The Incessant Arguments about MWI

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Alan Grayson

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Nov 15, 2024, 3:02:14 AM11/15/24
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As I see it, JC's core claim about the MWI is that it follows from S's equation; namely, that anything the can happen (has a non-zero probability), must happen (in some world). I fail to see anything in S's equation to support this claim. And, I fail to see JC argue for this claim. Thus, IMO, I've put the nail in the coffin to the MWI. AG


Russell Standish

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Nov 15, 2024, 9:38:06 PM11/15/24
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On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
> As I see it, JC's core claim about the MWI is that it follows from S's
> equation

It comes about by not making any further assumptions, like the
wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
privilege one branch over the others.

> ; namely, that anything the can happen (has a non-zero probability),
> must happen (in some world). I fail to see anything in S's equation to support
> this claim. And, I fail to see JC argue for this claim. Thus, IMO, I've put the
> nail in the coffin to the MWI. AG
>

You think!



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Bruce Kellett

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Nov 15, 2024, 9:58:33 PM11/15/24
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On Sat, Nov 16, 2024 at 1:38 PM Russell Standish <li...@hpcoders.com.au> wrote:
On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
> As I see it, JC's core claim about the MWI is that it follows from S's
> equation

It comes about by not making any further assumptions, like the
wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
privilege one branch over the others.

But MWI does assume that the wavefunction is a real physical object, even though it exists only in 3N-dimensional configuration space; and it also has to make some assumptions about probability that are equivalent to just assuming the Born Rule. So the idea that it does not make any further assumptions beyond the Schrodinger equation is something of a pipe dream.

Bruce

Russell Standish

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Nov 15, 2024, 10:41:44 PM11/15/24
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On Sat, Nov 16, 2024 at 01:58:08PM +1100, Bruce Kellett wrote:
> On Sat, Nov 16, 2024 at 1:38 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
> On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
> > As I see it, JC's core claim about the MWI is that it follows from S's
> > equation
>
> It comes about by not making any further assumptions, like the
> wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
> privilege one branch over the others.
>
>
> But MWI does assume that the wavefunction is a real physical object, even
> though it exists only in 3N-dimensional configuration space;

I don't think it requires this assumption. In fact "physically real"
is a rather nebulous concept anyway.

> and it also has to
> make some assumptions about probability that are equivalent to just assuming
> the Born Rule. So the idea that it does not make any further assumptions beyond
> the Schrodinger equation is something of a pipe dream.
>

You need to assume something like the Kolmogorov axioms of
probability anyway, but these are by and large definitional.

For the rest, the Gleason theorem really does the heavy lifting.

My disatisfaction with the state of the art stems from wanting to
derive Schroedinger's equation from something more basic. SE already
assumes a complex Hilbert space, from which the rest follows. We do
know that the SE is essentially a statement of energy conservation, in
the context of a complex Hilbert space.

Bruce Kellett

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Nov 15, 2024, 11:08:16 PM11/15/24
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On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au> wrote:
On Sat, Nov 16, 2024 at 01:58:08PM +1100, Bruce Kellett wrote:
> On Sat, Nov 16, 2024 at 1:38 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
>     On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
>     > As I see it, JC's core claim about the MWI is that it follows from S's
>     > equation
>
>     It comes about by not making any further assumptions, like the
>     wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
>     privilege one branch over the others.
>
>
> But MWI does assume that the wavefunction is a real physical object, even
> though it exists only in 3N-dimensional configuration space;

I don't think it requires this assumption. In fact "physically real"
is a rather nebulous concept anyway.

If you want the 'other worlds' to be physically real, then the original wave function must be physically real.

> and it also has to
> make some assumptions about probability that are equivalent to just assuming
> the Born Rule. So the idea that it does not make any further assumptions beyond
> the Schrodinger equation is something of a pipe dream.
>

You need to assume something like the Kolmogorov axioms of
probability anyway, but these are by and large definitional.

For the rest, the Gleason theorem really does the heavy lifting.

But one somehow has to relate the amplitudes of the wave function basis vectors to the probabilities. And since the Schrodinger equation is deterministic, introducing a probability interpretation is problematic.

Bruce

Russell Standish

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Nov 15, 2024, 11:28:59 PM11/15/24
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On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote:
> On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
> I don't think it requires this assumption. In fact "physically real"
> is a rather nebulous concept anyway.
>
>
> If you want the 'other worlds' to be physically real, then the original wave
> function must be physically real.

That's a non-sequitur. The 'other worlds' are as real as this one. The
reality of the wave function doesn't enter into it.

>
>
> > and it also has to
> > make some assumptions about probability that are equivalent to just
> assuming
> > the Born Rule. So the idea that it does not make any further assumptions
> beyond
> > the Schrodinger equation is something of a pipe dream.
> >
>
> You need to assume something like the Kolmogorov axioms of
> probability anyway, but these are by and large definitional.
>
> For the rest, the Gleason theorem really does the heavy lifting.
>
>
> But one somehow has to relate the amplitudes of the wave function basis vectors
> to the probabilities. And since the Schrodinger equation is deterministic,
> introducing a probability interpretation is problematic.
>

I never followed that line of argument. I know you've raised this
multiple times over the years, but it made little sense to me.

For example - in classical statistical physics, the connection between
entropy and the classical microstate is statistical in nature. The
assumed deterministic nature of classical microphysics does not
prevent a probabilistic interpretation of the macrophysics. On your
line of argument, you'd need to reject Boltzmann's H-theorem.

Cheers

Bruce Kellett

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Nov 15, 2024, 11:52:41 PM11/15/24
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On Sat, Nov 16, 2024 at 3:28 PM Russell Standish <li...@hpcoders.com.au> wrote:
On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote:
> On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
>     I don't think it requires this assumption. In fact "physically real"
>     is a rather nebulous concept anyway.
>
>
> If you want the 'other worlds' to be physically real, then the original wave
> function must be physically real.

That's a non-sequitur. The 'other worlds' are as real as this one. The
reality of the wave function doesn't enter into it.

