On Tue, Sep 8, 2015 at 9:44 PM, Bruce Kellett <[email protected]> wrote:
> On 9/09/2015 12:26 pm, Stathis Papaioannou wrote: > > On 9 September 2015 at 10:43, Bruce Kellett <[email protected]> > wrote: > >> >> On 9/09/2015 9:30 am, Stathis Papaioannou wrote: >> >> On 9 September 2015 at 09:23, Bruce Kellett < <[email protected]> >> [email protected]> wrote: >> >>> On 9/09/2015 8:56 am, Stathis Papaioannou wrote: >>> >>> On 8 September 2015 at 22:11, Bruce Kellett < >>> <[email protected]>[email protected]> wrote: >>> >>>> On 8/09/2015 9:14 pm, Stathis Papaioannou wrote: >>>> >>>> On 8 September 2015 at 20:48, Bruce Kellett < >>>> <[email protected]>[email protected]> wrote: >>>> >>>>> On 8/09/2015 8:40 pm, Stathis Papaioannou wrote: >>>>> >>>>> >>>>> On 8 September 2015 at 17:39, Bruce Kellett < >>>>> <[email protected]>[email protected]> wrote: >>>>> >>>>>> On 8/09/2015 4:56 pm, Stathis Papaioannou wrote: >>>>>> >>>>>> I will ask you the same question as I did Brent: do you conclude from >>>>>> the fact that when you toss a coin it comes up either as head or tails >>>>>> that >>>>>> the world does not split into two parallel versions of you, one of which >>>>>> sees heads and the other tails? >>>>>> >>>>>> I would conclude that a coin toss does not provide any evidence for >>>>>> multiple worlds or a split. The only evidence we have from this data is >>>>>> that the outcome of the toss is uncertain. There is no evidence there for >>>>>> any split of anything. >>>>>> >>>>> >>>>> It is not evidence FOR a split but is it evidence AGAINST a split? >>>>> >>>>> >>>>> It is evidence that the assumption of a split is not necessary in >>>>> order to understand everyday happenings. So, by the application of Occam's >>>>> Razor, no split happens. >>>>> >>>> >>>> So you agree that we would still observe the probabilities we do if we >>>> lived in a deterministic world in whaich all possibilities are realised? >>>> >>>> No, because not all possibilities happen in this world. If all >>>> possibilities were realized in this world, then there would be no >>>> uncertainty, no probabilities. Possibility and actuality would be the same >>>> thing. All the horses would win the Melbourne cup; and we don't live in >>>> such a world. >>>> >>> >>> Obviously, not all possibilities happen in this world, but they might >>> happen in parallel worlds that don't interact with each other. The argument >>> is that probabilities emerge from this, since you don't know which world >>> you will find yourself in. You bet on the favourite in the race because you >>> think you are more likely to end up in a world in which the favourite wins. >>> >>> In other words, probabilities can make perfect sense in a single >>> deterministic world. This was understood a long time ago with the >>> development of statistical mechanics. The idea that "all possibilities >>> happen in parallel worlds" does not actually make a lot of sense. There is >>> no current physical theory that implies this (without the addition of a lot >>> of unevidenced assumptions). So probabilities do not emerge from this, they >>> come from quite simple assumptions of randomness and ignorance. >>> >>> Probability in the MWI of quantum mechanics is problematic. Regardless >>> of claims to be able to derive the Born Rule in Everettian models, all >>> attempts fail because they are circular -- they need the Born rule in order >>> to have non-interacting worlds, so you cannot then use these independent >>> worlds to derive the Born rule. Gleason's theorem is no help -- it suffers >>> from all the same problems as the Deutsch-Wallace approach. >>> >> >> You don't seem to be disputing that we would still experience a >> probabilistic world even if all possibilities were actually realised, even >> though you do dispute that we in fact live in such a world. >> >> I'm not sure if you are disputing that, to give a simple model case, if a >> coin was tossed and the world split in two, with one version of you seeing >> heads and the other tails, the probability of each outcome is 1/2. >> >> Whether or not all possibilities are realized, they are not in evidence, >> so their relevance to the question of probabilities is questionable. >> >> Your simple model case of a coin toss causing a world split is just a >> made-up example to give the result you want, so again its relevance is >> dubious. There is no sensible physical theory in which the world splits on >> classical coin tosses. >> > > If you can't imagine a world split, consider a virtual reality in which > the program forks every time a coin is tossed, one fork seeing heads and > the other tails. You are an observer in this world and you have this > information, so you know for certain that "all possibilities are realised" > when the coin is tossed. What would you say about your expectation of > seeing heads? > > I presume you mean that the world is duplicated on each toss, with one > branch showing each outcome. We are back to the dreaded "person > duplication" problem. My opinion on this is that on such a duplication, two > new persons are created, so the probability that the original person will > see either heads or tails is precisely zero, because that person no longer > exists after the duplication. > So if some aliens create a copy of you in Andromeda, then you cease to exist as a person? Note: according to current comological models, space is infinite and uniform, which means infinite copies of you exist (though very far away). Jason -- 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 http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
