THE PROBLEM Within classical physics the relation between physical theory and ordinary experience was conceived in the following way: ordinary experience is something that can be described and understood in terms of physics. Such a description involves, apart from physical theory, certain approximations. But the conditons under which those approximations apply (they correspond to the initial conditions of, say, celestial mechanics), taken together with the theory, are supposed to be sufficient for giving a full account of ordinary experience. Consequently, classical theory of measurement (which, like any other theory of measurement, links together terms of ordinary experience and theoretical terms), is a piece of applied physics and all processes which happen during measurement can be analysed on the basis of the equations of motion only. When we enter quantum mechanics (QM), we are apparently presented with a completely different picture. For according to the current interpretation of elementary quantum mechanics, ordinary experience – and this now means classical physics – and physical theory (and this now means QM), belong to two completely different levels and it is impossible to give an account of the first in terms of the second. Any transition from the quantum level to the level of classical physics must be taken, not as a transition within QM from the general to the particular, but as an essentially new element which is incapable of further analysis.THE PROBLEM Within classical physics the relation between physical theory and ordinary experience was conceived in the following way: ordinary experience is something that can be described and understood in terms of physics. Such a description involves, apart from physical theory, certain approximations. But the conditons under which those approximations apply (they correspond to the initial conditions of, say, celestial mechanics), taken together with the theory, are supposed to be sufficient for giving a full account of ordinary experience. Consequently, classical theory of measurement (which, like any other theory of measurement, links together terms of ordinary experience and theoretical terms), is a piece of applied physics and all processes which happen during measurement can be analysed on the basis of the equations of motion only. When we enter quantum mechanics (QM), we are apparently presented with a completely different picture. For according to the current interpretation of elementary quantum mechanics, ordinary experience – and this now means classical physics – and physical theory (and this now means QM), belong to two completely different levels and it is impossible to give an account of the first in terms of the second. Any transition from the quantum level to the level of classical physics must be taken, not as a transition within QM from the general to the particular, but as an essentially new element which is incapable of further analysis.

Cambridge University Press eBooksOct 29, 198119 citations

On the Classical Limit of Quantum Mechanics

M. Baldo

One of the main unsolved question in Quantum Mechanics (QM) is its compatibility with classical mechanics. The laws of QM, which describe the microscopic world, must merge into the classical ones for large enough physical systems, but it is still unknown at which point, if any, the transition occurs and if the transition is smooth or sudden as the size increases. Furthermore, a strict extension of QM to the macroscopic world leads to well known 'paradoxes', which is not straightforward to solve. This question is tightly connected with the measurement problem, since any measurement apparatus must give a response which can be described at classical level. Many experiments have been performed to answer to this question. They mainly try to find to which extent the number of particles can be increased in order to observe clear evidence of violation of standard QM. In this paper we argue that the macroscopicity parameter is not the number of particles but the number of independent degrees of freedom, as proposed in a recent model for the completion of QM. This introduces a sort of change of paradigm. To support this claim a representative set of well known experiments are analyzed from this point of view. This brings to a new interpretation of the experiments. A general scheme for the quantum-classical transition is discussed in some details.One of the main unsolved question in Quantum Mechanics (QM) is its compatibility with classical mechanics. The laws of QM, which describe the microscopic world, must merge into the classical ones for large enough physical systems, but it is still unknown at which point, if any, the transition occurs and if the transition is smooth or sudden as the size increases. Furthermore, a strict extension of QM to the macroscopic world leads to well known 'paradoxes', which is not straightforward to solve. This question is tightly connected with the measurement problem, since any measurement apparatus must give a response which can be described at classical level. Many experiments have been performed to answer to this question. They mainly try to find to which extent the number of particles can be increased in order to observe clear evidence of violation of standard QM. In this paper we argue that the macroscopicity parameter is not the number of particles but the number of independent degrees of freedom, as proposed in a recent model for the completion of QM. This introduces a sort of change of paradigm. To support this claim a representative set of well known experiments are analyzed from this point of view. This brings to a new interpretation of the experiments. A general scheme for the quantum-classical transition is discussed in some details.

arXiv:2607.09735Jul 2, 20260 citations

Quantum mechanics and experience

Dennis Dieks

Studies in History and Philosophy of Science Part ADec 1, 1993179 citations

Quantum Mechanics and Classical Physics

N. Rosen

Jan 1, 19900 citations

Anomalies in experimental data for the EPR-Bohm experiment: Are both classical and quantum mechanics wrong?