It does if the wave function is purely epistemic. In other words, if it is merely a means of calculating probabilities, then the supposed 'other worlds' do not exist. The probabilities are the probability that one, and only one, outcome is realized for each experiment.

>
>
>     > and it also has to
>     > make some assumptions about probability that are equivalent to just
>     assuming
>     > the Born Rule. So the idea that it does not make any further assumptions
>     beyond
>     > the Schrodinger equation is something of a pipe dream.
>     >
>
>     You need to assume something like the Kolmogorov axioms of
>     probability anyway, but these are by and large definitional.
>
>     For the rest, the Gleason theorem really does the heavy lifting.
>
>
> But one somehow has to relate the amplitudes of the wave function basis vectors
> to the probabilities. And since the Schrodinger equation is deterministic,
> introducing a probability interpretation is problematic.
>

I never followed that line of argument. I know you've raised this
multiple times over the years, but it made little sense to me.

For example - in classical statistical physics, the connection between
entropy and the classical microstate is statistical in nature. The
assumed deterministic nature of classical microphysics does not
prevent a probabilistic interpretation of the macrophysics. On your
line of argument, you'd need to reject Boltzmann's H-theorem.

But in the classical statistical mechanics case one relies on an ignorance interpretation of probability. This is not available in the quantum case because, given the SE, nothing is unknown.This has been discussed at length in the literature on the philosophy of quantum mechanics.

One problem with the probability interpretation is that the SE is insensitive to the amplitudes -- you get the same set of worlds for an amplitude of 0.001 as for an amplitude of 0.9.

Bruce

Alan Grayson

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Nov 16, 2024, 12:05:30 AM11/16/24
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On Friday, November 15, 2024 at 7:38:06 PM UTC-7 Russell Standish wrote:
On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
> As I see it, JC's core claim about the MWI is that it follows from S's
> equation

It comes about by not making any further assumptions, like the
wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
privilege one branch over the others.

> ; namely, that anything that can happen (has a non-zero probability),
> must happen (in some world). I fail to see anything in S's equation to support
> this claim. And, I fail to see JC argue for this claim. Thus, IMO, I've put the
> nail in the coffin to the MWI. AG
>

You think!

Yes, I do. It's obvious we use the frequentist probability theory in QM because we use multiple trials to get the interference pattern in slit experiments. So, the probabilities in S's equation imply we need multiple trials (in this world) to realize these probabilities. There's no suggestion of other worlds where these probabilities are realized.  And note; the main advocate of MWI, JC, refuses to engage this argument. Like I wrote above; this puts the nail in the coffin of the MWI. AG

John Clark

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Nov 16, 2024, 8:59:57 AM11/16/24
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On Fri, Nov 15, 2024 at 9:58 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> one somehow has to relate the amplitudes of the wave function basis vectors to the probabilities. 

True. And if the amplitude of the wave function of an electron at a point is 1/√2  (or 0.5 + 0.5i since it's a complex function) and if you take the square of the absolute value of that amplitude then you get 0.5, which an experimentalist will note is also the probability of observing the electron at that point. 

 MWI does assume that the wavefunction is a real physical object, 
 
It seems to me that you're OK with assuming that the wave function is a "real physical object", whatever that precisely means, as long as it predicts something that you're comfortable with, but as soon as it makes you uncomfortable it suddenly becomes unreal and you declare that people should stop believing what the equation is saying. 

It's interesting that in the modern physics community the long debate about whether at the deepest level things are made of particles or waves is largely over, and waves have won. The vast majority of new papers about fundamental physics are about Quantum Field Theory not particles; and even in papers where they do mention particles, nearly all the calculations they do to figure out what they will do involve quantum waves and fields, not other particles. Let me put it another way, particles are what we observe but if you want to calculate what particle will result when particle X interacts with particle Y your calculations will almost entirely be about fields and waves.  

And since the Schrodinger equation is deterministic, introducing a probability interpretation is problematic.

Many Worlds has no problem with that. Let's say you calculate with Schrodinger's Equation and the Born Rule and figure out there will be a 75% chance you will see the electron move left and a 25% chance you will see the electron move right. You set up your equipment to actually perform the experiment, you then put on a blindfold and push the "on" button. If Many Worlds is correct there is a 75% chance you are now in the "electron moves left" world, but with the blindfold still on you have no way of being certain.  However if somebody gave you even odds and bet you $10 that you were in the "electron moves right" world you would be wise to take that bet. And if you repeated that experiment many times you could make an arbitrarily large amount of money.  

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


Quentin Anciaux

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Nov 16, 2024, 2:57:48 PM11/16/24
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Who's you who make that large amount of money ? Are the 1/4 you who lose are less real ? 3/4 less real so they're not you ? Living in a 1/4 real world feel is 3/4 less vivid than 3/4 world ? The only valid meaning is a frequentist view
.. but again there is a you witnessing continuously impossible things... yes, it is the one living in an infinitesimally reality... does this reality is less real 🤔? 

Quentin 

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


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John Clark

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Nov 16, 2024, 3:11:50 PM11/16/24
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On Sat, Nov 16, 2024 at 2:57 PM Quentin Anciaux <allc...@gmail.com> wrote:



>>> Bruce Kellett <bhkel...@gmail.com> since the Schrodinger equation is deterministic, introducing a probability interpretation is problematic.

>> Many Worlds has no problem with that. Let's say you calculate with Schrodinger's Equation and the Born Rule and figure out there will be a 75% chance you will see the electron move left and a 25% chance you will see the electron move right. You set up your equipment to actually perform the experiment, you then put on a blindfold and push the "on" button. If Many Worlds is correct there is a 75% chance you are now in the "electron moves left" world, but with the blindfold still on you have no way of being certain.  However if somebody gave you even odds and bet you $10 that you were in the "electron moves right" world you would be wise to take that bet. And if you repeated that experiment many times you could make an arbitrarily large amount of money.  

Who's you who make that large amount of money ?

Mr.You is A guy (but not THE guy) who remembers being John K Clark yesterday.  

