Entropy ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 759
Author(s):  
Frank Lad

I reassess the gedankenexperiment of Greenberger, Horne, Shimony, and Zeilinger after twenty-five years, finding their influential claim to the discovery of an inconsistency inherent in high dimensional formulations of local realism to arise from a fundamental error of logic. They manage this by presuming contradictory premises: that a specific linear combination of four angles involved in their proposed parallel experiments on two pairs of electrons equals both π and 0 at the same time. Ignoring this while presuming the contradictory implications of these two conditions, they introduce the contradiction themselves. The notation they use in their “derivation” is not sufficiently ornate to represent the entanglement in the double electron spin pair problem they design, confounding their error. The situation they propose actually motivates only an understanding of the full array of symmetries involved in their problem. In tandem with the error now recognised in the supposed defiance of Bell’s inequality by quantum probabilities, my reassessment of their work should motivate a reevaluation of the current consensus outlook regarding the principle of local realism and the proposition of hidden variables.


Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1660
Author(s):  
Philippe Grangier

It is known that “quantum non locality”, leading to the violation of Bell’s inequality and more generally of classical local realism, can be attributed to the conjunction of two properties, which we call here elementary locality and predictive completeness. Taking this point of view, we show again that quantum mechanics violates predictive completeness, allowing the making of contextual inferences, which can, in turn, explain why quantum non locality does not contradict relativistic causality. An important question remains: if the usual quantum state ψ is predictively incomplete, how do we complete it? We give here a set of new arguments to show that ψ should be completed indeed, not by looking for any “hidden variables”, but rather by specifying the measurement context, which is required to define actual probabilities over a set of mutually exclusive physical events.


Author(s):  
Yu Shi ◽  
Ji-Chong Yang

Abstract Bell inequalities are consequences of local realism while violated by quantum mechanics. In particle physics, entangled high energy particles can be produced from a common source, and the decay of each particle plays the role of measurement. However, in a hidden variable theory, the decay could be determined by hidden variables. This loophole killed such approaches to Bell test in particle physics. It is a special form of measurement-setting or free-will loophole, which also exists in other systems. Using entangled baryons, we present new inequalities of local realism with the explicit assumption of the dependence of the decays on hidden variables, as well as the consideration of the statistical mixture of polarizations and the separation of local hidden variables for objects with spacelike distances. These violations closes the measurement-setting loophole once and for all. We propose to use the processes $$\eta _c\rightarrow \varLambda {\bar{\varLambda }}$$ηc→ΛΛ¯ and $$\chi _{c0} \rightarrow \varLambda {\bar{\varLambda }}$$χc0→ΛΛ¯ to test our inequalities, and show that their violations are likely to be observed with the data already collected in BESIII.


Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 87 ◽  
Author(s):  
Gilles Brassard ◽  
Paul Raymond-Robichaud

We carry out a thought experiment in an imaginary world. Our world is both local and realistic, yet it violates a Bell inequality more than does quantum theory. This serves to debunk the myth that equates local realism with local hidden variables in the simplest possible manner. Along the way, we reinterpret the celebrated 1935 argument of Einstein, Podolsky and Rosen, and come to the conclusion that they were right in their questioning the completeness of the Copenhagen version of quantum theory, provided one believes in a local-realistic universe. Throughout our journey, we strive to explain our views from first principles, without expecting mathematical sophistication nor specialized prior knowledge from the reader.


2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Yu Shi ◽  
Ji-Chong Yang

AbstractIt has been well established that quantum mechanics (QM) violates Bell inequalities (BI), which are consequences of local realism (LR). Remarkably QM also violates Leggett inequalities (LI), which are consequences of a class of nonlocal realism called crypto-nonlocal realism (CNR). Both LR and CNR assume that measurement outcomes are determined by preexisting objective properties, as well as hidden variables (HV) not considered in QM. We extend CNR and LI to include the case that the measurement settings are not externally fixed, but determined by HV. We derive a new version of LI, which is then shown to be violated by entangled $$B_d$$ B d mesons, if charge–conjugation–parity (CP) symmetry is indirectly violated, as indeed established. The experimental result is quantitatively estimated by using the indirect CP violation parameters, and the maximum of a suitably defined relative violation is about $$2.7\%$$ 2.7 % . Our work implies that particle physics violates CNR. Our LI can also be tested in other systems such as photon polarizations.


2020 ◽  
Vol 75 (3) ◽  
pp. 265-293
Author(s):  
Paul Giles

Paul Giles, “‘By Degrees’: Jane Austen’s Chronometric Style of World Literature” (pp. 265–293) This essay considers how Jane Austen’s work relates to “World Literature” by internalizing a chronometric style. Examining the emergence of the chronometer in the eighteenth century, it suggests how Austen drew on nautical frames of reference to combine disparate trajectories of local realism, geographical distance, and historical time. The essay thus argues that Austen’s fiction is interwoven with a reflexive mode of cartographic mapping, one that draws aesthetically on nautical instruments to remap time and space. This style involves charting various fluctuations of perspective that reorder history, memory, and genealogy, while also recalibrating Britain’s position in relation to the wider world. Moving on from an initial analysis of Austen’s juvenilia and early novels, the essay proceeds in its second part to discuss Mansfield Park (1814) in relation to Pacific exploration and trade. In its third part, it considers Emma (1815) in the context of comic distortions and the misreadings that arise from temporal and spatial compressions in the narrative, a form heightened by the novel’s reflexive wordplay. Hence the essay argues that Austen’s particular style of World Literature integrates chronometric cartography with domestic circumstances, an elusive idiom that also manifests itself in relation to the gender dynamics of Persuasion (1817) and the unfinished “Sanditon,” as discussed in the essay’s concluding pages. This is correlated finally with the way Austen’s novels are calibrated, either directly or indirectly, in relation to a global orbit.


1987 ◽  
Vol 54 (4) ◽  
pp. 558-576 ◽  
Author(s):  
Geoffrey Hellman
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