In physics, the principle of locality / short-range states that an object is affected only by its immediate environment. Quantum mechanics predicts through Bell's inequalities a direct violation of this principle [1] . showed that quantum entangled particles violate this principle. It was shown that they affect each other, being physically distant from each other at considerable distances, thereby confirming that the principle of locality / proximity is incorrect [2] [3] [4] [5] [6] [7] [8 ] [9] [10] [11] [12] [13] [14] [15] [16] [17] .
Einstein's Opinion
The Einstein – Podolsky – Rosen Paradox
Albert Einstein felt that, in his opinion, there was something fundamentally wrong in quantum mechanics because of its predictions of locality / near-range violation. In a famous work, he and his coauthors described the EPR paradox . Thirty years later, John Stuart Bell answered this with a paper that showed that no physical theory of local hidden variables / parameters can reproduce all the predictions of quantum mechanics ( Bell's theorem ).
Philosophical Vision
Einstein admitted / assumed that the principle of locality / proximity was necessary and that there could be no violations of it. He noted [18] :
 | The following idea characterizes the relative independence of spatially separated / distant objects A and B: external influence on A does not directly affect B; this is known as the Locality / Proximity Principle, which is used accordingly only in field theory. If this axiom is completely rejected, then the idea of the existence of quasienclosed systems, and therefore thereby the postulation of laws that can be tested empirically in the generally accepted sense (accepted sense), would become impossible. |  |
It is believed that in the absence of locality, the world would have magical properties , "and not in a good way" [19] .
Local Realism
Local realism is a combination of the principle of locality with the “realistic” assumption that all objects have “objectively existing” values of their parameters and characteristics for any possible measurements that can be made on these objects BEFORE these measurements are made. Einstein, being, apparently, a supporter of local realism, loved in this connection to say that the Moon does not disappear from the sky, even if no one is watching it. The data of modern quantum mechanics based on the conducted experiments (see Bell Inequalities , Bell test experiments ) cast doubt on the adequacy of the local realism model to the “device” of reality [20] .
Realism
Realism in the sense in which physicists use it is not directly identical to the meaning of the word realism in metaphysics [21] . The latter is a kind of statement that in a sense there is a world independent of consciousness. Even if the results of any possible measurement do not exist before the measurement, this does not mean that they are created by the observer (as in the interpretation of quantum mechanics called “ consciousness causes collapse ”). Moreover, a property independent of consciousness may not be the value of any physical variable / parameter, for example, position or impulse . The property can be disposed - that is, it has a tendency , that is, it can be a tendency, in the sense that glass objects tend to break, or are located / have a tendency to break, even if they do not break in reality / in fact . Similarly, the properties of quantum systems independent of consciousness could consist of a tendency to respond to a certain kind of measurement with a certain kind of value with some probability. [22] Such an ontology would be metaphysically realistic and not being realistic in the sense that physicists put in the phrase “local realism” (which requires that a clear and only definite value of the measurand be obtained with certainty and certainty).
Local realism is an essential feature of classical mechanics, general relativity, and Maxwell's theory , but quantum mechanics largely rejects this principle because of the presence of quantum entanglement regardless of the distance most clearly demonstrated by the EPR Paradox and quantitatively formalized by Bell's inequalities. [23] Any theory, such as quantum mechanics, which violates Bell's inequalities, must reject either local realism or anti-factual certainty-finiteness . (Some physicists during the debate indicate that the experiments showed violations of Bell's inequalities, on the basis that the subclass of heterogeneous Bell's inequalities not tested / verified, or considerations of this order: experimental limitations ). Different interpretations of quantum mechanics reject various parts of local realism and / or anti-factual certainty.
Copenhagen interpretation
In most conventional interpretations, such as the Copenhagen interpretation and the interpretation based on consistent histories , where the wave function is not supposed to have a direct physical interpretation of reality, it is realism that is rejected. Certain final properties of the physical system “do not exist” before measurement, and the wave function has a limited interpretation as nothing more than a mathematical tool used to calculate the probabilities of experimental outcomes, which is in agreement with positivism in philosophy as the only possible material / plot / topic that science and should discuss.
In the version of the Copenhagen interpretation , where the wave function is assumed to have a physical interpretation of reality (the nature of which is not specified ), the principle of locality / proximity is violated during the measurement process through the collapse of the wave function . This is not a local process since the Bourne rule , applied to the wave function of the system, gives the probability density for all areas of space and time. When measuring a physical system, the probability density disappears simultaneously everywhere, except for the place where (and when - the point in time) the system over which the measurement is made is detected as existing. This “disappearance” is considered as a real physical process, and definitely nonlocal (occurring faster than the speed of light) if the wave function is considered as physically real and the probability density tends to zero at arbitrarily far distances during the finite time required for the measurement process.
Bohm interpretation
Bohm's interpretation wants to preserve realism, and for this she needs to violate the principle of locality in order to achieve the necessary correlations.