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


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Quentin Anciaux

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Nov 16, 2024, 4:12:04 PM11/16/24
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Le sam. 16 nov. 2024, 21:11, John Clark <johnk...@gmail.com> a écrit :


On Sat, Nov 16, 2024 at 2:57 PM Quentin Anciaux <allc...@gmail.com> wrote:



>>> Bruce Kellett <bhkel...@gmail.com> since the Schrodinger equation is deterministic, introducing a probability interpretation is problematic.

>> Many Worlds has no problem with that. Let's say you calculate with Schrodinger's Equation and the Born Rule and figure out there will be a 75% chance you will see the electron move left and a 25% chance you will see the electron move right. You set up your equipment to actually perform the experiment, you then put on a blindfold and push the "on" button. If Many Worlds is correct there is a 75% chance you are now in the "electron moves left" world, but with the blindfold still on you have no way of being certain.  However if somebody gave you even odds and bet you $10 that you were in the "electron moves right" world you would be wise to take that bet. And if you repeated that experiment many times you could make an arbitrarily large amount of money.  

Who's you who make that large amount of money ?

Mr.You is A guy (but not THE guy) who remembers being John K Clark yesterday.  

Yes but there is a guy who remember being John K Clark yesterday and made the wrong bet and lost money... is he less real being 1/4 continuation of John K Clark ? What does it change having 3 times more JKC who win than who lose ? Are the losing experiences less real ? Aren't they affect a John K Clark ?

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


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Bruce Kellett

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Nov 16, 2024, 4:51:20 PM11/16/24
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On Sun, Nov 17, 2024 at 12:59 AM John Clark <johnk...@gmail.com> wrote:
On Fri, Nov 15, 2024 at 9:58 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> one somehow has to relate the amplitudes of the wave function basis vectors to the probabilities. 

True. And if the amplitude of the wave function of an electron at a point is 1/√2  (or 0.5 + 0.5i since it's a complex function) and if you take the square of the absolute value of that amplitude then you get 0.5, which an experimentalist will note is also the probability of observing the electron at that point. 

 MWI does assume that the wavefunction is a real physical object, 
 
It seems to me that you're OK with assuming that the wave function is a "real physical object",

I think it is the MWI advocates who are obsessed with the wave function being a physical object. A reason that is routinely put forward in favour of MWI is that it avoids the "collapse". But collapse is only a problem (involving instantaneous action at a distance, or FTL effects) if the wave function is a real physical object. If the wave function is purely epistemic (or a summary of our knowledge of the physics), and hence only a way of calculating probabilities, there is no physical collapse, and therefore no more problem than occurs thousands of times a day on a roulette wheel at the casino.

Bruce

John Clark

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Nov 16, 2024, 5:11:36 PM11/16/24
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On Sat, Nov 16, 2024 at 4:12 PM Quentin Anciaux <allc...@gmail.com> wrote:

>>> Who's you who make that large amount of money ?

>> Mr.You is A guy (but not THE guy) who remembers being John K Clark yesterday.  

Yes but there is a guy who remember being John K Clark yesterday and made the wrong bet and lost money

Yep, but that guy is not Mr. You.  
 
... is he less real

Nope.
 
being 1/4 continuation of John K Clark ?

I don't know what you mean by that.  

What does it change having 3 times more JKC who win than who lose ?

If you were betting you would have a 75% chance of winning your bet. 

Are the losing experiences less real ?

Not from a global perspective, but the losing experience is certainly less real to Mr. You because that fellow is a winner.  
 
Aren't they affect a John K Clark ?

Yes but Mr.You is not one of the losers, Mr.You is one of the many winners. "Which one?", I hear you ask. The one that you were having a conversation with.   What happens or does not happen to the other John K Clark's has nothing to do with Mr. You. 

If all this sounds strange and rather convoluted it's not my fault, it's the fault of the English language and the way it handles personal pronouns. It was never designed with this sort of discussion in mind.  If the acceptance of Many Worlds becomes common, and I think it's only a matter of time before it does, then the English language is going to need a major overhaul in the way it handles pronouns, especially personal pronouns. That's why I kept talking about Mr. You when I wanted to be specific, using a personal pronoun would be ridiculous and I couldn't use John K Clark because they all have an equal right to call themselves John K Clark.    
John K Clark    See what's on my new list at  Extropolis
enq

Alan Grayson

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Nov 16, 2024, 6:52:05 PM11/16/24
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On Friday, November 15, 2024 at 7:38:06 PM UTC-7 Russell Standish wrote:
On Fri, Nov 15, 2024 at 12:02:14AM -0800, Alan Grayson wrote:
> As I see it, JC's core claim about the MWI is that it follows from S's
> equation

It comes about by not making any further assumptions, like the
wavefunction collapse of CI, or pilot waves of Bohmian mechanics which
privilege one branch over the others.

> ; namely, that anything the can happen (has a non-zero probability),
> must happen (in some world). I fail to see anything in S's equation to support
> this claim. And, I fail to see JC argue for this claim. Thus, IMO, I've put the
> nail in the coffin to the MWI. AG
>

You think!

Your mockery is well-deserved. How could I be so stupid, really fuckin' stupid?
You, with your Ph'D, can see the obvious when when it comes to S's equation --
that it implies what CAN happen, MUST happen! So obvious! What could I be
thinking? Hence, when a prairie dog turns its head, or someone turns left or right, 
whole universes are created. All this with the FATUOUS claim that you haven't added
anything to S's equation! With such myopia, I sure can imagine you'd vote
for Trump if you were an American. So let's called the MWI the Trumper form
of physics, all the while we can jerkoff on how probabilities might exist in the
context of these obviously NON-EXISTENT worlds. Nice work if you can get it.
Now let me tell you an obvious truth; what S's equation tells us, is that if you
repeat the same experiment numerous times, the frequencies of outcomes 
will approach the probabilities indicate in its wf solution. Too simple for a 
physics Trumper? Rather than that, you prefer the stupid, yes STUPID concept
of worlds proliferating. or better yet metastasting, on the basis of a clearly
unfounded claim that you've added nothing to S's equation. And JC is the 
MB leader of this crap, while reasonably intelligent people here fall for the 
bait.  AG 

