Aeon has just re-sent this essay from last spring in which Jim Baggot discusses, and thereby contributes to, the ongoing public fixation about Schrödinger’s un(?)dead cat. But while Baggot’s professed emphasis is more on the history of the meme than its implications, the (now closed) comments focus more on the latter. And despite the evident irritation in his responses, this should be unsurprising as he persists in identifying things that are seen by some as paradoxical and/or indicative of incompleteness in the theory without giving any indication of widely accepted resolutions. One such alleged resolution is the understanding that the quantum state of a system is not a property just of the system itself but of its relation to an observer from which it is temporarily isolated. The question of whether or not such a state is all that is “real” or just a “mathematical trick” begs that of what, if anything, is meant by “reality” in the first place. And the question of how big a system must be in order for classical physics to apply should not be raised without giving the obvious answer that it’s not the size of the system but its isolation that matters – and there is no inherent limit on the size of a system that can in principle be suitably isolated. With increasingly sophisticated experiments it is becoming possible to truly isolate larger and larger systems, but to truly isolate the cat in the story would require a mechanism of such complexity that it might seem quite natural to accept absolute uncertainty as to whether anything “real” was happening inside it.
Source: No, Schrödinger’s cat is not alive and dead at the same time | Aeon Essays