Multiworld Interpretation
In a world-wide interpretation, realism and locality / intimacy are retained, but “ counterfactual definiteness ” (translation option: certainty contrary to facts ) is rejected by expanding the concept of reality to accept the possibility of parallel universes .
Due to the fact that the differences between the interpretations are mainly philosophical (except for Bohm’s interpretation and a world-wide interpretation), physicists usually use a language in which important statements are independent of the interpretation we choose. In this framework, only the measured remote action at a distance - superluminal motion transmission / dissemination of real, physical information is considered by physicists as a violation of locality / short range. Such phenomena were not registered by the scientific community and are not predicted by modern theories (possibly with the exception of Bohm's theory).
Relativity
Locality / short-range interaction is one of the axioms of relativistic quantum field theory , as required for causality . The formalization of locality / short range in this case is as follows: if we have two observables, each of which is localized in the corresponding separate space-time segment / region, which are spatially similar separated from each other, then these observables must commute. Alternatively, the solution of the field equations is local if the underlying equations are either a Lorentz invariant or, in a more general case, are generally covariant or are a local Lorentz invariant.
Related Topics
- EPR paradox
- Quantum nonlocality
Notes
- ↑ JS Bell, Speakable and Unspeakable in Quantum Mechanics , (Cambridge University Press 1987)
- ↑ A. Aspect et al., Experimental Tests of Realistic Local Theories via Bell's Theorem , Phys. Rev. Lett. 47 , 460 (1981)
- ↑ A. Aspect et al., Experimental Realization of Einstein-Podolsky-Rosen-Bohm Gedankenexperiment: A New Violation of Bell's Inequalities , Phys. Rev. Lett. 49 , 91 (1982),
- ↑ A. Aspect et al., Experimental Test of Bell's Inequalities Using Time-Varying Analyzers , Phys. Rev. Lett. 49 , 1804 (1982),
- ↑ Barrett, 2002 Quantum Nonlocality, Bell Inequalities and the Memory Loophole: quant-ph / 0205016 (2002).
- ↑ JF Clauser, MA Horne, A. Shimony and RA Holt, Proposed experiment to test local hidden-variable theories , Phys. Rev. Lett. 23 , 880-884 (1969),
- ↑ JF Clauser and MA Horne, Experimental consequences of objective local theories , Phys. Rev. D 10 , 526-35 (1974)
- ↑ SJ Freedman and JF Clauser, Experimental test of local hidden-variable theories , Phys. Rev. Lett. 28 , 938 (1972)
- ↑ R. García-Patrón, J. Fiurácek, NJ Cerf, J. Wenger, R. Tualle-Brouri, and Ph. Grangier, Proposal for a Loophole-Free Bell Test Using Homodyne Detection , Phys. Rev. Lett. 93 , 130409 (2004)
- ↑ RD Gill, Time, Finite Statistics, and Bell's Fifth Position: quant-ph / 0301059 , Foundations of Probability and Physics - 2, Vaxjo Univ. Press, 2003, 179-206 (2003)
- ↑ D. Kielpinski et al., Recent Results in Trapped-Ion Quantum Computing (2001)
- ↑ PG Kwiat, et al., Ultrabright source of polarization-entangled photons , Physical Review A 60 (2), R773-R776 (1999)
- ↑ M. Rowe et al., Experimental violation of a Bell's inequality with efficient detection , Nature 409 , 791 (2001)
- ↑ E. Santos, Bell's theorem and the experiments: Increasing empirical support to local realism: quant-ph / 0410193 , Studies In History and Philosophy of Modern Physics, 36, 544-565 (2005)
- ↑ Tittel, 1997 : W. Tittel et al., Experimental demonstration of quantum correlations over more than 10 kilometers , Phys. Rev. A, 57 , 3229 (1997)
- ↑ Tittel, 1998 : W. Tittel et al., Experimental demonstration of quantum correlations over more than 10 kilometers , Physical Review A 57 , 3229 (1998); Violation of Bell inequalities by photons more than 10 km apart , Physical Review Letters 81 , 3563 (1998)
- ↑ Weihs, 1998 : G. Weihs, et al., Violation of Bell's inequality under strict Einstein locality conditions , Phys. Rev. Lett. 81 , 5039 (1998)
- ↑ "Quantum Mechanics and Reality" ("Quanten-Mechanik und Wirklichkeit", Dialectica 2: 320-324, 1948)
- ↑ Masser, 2018 , p. eleven.
- ↑ The existence of objective reality has again been called into question
- ↑ Norsen, T. - Against "Realism"
- ↑ Ian Thomson's dispositional quantum mechanics
- ↑ Ben Dov, Y. Local Realism and the Crucial experiment.
Literature
- George Masser . Nonlocality. A phenomenon that changes the concept of space and time, and its significance for black holes, the Big Bang and theories of everything = Musser George. Spooky action at a distance. - Alpina Non-Fiction, 2018 .-- ISBN 978-5-91671-810-2 .