… that’s not totally correct, because a macroscopic state, even in principle, cannot be a superposition of macroscopic eigenstates.
A macrosopic state is an actual physical state.
A macrosopic state, by definition, cannot be a superposition of different macroscopic states. A superposition must be of different macroscopically-indistinguishable microscopic states.
In other words, a physical state, by definition, cannot be a superposition of different physically-distinguishable physical states. A superposition must be of different physically-indistinguishable mathematical states.
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