On Fri, Jun 21, 2019 at 3:38 PM 'Brent Meeker' via Everything List < [email protected]> wrote:
> On 6/20/2019 10:00 PM, Bruce Kellett wrote: > > On Fri, Jun 21, 2019 at 2:35 PM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> On 6/20/2019 9:09 PM, Bruce Kellett wrote: >> >> On Fri, Jun 21, 2019 at 1:19 PM 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> >>> On 6/20/2019 5:56 PM, Bruce Kellett wrote: >>> >>> From: Bruno Marchal <[email protected]> >>> >>> >>> I don’t think your refutation of step 3 has been understood by anyone. >>> >>> If someone else want to argue that there is no indeterminacy in the self >>> duplication experience, he is welcome. >>> >>> >>> I think that some might challenge your interpretation of this >>> indeterminacy. This might not be exactly JC's objection to step 3, but, to >>> my mind, it is a serious difficulty in its own right. >>> >>> This comes from a recent podcast of a conversation between Sean Carroll >>> and David Albert: >>> >>> https://www.youtube.com/watch?v=AglOFx6eySE >>> >>> This is a long discussion, and the relevant parts of Albert's objections >>> to MWI and self-locating uncertainty come towards the end. >>> >>> The essence of Albert's point is that in the duplication case, you ask >>> "What is the probability that you will find yourself in Moscow (resp. >>> Washington)?" Putting aside objections to the non-specificity of the >>> pronoun 'you', I think your answer is that the probabilities are 0.5 for >>> either city. Albert points out that to reach this conclusion, you use some >>> principle of indifference, or point to some symmetry between the possible >>> outcomes. Using this symmetry, you claim that the probabilities must be >>> equal, hence 0.5 for each city. Now, says Albert, there is another solution >>> that also respects all the symmetries involved, viz., "I have not idea what >>> the probability is." >>> >>> You can then easily argue that this is a better solution. Because the >>> probability 0.5 is not written in the physics of the situation -- it comes >>> entirely from the classical principle of indifference. So Albert asks how >>> you are going to verify this probability experimentally -- as a large N >>> limit, or something similar. So you repeat the duplication N times on your >>> participants. i.e. after the original duplication you transport the >>> subjects back to Helsinki and repeat the duplication to Washington and >>> Moscow. You end up with 2^N copies, each of which has a record of the N >>> cities they found themselves in after each duplication. You now ask each of >>> them their best estimate of the probabilities for W or M on each >>> duplication. Of course, you then get all possible answers, from 1/N for M >>> to 1/N for W. Since, withprobaility one, the will always be someone who >>> found himself in M each time, and similarly, someone who found himself in W >>> each time. Plus all other 2^ possible combinations of results. >>> >>> >>> But most participants will say they were in Washington approximately N/2 >>> times and Moscow N/2 times, in accordance with a binomial distribution. >>> >> >> But I am not "most participants". I am just me, only one of me. I could >> easily be the guy who sees 100% Moscow. >> >> >> Not "easily" since seeing only Moscow has probability 1/2^N. And it's >> not just you I need to convince. I need to write a paper showing that my >> P(M)=P(W)=0.5 theory is supported and the statistics reported by the >> participants do exactly that. >> > > As Bruno might say, that is to take the 3p view of things. I am concerned > about the 1p view, where this survey of all participants is not possible. > > The point, of course, is to relate this to the many worlds interpretation > of QM. There one does not have the option of surveying outcomes over all > branches in order to reach one's conclusions about probabilities. Put > another way, if MWI is true, why do we not regularly see substantial > deviations from the Born Rule probabilities? > > > A good question *if* the premise is true. Are you saying that splitting > photons by a half-silvered mirror doesn't produce binomial statistics, > which the variance = Np(1-p)? Are you saying the measured variance is > greater than expected... or less? > > After all, repetitions of the relevant interactions are happening all the > time: and not just in our controlled experiments. How can there be such > things as objective probabilities in the MWI scenario? How can we use > experimental evidence to support theories when we do not know whether our > observer probabilities are representative or not? > > > The same as in any probabilistic theory. We repeat it so many times that > we have statistics that we can compare to the theoretical distribution. > The same way you would test your theory that a coin was fair. > In other words, MWI is experimentally disconfirmed. 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLQxj2_hEnAtFp7UpJ_S4kPN%3Dip03V1v%2Bd_HL5K5coNs-g%40mail.gmail.com.
