Quantum experiments detect particles, but they reveal information about wave properties. No matter how quanta are detected, they always express the local net state of the corresponding wave-function. The mechanism behind this process is still a mystery. However, quantum wave-functions evolve like classical waves. If they determine all the observations, why do they entail "weird" phenomena? In particular, why do they produce conceptual problems, such as the EPR paradox? It turns out that all the major interpretations in quantum mechanics are particle-based ontologies. Variables of fundamental interest, such as momentum and position, are assumed to reflect the input states of discrete entities, even when their evolution is predicted by wave equations. Here I show that a whole class of microscopic phenomena, including entanglement, can be interpreted without contradictions if the variables of quantum mechanics are actually treated as wave properties. The main recommendation is to assume that sharp spectral states are transient outcomes of superposition, rather than permanent input components.
Quantum experiments detect particles, but they reveal information about wave properties. No matter how quanta are detected, they always express the local net state of the corresponding wave-function. The mechanism behind this process is still a mystery. However, quantum wave-functions evolve like classical waves. If they determine all the observations, why do they entail "weird" phenomena? In particular, why do they produce conceptual problems, such as the EPR paradox? It turns out that all the major interpretations in quantum mechanics are particle-based ontologies. Variables of fundamental interest, such as momentum and position, are assumed to reflect the input states of discrete entities, even when their evolution is predicted by wave equations. Here I show that a whole class of microscopic phenomena, including entanglement, can be interpreted without contradictions if the variables of quantum mechanics are actually treated as wave properties. The main recommendation is to assume that sharp spectral states are transient outcomes of superposition, rather than permanent input components.
Quantum mechanics is an immensely successful theory, occupying a unique position in the history of science. It has solved mysteries ranging from macroscopic superconductivity to the microscopic theory of elementary particles and has provided deep insights into the nature of vacuum on the one hand and the description of the nucleon on the other. Whole new fields such as quantum optics and quantum electronics owe their very existence to this body of knowledge. However, despite the stunning successes of quantum mechanics, there is no general agreement on the conceptual foundations and interpretation of the subject. The theory provides unambiguous information about the outcome of a measurement of a physical object. However, many feel that it does not provide a satisfactory answer to the nature of the “reality” we should attribute to the physical objects between the acts of measurement. The conceptual difficulty comes about because the wave function |ψ〉 is usually given by a coherent superposition of various distinguishable experimental outcomes. If we denote the collection of states that represent the possible outcomes of an experiment by |ψ j 〉, then |ψ〉 = ∑ j c j |ψ j 〉 where c j = 〈ψ j |ψ〉. The probability of the outcome |ψ j 〉 is P j =|c j | 2 . In the process of measurement, the so called collapse of the wave function takes place and a single, definite state |ψ i 〉 of the physical object is chosen. The difficulty comes about in the interpretation of the mechanism by which this definite state is chosen from amongst all the possible outcomes.
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.
There is a gap between experiment and theory in quantum mechanics. On paper, quantum observables collapse to sharp states instantaneously, as soon as there is a possibility of extracting information. In real life, experimenters have to wait until the wave-function evolves to acquire sharp states, or they have to modify the physical context. Furthermore, the general perception is that quanta reveal component properties (with corresponding histories) during collapse, whereas they always express the local net state of the wave-function in any experiment. This discrepancy is due to the fact that operator algebra is too abstract. It gives correct predictions, but leaves out the transient details of the wave-like processes behind quantum phenomena. This oversimplification is the reason for the measurement problem, and ultimately for the EPR paradox. If the theory is expanded to include the irrelevant physical details, then many conceptual complications can be avoided, including the problem of non-locality. Furthermore, this conclusion entails new ways to violate Bell's inequality, with pairs of variables that are not otherwise expected to do that.
We propose a novel interpretation of quantum mechanics in which microscopic particles possess definite positions, momenta, and spins at every moment, independent of measurement. These physical quantities are not determined by hidden variables but are randomly realized according to the wave function’s probability distribution. Measurement outcomes reflect the particle’s actual state rather than a wave-function collapse. By treating the measured and measuring systems as a single composite system, we introduce a conditional probability decomposition of the wave function that preserves interference without invoking instantaneous collapse. Potential experimental tests of the conditional probability decomposition are discussed. This framework provides a coherent understanding of quantum measurement, nonlocal correlations, and the EPR paradox, while remaining consistent with all standard quantum predictions including Bell inequality violations and GHZ state.
The EPR paradox was caused by the provision that quantum variables must have pre-existing values. This type of “hidden property realism” was later falsified by Bell’s Theorem. Yet, modern interpretations of quantum entanglement still insist on the reality of pre-existing properties, whether explicitly or implicitly. Instead, they treat Bell’s inequality as a Locality Criterion. This is a questionable practice, considering that classical joint measurements also violate such inequalities for mutually exclusive wave properties. In particular, consecutive measurements of polarization produce the same coefficients of correlation as parallel measurements with polarization-entangled quanta, yet they are explicitly local. Nonetheless, they also require nonlocal interpretations if pre-existing properties are taken for granted. The solution is to reject the models with pre-existing properties for both classical and quantum wave-like phenomena.
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 paradox1-2, in which Einstein and his co-authors examined the measurement of entangled particles in space-like separation. 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 theorem3-5, along with the Bell-Kochen-Specker theorem6-10 and subsequent experiments, has largely ruled out local hidden variable theories. In this work, I apply the quantum decoherence framework11-13, pioneered by Zeh, Zurek, Joos and Leggett et al. to analyze an EPR-like system using system-environment interactions as a measurement model. I demonstrate 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 local interactions, giving rise to the appearance of wavefunction collapse. These findings suggest that quantum mechanics can be reconciled with local realism if the wavefunction is treated as an ontic entity, offering a potential path toward a locally realistic quantum theory in alignment with Einstein’s vision.