Alan Grayson

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Nov 17, 2024, 1:13:52 AM11/17/24
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Of course, if some outcome has a non-zero probability of occurring, it will occur as the
number of trials increases. However, there's nothing in S's equation to assume that on a
single trial, all outcomes occur, and we therefore need multiple worlds to accomodate 
that result. AG

Alan Grayson

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Nov 17, 2024, 2:44:03 AM11/17/24
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One further point needs attention; claiming that all probabilities are realized on a single
trial, necessitating multiple worlds, is like assuming the interference patterns in slit 
experiments can be reified by a single particle hitting the screen. Probabilities, by their
inherent nature, require multiple trials to be realized. AG 

Alan Grayson

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Nov 17, 2024, 3:53:13 PM11/17/24
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In sum, what MWI has accomplished is to transform one unknown, collapse of the wf, into
another, Many Worlds created for single trials, which is many orders of magnitude worse. AG 

Russell Standish

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Nov 17, 2024, 5:30:11 PM11/17/24
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On Sat, Nov 16, 2024 at 03:52:25PM +1100, Bruce Kellett wrote:
>
> On Sat, Nov 16, 2024 at 3:28 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
> On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote:
> > On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au>
> wrote:
> >
> >     I don't think it requires this assumption. In fact "physically real"
> >     is a rather nebulous concept anyway.
> >
> >
> > If you want the 'other worlds' to be physically real, then the original
> wave
> > function must be physically real.
>
> That's a non-sequitur. The 'other worlds' are as real as this one. The
> reality of the wave function doesn't enter into it.
>
>
> It does if the wave function is purely epistemic. In other words, if it is
> merely a means of calculating probabilities, then the supposed 'other worlds'
> do not exist. The probabilities are the probability that one, and only one,
> outcome is realized for each experiment.

You've lost me here. Even if the wf is epistemic, it has no bearing on
whether other branches are as real as this one or not.

The MWI states that all branches are equally real. Other
interpretations assert that only one branch is real, because... (fill
in the blanks).
I have seen various arguments along those lines, but found them
unconvincing, and to be frank confusing.

They are along the lines of "the probability of Knight's Choice
winning the Melbourne cup in 2025 is either 1 or 0, because either it
will happen or it won't".

That is not exactly a useful notion of probability.

Bruce Kellett

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Nov 17, 2024, 6:06:11 PM11/17/24
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On Mon, Nov 18, 2024 at 9:30 AM Russell Standish <li...@hpcoders.com.au> wrote:
On Sat, Nov 16, 2024 at 03:52:25PM +1100, Bruce Kellett wrote:
>
> On Sat, Nov 16, 2024 at 3:28 PM Russell Standish <li...@hpcoders.com.au> wrote:
>
>     On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote:
>     > On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au wrote:
>     >
>     >     I don't think it requires this assumption. In fact "physically real"
>     >     is a rather nebulous concept anyway.
>     >
>     >
>     > If you want the 'other worlds' to be physically real, then the original  wave
>     > function must be physically real.
>
>     That's a non-sequitur. The 'other worlds' are as real as this one. The
>     reality of the wave function doesn't enter into it.
>
>
> It does if the wave function is purely epistemic. In other words, if it is
> merely a means of calculating probabilities, then the supposed 'other worlds'
> do not exist. The probabilities are the probability that one, and only one,
> outcome is realized for each experiment.

You've lost me here. Even if the wf is epistemic, it has no bearing on
whether other branches are as real as this one or not.

It does have a significant bearing on the reality of the other branches. One of the frequently stated arguments for many worlds is that it avoids the problem of the wave function collapse. The collapse of the wave function is only a problem if the wave function is a physical object, because then you run into problems with instantaneous action at a distance or FTL physical action. If the wave function is purely epistemic, namely, nothing more than a summary of our knowledge about the physical system, there is no problem with collapse, because the result of an experiment merely updates our knowledge, and the wave function is updated to reflect this change in knowledge. This is exactly what happens in classical probability.

If the wave function is purely epistemic, there is no problem with collapse, and the additional worlds that MWI introduces play no useful role and can readily be discarded. The other worlds need be real only if the wave function itself is real, and some way of avoiding a physical collapse is required. Once you avoid the collapse problem, the many-worlds scenario becomes otiose.

If you insist that you can have a purely epistemic wave function, and also have all the other branches being as real as this one, then there is no knock-down argument against your position. But such a position is clearly contrived, and otiose, having no basis in quantum theory.

Bruce

Brent Meeker

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Nov 17, 2024, 6:11:32 PM11/17/24
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On 11/17/2024 2:29 PM, Russell Standish wrote:
> On Sat, Nov 16, 2024 at 03:52:25PM +1100, Bruce Kellett wrote:
>> On Sat, Nov 16, 2024 at 3:28 PM Russell Standish <li...@hpcoders.com.au> wrote:
>>
>> On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote:
>> > On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <li...@hpcoders.com.au>
>> wrote:
>> >
>> >     I don't think it requires this assumption. In fact "physically real"
>> >     is a rather nebulous concept anyway.
>> >
>> >
>> > If you want the 'other worlds' to be physically real, then the original
>> wave
>> > function must be physically real.
>>
>> That's a non-sequitur. The 'other worlds' are as real as this one. The
>> reality of the wave function doesn't enter into it.
>>
>>
>> It does if the wave function is purely epistemic. In other words, if it is
>> merely a means of calculating probabilities, then the supposed 'other worlds'
>> do not exist. The probabilities are the probability that one, and only one,
>> outcome is realized for each experiment.
> You've lost me here. Even if the wf is epistemic, it has no bearing on
> whether other branches are as real as this one or not.
>
> The MWI states that all branches are equally real. Other
> interpretations assert that only one branch is real, because... (fill
> in the blanks).
And a the epistemic interpretation says that there are no branches,
there are just calculations of probabilities of what the world will be
like in the future.

Brent

Bruce Kellett

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Nov 17, 2024, 6:24:39 PM11/17/24
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That is an excellent point. I wish I had made the argument as clearly as that.

