Brent Meeker wrote: > Stathis Papaioannou wrote: > > > > > > Brent Meeker writes: > > > >>>>> If you died today and just by accident a possible next > >>>>> moment of consciousness was generated by a computer a trillion years in > >>>>> the > >>>>> future, then ipso facto you would find yourself a trillion years in the > >>>>> future. > >>>> That's the whole problem. I could just as easily find myself in an HP > >>>> universe. But I never do. > >>> Not "just as easily". If you are destructively scanned and a moment from > >>> now 2 copies > >>> of you are created in Moscow and 1 copy created in Washington, you have a > >>> 2/3 chance > >>> of finding yourself in Moscow and a 1/3 chance of finding yourself in > >>> Washington. It is a > >>> real problem to explain why the HP universes are less likely to be > >>> experienced than the > >>> orderly ones (see chapter 4.2 of Russell Standish' book for a summary of > >>> some of the > >>> debates on this issue), but it is not any more of a problem for a > >>> mathematical as opposed > >>> to a physical multiverse. > >> I'm not sure what a mathematical MV is: if you mean the Tegmark idea of > >> the set of all mathematically consistent universes then I think you're > >> wrong. There is no measure defined over that set (and I doubt it's > >> possible to define one). But the physical universe obeys the laws of QM > >> and it appears that eigenselection, as proposed by Zeh, Joos, and others, > >> may provide a natural measure favoring order. > > > > What if the set of all mathematically consistent universes were actually, > > physically instatiated? > > My point is that physical instantiation per se does not solve the HP > > problem, unless we say that > > only the non-HP universes are instantiated, making "multiverse" narrower > > than "all mathematically > > consistent universes". I gather that Tegmark's grand ensembles are not > > mainstream physics, even > > among those who accept the MWI. > > The MWI posits multiple worlds in which every evolution of the world > consistent with quantum physics is realized - it's really just one Hilbert > space and the "multiple" arises only because macroscopically different worlds > are projected onto orthogonal subspaces. But it is assumed that evolution in > this Hilbert space is due to one Hamiltonian with specific values of coupling > constants etc. Tegmark's "all mathematically consistent" universes would > seem to include a Newtonian universe, an Aristotelean universe, a Biblical > universe, and in fact any universe that didn't include a flat contradiction, > X and not-X. > > Brent Meeker
The "set of all mathematically consistent universes", i.e. defined by NOT(X and not-X), is very telling. A universe has to have some kind of coordinate/reference system and/or language/units in order for a property or predicate X to be able to be well-defined enough to define not-X. But once that is done, and it is determined that not-X does not hold, then there exists a change to the coordinate system or language that results in X and not-X. This argues for the essentiality of the definer. Otherwise no X could exist at all. Tom --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---
