> On 8 Feb 2020, at 02:53, Bruce Kellett <bhkellet...@gmail.com> wrote: > > On Sat, Feb 8, 2020 at 12:23 PM 'Brent Meeker' via Everything List > <everything-list@googlegroups.com <mailto:everything-list@googlegroups.com>> > wrote: > On 2/7/2020 2:16 PM, Bruce Kellett wrote: >> >> The point of Kent's argument is that in MWI where all outcomes occur, you >> will get the same set of sequences of results whatever the intrinsic >> probabilities might be. So you cannot use data from any one sequence to test >> a hypothesis about the probabilities: the sequences obtained are independent >> of any underlying probability measure. > > Why not? Most copies of me will see sequences with approximately equal > numbers of H and T. > > You are making the mistake that many commentators make: you are thinking of > the distribution over the set of all possible sequences, and then assuming > that we sample at random from this set. But that is not how experiments are > done. We run the experiment N times and obtain some sequence of results. We > then use the data so obtained to compare with our theory. There is no random > selection from the set of all possible sequences. In fact, in MWI, there is > one observer for every possible sequence, and we have to consider what each > of them, in isolation, will conclude. Many will see the Born rule > disconfirmed. > > > > In fact we do use data from one sequence, which ever one our accelerator > produces, even though the theory we're testing predicts that all sequences > are possible. But we don't compare sequences; we compare statistics on the > sequences and compare those to predicted probabilities. > > That is just a fantasy made up to get out of a difficulty. That is not how > science proceeds. > > Of course, if many-worlds is correct and every possible outcome occurs for > every trial, then given the probability deduced from one set of N trials, we > can always attempt to confirm this result by doing another set of trials. The > problem is that the second set of trials is quite like to give a different > result from the first. That also would count as a disconfirmation of the > theory. > > Whether sequences are independent of "underlying probabilities" is a > different problem. First, one can't legitimately assume underlying > probabilities when trying to justify the existence of a probability measure. > > In the first instance, we are not trying to justify the existence of a > probability measure. We are trying to see if experimental data can confirm a > particular theory. > > > Second, the simple way to postulate a measure is just counting branches, > which means that there must be many repetitions of the same sequence on > different branches in order to realize probability values that aren't integer > ratios > > > Branch counting has a bad reputation as a basis for a probability measure. > One problem, as Wallace for instance points out, is that the number of > branches is never well-defined, so no clear count is available. There are > other problems, which have led to the abandonment of this approach to > probability.
With QM, the number of branch is arguably equal to 2^aleph_0, but with Mechanism it might need to be bigger than that. Bruno > > Bruce > > -- > 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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLRz_BuLmdop77QFAf0Ms27RmOdcY79pFV6un7SsO6wamQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLRz_BuLmdop77QFAf0Ms27RmOdcY79pFV6un7SsO6wamQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/9BB3972D-2AA9-4DBF-985F-E66C787767BA%40ulb.ac.be.