Bruce

Russell Standish

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Nov 17, 2024, 6:35:41 PM11/17/24
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I do agree with you that an epistemic wave function has no problem
with collapse, but I've always said the collapse issue was rather
secondary compared with the issue of what privileges one branch over
all the others as being "real".

Stating that all branches are equally real with the one we observer
obviates the need for something to say one branch is more real than
the others, without committing to saying whether anything is real, or
even what "real" really means.

In contrast to your last statement, I find "single world
interpretations" otiose, in much the same way as I find Christian
theology otiose.

>
> If you insist that you can have a purely epistemic wave function, and also have
> all the other branches being as real as this one, then there is no knock-down
> argument against your position. But such a position is clearly contrived, and
> otiose, having no basis in quantum theory.
>

The latter sentence is a non-sequitur. See above.

> Bruce
>
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Bruce Kellett

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Nov 17, 2024, 7:14:29 PM11/17/24
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Not a problem if the branches do not exist. All we have on the epistemic interpretation is the probabilities that the future will be one way or another.

Stating that all branches are equally real with the one we observer
obviates the need for something to say one branch is more real than
the others, without committing to saying whether anything is real, or
even what "real" really means.

But there are no branches to be "equally real". You are fond of calling sound arguments "non sequitur". Your claim that all branches are equally real is indeed a non sequitur, in that it does not follow from anything at all.

In contrast to your last statement, I find "single world
interpretations" otiose, in much the same way as I find Christian
theology otiose.

That is among the sillier remarks that you have made.

Bruce

Russell Standish

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Nov 17, 2024, 7:35:56 PM11/17/24
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If the arguments were sound, I would not call them non-sequitur. There
is the possibility I missed something you consider obvious, but in
that case, I just ask you to dig deeper to join the dots.

> Your claim that all branches are equally real is
> indeed a non sequitur, in that it does not follow from anything at all.
>

Indeed. As is that there is only a single reality. But one is simpler than
the other. A lot of people get Occam's razor wrong here.

But my claim was "Stating that all branches are equally real with the
one we observe [sic] obviates the need for something to say one branch is
more real than the others". This is a pretty logical statement, some
would say of the bleeding obvious, but it does seem necesseary to point it
out.

>
> In contrast to your last statement, I find "single world
> interpretations" otiose, in much the same way as I find Christian
> theology otiose.
>
>
> That is among the sillier remarks that you have made.

In order to have a single world interpretation, you need a something
that privileges that single world. It is remarkably analogous to
saying "God did it", and equally as mysterious. It is certainly not
intended as a silly remark.

Bruce Kellett

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Nov 17, 2024, 7:48:43 PM11/17/24
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On Mon, Nov 18, 2024 at 11:35 AM Russell Standish <li...@hpcoders.com.au> wrote:
On Mon, Nov 18, 2024 at 11:14:16AM +1100, Bruce Kellett wrote:
>
> But there are no branches to be "equally real". You are fond of calling sound
> arguments "non sequitur".

If the arguments were sound, I would not call them non-sequitur. There
is the possibility I missed something you consider obvious, but in
that case, I just ask you to dig deeper to join the dots.

The epistemic interpretation says that the wave function is merely a summary of our knowledge of the physical situation. And it gives the probabilities for various future outcomes. There are no "branches", so there is nothing to be "equally real".


> Your claim that all branches are equally real is
> indeed a non sequitur, in that it does not follow from anything at all.

Indeed. As is that there is only a single reality. But one is simpler than
the other. A lot of people get Occam's razor wrong here.

There is only one reality, and a set of probabilities for future outcomes. The simplest solution is that the so-called "other worlds" do not exist. They are just a figment of your imagination. I know that your starting point is that "everything exists" is simpler than any other proposition. But if you do not start from there, you can see that this position is indeed otiose.

Bruce

Brent Meeker

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Nov 17, 2024, 7:52:54 PM11/17/24
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Not if you don't have a bunch of other worlds.  If there's only one
world then there are none over which to privilege it.  You seem to be
avoiding the meaning of "epistemic", i.e. "contained in one's
knowledge". If the theory, i.e. Schoerdinger's equation, predicts the
probability of how the world will become, then there is nothing said
about other worlds.  The probability is the rational expectation of one
and not the others.  The future of the world isn't privileged, it just
exists as the one realized.

Brent
>
>

Russell Standish

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Nov 17, 2024, 8:16:30 PM11/17/24
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On Mon, Nov 18, 2024 at 11:48:28AM +1100, Bruce Kellett wrote:
> On Mon, Nov 18, 2024 at 11:35 AM Russell Standish <li...@hpcoders.com.au>
> wrote:
>
> On Mon, Nov 18, 2024 at 11:14:16AM +1100, Bruce Kellett wrote:
> >
> > But there are no branches to be "equally real". You are fond of calling
> sound
> > arguments "non sequitur".
>
> If the arguments were sound, I would not call them non-sequitur. There
> is the possibility I missed something you consider obvious, but in
> that case, I just ask you to dig deeper to join the dots.
>
>
> The epistemic interpretation says that the wave function is merely a summary of
> our knowledge of the physical situation. And it gives the probabilities for
> various future outcomes. There are no "branches", so there is nothing to be
> "equally real".
>

There is observational evidence for at least one branch. To say an
epistemic interpretion implies there are no branches is a
misinterpretation of epistemic interpretation, if not a complete
strawman.

>
>
> > Your claim that all branches are equally real is
> > indeed a non sequitur, in that it does not follow from anything at all.
>
> Indeed. As is that there is only a single reality. But one is simpler than
> the other. A lot of people get Occam's razor wrong here.
>
>
> There is only one reality, and a set of probabilities for future outcomes. The
> simplest solution is that the so-called "other worlds" do not exist. They are
> just a figment of your imagination. I know that your starting point is that
> "everything exists" is simpler than any other proposition. But if you do not
> start from there, you can see that this position is indeed otiose.
>

But I do start from there. Because it is a consequence of Solomonoff-Levi
induction, sometimes known as Occam's razor theorem.

