> On 7 Feb 2020, at 20:45, 'Brent Meeker' via Everything List > <everything-list@googlegroups.com> wrote: > > > > On 2/7/2020 3:07 AM, Bruce Kellett wrote: >> On Fri, Feb 7, 2020 at 9:54 PM Lawrence Crowell >> <goldenfieldquaterni...@gmail.com <mailto:goldenfieldquaterni...@gmail.com>> >> wrote: >> On Thursday, February 6, 2020 at 10:59:27 PM UTC-6, Bruce wrote: >> >> This argument from Kent completely destroys Everett's attempt to derive the >> Born rule from his many-worlds approach to quantum mechanics. In fact, it >> totally undermines most attempts to derive the Born rule from any branching >> theory, and undermines attempts to justify ignoring branches on which the >> Born rule weights are disconfirmed. In the many-worlds case, recall, all >> observers are aware that other observers with other data must exist, but >> each is led to construct a spurious measure of importance that favours their >> own observations against the others', and this leads to an obvious >> absurdity. In the one-world case, observers treat what actually happened as >> important, and ignore what didn't happen: this doesn't lead to the same >> difficulty. >> >> Bruce >> >> This appears to argue that observers in a branch are limited in their >> ability to take the results of their branch as a Bayesian prior. This >> limitation occurs for the coin flip case where some combinations have a high >> degree of structure. Say all heads or a repeated sequence of heads and tails >> with some structure, or apparent structure. For large N though these are a >> diminishing measure. >> >> I don't think you have fully come to terms with Kent's argument. How do you >> determine the measure on the observed outcomes? The argument that such >> 'outlier' sequences are of small measure fails at the first hurdle, because >> all sequences have equal measure -- all are equally likely. In fact, all >> occur with unit probability in MWI. > > In practice one doesn't look for a measure on specific outcomes sequences > because you're testing a theory that only predicts one probability. You flip > coins to test whether P(heads)=0.5 which you can confirm or refute without > even knowing the sequences. It might be that every sequence you get by > flipping is in the form HTHTHTHTHTHTHT... which would support P(H)=0.5. It > would be a different world than ours, possibly with different physics; but > that would be a matter of testing a different theory. > > One of the problems with MWI is that can't seem to explain probability > without sneaking in some equivalent concept. The obvious version of MWI would > be branch counting in which every measurement-like event produces an enormous > number of branches and the number of branches with spin UP relative to the > number with spin DOWN gives the odds of spin UP. A meta-physical difficulty > is the all the spin UP branches are identical and so by Leibniz's identity of > indiscernibles are really only one; but maybe this inapplicable since the > measure involves lots of environment that would make it discernible.
With Mechanism, and apparently with Everett QM, we are multiplied by everything we don’t depend on. The reason why “the particles go through both silts” is that your mind state does not depend on which slit the particle go through. Well, it is actually a bit more complex, but it is the general idea. In fact, I got recently some argument that we might need the large cardinals, even the very large one (like the cardinal of Woodin or of Laver) in this quest for the measure. In fact the first person requires the full sigma_1(a) truth, that the sigma_1 in the oracle a, for all oracles. That provides the ability to use string axioms in set theory to get a measure space, but that is required intuitively also, with the step 7 of the UDA, actually. Bruno > > Brent > >> >> Bruce >> >> >> An observer might see their branch as having sufficient randomness to be a >> Bayesian prior, but to derive a full theory these outlier branches with the >> appearance of structure have to be eliminated. This is not a devastating >> blow to MWI, but it is a limitation on its explanatory power. Of course with >> statistical physics we have these logarithms and the rest and such slop >> tends to be "washed out" for large enough sample space. >> >> No matter how hard we try it is tough to make this all epistemic, say >> Bayesian etc, or ontological with frequentist statistics. >> >> LC >> -- >> 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%3D6MzUV13uBDrKrH%2BAO_RhizyyCaT1wcdpF6ctLxBUA%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/everything-list/CAFxXSLRz%3D6MzUV13uBDrKrH%2BAO_RhizyyCaT1wcdpF6ctLxBUA%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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/7cb33d91-e427-f81d-846f-ee55616624e4%40verizon.net > > <https://groups.google.com/d/msgid/everything-list/7cb33d91-e427-f81d-846f-ee55616624e4%40verizon.net?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/DBA48646-1599-4E87-B984-541C51AF315B%40ulb.ac.be.
