Comments on ?quantum theory does not require action at a distance?

1989 ◽  
Vol 2 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Henry P. Stapp
Keyword(s):  
Quantum Theory ◽  
Action At A Distance

“Non-locality”

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
Quantum Entanglement ◽  
Quantum States ◽  
Entangled States ◽  
Entangled Quantum States ◽  
Action At A Distance ◽  
Insight Into ◽  
Non Locality

Quantum entanglement is popularly believed to give rise to spooky action at a distance of a kind that Einstein decisively rejected. Indeed, important recent experiments on systems assigned entangled states have been claimed to refute Einstein by exhibiting such spooky action. After reviewing two considerations in favor of this view I argue that quantum theory can be used to explain puzzling correlations correctly predicted by assignment of entangled quantum states with no such instantaneous action at a distance. We owe both considerations in favor of the view to arguments of John Bell. I present simplified forms of these arguments as well as a game that provides insight into the situation. The argument I give in response turns on a prescriptive view of quantum states that differs both from Dirac’s (as stated in Chapter 2) and Einstein’s.

Bell’s theorem

2018 ◽  
Author(s):  
Arthur Fine
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Experimental Tests ◽  
Bell Inequalities ◽  
Bell’S Theorem ◽  
Bell's Theorem ◽  
Bell Theorem ◽  
System Of Inequalities ◽  
Action At A Distance ◽  
High Degree

Bell’s theorem is concerned with the outcomes of a special type of ‘correlation experiment’ in quantum mechanics. It shows that under certain conditions these outcomes would be restricted by a system of inequalities (the ‘Bell inequalities’) that contradict the predictions of quantum mechanics. Various experimental tests confirm the quantum predictions to a high degree and hence violate the Bell inequalities. Although these tests contain loopholes due to experimental inefficiencies, they do suggest that the assumptions behind the Bell inequalities are incompatible not only with quantum theory but also with nature. A central assumption used to derive the Bell inequalities is a species of no-action-at-a-distance, called ‘locality’: roughly, that the outcomes in one wing of the experiment cannot immediately be affected by measurements performed in another wing (spatially distant from the first). For this reason the Bell theorem is sometimes cited as showing that locality is incompatible with the quantum theory, and the experimental tests as demonstrating that nature is nonlocal. These claims have been contested.

scholarly journals Action at a Distance in Quantum Theory

Mathematics ◽  
2015 ◽  
Vol 3 (2) ◽  
pp. 329-336
Author(s):  
Jerome Blackman
Keyword(s):  
Quantum Theory ◽  
Action At A Distance

scholarly journals Quantum nonlocality and the end of classical spacetime

2016 ◽  
Vol 25 (12) ◽  
pp. 1644005 ◽  
Author(s):  
Shreya Banerjee ◽  
Sayantani Bera ◽  
Tejinder P. Singh
Keyword(s):  
Quantum Theory ◽  
Quantum Nonlocality ◽  
Entangled State ◽  
Problem Of Time ◽  
Spacetime Geometry ◽  
Causality Violation ◽  
Stochastic Fluctuations ◽  
Noncommutative Spacetime ◽  
Action At A Distance ◽  
Noncommutative Quantum

Quantum nonlocal correlations and the acausal, spooky action at a distance suggest a discord between quantum theory and special relativity. We propose a resolution for this discord by first observing that there is a problem of time in quantum theory. There should exist a reformulation of quantum theory which does not refer to classical time. Such a reformulation is obtained by suggesting that spacetime is fundamentally noncommutative. Quantum theory without classical time is the equilibrium statistical thermodynamics of the underlying noncommutative relativity. Stochastic fluctuations about equilibrium give rise to the classical limit and ordinary spacetime geometry. However, measurement on an entangled state can be correctly described only in the underlying noncommutative spacetime, where there is no causality violation, nor a spooky action at a distance.

Conclusion

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
Quantum Entanglement ◽  
Natural Philosophy ◽  
Natural World ◽  
Special Role ◽  
The World ◽  
Action At A Distance ◽  
Quantum Revolution

Quantum theory does not describe the world and so contributes little to natural philosophy: it implies neither that a particle can be in two places at once, that a cat can be neither dead nor alive, that there is instantaneous action at a distance, nor that our observations create the world they reveal. Quantum entanglement does not say that the world is radically holist or non-separable, that the world is indeterministic or deterministic, that mind influences matter, or that consciousness plays a special role in the natural world. But the theory does have lessons to teach about how philosophy should approach topics including causation, probability, laws, composition, and ontology that traditionally fall within metaphysics. Here the quantum revolution reinforces the pragmatist lesson that such topics are best approached by asking why agents like us should have developed the concepts we have when physically situated in a world like this.

Causation and Locality

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
Causal Explanation ◽  
Bell Inequalities ◽  
Space Time ◽  
Counterfactual Dependence ◽  
The Other ◽  
Entangled State ◽  
Space Time Structure ◽  
Action At A Distance ◽  
Time Point

By moving to the context of relativistic space-time structure, this chapter completes the argument of Chapter 4 that we can use quantum theory locally to explain correlations that violate Bell inequalities with no instantaneous action at a distance. Chance here must be relativized not just to time but to a space-time point, so that an event may have more than one chance at the same time—it may even be certain relative to one space-time point but ‘at the same time’ completely uncertain relative to another. This renders Bell’s principle of Local Causality either inapplicable or intuitively unmotivated. Counterfactual dependence between the outcomes of measurements on systems assigned an entangled state is not causal since neither outcome is subject to intervention: but it may still be appealed to in a non-causal explanation of one in terms of the other.

Quantum theory of light in nonlinear media with dispersion and absorption

1998 ◽  
Vol 45 (2) ◽  
pp. 377-402 ◽  
Author(s):  
EDUARD SCHMIDT , JOHN JEFFERS , STEPHEN M.
Keyword(s):  
Quantum Theory ◽  
Nonlinear Media
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