic (LR) properties, regardless of their inclusion or exclusion of hidden variables. To demonstrate the conflict between experimental results described by QM and LR models, a physical realization of the quantum state must be chosen. Entangled photons or electrons provide the most viable choices. In this work we consider a simplified version of a Bell inequality (BI) that focuses entirely on the physical state properties of photons in order to demonstrate the difference between QM and LR correlations. While the experiment we propose is in principle similar in intent to prior Bell inequality experiments, our version requires fewer measurements, and is more advantageous in its conceptual clarity.