Guillaume Adenier, Andrei Yu. Khrennikov

We analyze anomalies in data to test the violation of Bell's inequality for the EPR-Bohm experiment. We found that the experimental correlations for photon polarization have an intriguing property. In the experimental data there are visible non-negligible deviations of probabilities $P_{++}^{\rm{exp}}(α, β), P_{+-}^{\rm{exp}}(α, β), P_{-+}^{\rm{exp}}(α, β), P_{--}^{\rm{exp}}(α, β) $ from the predictions of quantum mechanics, namely, $P_{++}(α, β)=P_{--}(α, β)= {1/2}\cos^2(α-β)$ and $P_{+-}=P_{-+}(α, β)={1/2}\sin^2(α-β).$ However, in some mysterious way those deviations compensate each other and finally the correlation $E^{\rm{exp}}(α, β)= P_{++}^{\rm{exp}}(α, β)- P_{+-}^{\rm{exp}}(α, β)- P_{-+}^{\rm{exp}}(α, β)+ P_{--}^{\rm{exp}}(α, β)$ is in the complete agreement with the QM-prediction, namely, $E(α, β)= P_{++}(α, β)- P_{+-}(α, β)- P_{-+}(α, β)+ P_{--}(α, β)= \cos 2(α-β).$ Therefore such anomalies play no role in the Bell's inequality framework. Nevertheless, other linear combinations of experimental probabilities do not have such a compensation property. There can be found non-negligible deviations from predictions of quantum mechanics. Thus neither classical nor quantum model can pass the whole family of statistical tests given by all possible linear combinations of the EPR-Bohm probabilities. Does it mean that both models are wrong?We analyze anomalies in data to test the violation of Bell's inequality for the EPR-Bohm experiment. We found that the experimental correlations for photon polarization have an intriguing property. In the experimental data there are visible non-negligible deviations of probabilities $P_{++}^{\rm{exp}}(α, β), P_{+-}^{\rm{exp}}(α, β), P_{-+}^{\rm{exp}}(α, β), P_{--}^{\rm{exp}}(α, β) $ from the predictions of quantum mechanics, namely, $P_{++}(α, β)=P_{--}(α, β)= {1/2}\cos^2(α-β)$ and $P_{+-}=P_{-+}(α, β)={1/2}\sin^2(α-β).$ However, in some mysterious way those deviations compensate each other and finally the correlation $E^{\rm{exp}}(α, β)= P_{++}^{\rm{exp}}(α, β)- P_{+-}^{\rm{exp}}(α, β)- P_{-+}^{\rm{exp}}(α, β)+ P_{--}^{\rm{exp}}(α, β)$ is in the complete agreement with the QM-prediction, namely, $E(α, β)= P_{++}(α, β)- P_{+-}(α, β)- P_{-+}(α, β)+ P_{--}(α, β)= \cos 2(α-β).$ Therefore such anomalies play no role in the Bell's inequality framework. Nevertheless, other linear combinations of experimental probabilities do not have such a compensation property. There can be found non-negligible deviations from predictions of quantum mechanics. Thus neither classical nor quantum model can pass the whole family of statistical tests given by all possible linear combinations of the EPR-Bohm probabilities. Does it mean that both models are wrong?

arXiv:quant-ph/0607172Jul 25, 20066 citations

P_{++}(α, β)=P_{--}(α, β)= {1/2}\cos^2(α-β)

and

P_{+-}=P_{-+}(α, β)={1/2}\sin^2(α-β).

However, in some mysterious way those deviations compensate each other and finally the correlation

E^{\rm{exp}}(α, β)= P_{++}^{\rm{exp}}(α, β)- P_{+-}^{\rm{exp}}(α, β)- P_{-+}^{\rm{exp}}(α, β)+ P_{--}^{\rm{exp}}(α, β)

is in the complete agreement with the QM-prediction, namely,

E(α, β)= P_{++}(α, β)- P_{+-}(α, β)- P_{-+}(α, β)+ P_{--}(α, β)= \cos 2(α-β).

Therefore such anomalies play no role in the Bell's inequality framework. Nevertheless, other linear combinations of experimental probabilities do not have such a compensation property. There can be found non-negligible deviations from predictions of quantum mechanics. Thus neither classical nor quantum model can pass the whole family of statistical tests given by all possible linear combinations of the EPR-Bohm probabilities. Does it mean that both models are wrong?