This thesis is an examination of the measurement problem from within the Copenhagen interpretation of quantum mechanics where I take issue with von Neumann’s theory of measurement which argues for the subjective collapse of the wave function by a conscious observer. I argue that von Neumann’s postulate of collapse has led to several intractable philosophical and conceptual problems in its account of quantum measurement. I argue that these problems arise from von Neumann’s misreading of Bohr’s complementarity regarding the relationship between subject and object as distinct metaphysical entities. Instead, I offer a new way of defining the subject-object relation based on Don Howard’s reading of Bohr’s complementarity as subject-object nonseparability (SON). I argue that the SON principle has the potential of placing Copenhagen on more solid philosophical footing by viewing the subject-object relationship not as a causal relation, but as a relation of ontological dependence to avoid the idea of collapse altogether.
This thesis is an examination of the measurement problem from within the Copenhagen interpretation of quantum mechanics where I take issue with von Neumann’s theory of measurement which argues for the subjective collapse of the wave function by a conscious observer. I argue that von Neumann’s postulate of collapse has led to several intractable philosophical and conceptual problems in its account of quantum measurement. I argue that these problems arise from von Neumann’s misreading of Bohr’s complementarity regarding the relationship between subject and object as distinct metaphysical entities. Instead, I offer a new way of defining the subject-object relation based on Don Howard’s reading of Bohr’s complementarity as subject-object nonseparability (SON). I argue that the SON principle has the potential of placing Copenhagen on more solid philosophical footing by viewing the subject-object relationship not as a causal relation, but as a relation of ontological dependence to avoid the idea of collapse altogether.
The field of interpretation of quantum mechanics emerged in an attempt to solve the measurement problem. This turned on the perception that Niels Bohr avoided addressing the measurement problem by taking an instrumentalist view of quantum mechanics. I argue that this view is mistaken and Bohr's interpretation of quantum mechanics is realist. Moreover, Bohr's interpretation, which is different from textbook quantum mechanics (which is due more to Von Neumann and Paul Dirac), succeeds in solving the measurement problem. While the claim that Bohr dissolves the measurement problem within the limits of the epistemological framework he assumes has been made by a few authors, rarely has the case been made that Bohr's project unambiguously and completely overcomes the measurement problem. I make the strong case that Bohr eliminated the measurement problem altogether. For this, I put forward two new postulates through which to make sense of Bohr's interpretation. The article thus seeks to single out Bohr's interpretation from the various views that go together under the umbrella of orthodox quantum mechanics, and which have been traditionally considered susceptible to the measurement problem. It shows that Bohr's interpretation should be classified along with those like hidden variable theories, collapse models, modal interpretations etc., which offer a solution to the measurement problem and are committed to a realist ontology.
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.
The Copenhagen interpretation, which informs the textbook presentation of quantum mechanics, depends fundamentally on the notion of ontological wave-particle duality and a viewpoint called “complementarity.” In this paper, Bohr's own interpretation is traced in detail and is shown to be fundamentally different from and even opposed to the Copenhagen interpretation in virtually all its particulars. In particular, Bohr's interpretation avoids the ad hoc postulate of wave function ‘collapse’ that is central to the Copenhagen interpretation. The strengths and weakness of both interpretations are summarized.
Abstract In this paper, I suggest that a closer look at Bohr’s analogies to psychology helps us to better understand his interpretation of quantum measurement and how he conceived of the role of the subject in quantum physics. This focus helps us to pinpoint how Bohr’s view on quantum measurement differed from John von Neumann’s and Wolfgang Pauli’s understandings of it. I argue that Bohr’s interpretation of quantum measurement was about ensuring that quantum mechanics is an objective description of quantum phenomena. For Bohr, objective knowledge meant knowledge that can be communicated unambiguously, which requires that there is a sharp division between subject and object. He was adamant that in physics, there is such a sharp division, including in quantum physics. Therefore, he argued, there is no measurement problem in quantum physics.
Quantum-mechanical interpretation-related implications of the theory of unitary premeasurement [1] on complete measurement (objectification or collapse included) are investigated in the present article with a view to give an affirmative answer to the question in the title. It is argued that both Bohr's and von Neumann's ideas lead to those of Everett. Hence, the latter can be, in some sense, considered to be a continuation and elaboration of both former approaches. The importance of the idea of relativeness in Everett's theory is emphasized. To free the relative-state theory from its roots both of classicalness and of subjective observation in the argument of this study, the general or unfolded version of Everett's theory is sketched.
Duality, not monism, constitutes the hermeneutic lens that characterizes the original Copenhagen interpretation of Quantum Mechanics. Therefore, evoking the principles of correspondence and complementarity, in this work we re-assert a dual-aspect reading of quantum theory, structured through a multi-perspective schema encompassing its ontological, analytical, epistemological, causal, and information dimensions. We then show how this schema dissolves the so-called 'measurement problem', along with the associated 'knowledge-information' and 'macro-micro' dichotomies, issues historically raised within later monistic or universalist philosophical settings that ultimately depart from the traditional Copenhagen spirit.