Wholeness, measurement and hidden variables : a study of philosophical problems in non-relativistic quantum mechanics

Kurt H�bner

William Demopoulos

Abstract A central problem in the interpretation of non‐relativistic quantum mechanics is to relate the conceptual structure of the theory to the classical idea of the state of a physical system. This paper approaches the problem by presenting an analysis of the notion of an elementary physical proposition. The notion is shown to be realized in standard formulations of the theory and to illuminate the significance of proofs of the impossibility of hidden variable extensions. In the interpretation of quantum mechanics that emerges from this analysis, the philosophically distinctive features of the theory derive from the fact that it seeks to represent a reality of which complete knowledge is essentially unattainable.

Dirk John Pons, Arion Douglas Pons, Aiden Jasper Pons

Problem: Superposition and entanglement are coherent effects, which can be quantified by quantum mechanics (QM), but lack descriptive explanations. They are typically analysed with inequality methods, and the results favour QM and reject physical realism and hidden-variable solutions. In particular, Colbeck & Renner (2011) showed that no extension of quantum theory can exist with better predictive power than quantum mechanics itself. Purpose: The purpose here is to critically evaluate from a conceptual and philosophical perspective the ontological underpinnings of the inequality approach. The current work is speculative in nature as it is based on a conjectured non-local hidden-variable (NLHV) design for particles, and does not yet have a mathematical formalism. Nonetheless this is worth attempting for the philosophical questions it poses about the nature of reality, and the pointers it gives to possible future directions in fundamental physics. Findings: The premises of the C & R proof (that particles are points, that locality exists, that quantum theory is correct) are inconsistent, hence invalidate its conclusion. We also show that superposition and entanglement may be qualitatively explained if particles were to have the internal structure proposed by the Cordus NLHV theory. Originality: The ability to explain superposition and entanglement conceptually in terms of physical realism is relevant because it rebuts the claim that it is impossible that such a hidden-variable theory could exist. This is significant because previously it has been believed that these phenomena are explainable by QM only.

Mansouri Ali Reza

Graeme Donald Robertson

What is a physical object according to the theory of quantum mechanics? The first answer to be considered is that given by Bohr in terms of the concept of complementarity. This interpretation is illustrated by way of an example, the two slit experiment, which highlights some of the associated problems of ontology. One such problem is the so-called problem of measurement or observation. Various interpretations of measurement in Quantum Theory, including those of Heisenberg, von Neumann, Everett and Bohr, are compared and contrasted. A second problem concerns whether or not QT can be considered complete and therefore satisfactory as a basis for physics. Various attempts to complete QT by means of the addition of ‘hidden variables’ to the quantum mechanical state function are considered and their aims and achievements assessed. Finally, we investigate some of the characteristic ontological problems for the orthodox interpretation of Relativistic Quantum Theory.