Existing experiments do not disprove local realistic quantum theories. To overcome logical difficulties of the standard quantum theory, a nondeterministic irreversible local realistic theory was proposed, in which the wave-particle duality is objective in contrast to the complementarity principle. The statistical characteristics of these two theories can be distinguished by a proposed experiment within presently available technology. 03.65.Bz(found), 03.75.-b(m.w), 05.30.-d(q.sm), 05.40.+j(fluct)
Existing experiments do not disprove local realistic quantum theories. To overcome logical difficulties of the standard quantum theory, a nondeterministic irreversible local realistic theory was proposed, in which the wave-particle duality is objective in contrast to the complementarity principle. The statistical characteristics of these two theories can be distinguished by a proposed experiment within presently available technology. 03.65.Bz(found), 03.75.-b(m.w), 05.30.-d(q.sm), 05.40.+j(fluct)
Complementarity, e.g., the wave–particle duality of nature, lies at the heart of quantum mechanics. It distinguishes the world of quantum phenomena from the reality of classical physics. In the 1920s, quantum theory as we know it today was still new, and examples used to illustrate complementarity emphasized the position (particle-like) and momentum (wave-like) attributes of a quantum mechanical object, be it a photon or a massive particle. This is the historical reason why complementarity is often superficially identified with the so-called wave-particle duality of matter . Complementarity, however, is a more general concept. We say that two observables are complementary if precise knowledge of one of them implies that all possible outcomes of measuring the other one are equally probable. We may illustrate this by two extreme examples. The first example consists of the position and momentum (along one direction) of a particle: if, say, the position is predetermined then the result of a momentum measurement cannot be predicted, all momentum values are equally probable (in a large range). The second extreme involves two orthogonal spin components of a spin- 1/2 particle: if, say, the vertical spin component has a definite value ( up or down ) then upon measuring a horizontal component both values ( left or right , for instance) are found, each with a probability of 50%. Thus, in the microcosmos complete knowledge in the sense of classical physics is not available. The classic example of the merger of wave and particle behavior is provided by Young's double-slit experiment.
The problem of wave-particle duality is considered within the framework of the algebraic approach. Contrary to the widespread belief, we demonstrate that wave-particle duality can be reconciled with the assumption that there exists some local physical reality determining the results of local measurements. A number of quantum experiments—double-slit electron scattering, Wheeler’s delayed choice experiment, the past of photons passed through the interferometer—are discussed using the concept of locality. A clear physical interpretation of these experiments that does not contradict classical concepts is provided.
For nearly a century, quantum mechanics (QM) has established itself as an exceptionally effective framework for predicting the collective movements and statistical distributions of particles. However, its predictive success comes with a significant conceptual cost: the apparent abandonment of local realism. When one attempts to apply the standard quantum formalism at the scale of an individual particle, paradoxes inevitably arise. This article argues that these contradictions are not intrinsic properties of nature, but rather stem from a fundamental category error: the misapplication of ensemble statistical laws to individual events, which unrightfully promotes statistical averages to instantaneous physical realities. To address the root cause of this conceptual deviation, we must establish a foundational axiom: the Principle of Particle Reality. This principle posits that if a particle exists as a real entity, it must inherently possess definite physical properties—such as a precise polarization, velocity, and trajectory—independent of our capacity to detect them. Ignoring this ontology has led the standard model to treat physical realities as abstract paradoxes. To resolve them, this work proposes a unified reconsideration of three main pillars of quantum interpretation. First, regarding locality, we demonstrate that the passage probabilities through two polarizers for a particle within an unpolarized beam remain identical regardless of their order. Governed by Malus's law and the strict mathematical symmetry \cos^2(a-b) = \cos^2(b-a), this establishes that polarizers can be arranged in any sequential order or even in parallel for statistically identical pairs without altering the total passage probabilities. By establishing a physical equivalence, we show that exact quantum correlations emerge directly from a particle-by-particle application of the strictly positive classical Malus's law (0 \le p \le 1). This successfully explains the violation of Bell’s inequalities within a strictly local framework, bypassing the non-physical negative quasi-probabilities encountered in previous angular hidden-variable models. Secondly, on the illusion of state superposition, we show that failing to recognize that an interferometer physically and deterministically alters the polarization orientation of a particle led to an abstract formulation; in reality, this involves a deterministic geometric transformation of probability distributions. Finally, addressing wave-particle duality, we challenge the standard postulate of artificial simultaneity in the double-slit configuration, which caused a deep confusion between the collective behavior of a group and the sequential passage of an individual entity. We introduce an ``event-by-event'' formulation where interference fringes emerge instead from temporal correlations preserved by the non-commutativity of averaging. By restoring the strict distinction between statistical ensemble laws and individual reality through the Principle of Particle Reality, this work aims to definitively end ``quantum geocentrism'' and to lay the foundations for a coherent, local, and realistic sub-quantum physics.
