A blog has sprung up here. Presently from the recesses of a chaotic and a confused mind space, and re-looking at one of my first loves unintentionally (And ah! a momentary break from finance), here is a little wayward muse on penetrating quantum epistemology versus ontology dichotomy, which has been brewing contentions upon contentions. If the dichotomy remains unresolved, then there are fecund grounds of falsities, and confusions rule. We call physicists as ontological realists since they deal with the outside world, and it is ontological realism that gets opposed to idealism. Let us halt for a moment and reflect if in the dichotomy of ontological realism versus idealism (I am parking epistemological realism for the time being, as it is in a halted state), would idealism mean dressing up in the garb of anti-realism? Fair enough question to spring up. Right? Anti-realism means that only phenomena have real existence, and behind the scenes of phenomena, this reality of the existence vanishes. We somehow cannot account for noumena then. This makes it difficult for physicists to accept the tag of anti-realists. Moving on from here, I unlock the halt status now: Epistemological realism’ refers to a certain way of attributing physical meaning to the terms of a physical theory. Hence, ‘epistemological realism’ is about interpretation, that is, about ‘what one thinks the theory is describing’. An interpretation of a physical theory in which the (theoretical) terms are taken in an ‘epistemologically realist’ sense, is referred to as a realist interpretation. At the epistemological level a ‘realist interpretation’ may be involved in different dichotomies. First, the ‘realist interpretation’ may be opposed to the instrumentalist one’. Another dichotomy is that between realist and empiricist interpretations. This latter dichotomy is expressing the possibility that the mathematical formalism of quantum mechanics may be thought either to refer to the microscopic objects themselves (realist interpretations), or to macroscopic phenomena that are directly observed (empiricist interpretation). It is important to distinguish ontological and epistemological levels of discourse. Physicists usually combine ‘ontological realism’ with the ‘realist’ interpretation of ‘epistemological realism’. That’s why the distinction is often not noticed. However, it is very well possible to combine ‘ontological realism’ with an empiricist interpretation. There is a difference between quantum mechanics (the theory) and the reality it is describing (electrons etc.). Electrons are not wave packets flying around in space: electrons are physical objects, wave packets are theoretical notions. Probably the only way to have a wave packet flying in space is by throwing one’s quantum mechanics textbook!!!. If a quantum mechanical observable were a Hermitian operator, one could observe it by looking into one’s quantum mechanics textbook. Unfortunately, these trivial remarks are not superfluous because whole generations of physicists have been trained to think about electrons as ‘wave packets flying around in space’, and to look upon values of Hermitian operators as ‘properties of microscopic objects’ (sorry for the technicalities here: In brief, There is a special class of operators which are called Hermitian operators. They are of particular importance in quantum mechanics because they have the property that all of their eigenvalues are real (not complex).
This is convenient for the measurement outcome of any experiment must be a real number. There are non-Hermitian operators, but they do not correspond to observable properties. All observable properties are represented by Hermitian operators (but not all Hermitian operators correspond to an observable property)). Moving on, One should know of the possibility that quantum mechanics is not the ‘theory of everything’, yielding a complete description of ‘all there is’, but that it may only be yielding a description of certain aspects of microscopic reality, much in the same way as classical mechanics just describes certain aspects of macroscopic reality. The domain of application of quantum mechanics is microscopic reality. It is an open question whether this domain can be extended either to the macroscopic world or to the far submicroscopic world at the Planck length. Of course, it is recommendable to explore the applicability of quantum mechanics by applying it to experiments on a wider set of objects than just the microscopic ones (for instance, mesoscopic objects and submicroscopic elementary particles), but there is no warrant that this will keep working all the way up to the macroscopic and/or down to the submicroscopic domains. The idea that quantum mechanics should also be applicable to the macroscopic and submicroscopic worlds is a consequence of a scientific methodology in which theories are supposed to be either true (i.e. universally applicable) or false.