Contrary to Mermin, Bohr Did Acknowledge a Significant Quantum Measurement Problem - The Importance of William James, The Early American Psychologist, To Bohr, Mermin, And Carroll’s Epistemic Option For Quantum Measurement

James’s complementarity works very well with the proofs that are at the heart of null and positive measurements in quantum mechanics. It is important for the physics community to know that complementarity originated in psychology in 1890, in the work of William James, to know James’s finding that “the total possible consciousnesses may be split into parts which coexist but mutually ignore each other, and share the objects of knowledge between them.” The human observer is central in James’s formulation of complementarity. Consciousness and knowledge are essential. It appears that James’s concept of complementarity may truly characterize what Carroll is referring to as the epistemic option. It seems it is likely the correct conceptual model for quantum mechanical measurement. For example, there can be no hidden physical variables with a null measurement because the outcome of a null measurement as discussed above is not dependent on a physical interaction. Bohr was open to ideas from psychology. Bohr borrowed James’s complementarity and adapted it for physics by introducing an unavoidable physical interaction between a physical measuring instrument and the physical system measured. This physical interaction has an aspect that cannot be controlled. This lack of control allowed Bohr to apply the uncertainty principle. Bohr’s complementarity for physics is unwarranted. Once there is a logical proof that the electron will not pass through one of the slits, the wave component associated with the slit through which the electron does not pass vanishes. No superposition is possible because that wave component has vanished. Contrary to Mermin, Bohr did acknowledge a significant quantum measurement problem. Bohr held to his view discussed above of complementarity for physics instead of adopting James’s approach where the knowing individual is directly related to the physical system measured as an object of knowledge. Perhaps through the collaboration of physics and other fields, in particular psychology, further progress can be made in developing a self-consistent view of quantum mechanical measurement that is supported by empirical evidence.