This thesis addresses some of the consequences of giving quantum mechanics a realist interpretation. We consider three main topics: wave-particle duality, locality, and Lorentz invariance. First we show that classical particles alone or classical waves alone cannot explain all single particle quantum phenomena. Then we consider the possibility that a quantum particle is composed of a particle and a wave, both being taken to exist objectively. We are able to demonstrate the reality of empty waves (that is, waves without a particle) if we make three realist motivated assumptions. The main part of this thesis concerns locality. In 1964 Bell demonstrated that a local realist interpretation of quantum mechanics is not possible by deriving a set of inequalities that apply to two particle systems. More recently Greenberger, Home, and Zeilinger have demonstrated this for systems with more than two particles without the need for inequalities. We present a new way to derive Bell inequalities for two particles and show how this can be extended to systems with more than two particles. A number of proposals for experiments to test local realism are put forward. In particular, we show how it is possible to demonstrate the nonlocality of a single photon. A new demonstration of Bell's theorem is presented for two particles but without inequalities. A realizable quantum optical version is proposed and inequalities are proposed which would be required in a non-ideal experiment. Finally, the question of Lorentz invariance is considered. We define a condition for the existence of elements of reality and a condition for the Lorentz invariance of these elements of reality. Then we show that, by considering a particular gedanken experiment, we obtain a contradiction demonstrating that Lorentz-invariant realistic interpretations of quantum theory are not possible.
In spite of the recent extraordinary progresses of experimental techniques it does not seem that, after more than seventy years from the birth of quantum mechanics, a unanimous consensus has been reached in the physicist's community on how to understand the "strange" properties of quantons, the wavelike/particlelike objects of the quantum world. In the first paragraph I will briefly recall some results on the problem of decoherence in large quantum systems, which at the same time may be viewed as an attempt of providing a "realistic" physical interpretation of the standard mathematical formulation of the theory. In the following ones I will present a derivation from first principles of the Wigner representation of quantum mechanics in phase space which eliminates altogether from the theory the Schrödinger waves and their questionable properties. This approach leads to the conclusion that the wave/particle duality has nothing to do with "probability waves", but is simply the manifestation of two complementary aspects (continuity vs. discontinuity) of an intrinsically nonlocal physical entity (the quantum field) which objectively exists in ordinary three dimensional space.
Updating the wave-particle duality Maria C. Bosca e-mail: bosca@ugr.es Departamento de Fisica Atomica, Molecular y Nuclear Universidad de Granada E-18071. Granada Spain The wave-particle-duality, the fundamental component of the new quantum formalism in Bohr’s opinion, must be reformulated by incorporating the results of some experiments accomplished in the last decades of twentieth century. The Bohr´s complementarity principle stated the mutual exclusiveness and joint full completeness of the two (classical) descriptions of quantum systems; after Einstein-Podolsky-Rosen’paper, the wave-particle duality, or wave-particle complementarity, could be expressed by stating that it is impossible to build up an experimental arrangement in which we observe at the same time both corpuscular and wave aspects. In a two-slit experiment, they would correspond, respectively, to the which-way knowledge and the observation of interference pattern. Bohr showed this mutual exclusivity in numerous examples , and linked it to the unavoidable disturbance inherent in any measurement event. In quantum mechanical formalism, the complementarity principle has a clear mathematical expression: two observables are complementary if precise knowledge of one of them implies that all possible outcomes of the other are equally probable; their extension to classical concepts (as wave and particle) is not concerned. In 1991 Scully et al published a variant of the two-slit experiment that incorporates two micromasers cavities and a laser beam to provide which-path information without net momentum transferred during the interaction ; the impossibility of know which slit an atom went through and still observe the interference fringes is preserved by the establishing of quantum correlations between the measuring apparatus and the system being observed. They claimed that complementarity, of which wave-particle duality would be to them a manifestation, is more fundamental than the uncertainty principle . In 1996 B-G. Englert, following an approach originally due to Wooters and Zurek , derived , without making use of Heisenberg’s uncertainty relation, an inequality that quantifies the mutual compatibility relation between fringe visibility and which-way information. The inequality, that they denominated as “interferometric duality”, has the expression D^2 + V^2 ≤ 1, where D stands for the distinguishability of the ways and V for the fringe visibility; both of them are mathematical expressions that can be measured to check experimentally the inequality . Today, it is clear that intermediate particle-wave behaviours exist and, in addition to that, there are single experiments in which both classical wave-like and particle-like behaviours are showed total and simultaneously on an individual system. For instance, in the Bose’s double-prism experiment , tunnelling and perfect anticoincidence were observed in single photon states. Consequently, the meaning of the wave-particle duality must incorporate the simultaneous use of the two classical descriptions in the interpretation of experiments, loosing their original mutual exclusivity , which is incorporated as an extreme case in the new interferometric duality, a continuous quantum concept . The wave-particle duality, therefore, must be formulated as an interpretative addition to quantum mechanics, to which is possible to renounce if any pretension of visualize quantum phenomena in terms of classical concepts and intuitions is abandoned.