On 9 September 2015 at 09:23, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> On 9/09/2015 8:56 am, Stathis Papaioannou wrote: > > On 8 September 2015 at 22:11, Bruce Kellett <bhkell...@optusnet.com.au> > wrote: > >> On 8/09/2015 9:14 pm, Stathis Papaioannou wrote: >> >> On 8 September 2015 at 20:48, Bruce Kellett < <bhkell...@optusnet.com.au> >> bhkell...@optusnet.com.au> wrote: >> >>> On 8/09/2015 8:40 pm, Stathis Papaioannou wrote: >>> >>> >>> On 8 September 2015 at 17:39, Bruce Kellett < >>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> 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. -- Stathis Papaioannou -- 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 http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
