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arXiv:2509.02085

Is the EPR paradox really a paradox?

Natalia N. Gorobey, Alexander S. Lukyanenko

Published Sep 2, 2025• 0 citations
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Abstract

If the excitation of a system of quantized fields with a given set of quantum numbers does not exist, the amplitude of the triggering of the source is zero. A system with a source of two photons in a singlet state and two photon detectors is considered in detail. It is shown that the condition of operation of one detector with a given direction of photon polarization uniquely determines the adequate choice of direction and polarization for the second detector. This conclusion is in accordance with the laws of motion and conservation of quantum numbers of excitations in a system of quantized fields.

DOI
10.48550/arxiv.2509.02085

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If the excitation of a system of quantized fields with a given set of quantum numbers does not exist, the amplitude of the triggering of the source is zero. A system with a source of two photons in a singlet state and two photon detectors is considered in detail. It is shown that the condition of operation of one detector with a given direction of photon polarization uniquely determines the adequate choice of direction and polarization for the second detector. This conclusion is in accordance with the laws of motion and conservation of quantum numbers of excitations in a system of quantized fields.
A system of two polarized photons in singlet state appears as being in one of two product states independent of any measurement. These states depend on the selected polarization angles. With the polarizers on either side perpendicular to each other, both photons pass the polarizers without any disturbance. Action at a distance is therefore not needed to explain the results of the measurements. In general, the elements of physical reality demanded by EPR are the polarization states of the two photons of the entangled pair. As these are local elements in the regions of space of the polarizers the EPR paradox for the case of entangled photons can be regarded as resolved.
The famous EPR paradox shows that if we describe quantum particles in the usual way -- by their wave functions -- then we get the following seeming contradiction. If we entangle the states of the two particles, then move them far away from each other, and measure the state of the first particle, then the state of the second particle immediately changes -- which contradicts to special relativity, according to which such immediate-action-at-a-distance is not possible. It is known that, from the physical viewpoint, this is not a real paradox: if we measure any property of the second particle, the results will not change whether we perform the measurement on the first particle or not. What the above argument shows is that the usual wave function description of a quantum state does not always adequately describe the corresponding physics. In this paper, we propose a new, more physically adequate description of a quantum state, a description in which there is no EPR paradox: measurements performed at the first particle does not change the state of the remote second one.
The authors believe that much of the contradiction they hear about the Einstein Podoisky Rosen Paradox (EPR), can be framed into the diverse ways of using or misusing the principle of ``collapse,`` (a principle, which according to Wigner, is very attractive, but not very informative). To make their points, they will mainly use the model [Lamehi-Rachti, Mittig, Phys. Rev. D14 (1976)] of two free protons scattering in the well known state of singlet, ud-du = SS, according to the Pauli Principle. (An equivalent description can be done with the polarization of photons.) The authors ask the important question whether, on separation, the two fermions will remain in the state SS, where neither proton has a definite state and the whole two fermion system has exactly zero component in any direction.
The EPR paradox is shown to be a result of the wrong definitions in quantum mechanics of such physical quantities as momentum and position. The corrected definitions show that momentum and position of particles can be precisely defined simultaneously and uncertainty relations do not prevent it. Therefore, with correct definition of physical quantities in quantum mechanics, the paradox disappears. The Bohm Aharonov version of the EPR paradox is illustrated by the example of measuring the polarization of photon pairs. The common view of the two photon state radiated by a source is presented. The common Bell’s inequality is discussed and the simplest version of it for a specific hidden variable is derived. A possibility of an experimental study of whether a photon and its polarization are preexistent before measurements is considered.
We first consider the Einstein-Podolsky-Rosen (EPR) paradox for the system of two particles with spin 1/2 with entangled spins in first-quantized quantum mechanics (QM). If measurement is governed by wavefunction collapse, then gedanken experiments show that a number of fundamental principles including conservation of angular momentum and the Heisenberg uncertainty principle can be violated. We conclude that the collapse of the spin part of the wavefunction cannot happen and therefore an EPR paradox does not arise for this system. QM unitarity alone is sufficient to rule out "spooky" action at a distance. The absence of spin wavefunction collapse leads to several interesting conclusions about how measurement works in QM: When wavefunction collapse does not happen, (i) a signal from a macroscopic measuring device indicating that a system is in a state S does not necessarily mean that it is or was in S and (ii) the uncertainty in QM at the microscopic level is transmitted to uncertainty in signals for the macroscopic measuring device. We derive two general results on how quantum measurement works and illustrate them in a spin-1/2 measurement. In contrast to first-quantized QM, in quantum field theory we are unable to fully rule out the possibility of wavefunction collapse. However, when we insist on unitarity (thereby excluding the possibility of wavefunction collapse) and additionally take into account in the wavefunction all degrees of freedom involved in the measurement (including those of the equipment, experimentalists, etc.), a consistant acceptable understanding of the Bell-inequality-type experiments involving entangled photon polarizations emerges including the absence of an EPR paradox. The ability of an experimentalist to be aware of his perceptions but unable to be conscious of other components of a generalized Schrodinger Cat plays a role in resolving the Measurement Problem.