About Hidden Variables

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Alan Grayson

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Feb 16, 2021, 10:35:11 PM2/16/21
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Suppose I posited a model of double slit experiment where the position of detection depended on the interactions of wf's of atoms in the screen with the wf of the detected particle. Would this run afoul of the results of Bell experiments? TIA, AG

John Clark

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Feb 17, 2021, 6:27:56 AM2/17/21
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On Tue, Feb 16, 2021 at 10:35 PM Alan Grayson <agrays...@gmail.com> wrote:

> Suppose I posited a model of double slit experiment where the position of detection depended on the interactions of wf's of atoms in the screen with the wf of the detected particle. Would this run afoul of the results of Bell experiments? TIA, AG


Why are you asking us? The only thing anybody around here knows is Trump physics, you said so yourself.

John K Clark   See what's on my new list at  Extropolis

Alan Grayson

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Feb 17, 2021, 9:14:12 AM2/17/21
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On Wednesday, February 17, 2021 at 4:27:56 AM UTC-7 johnk...@gmail.com wrote:
On Tue, Feb 16, 2021 at 10:35 PM Alan Grayson <agrays...@gmail.com> wrote:

> Suppose I posited a model of double slit experiment where the position of detection depended on the interactions of wf's of atoms in the screen with the wf of the detected particle. Would this run afoul of the results of Bell experiments? TIA, AG


Why are you asking us? The only thing anybody around here knows is Trump physics, you said so yourself.

One of the key properties of Trumpism is conscious (so it seems) distortion of facts. In this case, I never made the claim you allege. But I think the answer to my query is No. The wf's of atoms in the screen would be NON-LOCAL hidden variables. I also think my conjecture is related to Decoherence theory. CMIIAW. AG 

John Clark

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Feb 17, 2021, 10:43:30 AM2/17/21
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On Wed, Feb 17, 2021 at 9:14 AM Alan Grayson <agrays...@gmail.com> wrote:

>>Why are you asking us? The only thing anybody around here knows is Trump physics, you said so yourself.

> One of the key properties of Trumpism is conscious (so it seems) distortion of facts. In this case, I never made the claim you allege.

You claimed I was a practitioner of "Trump physics" !  Alan, I don't mind if you call me a son of a bitch but you associated my name with that of Donald Trump. and that's hitting below the belt. If you really believe your claim I don't understand why you would even care what my opinion was on this subject, or even bother to read my posts, unless that is you're retracting your claim. Is that in fact what you were doing?
John K Clark   See what's on my new list at  Extropolis
.

Alan Grayson

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Feb 17, 2021, 11:04:39 AM2/17/21
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I didn't ask for "your" opinion; rather, anyone's opinion. Moreover, and more important, you have a strong tendency to distort or ignore facts, which reminds me of Trumpism. For example, I refer you to your opening comment which alleged something I never claimed. Do you also think the election was rigged? AG

John Clark

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Feb 17, 2021, 11:53:47 AM2/17/21
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On Wed, Feb 17, 2021 at 11:04 AM Alan Grayson <agrays...@gmail.com> wrote:

> I didn't ask for "your" opinion; rather, anyone's opinion. Moreover, and more important, you have a strong tendency to distort or ignore facts, which reminds me of Trumpism. For example, I refer you to your opening comment which alleged something I never claimed. Do you also think the election was rigged? AG

OK I was right the first time, you sir are an ass.  

John K Clark   See what's on my new list at  Extropolis 

.

scerir

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Feb 17, 2021, 3:26:24 PM2/17/21
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Bruce Kellett

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Feb 17, 2021, 5:07:34 PM2/17/21
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On Thu, Feb 18, 2021 at 7:26 AM 'scerir' via Everything List <everyth...@googlegroups.com> wrote:

This is an interesting paper. I was amused to see that after a long discussion, their conclusions section says essentially the things I have been saying for ages.

