At 10:54 AM 11/6/2008, Bruno Marchal wrote:

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>On 06 Nov 2008, at 02:37, Thomas Laursen wrote: > > > > > Hi everyone, I am a complete layman but still got the illusion that > > maybe one day I would be able to understand the probability part of MW > > if explained in a simple way. I know it's the most controversal part > > of MW and that there are several competing understandings of > > probability in MW, but still: none of them make sense to me! If every > > line of history is realized then how can any line of history be more > > probable than any other? > >Wolf's answer is probably correct, but certainly incomplete. If you >take QM (without collapse) norma distribution and measure can be >extracted from Gleason theorem. Born rule can be deduce from first >person indeterminacy or more politically correct variant through >decison theory (like Deutsch and Wallace). It is a whole field. My >point in this list consists to show that if you assume the mechanist >thesis (like Everett) then even if Deutsch proposal works it is not >enough to justify the probabilities. There is a big work which remains >to be done, but it has the advantage of taking into account the non >communicable part of the experiments (usually known as "the >experience"). But there are more abherant histories to evacuate (like >infinities in field theories). > >Anna Wolf's answer can be wrong in case physics is eventually purely >discrete, in which case probabilties should arise from pure relative >proportion based on dircrete relative partitioning of the multiverse. >I think the comp hyp excludes this though, like I think M theory, as >far as I grasp something there, too. Loop gravity, if literally true, >could lead to such ultimate discretization or provide models. > >For each position of an electron in your brain there is a (quantum) >computational history going through that state, and probabilities are >eventually all related self-indiscernibility relations (if it is >english). > >Bruno Marchal > >http://iridia.ulb.ac.be/~marchal/ > > >First of all, Bruno, that answer seemed Palenesque in the extreme, >even for someone whose job it is to know this stuff. The >correspondent indicated his was a layman's perspective. How about >another go at it without shortcut references to Born, David Deutsch, >Wallace (who?) et al. As a firm believer in the adage that one who >really knows the subject should be able to explain it in such a way >that a bright ten-year-old can understand the concept. >R Miller > --~--~---------~--~----~------------~-------~--~----~ 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?hl=en -~----------~----~----~----~------~----~------~--~---