If I have two linear polarizing filters that are at 0º and 45º, then 50% of the photons from a source of non-polarized light will pass through the first first, and 50% of these will pass through to the second filter:
It is correct to say that the photons between the 0º filter and the 45º filter are in the "cat state" ?
Wikipedia defines the so-called cat state as "a quantum state that is composed of two diametrically opposed conditions at the same time, such as the possibilities that a cat be alive and dead at the same time." Part of my confusion is that it would seem that Schrödinger's wave equation allows every particle to be described as a linear combination of any number of other wave equations, so it would seem that every particle is always in a cat state, and that the term in meaningless. I gather that there isn't anything fundamentally different between the photons about to hit the filter that's at 0º and the filter that's at 45º—in both cases only 50% of the photons will proceed. But that's this diagram. If the second filter was also at 0º, then all of the photons passing through the first would pass through the second. So would they be in the cat state then?