Bruce

Alan Grayson

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Feb 17, 2021, 5:22:17 PM2/17/21
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On Wednesday, February 17, 2021 at 9:53:47 AM UTC-7 johnk...@gmail.com wrote:
On Wed, Feb 17, 2021 at 11:04 AM Alan Grayson <agrays...@gmail.com> wrote:

> I didn't ask for "your" opinion; rather, anyone's opinion. Moreover, and more important, you have a strong tendency to distort or ignore facts, which reminds me of Trumpism. For example, I refer you to your opening comment which alleged something I never claimed. Do you also think the election was rigged? AG

OK I was right the first time, you sir are an ass.  

FYI, my last sentence above was a joke. I know you're NOT a POLITICAL trumper! But you apply techniques in discussions here that DO remind me of trumper techniques that I've encountered repeatedly on another MB; for example, using the 'old age' issue in an attempt to make a point when it's obviously irrelevant.  And on the MWI you bend over backward to support that POV despite the problems it engenders, capsulated in the phrase "creating more problems than it solves", such as a joke I used to make a point; are rest rooms provided for my alleged copies? AG

Brent Meeker

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Feb 17, 2021, 6:51:18 PM2/17/21
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Yes it says what you've been saying, but it's the thing that I think Hossenfelder said better.  Hemmo and Pitowsky write:

 if probability is supposed to do its
job, it must be related at least a-posteriori to the statistical pattern in which
events occur in our world in such a way that the relative frequencies that actually
occur in our world turn out to be typical. We take this as a necessary condition
on whatever it is that plays the role of probability in our physical theory. Now,
the quantum probability rule cannot satisfy this condition in the many worlds
theory (nor can any other non-trivial probability rule), since in this theory
the dynamics logically entails that any combinatorially possible sequence of
outcomes occurs with complete certainty, regardless of its quantum probability.

But Hossenfelder notes, correctly, that advocates of MWI say you must take the probability of an outcome to be it's relative frequency as single outcome among all the branches, not just whether of not it occurred.  To may it must be "typical" is ambigous.  Flipping a 100 head in a row, isn't typical, but it's possible and we have a theory of how to assign a probability to it and how to test whether that assignment is consistent.  It's a possible sequence, and it "occurs" in the sample space, but that doesn't make its probability=1.

In Sean Carroll's monthly "Ask me anything" blog he wrote this:

0:40:16.3 SC: Sherman Flips says, "How does the weight assigned to a given branch of the wave function correspond to the number of micro-states that are in superposition in that branch?" So, you gotta be a little bit careful. Basically, it is that number, but I wanna be careful here because number of micro-states is a slightly ambiguous concept in quantum mechanics. If what you mean is the number of dimensions of Hilbert space that correspond to that branch, that's what it means, the number of different directions in Hilbert space that you can add together in some principled way to make that particular vector corresponding to that branch. Whether you wanna call a dimension of Hilbert space a micro-state or not is up to you.


0:41:00.7 SC: There's another way of thinking about things if you just had like a bunch of spins. So you have a bunch of two-dimensional Hilbert spaces, one for each spin, spin up or spin down, but the dimensionality of the combined Hilbert space is not 2N. If you have N spins, it's 2 to the N. So you don't have one dimension of Hilbert space for each dimension of the subspaces; you exponentiate them. That's why it depends on what you mean by micro-state, but basically, that is what the weight means. You're on the right track thinking about that.

So he's definitely branch counting, but not describing the mechanism whereby the amplitude of one component of a superposition is translated into a different dimensionality of the combined Hilbert space.

Brent

Bruce Kellett

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Feb 17, 2021, 7:30:00 PM2/17/21
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On Thu, Feb 18, 2021 at 10:51 AM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 2:07 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 7:26 AM 'scerir' via Everything List <everyth...@googlegroups.com> wrote:

This is an interesting paper. I was amused to see that after a long discussion, their conclusions section says essentially the things I have been saying for ages.

Bruce

Yes it says what you've been saying, but it's the thing that I think Hossenfelder said better.


That might be a matter of opinion. Sabine talks about MWI introducing something equivalent to collapse in the measurement process, I have said that asking the question "which branch will I end up on?" introduces a dualist notion of personal identity. This is exactly the 'collapse' that Sabine sees in MWI.


