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]
<mailto:[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]
<mailto:[email protected]>> wrote:
On 6/20/2019 5:56 PM, Bruce Kellett wrote:
From: *Bruno Marchal* <[email protected]
<mailto:[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.
Brent
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]
<mailto:[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/CAFxXSLSV4OPkXpj4V_7a3k2i%2BqjHryfCDr2uPEzE-3QyHbF1%2Bg%40mail.gmail.com
<https://groups.google.com/d/msgid/everything-list/CAFxXSLSV4OPkXpj4V_7a3k2i%2BqjHryfCDr2uPEzE-3QyHbF1%2Bg%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 [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/66a67812-e7f0-cbe0-2fe5-2363ffc486f1%40verizon.net.
