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.

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 Violations of locality and free choice are equivalent resources in Bell experiments

2021 ◽  
Vol 118 (17) ◽  
pp. e2020569118
Author(s):  
Pawel Blasiak ◽  
Emmanuel M. Pothos ◽  
James M. Yearsley ◽  
Christoph Gallus ◽  
Ewa Borsuk
Keyword(s):  
Infinite Number ◽  
Free Choice ◽  
Causal Explanation ◽  
Bell Inequalities ◽  
The Other ◽  
Quantum Mechanical ◽  
Causal Explanations ◽  
Experimental Trial ◽  
Experimental Behavior ◽  
Is Theory

Bell inequalities rest on three fundamental assumptions: realism, locality, and free choice, which lead to nontrivial constraints on correlations in very simple experiments. If we retain realism, then violation of the inequalities implies that at least one of the remaining two assumptions must fail, which can have profound consequences for the causal explanation of the experiment. We investigate the extent to which a given assumption needs to be relaxed for the other to hold at all costs, based on the observation that a violation need not occur on every experimental trial, even when describing correlations violating Bell inequalities. How often this needs to be the case determines the degree of, respectively, locality or free choice in the observed experimental behavior. Despite their disparate character, we show that both assumptions are equally costly. Namely, the resources required to explain the experimental statistics (measured by the frequency of causal interventions of either sort) are exactly the same. Furthermore, we compute such defined measures of locality and free choice for any nonsignaling statistics in a Bell experiment with binary settings, showing that it is directly related to the amount of violation of the so-called Clauser–Horne–Shimony–Holt inequalities. This result is theory independent as it refers directly to the experimental statistics. Additionally, we show how the local fraction results for quantum-mechanical frameworks with infinite number of settings translate into analogous statements for the measure of free choice we introduce. Thus, concerning statistics, causal explanations resorting to either locality or free choice violations are fully interchangeable.

On the Independent Emergence of Space-time

2020 ◽  
pp. 183-194
Author(s):  
Richard Healey
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Gravitational Field ◽  
Physical Theory ◽  
Space Time ◽  
Structural Quality ◽  
Space Time Structure ◽  
Emergent Structure ◽  
Fundamental Physical

Physics might show that space-time is an emergent structure without describing its ontological basis. Space and time are fundamental to metaphysics and physics. Their union remained fundamental after special relativity doomed each separately to fade away as a mere shadow of the space-time that Einstein later took to exist only as a structural quality of the gravitational field of general relativity. But problems meshing general relativity with quantum theory appear to show that space-time structure is not fundamental but emerges within a quantum theory of gravity. In a pragmatist view, quantum theory is typically applied not to represent target systems but to guide rational credence about events involving other systems. Applied to a gravitational field, quantum theory may guide credence about events in an emergent space-time without itself representing that field. If so, a fundamental physical theory would not describe any ultimate ground of space-time and its contents.

Chapter X: Language and the Natural Arts of Space and Time

1980 ◽  
Vol 25 (S1) ◽  
pp. 133-137
Author(s):  
Richard Albert Wilson
Keyword(s):  
Space Time ◽  
Time Sequence ◽  
Time Structure ◽  
The Other ◽  
Thought Process ◽  
Space And Time ◽  
Space Time Structure ◽  
The World ◽  
Actual Space ◽  
Language Issues

‘Behold at last the poet’s sphere!But who,’ I said, ‘suffices here?For, ah! so much he has to do;Be painter and musician too!. . . .No painter yet hath such a way,Nor no musician made, as they;And gather’d on immortal knollsSuch lovely flowers for cheering souls.Beethoven, Raphael, cannot reachThe charm which Homer, Shakespeare, teach.’ARNOLD, Epilogue to Lessing’s Laocoön.Nevertheless, the sensuous sound element does remain as the substratum of articulate language, and as language issues from the lips it issues in the same time sequence as does pure sound, for example, in music. But here is the unique difference which separates language fundamentally from the other four arts. As language issues from the lips, the pure ‘timeness’ of it, as we might say, is immediately transmuted and absorbed in the conventionalized connotation which is arbitrarily given to the differentiated sounds. Hence in the thought-process of intellecting the world by language the actual space-time world is translated first into pure time, that is, into sound, but is immediately, in the very act as it were, retranslated by the conventionalization of sound into its former space-time structure within the world of mind.

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.

Topology knots and hierarchy problem

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Quantum Theory ◽  
String Theory ◽  
Quantum Gravity ◽  
Dimensional Space ◽  
Space Time ◽  
Elementary Particles ◽  
Hierarchy Problem ◽  
Topological Quantum ◽  
Dimensional Space Time ◽  
New Formula

Many approaches to quantum gravity consider the revision of the space-time geometry and the structure of elementary particles. One of the main candidates is string theory. It is possible that this theory will be able to describe the problem of hierarchy, provided that there is an appropriate Calabi-Yau geometry. In this paper we will proceed from the traditional view on the structure of elementary particles in the usual four-dimensional space-time. The only condition is that quarks and leptons should have a common emerging structure. When a new formula for the mass of the hierarchy is obtained, this structure arises from topological quantum theory and a suitable choice of dimensional units.

Probability and Explanation

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
Quantum State ◽  
Causal Explanation ◽  
Born Rule ◽  
Correct Application

We can use quantum theory to explain an enormous variety of phenomena by showing why they were to be expected and what they depend on. These explanations of probabilistic phenomena involve applications of the Born rule: to accept quantum theory is to let relevant Born probabilities guide one’s credences about presently inaccessible events. We use quantum theory to explain a probabilistic phenomenon by showing how its probabilities follow from a correct application of the Born rule, thereby exhibiting the phenomenon’s dependence on the quantum state to be assigned in circumstances of that type. This is not a causal explanation since a probabilistic phenomenon is not constituted by events that may manifest it: but each of those events does depend causally on events that actually occur in those circumstances. Born probabilities are objective and sui generis, but not all Born probabilities are chances.

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