In order to get to your "There is only one reality", you _have_ to add
a mysterious something, call it what you will. My assertion is that
that "something" is probably a figment of imagination. Nobody in 20
odd years of arguing about this has been able to point their finger at
anything that will do the job. The closest I've seen is an appeal to
Goedel incompleteness, that (if believed) would privilege the integers
as something more real than anything else, but that seems to lead to
an even deeper multiverse than the MWI.

Bruce Kellett

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Nov 17, 2024, 8:39:40 PM11/17/24
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On Mon, Nov 18, 2024 at 12:16 PM Russell Standish <li...@hpcoders.com.au> wrote:
On Mon, Nov 18, 2024 at 11:48:28AM +1100, Bruce Kellett wrote:
> On Mon, Nov 18, 2024 at 11:35 AM Russell Standish <li...@hpcoders.com.au>
> wrote:
>
>     On Mon, Nov 18, 2024 at 11:14:16AM +1100, Bruce Kellett wrote:
>     >
>     > But there are no branches to be "equally real". You are fond of calling
>     sound
>     > arguments "non sequitur".
>
>     If the arguments were sound, I would not call them non-sequitur. There
>     is the possibility I missed something you consider obvious, but in
>     that case, I just ask you to dig deeper to join the dots.
>
>
> The epistemic interpretation says that the wave function is merely a summary of
> our knowledge of the physical situation. And it gives the probabilities for
> various future outcomes. There are no "branches", so there is nothing to be
> "equally real".
>

There is observational evidence for at least one branch. To say an
epistemic interpretion implies there are no branches is a
misinterpretation of epistemic interpretation, if not a complete
strawman.

Possibly the trouble here is that your argument really has nothing to do with quantum mechanics. So arguments about interpretations of quantum mechanics, and the difference between Everett and the epistemic interpretation, are beside the point as far as you are concerned.

>     > Your claim that all branches are equally real is
>     > indeed a non sequitur, in that it does not follow from anything at all.
>
>     Indeed. As is that there is only a single reality. But one is simpler than
>     the other. A lot of people get Occam's razor wrong here.
>
>
> There is only one reality, and a set of probabilities for future outcomes. The
> simplest solution is that the so-called "other worlds" do not exist. They are
> just a figment of your imagination. I know that your starting point is that
> "everything exists" is simpler than any other proposition. But if you do not
> start from there, you can see that this position is indeed otiose.
>

But I do start from there. Because it is a consequence of Solomonoff-Levi
induction, sometimes known as Occam's razor theorem.

Any so-called theorem depends on its assumptions. And Solomonoff induction may not amount to a hill of beans.

I know that your position stems from many years of discussions on the "everything" list, but I have never bought into the idea that everything is simpler than the scientific approach based on the phenomenology of the world around us. Science trumps speculative philosophy every time, and this thread started as a discussion of interpretations of quantum mechanics. So arguments from quantum mechanics are relevant, and not "non sequiturs" as you so frequently claim.

Bruce
Message has been deleted

PGC

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Nov 18, 2024, 12:18:42 AM11/18/24
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Bruce, let’s directly address the epistemic interpretation of the wavefunction. While this view neatly avoids ontological commitments and sidesteps issues like FTL action, it doesn’t fully account for experimentally observed phenomena such as violations of Bell’s inequalities. These correlations are not just statistical artifacts of knowledge updates; they point to an underlying structure that resists dismissal as mere epistemic bookkeeping. The wavefunction’s role in consistently modeling entanglement and its statistical implications suggests questioning the existence of a deeper reality, challenging the sufficiency of an epistemic-only framework.

Your dismissal of the many-worlds interpretation (MWI) as "otiose" seems to rest on the assumption that collapse problems vanish within an epistemic interpretation. However, this presumes that the wavefunction need not be universal, a presumption computationalism challenges by treating the wavefunction as a measure over all computations. These computations are integral to the self-referential experiences of observers supported by them. MWI coherently explains quantum phenomena without relying on ad hoc collapse mechanisms, aligning seamlessly with observation and the mathematical structure of quantum theory.

While you assert that "science trumps speculative philosophy," computationalism reframes this dichotomy. The scientific method remains central but is contextualized as a study of observable phenomena emerging from the constraints of self-referentially correct systems. Computationalism is firmly grounded in formal structures such as arithmetic, computer science, mathematical self-reference, and modal logics, all of which have demonstrable explanatory power in areas like quantum mechanics with lots of open problems. Everett’s MWI aligns naturally with these foundations, dispensing with external collapse mechanisms and treating the universal wavefunction as the generator of first-person phenomenological experiences.

Solomonoff-Levi induction, while dismissed by some as speculative, provides a rigorous framework for algorithmic modeling of phenomena. Extending this into computational metaphysics reveals reality as fundamentally mathematical, with physicality arising as a projection supported by universal computation. Ignoring this recursive and hierarchical view of knowledge—where phenomenological "worlds" emerge from simpler computational interactions—has potential to limit our grasp of the conjunction between physics and consciousness. At least, that’s how it seems to me.

Critiques suggesting that computationalism or MWI are disconnected from quantum mechanics misrepresent their relevance. Computationalism doesn’t dismiss quantum mechanics; it reinterprets it as a statistical and phenomenological consequence of universal computation. The many-worlds framework naturally incorporates first-person indeterminacy and avoids introducing unexplained collapse phenomena. By adhering to mathematical completeness and Occam’s razor, MWI addresses the same quantum phenomena while offering a broader explanatory scope.

While physicalism and phenomenology contribute valuable insights, they often fail to account for the structures underpinning experience. Now, regarding your can of beans: it’s undeniably nutritious, and its taste surely arises from... well, something. Skipping over such questions feels like an oddly flavorless game. The divide between science and metaphysics, much like the divide between bland food and flavorful cuisine, could be artificial. Computationalism bridges this gap by situating observable physicality upon a logically consistent, mathematical foundation that respects both third-person objectivity and first-person experiential realities. If you prefer your meals devoid of taste, no one will stop you—but to others, it’s hardly an inspiring feast. For example, how would we ever explain why the cheap can imparts the same metallic tang in all those Everett branches and why fresha could be betta in the meta? 

