Russell, do you believe that Schrödinger's cat is in a superposition of dead and alive before we open the box?
On Monday, May 29, 2017 at 3:26:49 PM UTC+10, Bruce wrote: > > On 29/05/2017 2:52 pm, Russell Standish wrote: > > On Mon, May 29, 2017 at 11:26:18AM +1000, Bruce Kellett wrote: > >> There is another question as to whether we are in a superposition, > >> of say red and green T.Rexes, but that they are in separate > >> decohered worlds and the overlap function is zero FAPP, as Russell > >> says. I don't think such a question has a definitive answer. Despite > >> what some people say, viz., that in the QM MWI, everything that is > >> possible happens in some branch or other, I don't think that the > >> branches of the quantum tree necessarily pass through every point in > >> the possibility space. Quantum evolution in the Everettian picture > >> is strictly deterministic, so if some apparently possible state of > >> affairs is not consistent with the initial conditions, then if will > >> never appear anywhere. Given any particular imagined possibility, > >> one cannot say whether it occurs in some world or other, or in no > >> world whatsoever. > >> > > It is true that you have laid bare an unstated assumption - that the > > two different coloured T. Rexes are compatible with the universe's > > initial conditions, as we know them. Obviously, if it possible to > > deduce the colour of T. Rexes from first principles without making any > > further measurements, then we don't live in such a superposition. But I > > still think that if it requires a measurement (no matter how indirect) > > to determine the fact of colour, than we do live in a superposition. > > I don't think that follows. If the initial conditions are such that only > red T. Rexes can evolve, it would still require a colour measurement to > determine that colour. There would be no superposition of different > coloured T. Rexes, with or without any necessary measurement. The point, > I think, is that colour, in the sense that we are using that concept > here, is really a classical property that does not necessarily exist in > superpositions. > > Bruce > -- 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.
