> On 21 Aug 2018, at 15:51, Bruno Marchal <[email protected]> wrote: > > The symmetry is destroyed from the perspective of the one doing the > experiment. But it is extended to the couple Alice + the singlet state, > although “rational symmetry” might be have its usual definition slightly > enlarged.
Of course I meant "rotational symmetry. Not "rational”! Bruce, let add this. The “problem” with quantum mechanics is that a system can have a precise state without its subsystem having any definite state. But each subsystem can still have perfectly definable relative state with respect to another subsystem. The universal wave, if that exists, might not have any well defined subway, but all relative histories admitting consistent histories to develop exists, in my way to understand Everett. It is not much that the singlet state describe a collection of different sort of superposition, it is that a superposition is equal to a different superposition, which could have been selected would Alice changed its mind. When I will be back to QM in my course, I will try to analyse this on the GHZ state with my student. Plausibly. Anyway, if the wave is the correct description of physics, when we use the mechanist theory of mind, like Everett, the wave itself has to be recovered by a solution of a more complex measure problem, but for which computer science and mathematical logics provides many technical tools. Bruno -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