Maybe the real mystery here is why we keep coming back to the same beans—and not a single collapse has spilled them yet. 

Just a matter of taste.

Bruce Kellett

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Nov 18, 2024, 1:03:02 AM11/18/24
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On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com> wrote:

Your response presents strong points but contains some redundancies and overlapping arguments. Here's a revised version with greater focus, while maintaining the original’s precision and accuracy:


Bruce, let’s directly address the epistemic interpretation of the wavefunction. While this view neatly avoids ontological commitments and sidesteps issues like FTL action, it doesn’t fully account for experimentally observed phenomena such as violations of Bell’s inequalities.

The violation of Bell inequalities implies non-locality, and the epistemic interpretation of the wave function is perfectly compatible with non-locality.

These correlations are not just statistical artifacts of knowledge updates; they point to an underlying structure that resists dismissal as mere epistemic bookkeeping. The wavefunction’s role in consistently modeling entanglement and its statistical implications suggests questioning the existence of a deeper reality, challenging the sufficiency of an epistemic-only framework.


Unfortunately, Everettian QM, or MWI, cannot even account for the correlations, much less the violations of the Bell inequalities. I have made this argument before, but failed to make any impact. Let me try again.

The essence of Everett, as I see it, is that every possible outcome is realized on every experiment, albeit on separate branches, or in disjoint worlds. Given this interpretation, when Alice and Bob each separately measure their particles, say spin one-half particles, they split at random on to two branches, one getting spin-up and the other branch seeing spin-down. This happens for both Alice and Bob, independent of their particular polarization orientations. If this were not so, the correlations could be used to send messages at spacelike separations, i.e, FTL.

If N entangled pairs are exchanged, each of Alice and Bob split into 2^N branches, covering all possible combinations of UP and DOWN. When Alice and Bob meet, there is no control over which Alice-branch meets which Bob-branch. If the branch meet-up is random, then in general there will be zero correlation, since out of the 2^N Bob branches for each Alice branch, only one will give the observed correlations -- a 1/2^N chance. In the literature, some attempts have been made to solve this problem: for instance, it is sometimes claimed that Alice and Bob interact when they meet, and this interaction sorts out the relevant branches. But no account of any suitable interaction has ever been given, and also, one can reduce the possible interaction between  Alice and Bob to as little as desired, say by having them exchange their data by email, or some such. Another suggestion has been that since the original particles are entangled, some magic keeps everything straight. I do not find either line of attempted explanation in the least convincing, so I conclude that Everettian QM cannot account for any correlations, much less those that are observed to violate the Bell inequalities.

Attempts to relate Everettian many worlds to computationalism, or theories of everything, are just disingenuous. There is no reason why these many-worlds theories should have anything in common.

Bruce

Your dismissal of the many-worlds interpretation (MWI) as "otiose" seems to rest on the assumption that collapse problems vanish within an epistemic interpretation. However, this presumes that the wavefunction need not be universal, a presumption computationalism challenges by treating the wavefunction as a measure over all computations. These computations are integral to the self-referential experiences of observers supported by them. MWI coherently explains quantum phenomena without relying on ad hoc collapse mechanisms, aligning seamlessly with observation and the mathematical structure of quantum theory.

While you assert that "science trumps speculative philosophy," computationalism reframes this dichotomy. The scientific method remains central but is contextualized as a study of observable phenomena emerging from the constraints of self-referentially correct systems. Computationalism is firmly grounded in formal structures such as arithmetic, computer science, mathematical self-reference, and modal logics, all of which have demonstrable explanatory power in areas like quantum mechanics with lots of open problems. Everett’s MWI aligns naturally with these foundations, dispensing with external collapse mechanisms and treating the universal wavefunction as the generator of first-person phenomenological experiences.

Solomonoff-Levi induction, while dismissed by some as speculative, provides a rigorous framework for algorithmic modeling of phenomena. Extending this into computational metaphysics reveals reality as fundamentally mathematical, with physicality arising as a projection supported by universal computation. Ignoring this recursive and hierarchical view of knowledge—where phenomenological "worlds" emerge from simpler computational interactions—has potential to limit our grasp of the conjunction between physics and consciousness. At least, that’s how it seems to me.

Critiques suggesting that computationalism or MWI are disconnected from quantum mechanics misrepresent their relevance. Computationalism doesn’t dismiss quantum mechanics; it reinterprets it as a statistical and phenomenological consequence of universal computation. The many-worlds framework naturally incorporates first-person indeterminacy and avoids introducing unexplained collapse phenomena. By adhering to mathematical completeness and Occam’s razor, MWI addresses the same quantum phenomena while offering a broader explanatory scope.

While physicalism and phenomenology contribute valuable insights, they often fail to account for the structures underpinning experience. Now, regarding your can of beans: it’s undeniably nutritious, and its taste surely arises from... well, something. Skipping over such questions feels like an oddly flavorless game. The divide between science and metaphysics, much like the divide between bland food and flavorful cuisine, could be artificial. Computationalism bridges this gap by situating observable physicality upon a logically consistent, mathematical foundation that respects both third-person objectivity and first-person experiential realities. If you prefer your meals devoid of taste, no one will stop you—but to others, it’s hardly an inspiring feast. For example, how would we ever explain why the cheap can imparts the same metallic tang in all those Everett branches and why fresha could be betta in the meta? 

Maybe the real mystery here is why we keep coming back to the same beans—and not a single collapse has spilled them yet. 

Just a matter of taste.

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Brent Meeker

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Nov 18, 2024, 5:04:24 AM11/18/24
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Have you looked at the Minimal Modal Interpretation due to Barandes and Kagan: arxiv1405.6754 and arxiv1405.6755.  They claim to derive the Born rule as a consequence of decoherence and their take on MWI is:

Seen from this perspective, we can also better understand why it is so challenging [68] to make sense of a many-worlds-type interpretation as an ontologically and epistemologically reasonable interpretation of quantum theory: Attempting to do so leads to as much metaphysical difficulty as trying to make sense of the Lorenz gauge of Maxwell electromagnetism as an “ontologically correct interpretation” of the Maxwell theory.10 Hence, taking a lesson from classical gauge theories, we propose instead regarding many-worlds-type interpretations as merely a convenient mathematical tool—a particular “gauge choice”—for establishing definitively that a given “unitary-gauge” interpretation of quantum theory like our own is ultimately consistent with locality and Lorentz invariance.


