It has been advocated by Bell and Bohm that the Einstein-Podolsky-Rosen (EPR) correlations are mediated through faster-than-light (FTL) interactions. In a previous paper a way to avoid causal paradoxes derived from this FTL hypothesis (via the breakdown of Lorentz symmetry) has been suggested. Lorentz transformations would remain valid, but there would be no equivalence between active and passive Lorentz transformations in the case of EPR correlations. Some counterintuitive consequences of this assumption are briefly examined here.
It has been advocated by Bell and Bohm that the Einstein-Podolsky-Rosen (EPR) correlations are mediated through faster-than-light (FTL) interactions. In a previous paper a way to avoid causal paradoxes derived from this FTL hypothesis (via the breakdown of Lorentz symmetry) has been suggested. Lorentz transformations would remain valid, but there would be no equivalence between active and passive Lorentz transformations in the case of EPR correlations. Some counterintuitive consequences of this assumption are briefly examined here.
The possible connection between EPR correlations and superluminal interactions, as suggested by Bell and Bohm, is discussed using simple and palpable arguments: (a) It is shown how an experiment based on time-like events can allow us to answer the question "Can a measurement performed on one of the photons of an entangled pair change the state of the other?" (b) The theorem on superluminal finite-speed causal influences and superluminal signaling, introduced by Scarani and Gisin, is reexamined. (c) It is shown how faster-than-light interactions and Lorentz transformations might peacefully coexist.
The best case for thinking that quantum mechanics is nonlocal rests on Bell's Theorem, and later results of the same kind. However, the correlations characteristic of Einstein–Podolsky–Rosen (EPR)–Bell (EPRB) experiments also arise in familiar cases elsewhere in quantum mechanics (QM), where the two measurements involved are timelike rather than spacelike separated; and in which the correlations are usually assumed to have a local causal explanation, requiring no action-at-a-distance (AAD). It is interesting to ask how this is possible, in the light of Bell's Theorem. We investigate this question, and present two options. Either (i) the new cases are nonlocal too, in which case AAD is more widespread in QM than has previously been appreciated (and does not depend on entanglement, as usually construed); or (ii) the means of avoiding AAD in the new cases extends in a natural way to EPRB, removing AAD in these cases too. There is a third option, viz., that the new cases are strongly disanalogous to EPRB. But this option requires an argument, so far missing, that the physical world breaks the symmetries which otherwise support the analogy. In the absence of such an argument, the orthodox combination of views—action-at-a-distance in EPRB, but local causality in its timelike analogue—is less well established than it is usually assumed to be. 1 Introduction 1.1 Background 1.2 Outline of the argument2 The Experiments 2.1 Standard EPRB 2.2 Sideways EPRB 2.3 Comparing the experiments 2.4 The need for beables3 The Symmetry Considerations 3.1 The action symmetry 3.2 Time-symmetry in SEPRB4 The Basic Trilemma 4.1 An intuitive defence of Option III?5 Avoiding the Trilemma?6 The Classical Objection7 Defending Option III 7.1 The free will argument 7.2 Independence and consistency8 Entanglement and Epistemic Perspective
The long-standing puzzle of the nonlocal Einstein-Podolsky-Rosen correlations is resolved. The correct quantum mechanical correlations arise for the case of entangled particles when strict locality is assumed for the probability amplitudes instead of locality for probabilities. Locality of amplitudes implies that measurement on one particle does not collapse the companion particle to a definite state. Sixty five years ago, the most significant paper questioning a fundamental aspect of quantum phenomena was written by Einstein, Podolsky and Rosen (EPR) [1]. They addressed the question whether the wave-function represented a complete description of reality in quantum mechanics, and argued that it didn’t. Bohr’s reply to this paper [2] was not sufficient to resolve the fundamental issues raised by EPR. Decades later, Bohm rephrased the EPR problem [3] in terms of particles correlated in their spin and this helped enormously in analyzing the problem with clarity. John Bell analyzed the EPR problem in the early sixties and established the Bell’s inequalities obeyed by
Most physicists agree that the Einstein–Podolsky–Rosen–Bell paradox exemplifies much of the strange behavior of quantum mechanics, but argument persists about what assumptions underlie the paradox. To clarify what the debate is about, we employ a simple and well-known thought experiment involving two correlated photons to help us focus on the logical assumptions needed to construct the EPR and Bell arguments. The view presented in this paper is that the minimal assumptions behind Bell’s inequality are locality and counterfactual definiteness but not scientific realism, determinism, or hidden variables as are often suggested. We further examine the resulting constraints on physical theory with an illustration from the many-worlds interpretation of quantum mechanics—an interpretation that we argue is deterministic, local, and realist but that nonetheless violates the Bell inequality.
Quantum entanglement, a quintessential feature of quantum mechanics, has profound implications on our understanding of the fundamental nature of reality. This phenomenon, in which quantum particles exhibit correlations that defy classical intuition, has captivated physicists and philosophers alike. The existence of nonlocal correlations, a hallmark of entanglement, challenges the principles of local realism and calls into question our notions of causality and locality. This paper explores the theoretical foundations, experimental evidence, and interpretations surrounding quantum entanglement and nonlocal correlations. It delves into the historical context, highlighting the pioneering work of physicists such as Einstein, Podolsky, Rosen, and Bell, whose contributions paved the way for our current understanding of this enigmatic concept. The paper also examines the potential applications of entanglement in fields such as quantum computing, cryptography, and communication, underscoring its technological significance. Furthermore, it discusses the philosophical implications of nonlocal correlations, shedding light on the ongoing debates surrounding the interpretation of quantum mechanics and the nature of reality itself. Keywords: Quantum entanglement, Nonlocal correlations, Local realism, Causality, Locality, Quantum mechanics, Experimental evidence, Theoretical foundations, Einstein-Podolsky-Rosen (EPR) paradox, Bell's theorem, Quantum computing.