Quantum mechanics is nonlocal. Classical mechanics is local. Consequently classical mechanics can not explain all quantum phenomena. Conversely, it is cumbersome to use quantum mechanics to describe classical phenomena. Not only are the computations more complex, but - and this is the main point - it is conceptually more difficult: one has to argue that nonlocality, entanglement and the principle of superposition can be set aside when crossing the "quantum $\rightarrow$ classical" border. Clearly, nonlocality, entanglement and the principle of superposition should become irrelevant in the classical limit. But why should one argue? Shouldn't it just come out of the equations? Does it come out of the equations? This contribution is about the last question. And the answer is: "it depends on which equation".
Quantum mechanics is nonlocal. Classical mechanics is local. Consequently classical mechanics can not explain all quantum phenomena. Conversely, it is cumbersome to use quantum mechanics to describe classical phenomena. Not only are the computations more complex, but - and this is the main point - it is conceptually more difficult: one has to argue that nonlocality, entanglement and the principle of superposition can be set aside when crossing the "quantum → classical" border. Clearly, nonlocality, entanglement and the principle of superposition should become irrelevant in the classical limit. But why should one argue? Shouldn't it just come out of the equations? Does it come out of the equations? This contribution is about the last question. And the answer is: "it depends on which equation".
We argue that quantum nonlocality of entangled states is not an actual phenomenon. It appears in quantum mechanics as a consequence of the inconsistency of its superposition principle with the corpuscular properties of a quantum particle. In the existing form, this principle does not distinguish between macroscopically distinct states of a particle and their superpositions: it implies introducing observables for a particle, even if it is in an entangled state. However, a particle cannot take part simultaneously in two or more alternative macroscopically distinct sub-processes. Thus, calculating the expectation values of the one-particle's observables, for entangled states, is physically meaningless: Born's formula is not applicable to such states. The same concerns the entangled states of compound quantum systems. In the {\it existing} quantum mechanics, introducing Bell's inequalities is fully legal. However, these inequalities imply averaging over an entangled state, and, hence, they have no basis for their clear physical interpretation. Experiments to confirm the violation of Bell's inequalities do not prove the existence of nonlocality in microcosm. They confirm only that correlations introduced in the existing theory of entangled states have no physical sense, for they contradict special relativity.
In several recent communications (Khrennikov 2019a, b, c, 2020a, b), A. Khrennikov argued for "eliminating the issue of quantum nonlocality" from the analysis of quantum entanglement and quantum phenomena in general. He proposed to differentiate quantum and classical phenomena and entanglement not by their respective nonlocality and locality, as is common, but by the discreteness of quantum phenomena vs. the continuity of classical phenomena, supplemented by Bohr's complementarity in the case of quantum phenomena. As I argue here, however, the question may not be that of "eliminating the issue of quantum nonlocality" but instead of illuminating this issue, a task that can, I also argue, be pursued by relating quantum nonlocality to other key features of quantum phenomena. I suggest that the following features of quantum phenomena and quantum mechanics, distinguishing them from classical phenomena and classical physics--(1) the irreducible role of measuring instruments in defining quantum phenomena; (2) discreteness; (3) complementarity; (4) entanglement; (5) quantum nonlocality; and (6) the irreducibly probabilistic nature of quantum predictions--are all interconnected in defining quantum phenomena and distinguishing them from classical ones, so that it is difficult to give an unconditional priority to any one of them. To argue this case, I consider quantum phenomena and quantum mechanics from a nonrealist or, in terms adopted here, "reality-without-realism" (RWR) perspective. This perspective extends and gives new dimensions to Bohr's view, grounded in his analysis of the irreducible tole of measuring instruments in the constitution of quantum phenomena, with quantum measurement defined by the entanglements between the quantum object under investigation and the instrument used.
We analyze the difference between classical mechanics and quantum mechanics. We come to the conclusion that this difference can be found in the nature of the observables that are considered for the physical system under consideration. Classical mechanics can only describe a certain kind of what we called ‘‘classical observable.’’ Quantum mechanics can only describe another kind of observable; it cannot describe, however, classical observables. To perform this analysis, we use a theory where every kind of observable can be treated and which is in a natural way a generalization of both classical and quantum mechanics. If in a study of a physical system in this theory we restrict ourselves to the classical observables, we rediscover classical mechanics as a kind of first study of the physical system, where all the nonclassical properties are hidden. If we find that this first study is too rough we can also study the nonclassical part of the physical system by a theory which is eventually quantum mechanics.
It’s time to figure out time! We wish in this paper to answer what is time and how it works, as Einstein changed our whole idea about time, however, not even he answered this one question, which might seem of no importance, in answering it will change all of physics. This paper is bringing a whole new set of ideas, while one might think it is just about time, and that is the start and the original purpose of this paper, one will be shown that this paper will extend to much more beyond that, yielding some very excited and highly unexpected results, the paper will be based on a thought experiment, then going on to arguing and redefining what is time, by asking questions some are previously asked and others are not, then showing for starters how for instance the time dilation effect comes out naturally from this new definition of time both physically and mathematically, the paper then starts using its new ideas and applying it to some of the unsolved problems, however the biggest, unexpected, and most important result that will come out from this paper, The Detection Property, it will be shown how this property will lead not only to the interpretation of quantum mechanics, but a much more powerful effect will be produced, in that the detection property will even require the weird quantum behavior, it will be shown how one can start with simple classical world, and just by considering this new argument of time will be forced to introduce to it – in addition to special relativity - all the weird quantum behavior what will be most exciting about it, is that it will do so by the fact that all the phenomena of quantum mechanics like the measurement problem and Entanglement, and to go even further it will not only explain the phenomena of the Superposition and the wave function collapse, but it will even require its existence, this new definition of time along with the detection property will require that quantum mechanics behave in the way it does.
Quantum mechanics works exceedingly well in all practical applications. No example of conflict between its predictions and experiment is known. Without quantum physics we could not explain the behavior of solids, the structure and function of DNA, the color of the stars, the action of lasers or the properties of superfluids. Yet well over half a century after its inception, the debate about the relation of quantum mechanics to the familiar physical world continues. How can a theory that can account ith precision for everything we can measure still be deemed lacking?