Hemmo and Pitowsky write:

 if probability is supposed to do its
job, it must be related at least a-posteriori to the statistical pattern in which
events occur in our world in such a way that the relative frequencies that actually
occur in our world turn out to be typical. We take this as a necessary condition
on whatever it is that plays the role of probability in our physical theory. Now,
the quantum probability rule cannot satisfy this condition in the many worlds
theory (nor can any other non-trivial probability rule), since in this theory
the dynamics logically entails that any combinatorially possible sequence of
outcomes occurs with complete certainty, regardless of its quantum probability.

But Hossenfelder notes, correctly, that advocates of MWI say you must take the probability of an outcome to be it's relative frequency as single outcome among all the branches, not just whether of not it occurred.  To may it must be "typical" is ambigous.  Flipping a 100 head in a row, isn't typical, but it's possible and we have a theory of how to assign a probability to it and how to test whether that assignment is consistent.  It's a possible sequence, and it "occurs" in the sample space, but that doesn't make its probability=1.


That is to confuse ordinary probability in a chancy universe with the fact that these outlying branches certainly occur in MWI. I thought the point made by Hemmo and Pitowsky was relevant. They pointed out that no matter what sequence you have observed up to this time, you have no guarantee that the next N results you observe won't be contrary to Born rule expectations. Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important. And the statistical limiting theorems that David Albert quotes point to the significance of this difference.


In Sean Carroll's monthly "Ask me anything" blog he wrote this:

0:40:16.3 SC: Sherman Flips says, "How does the weight assigned to a given branch of the wave function correspond to the number of micro-states that are in superposition in that branch?" So, you gotta be a little bit careful. Basically, it is that number, but I wanna be careful here because number of micro-states is a slightly ambiguous concept in quantum mechanics. If what you mean is the number of dimensions of Hilbert space that correspond to that branch, that's what it means, the number of different directions in Hilbert space that you can add together in some principled way to make that particular vector corresponding to that branch. Whether you wanna call a dimension of Hilbert space a micro-state or not is up to you.


0:41:00.7 SC: There's another way of thinking about things if you just had like a bunch of spins. So you have a bunch of two-dimensional Hilbert spaces, one for each spin, spin up or spin down, but the dimensionality of the combined Hilbert space is not 2N. If you have N spins, it's 2 to the N. So you don't have one dimension of Hilbert space for each dimension of the subspaces; you exponentiate them. That's why it depends on what you mean by micro-state, but basically, that is what the weight means. You're on the right track thinking about that.

So he's definitely branch counting, but not describing the mechanism whereby the amplitude of one component of a superposition is translated into a different dimensionality of the combined Hilbert space.


Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

Bruce

Brent Meeker

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Feb 17, 2021, 9:05:23 PM2/17/21
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On 2/17/2021 4:29 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 10:51 AM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 2:07 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 7:26 AM 'scerir' via Everything List <everyth...@googlegroups.com> wrote:

This is an interesting paper. I was amused to see that after a long discussion, their conclusions section says essentially the things I have been saying for ages.

Bruce

Yes it says what you've been saying, but it's the thing that I think Hossenfelder said better.


That might be a matter of opinion. Sabine talks about MWI introducing something equivalent to collapse in the measurement process, I have said that asking the question "which branch will I end up on?" introduces a dualist notion of personal identity. This is exactly the 'collapse' that Sabine sees in MWI.


Hemmo and Pitowsky write:

 if probability is supposed to do its
job, it must be related at least a-posteriori to the statistical pattern in which
events occur in our world in such a way that the relative frequencies that actually
occur in our world turn out to be typical. We take this as a necessary condition
on whatever it is that plays the role of probability in our physical theory. Now,
the quantum probability rule cannot satisfy this condition in the many worlds
theory (nor can any other non-trivial probability rule), since in this theory
the dynamics logically entails that any combinatorially possible sequence of
outcomes occurs with complete certainty, regardless of its quantum probability.

