Huw Price [Show Biography] and Ken Wharton [Show Biography]

Quantum weirdness has been in the news recently, thanks to an ingenious new experiment by a team led by Roland Hanson, at the Delft University of Technology. Much of the coverage presents the experiment as good (even conclusive) news for spooky action-at-a-distance, and bad news for local realism. We point out that this interpretation ignores an alternative, namely that the quantum world is retrocausal. We conjecture that this loophole is missed because it is confused for superdeterminism on one side, or action-at-a-distance itself on the other. We explain why it is different from these options, and why it has clear advantages, in both cases.

]]>Andreas Schlatter [Show Biography]

We investigate the role of time and space from the perspective of the basic notions of “change” and “identity”. We formally analyze these notions and find primitive aspects of time and space, which we then rediscover in a realist model of quantum physics and in relativity. By our analysis of time and space we gain a coherent perspective on the relationship between both theories.v

]]>James L. Beck [Show Biography]

John Bell and others used a locality condition to establish inequalities that they believe must be satisfied by any local hidden-variable model for the spin probability distribution for two entangled particles in an EPR-Bohm experiment. We show that this condition is invalid because it contradicts the product rule of probability theory for any model that exhibits the quantum theory property of perfect correlation. This breaks the connection between Bell inequalities and the existence of any local hidden-variable model of interest. As already known, these inequalities give necessary conditions for the existence of third/fourth-order joint probability distributions for the spin outcomes from three/four separate EPR-Bohm experimental set-ups that are consistent with the second-order joint spin distributions for each experiment after marginalization. If a Bell inequality is violated, as quantum mechanics theory predicts and experiments show can happen, then at least one third-order joint probability is negative. However, this does not imply anything about the existence of local hidden-variable models for the second-order joint probability distributions for the spin outcomes of a single experiment. The locality condition does seem reasonable under the widely-applied frequentist interpretation of the spin probability distributions that views them as real properties of a random process that are manifested through their relative frequency of occurrence, which gives conditioning in the probabilities for the spin outcomes a causal role. In contrast, under the Bayesian interpretation of probability, probabilistic conditioning on one particle’s spin outcome in the product rule is viewed as information to make probabilistic predictions of the other particle’s spin outcome. There is nothing causal and so no reason to develop a locality condition. Thus, how probability is to be interpreted is critical to understanding quantum entanglement and locality.

]]>Christos Dedes [Show Biography]

A non-linear backward equation with diffusive terms is postulated for the probability density that depends on the Bohmian quantum potential. An associated nonlinear Schroedinger equation is also introduced and extension of the analysis to several particle compounds is sketched along with the implications following from this formalism regarding the non-conservation of probability in the non-equilibrium regime. Some further conclusions are educed with respect to the generalized optical theorem.

]]>Salim Yasmineh [Show Biography]

This paper aims to give an alternative interpretation of quantum mechanics based on conjecturing the existence of a hidden infinitesimal complex time. It is shown that many features of quantum mechanics emerge from the conjectured hidden-time. The goal of this paper is to better understand quantum phenomena or at least to render them more logical to our understanding.

]]>Daniel Shanahan [Show Biography]

Various attempts at a thoroughly wave-theoretic explanation of matter have taken as their fundamental ingredient the de Broglie or matter wave. But that wave is superluminal whereas it is implicit in the Lorentz transformation that influences propagate ultimately at the velocity c of light. It is shown that if the de Broglie wave is understood, not as a wave in its own right, but as the relativistically induced modulation of an underlying standing wave comprising counter-propagating influences of velocity c, the energy, momentum, mass and inertia of a massive particle can be explained from the manner in which the modulated wave structure must adapt to a change of inertial frame. With those properties of the particle explained entirely from wave structure, nothing then remains to be apportioned to anything discrete or “solid” within the wave. Consideration may thus be given to the possibility of wave-theoretic explanations of particle trajectories, and to a deeper understanding of the Klein-Gordon, Schroedinger and Dirac equations, all of which were conceived as equations for the de Broglie wave. It is argued that this wave-theoretic interpretation of matter favours a physically realistic, rather than inherently probabilistic, interpretation of quantum mechanics.

]]>Peter J. Lewis [Show Biography]

This is a review of Michael Silberstein, W. M. Stuckey, and Timothy McDevitt’s book Beyond the Dynamical Universe: Unifying Block Universe Physics and Time as Experienced (Oxford University Press, 2018).

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Travis Norsen [Show Biography]

]]>Anthony Sudbery [Show Biography]

This note is a critical examination of the argument of Frauchiger and Renner, in which they claim to show that three reasonable assumptions about the use of quantum mechanics jointly lead to a contradiction. It is shown that further assumptions are needed to establish the contradiction, and that each of these assumptions is invalid in some version of quantum mechanics.

]]>Aurélien Drezet [Show Biography]

This is an analysis of the recently published article “Quantum theory cannot consistently describe the use of itself” by D. Frauchiger and R. Renner [1]. Here I decipher the paradox and analyze it from the point of view of de Broglie-Bohm hidden variable theory (i.e., Bohmian mechanics). I also analyze the problem from the perspective obtained by the Copenhagen interpretation (i.e., the Bohrian interpretation) and show that both views are self consistent and do not lead to any contradiction with a `single-world’ description of quantum theory.

]]>Mohammed Sanduk [Show Biography]

The imaginary *i* in the formulation of the quantum mechanics is accepted within the axioms of the quantum mechanics theory, and, thus, there is no need for an explanation of its origin. Since 2012, in a non-quantum mechanics project, there has been an attempt to complexify a real function and build an analogy for relativistic quantum mechanics. In that theoretical attempt, a partial observation technique is proposed as one of the reasons behind the appearance of the imaginary *i*. The present article throws light on that attempt of complexification and tries to explain the logic of physics behind the complex phase factor. This physical process of partial observation acts as a process of physicalization of a virtual model. According to the positive results of analogy, the appeared imaginary *i* in quantum mechanics formulation *may b*e related to a partial observation case as well.