The Copenhagen Viewpoint On Schrödinger's Cat Viewed Through Systemic Functional Linguistics

Penrose (2004: 805):

Consider the Copenhagen viewpoint (a). As far as I can make out, this interpretation would simply regard the photon detector to be a ‘classical measuring device’, to which the rules of quantum superposition are not applied. The photon state between its emission and its detection (or non-detection) by the device is described by a wavefunction (state-vector), but no ‘physical reality’ is assigned to that. The wavefunction is used merely as a mathematical expression to be used for calculating probabilities. If the beam splitter is such that the photon amplitude is divided equally into two, then the calculation tells us that there is a 50% chance for the detector to register reception of the photon and a 50% chance that it will not. Therefore there is a 50% chance that the cat will be killed and a 50% chance that it will remain alive. 

This is physically the correct answer, where ‘physically’ refers to the behaviour of the world that we actually experience. Yet this description provides us with a very unsatisfactory picture of things if we wish to pursue the physical events in greater detail. What actually goes on inside a detector? Why are we allowed to treat it as a ‘classical device’ when, after all, it is constructed from the same quantum ingredients (protons, electrons, neutrons, virtual photons, etc.) as any other piece of physical material, large or small? I can well appreciate that, in the early days of quantum mechanics, something of the nature of Niels Bohr’s perspective on the subject was almost a necessity, so that the theory could actually be used, and progress in quantum physics could be made. Yet, as far as I can see, such a perspective can only be a temporary one, and it does not resolve the question of why, and at what stage, ‘classical behaviour’ might arise for large and complicated structures like ‘detectors’. Since viewpoint (a) requires such ‘classical structures’ for its interpretation of quantum mechanics, it can only be a ‘stop-gap’ position, in which the deeper issues concerning what actually constitutes a measurement are not addressed at all.

Blogger Comments:

From the perspective of Systemic Functional Linguistic Theory, the rules of quantum superposition do not apply to the (observed) photon detector because quantum superposition applies only to potential meaning.

The photon state when it is not observed, as described by the wavefunction, is potential 'physical reality', and probability is the quantification of that potential meaning.

What goes on inside the detector, like the detector itself, is potential meaning until it is observed, and thereby construed as an instance of meaning.

The problems of quantum physics are solved by taking an immanence view of meaning and by distinguishing potential meaning from instances of that potential.