But Hossenfelder notes, correctly, that advocates of MWI say you must take the probability of an outcome to be it's relative frequency as single outcome among all the branches, not just whether of not it occurred.  To may it must be "typical" is ambigous.  Flipping a 100 head in a row, isn't typical, but it's possible and we have a theory of how to assign a probability to it and how to test whether that assignment is consistent.  It's a possible sequence, and it "occurs" in the sample space, but that doesn't make its probability=1.


That is to confuse ordinary probability in a chancy universe with the fact that these outlying branches certainly occur in MWI. I thought the point made by Hemmo and Pitowsky was relevant. They pointed out that no matter what sequence you have observed up to this time, you have no guarantee that the next N results you observe won't be contrary to Born rule expectations.

You have not guarantee in one world...if it's probabilistic.


Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important.

I don't think it's even relevant.  It isn't "bound to happen" to you.  It's just a possibility for you, just as it is in the Kolmogorov sample space.


And the statistical limiting theorems that David Albert quotes point to the significance of this difference.

The statistics are the same the same as the probabilities in the N->oo limit.




In Sean Carroll's monthly "Ask me anything" blog he wrote this:

0:40:16.3 SC: Sherman Flips says, "How does the weight assigned to a given branch of the wave function correspond to the number of micro-states that are in superposition in that branch?" So, you gotta be a little bit careful. Basically, it is that number, but I wanna be careful here because number of micro-states is a slightly ambiguous concept in quantum mechanics. If what you mean is the number of dimensions of Hilbert space that correspond to that branch, that's what it means, the number of different directions in Hilbert space that you can add together in some principled way to make that particular vector corresponding to that branch. Whether you wanna call a dimension of Hilbert space a micro-state or not is up to you.


0:41:00.7 SC: There's another way of thinking about things if you just had like a bunch of spins. So you have a bunch of two-dimensional Hilbert spaces, one for each spin, spin up or spin down, but the dimensionality of the combined Hilbert space is not 2N. If you have N spins, it's 2 to the N. So you don't have one dimension of Hilbert space for each dimension of the subspaces; you exponentiate them. That's why it depends on what you mean by micro-state, but basically, that is what the weight means. You're on the right track thinking about that.

So he's definitely branch counting, but not describing the mechanism whereby the amplitude of one component of a superposition is translated into a different dimensionality of the combined Hilbert space.


Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

But then he could just postulate the Born rule as the way to partition, or create, branches and it would work; which is what Sabine says.  And that tells me that the Hemmo and Pitkowsky objection is wrong.

Brent

Bruce Kellett

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Feb 17, 2021, 9:46:40 PM2/17/21
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On Thu, Feb 18, 2021 at 1:05 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 4:29 PM, Bruce Kellett wrote:
Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important.

I don't think it's even relevant.  It isn't "bound to happen" to you.  It's just a possibility for you, just as it is in the Kolmogorov sample space.


This is the problem with personal identity in many worlds -- the copies are all *you*, so your comment is without force. You are sneaking in the collapse that Sabine mentions; or you are making a dualist assumption -- only one of the copies is *really you*.


<........>

Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

But then he could just postulate the Born rule as the way to partition, or create, branches and it would work; which is what Sabine says.  And that tells me that the Hemmo and Pitkowsky objection is wrong.


That is what Carroll and Bob are doing. But that rather defeats the purpose of deriving the Born rule from the Schrodinger equation alone. All such arguments are inherently circular.

Bruce

Brent Meeker

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Feb 17, 2021, 10:21:56 PM2/17/21
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On 2/17/2021 6:46 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 1:05 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 4:29 PM, Bruce Kellett wrote:
Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important.

I don't think it's even relevant.  It isn't "bound to happen" to you.  It's just a possibility for you, just as it is in the Kolmogorov sample space.


This is the problem with personal identity in many worlds -- the copies are all *you*, so your comment is without force. You are sneaking in the collapse that Sabine mentions; or you are making a dualist assumption -- only one of the copies is *really you*.

I don't think so.  Every copy post-test is some copy of you pre-test.  The Everett explicitly writes the post-test wave function with all the you's in it.  I don't see that as any more problematic than referring to possible you's pre-test.  In any probabilistic theory only one possibility is realized...that doesn't mean we have to assume there was some realism-spirit that got passed to it.




