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.
This report discusses the following: The analysis of the singlet state of separate fermions proves that the EPR contradicts QM. The violation of special relativity. The Schroedinger equation and the EPR. The conservation of angular momentum. The proposal of collapse. The factorization of the spin states. The superposition principle. No paradox exists within the theory. The original state of Einstein et al is not a valid example of the EPR, and it seems impossible to construct a valid linear momentum example. This is another indication that the EPR contradicts QM. Actions at a distance, the model of Einstein et al for particles with mass, and Bell's inequalities and their physical meaning.
This report discusses the following: The analysis of the singlet state of separate fermions proves that the EPR contradicts QM. The violation of special relativity. The Schroedinger equation and the EPR. The conservation of angular momentum. The proposal of collapse. The factorization of the spin states. The superposition principle. No paradox exists within the theory. The original state of Einstein et al is not a valid example of the EPR, and it seems impossible to construct a valid linear momentum example. This is another indication that the EPR contradicts QM. Actions at a distance, the model of Einstein et al for particles with mass, and Bell`s inequalities and their physical meaning.
The Einstein-Podolsky-Rosen (EPR) paradox was presented as an argument that quantum mechanics is an incomplete description of physical reality. However, the premises on which the argument is based are falsifiable by Bell experiments. In this paper, we examine the EPR paradox from the perspective of Schrodinger's reply to EPR. Schrodinger pointed out that the correlated states of the paradox enable the simultaneous measurement of
x^ and
p^, one by direct, the other by indirect measurement. Schrodinger's analysis takes on a timely importance because a recent experiment realizes these correlations for macroscopic atomic systems. Different to the original argument, Schrodinger's analysis applies to the experiment at the time when the measurement settings have been fixed. In this context, a subset of local realistic assumptions (not negated by Bell's theorem) implies that
x and
p are simultaneously precisely defined. Hence, an alternative EPR argument can be presented that quantum mechanics is incomplete, based on a set of (arguably) nonfalsifiable premises. As systems are amplified, macroscopic realism can be invoked, and the premises are referred to as weak macroscopic realism (wMR). In this paper, we propose a realization of Schrodinger's gedanken experiment where field quadrature phase amplitudes
X^ and
P^ replace position and momentum. Assuming wMR, we derive a criterion for the incompleteness of quantum mechanics, showing that the criterion is feasible for current experiments. Questions raised by Schrodinger are resolved. By performing simulations based on an objective-field (
Q-based) model for quantum mechanics, we illustrate the emergence on amplification of simultaneous predetermined values for
X^ and
P^. The values can be regarded as weak elements of reality, along the lines of Bell's macroscopic beables.
Einstein, Podolsky, and Rosen pointed out that the quantum-mechanical description of “physical reality” implies an unphysical, instantaneous action between distant measurements. To avoid such an action at a distance, these three concluded that quantum mechanics had to be incomplete. However, its extensions involving additional “hidden variables,” allowing for the recovery of determinism and locality, have been disproved experimentally (Bell’s theorem). In this paper, an opposite solution of the paradox is presented, based on the greater indeterminism of the modern quantum field theory (QFT) description of particle physics, which prevents the preparation of any state having a definite number of particles. The resulting uncertainty in photon radiation has interesting consequences in quantum information theory (e.g., cryptography and teleportation). Moreover, since it allows for fewer elements of Einstein-Podolsky-Rosen (EPR) physical reality than the old non-relativistic quantum mechanics, QFT satisfies the EPR condition of completeness without the need for hidden variables. The residual physical reality never violates locality; thus, the unique objective proof of “quantum nonlocality” is removed in an interpretation-independent way. At the same time, the supposed nonlocality of the EPR correlations turns out to be a problem in interpretation of the measurement process. If we do not rely on hidden variables or new physics beyond QFT, the viable interpretation is a minimal statistical one, which preserves locality and Lorentz symmetry.
Despite its remarkable success in describing microscopic phenomena, quantum mechanics continues to pose unresolved foundational questions concerning measurement, nonlocality, wavefunction collapse, and the nature of physical reality. These issues were highlighted by the EPR paradox. Quantum mechanics predicts that measuring one particle’s observable instantaneously determines the state of the other, seemingly violating special relativity’s prohibition of faster-than-light influences and suggesting an incomplete description of physical reality. However, Bell’s theorem has largely ruled out local hidden variable theories. In this paper, I critically examine the assumptions in deriving Bell’s theorem and demonstrate that the theorem does not apply strictly to quantum mechanics. By assuming measurement is always accompanied by uncontrollable environment interactions, I show that quantum theory can be local and realism with decoherence in EPR-like measurement. Specifically, I apply the quantum decoherence framework, pioneered by Zeh, Zurek and Leggett to analyze an EPR-like system using system-environment interactions as a measurement model. The results illustrate that measurement on one entangled particle does not instantaneously collapse the system's wavefunction. Instead, the local wavefunctions of the measured particle and its environment evolve dynamically, while the remote particle’s wavefunction remains unchanged. Environment-induced decoherence selects pointer states and rapidly suppresses quantum correlations through strictly local interactions, giving rise to the appearance of wavefunction collapse. These findings challenge the conventional interpretation of Bell’s theorem and suggest that quantum mechanics fundamentally respects locality and realism if the wavefunction is treated as an ontic entity. This work offers a potential path toward a locally realistic quantum theory in alignment with Einstein’s vision. It not only strengthens the conceptual foundations of quantum mechanics, but also carries tremendous implications for quantum information processing and computing.