[edit: found another comment which you replied to, and now I see that you already knew all this. Oops. Original comment follows] Maybe you know the thing I’m a

[edit: found another comment which you replied to, and now I see that you already knew all this. Oops. Original comment follows] Maybe you know the thing I’m about to say and just consider it to be too pedantic, but: The question to ask of a system is not [whether it is “in a superposition” or “not in a superposition”], but rather, [whether it is “in a superposition of these different states” or “in a specific one of these states”]. Suppose I have a particle which I know is spin up (ignore the position aspect of things, considering only the spin). Is it “in a superposition”? One might be tempted to say “no, it is spin up.”, but the correct response is “A superposition of what? Anything? If so, then trivially yes.” . Because “spin up” can be regarded as a superposition of “spin left” and “spin right”, or as “spin northeast” and “spin southwest”. Likewise, “spin left” can be regarded as a superposition of “spin up” and “spin down”. To usefully ask whether something is “in a superposition”, you have to specify what states you are regarding as the basis, as far as the question is concerned (or, alternatively, with respect to what observables, where “in a superposition with respect to those observables” would mean that if those observables were measured, the result would be random* ). Now, why don’t we observe superpositions of states of macroscopic things which differ according to ordinary observables such as “x coordinate of center of mass”? In don’t know. That may be something still not understood. I don’t really understand these attempts, but I think there are things called “pointer states” and a process known as “einselection” which are supposed to help explain that? (Though it has been argued that this explanation involving einselection may be somewhat circular?)