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. Cheers -- ---------------------------------------------------------------------------- Dr Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Senior Research Fellow hpco...@hpcoders.com.au Economics, Kingston University http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.