<........>

Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

But then he could just postulate the Born rule as the way to partition, or create, branches and it would work; which is what Sabine says.  And that tells me that the Hemmo and Pitkowsky objection is wrong.


That is what Carroll and Bob are doing. But that rather defeats the purpose of deriving the Born rule from the Schrodinger equation alone. All such arguments are inherently circular.

I agree with that.  Do you agree that it would work to simply add the Born rule to MWI as a postulate?

Brent

Bruce Kellett

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Feb 17, 2021, 10:40:02 PM2/17/21
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On Thu, Feb 18, 2021 at 2:21 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 6:46 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 1:05 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 4:29 PM, Bruce Kellett wrote:
Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important.

I don't think it's even relevant.  It isn't "bound to happen" to you.  It's just a possibility for you, just as it is in the Kolmogorov sample space.


This is the problem with personal identity in many worlds -- the copies are all *you*, so your comment is without force. You are sneaking in the collapse that Sabine mentions; or you are making a dualist assumption -- only one of the copies is *really you*.

I don't think so.  Every copy post-test is some copy of you pre-test.  The Everett explicitly writes the post-test wave function with all the you's in it.  I don't see that as any more problematic than referring to possible you's pre-test.  In any probabilistic theory only one possibility is realized


That is where you keep slipping in the implicit collapse (or dualist identity hypothesis). In MWI it is just not the case that only one possibility is realized.

 
...that doesn't mean we have to assume there was some realism-spirit that got passed to it.


If you don't like dualism, then you are left with an implicit collapse hypothesis. There are no other options in MWI.



<........>

Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

But then he could just postulate the Born rule as the way to partition, or create, branches and it would work; which is what Sabine says.  And that tells me that the Hemmo and Pitkowsky objection is wrong.


That is what Carroll and Bob are doing. But that rather defeats the purpose of deriving the Born rule from the Schrodinger equation alone. All such arguments are inherently circular.

I agree with that.  Do you agree that it would work to simply add the Born rule to MWI as a postulate?


I have difficulty seeing how that could work. For the Born rule to work, the dynamics have to 'see' the amplitudes rather than just the eigenstate basis vectors. But this does not happen in Everett. The set of histories arising in N repetitions of the spin measurement is the same for any two-component initial state -- there is no differentiation of the histories according to the Born probabilities.

You have attempted to remedy this by assuming that the number of branches on each trial splits in the Born rule ratios. But this is inconsistent with unitary evolution and the MWI. You might be able to construct a many worlds theory that has the Born rule as an independent postulate -- but  the resultant theory will not be quantum mechanics as we know it. I doubt that it can even be unitary.

Bruce

scerir

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Feb 19, 2021, 2:28:00 AM2/19/21
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Bruno Marchal

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Feb 19, 2021, 6:56:05 AM2/19/21
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I agree. Pitkowski made the sempiternal same error than a minority (I think) on this list are doing, by reasoning on the third person description, and concluding wrongly that the first person description of the superposed or duplicated people can assess.

They do forget that the probability are relative.

The WM duplication illustrate the error on this in a pure 3p way. If Bruce Kellet was right, the Helsinki gut must predict that he will feel to see Moscow and that he will feel to see Washington, both with probability one, and that is why he will write in his prediction diary book, but in this mechanist setting, it is clear that the two copies will have to acknowledge being only in one city, and that they could not have predicted it.

It is the 1p / 3p confusion, again and again. 

Bruno




Brent

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Bruno Marchal

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Feb 19, 2021, 7:10:58 AM2/19/21
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On 18 Feb 2021, at 04:39, Bruce Kellett <bhkel...@gmail.com> wrote:

On Thu, Feb 18, 2021 at 2:21 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 6:46 PM, Bruce Kellett wrote:
On Thu, Feb 18, 2021 at 1:05 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:
On 2/17/2021 4:29 PM, Bruce Kellett wrote:
Thus previous experience is no guide to the future in MWI. I know this is true also in ordinary classical probability theory, but the difference is that in MWI, one or more of your successors is bound to see the atypical sequences -- that is not guaranteed in classical probability theory. It *might* happen, but it is not *bound to* happen. This difference is important.

