Abstract We argue that the formalism of quantum theory can be given an empirical interpretation (in the sense of a connection with observable phenomena) in the same way as in any other empirical theory. In particular, there is no need to supplement the unitary time evolution governed by a Schrödinger‐type of equation with a “projection postulate” that applies only to measurements. As a consequence, the quantum formalism has the same status as the formalisms of older physical theories, and is capable of the same philosophical interpretations. The most natural interpretation, we argue, is to conceive of the formalism as an objective – although highly abstract – description of reality.
Abstract We argue that the formalism of quantum theory can be given an empirical interpretation (in the sense of a connection with observable phenomena) in the same way as in any other empirical theory. In particular, there is no need to supplement the unitary time evolution governed by a Schrödinger‐type of equation with a “projection postulate” that applies only to measurements. As a consequence, the quantum formalism has the same status as the formalisms of older physical theories, and is capable of the same philosophical interpretations. The most natural interpretation, we argue, is to conceive of the formalism as an objective – although highly abstract – description of reality.
The traditional, standard approach to quantum theory is to assume that the theory ``really'' contains only unitary physical dynamics--i.e., that the only physically quantifiable evolution is that given by the time-dependent Schrodinger equation. This leads to two distinct classes of interpretations for the standard theory in its orthodox form: (i) an Everettian-type approach assuming that all mutually exclusive outcomes occur in different ``branches'' of the universe; or (ii) single-outcome approaches that assume a ``projection postulate'' (PP) with no accompanying physical account within quantum theory. A contrasting, unorthodox approach is to suggest forms of quantum theory that involve physical non-unitarity; these are called ``objective collapse models.'' Among these are Penrose's theory of gravitation-induced collapse and the Transactional Interpretation. The primary focus of this paper is an example demonstrating that standard quantum theory (with or without the projection postulate) can in-principle yield empirically consequential inconsistencies. Thus, it appears that for quantum theory to be viable in a realist sense (as opposed to being an instrumentalist protocol in which inconsistencies are evaded by changing the protocol), it must possess genuine, physical non-unitarity yielding well-defined single outcomes. This leads to the conclusion that objective collapse models should be more seriously considered.
We argue that quantum mechanics makes sense without such controversial postulates as the wave function collapse, the quantum probability rule and the observable postulate. We only need the existence of a wave function as a representation of a state, its dynamical evolution rule and another rather trivial postulate proposed here (Read-Off Postulate). The wave function collapse and the probability rule are replaced with intrinsic properties of the theory, i.e. decoherence and relative frequency, respectively. Interpretation of the wave function as a faithful representation of the reality naturally emerges, although quantum reality has a peculiar feature which distinguishes it from classical reality.
Despite the unparalleled accuracy of quantum-theoretical predictions across an enormous range of phenomena, the theory's foundations are still in doubt. The theory deviates radically from classical physics, predicts counterintuitive phenomena, and seems inconsistent. The biggest stumbling block is measurement, where the Schrodinger equation's unitary evolution seems inconsistent with collapse. These doubts have inspired a variety of proposed interpretations and alterations of the theory. Most interpretations posit the theory represents only observed appearances rather than reality. The realistic interpretations, on the other hand, posit entities such as other universes, hidden variables, artificial collapse mechanisms, or human minds, that are not found in the standard mathematical formulation. Surprisingly, little attention has been paid to the possibility that the standard theory is both realistic and correct as it stands. This paper examines several controversial issues, namely quantization, field particle duality, quantum randomness, superposition, entanglement, non-locality, and measurement, to argue that standard quantum physics, realistically interpreted, is consistent with all of them.
The article discusses approaches to understanding the nature of probability in mathematics and physics with the consequences of these approaches, as well as the difficulties that arise. The ontological status of probability is discussed. It is shown that probability theory, contrary to R. Mises, should be classified as a mathematical science, using the definition formulated by A.N. Kolmogorov. The application of this definition in practice is provided within the framework of the classical approach, provided that the connection with physical reality is defined through the concept of equal opportunity. To do this, the concepts of simple and complex events are introduced, and the method of decomposing complex events into simple ones is explained. The point of view is substantiated, according to which a mathematical probability determined and related to physical reality in this way can be considered an objective probability, that is, existing independently of any tests. Various interpretations of quantum mechanics and approaches to understanding probability are also revealed. It is shown that in physics today the existing approaches to understanding the nature of probability contradict each other. In the Bohm interpretation, probability is an analogue of the classical approach – statistical objective probability, which has a mathematical formalization, and in quantum Bayesianism, probability quantifies the degree of reliability and depends on the subject conducting the experiment. The Copenhagen interpretation of quantum mechanics tries to eliminate the difficulties associated with combining the wave and corpuscular properties of light and electron beams into a single picture by giving the ontological status of probability, which leads to the problem of understanding physical reality. The article argues for the need for a new connection between the mathematical description of probability and physical reality. The empirical (frequency) approach of R. Mises is analyzed, which causes a lot of criticism, as it does not have a clear consistent formalization. The article argues that this approach is inconsistent with quantum mechanics. The probability given by M. Born in the Copenhagen interpretation of quantum mechanics is also considered, which formulates a new definition of probability, which does not exclude the difficulties associated with the physical interpretation of probability. Born’s approach is based on the classical approach and is reduced to a formal axiomatic definition, which assumes the interpretation of probability as a mathematical construct. The connection of probability with physical reality and the consistency of the statistical method of finding probability values remain unresolved problems, which creates a dualism of understanding probability: in mathematics – one thing, in physics – another. If in the mathematical approach, the solution of these problems is carried out through the connection of probability with physical properties, then in quantum mechanics, in the Copenhagen interpretation, problems persist, which is caused by giving the wave function an ontological status.
This chapter, based on the background information of the previous chapter, will review the formalism of quantum mechanics – its fundamental mathematical structure (the basic contents of Hilbert space representation and operator algebra representation) and physical assumptions (kinematics, dynamics, and measurement theory). These are the premise and foundation for discussing the quantum histories interpretation. Then, in combination with the viewpoints of some literature in recent years, we will explore what is the interpretation of quantum mechanics, analyze the relationship between the theory of quantum mechanics and its interpretation, and declare the author’s basic stance on these two issues. These two are the primary issues that all interpretive work in the philosophy of physics will face (not limited to the interpretation of quantum mechanics), and the necessary clarification here is also conducive to the subsequent discussion. Three common terms – theory, formalism, and interpretation – are explicated and differentiated by offering the necessary definitions of their meanings, based on the works of Acuña and Ruetsche. The clarification will help to make the subsequent related discussions more precise.
An interpretation of the quantum theory is proposed, allowing an explanation of the origins of the theory principles and its mathematical formalism. In contrast to the hitherto interpretations it is based on the ontology assuming existence of omniscience. The interpretation proposed explains ‐ in consistence with the relativity theory ‐ the results of the correlation experiments implying that an unobserved elementary particle does not exist objectively (beyond our consciousness) or that a quantum system makes o non-divisive unity bound through non-spacetime interactions. According to this interpretation, both these possibilities occur simultaneously.