I don't think it's even relevant.  It isn't "bound to happen" to you.  It's just a possibility for you, just as it is in the Kolmogorov sample space.


This is the problem with personal identity in many worlds -- the copies are all *you*, so your comment is without force. You are sneaking in the collapse that Sabine mentions; or you are making a dualist assumption -- only one of the copies is *really you*.

I don't think so.  Every copy post-test is some copy of you pre-test.  The Everett explicitly writes the post-test wave function with all the you's in it.  I don't see that as any more problematic than referring to possible you's pre-test.  In any probabilistic theory only one possibility is realized


That is where you keep slipping in the implicit collapse (or dualist identity hypothesis). In MWI it is just not the case that only one possibility is realized.

It is not the case that only one possibility is realised, in the 3p-view. But as the WM illustrates in a simpler (non quantum) setting, despite it is true that after the split “you” are both in Washington and Moscow, it is plain obvious that the two copies will feel differently, and will feel to see only one city. That is predictable using just mechanism, and the fact that they have no telepathic communication. The one in W will say “I see only Washington” and the one in Moscow will say “I see only Moscow”, and, as they bet on mechanism, they knew this in advance. This indeterminacy is provable, from the mechanist simple assumption. 







 
...that doesn't mean we have to assume there was some realism-spirit that got passed to it.


If you don't like dualism, then you are left with an implicit collapse hypothesis. There are no other options in MWI.


You are left with a phenomenological collapse, entirely explainable in a monist theory of mind. Now if that theory is mechanism, the indeterminacy can no more be related to any particular sort of computation (selected by some personal or impersonal ontology), making obligatory to extract the wave itself from the measure on all computations, and this is confirmed by what the universal machine already deduce in arithmetic: there is just no evidence for any needed ontological commitment, as we infer already the MWI from observation, after having it deduced from simple mechanism. And then, thanks to incompleteness we get different mathematics for the qualia and the quanta, where the naturalist are known to not address this question, if not abuse of identification which simply cannot work (unless abandoned,dong mechanism).

I think that you are just eliminating the first person discourse. You look at all the diaries, without reading any particular one.

Bruno






<........>

Yes. I think that the idea that Bob has been pursuing is a definite non-starter. Carroll is smart enough to see this, even though he does want to finally reduce probability to branch counting. The real trouble I see with Sean's approach is that he has to call on Born rule insights to know how many additional branches to manufacture. His approach is irreducibly circular.

But then he could just postulate the Born rule as the way to partition, or create, branches and it would work; which is what Sabine says.  And that tells me that the Hemmo and Pitkowsky objection is wrong.


That is what Carroll and Bob are doing. But that rather defeats the purpose of deriving the Born rule from the Schrodinger equation alone. All such arguments are inherently circular.

I agree with that.  Do you agree that it would work to simply add the Born rule to MWI as a postulate?


I have difficulty seeing how that could work. For the Born rule to work, the dynamics have to 'see' the amplitudes rather than just the eigenstate basis vectors. But this does not happen in Everett. The set of histories arising in N repetitions of the spin measurement is the same for any two-component initial state -- there is no differentiation of the histories according to the Born probabilities.

You have attempted to remedy this by assuming that the number of branches on each trial splits in the Born rule ratios. But this is inconsistent with unitary evolution and the MWI. You might be able to construct a many worlds theory that has the Born rule as an independent postulate -- but  the resultant theory will not be quantum mechanics as we know it. I doubt that it can even be unitary.

Bruce

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Bruno Marchal

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Feb 19, 2021, 7:28:29 AM2/19/21
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On 19 Feb 2021, at 08:27, 'scerir' via Everything List <everyth...@googlegroups.com> wrote:


Interesting. Slightly clearer than the Deutsch and Hayden paper. It illustrates also that the MWI is a “local theory”, with no FTL action. The violation of Bell’s inequality becomes evidences of the “other histories”. It is a cure against a form of Cosmo-solipisme.

Bruno





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