Brent
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John Clark

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Nov 18, 2024, 8:54:29 AM11/18/24
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On Sun, Nov 17, 2024 at 6:06 PM Bruce Kellett <bhkel...@gmail.com> wrote
 
One of the frequently stated arguments for many worlds is that it avoids the problem of the wave function collapse. The collapse of the wave function is only a problem if the wave function is a physical object,

Even if you assume, as Copenhagen does, that the quantum wave function is just a prediction device and not a "real physical object" you still have a grave problem; at exactly what point are you supposed to stop trusting what that prediction device is telling you? Copenhagen would answer that you should stop trusting it at the exact point you make a measurement. Physics is the most precise of all the sciences so it would be reasonable to then ask for the exact meaning of this word "measurement", but when you do Niels Bohr and his friends will respond with bafflegab, which I can only interpret as "shut up and calculate".

By the way, the integers are not physical objects and neither is the concept of "fast", does that mean that both are unreal? If so, how would things be different if both of those things WERE real? I believe that if the wave function didn't lead to conclusions that make some people, perhaps most people, uncomfortable, like there being many other versions of themselves in a multiverse, nobody would be insisting that the wave function is not real. Physicists whose primary focus is physics at its most fundamental level sure seem to behave as if they thought it's real because they spend about 95% of their time studying quantum field theory.  
 
because then you run into problems with instantaneous action at a distance or FTL physical action.

That's no problem in Many Worlds because you can say the split happens instantaneously or you can say the split propagates at the speed of light, it makes no difference because they both produce identical observable results.  


If the wave function is purely epistemic, namely, nothing more than a summary of our knowledge about the physical system, there is no problem with collapse, because the result of an experiment merely updates our knowledge, and the wave function is updated to reflect this change in knowledge. 

That's the Bayesian interpretation and if you use that you will always get the correct answer in your experiments. The exact same thing is true with Shut Up And Calculate. If you don't care what's going on and you're only interested in predicting if the needle on your voltmeter will point to 3 or to 4 then I have absolutely no problem with you using either, in fact I think the two ideas are identical, they just have different names.   

This is exactly what happens in classical probability.

Not quite. Nobody needed an interpretation of classical physics, nobody needed a definition of "measurement" or "observer" because regardless of the old cliché about a watched pot never boiling, the time it takes to boil a pot of water really doesn't change depending on if you are watching it or not, but in the weird quantum world you really CAN delay the decay of a radioactive atom if you watch it closely enough, and Many Worlds has no problem explaining how this "Quantum Zeno Effect" works.   

Suppose an atom has a half-life of one second and I'm watching it, the universe splits and so do I after one second. In one universe the atom decays and I observed that the atom has decayed, in the other universe the atom has not decayed and I observed that it has not decayed. 

In the universe where the atom didn't decay after another second the universe splits again, and again in one universe it decays but in the other it has not, it survived for 2 full seconds. So there will be a version of me that observes this atom, which has a one second half-life, surviving for 3 seconds, and 4 seconds, and 5 years, and 6 centuries, and you name it. By utilizing a series of increasingly complex and difficult procedures it is possible for the lab (and you) to be in the universe that contains labs and versions of you that see the atom surviving for an arbitrarily long length of time. But the longer the time past its half-life the more splits are involved, and the more difficult the experiment becomes.  Soon it becomes ridiculously impractical to go further, but it's not impossible. 


 
> If the wave function is purely epistemic, there is no problem with collapse, and the additional worlds that MWI introduces play no useful role and can readily be discarded.

The useful role that Many Worlds provides is that it doesn't need to explain what a "measurement" or an "observer" is, nor does it need to explain exactly, or even approximately, where the Heisenberg cut is. And it doesn't need to explain what consciousness is because it has nothing to do with it.  

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

PGC

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Nov 18, 2024, 1:11:19 PM11/18/24
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On Monday, November 18, 2024 at 7:03:02 AM UTC+1 Bruce Kellett wrote:
On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com> wrote:

Bruce, let’s directly address the epistemic interpretation of the wavefunction. While this view neatly avoids ontological commitments and sidesteps issues like FTL action, it doesn’t fully account for experimentally observed phenomena such as violations of Bell’s inequalities.

The violation of Bell inequalities implies non-locality, and the epistemic interpretation of the wave function is perfectly compatible with non-locality.

These correlations are not just statistical artifacts of knowledge updates; they point to an underlying structure that resists dismissal as mere epistemic bookkeeping. The wavefunction’s role in consistently modeling entanglement and its statistical implications suggests questioning the existence of a deeper reality, challenging the sufficiency of an epistemic-only framework.


Unfortunately, Everettian QM, or MWI, cannot even account for the correlations, much less the violations of the Bell inequalities. I have made this argument before, but failed to make any impact. Let me try again.

The essence of Everett, as I see it, is that every possible outcome is realized on every experiment, albeit on separate branches, or in disjoint worlds. Given this interpretation, when Alice and Bob each separately measure their particles, say spin one-half particles, they split at random on to two branches, one getting spin-up and the other branch seeing spin-down. This happens for both Alice and Bob, independent of their particular polarization orientations. If this were not so, the correlations could be used to send messages at spacelike separations, i.e, FTL.

If N entangled pairs are exchanged, each of Alice and Bob split into 2^N branches, covering all possible combinations of UP and DOWN. When Alice and Bob meet, there is no control over which Alice-branch meets which Bob-branch. If the branch meet-up is random, then in general there will be zero correlation, since out of the 2^N Bob branches for each Alice branch, only one will give the observed correlations -- a 1/2^N chance. In the literature, some attempts have been made to solve this problem: for instance, it is sometimes claimed that Alice and Bob interact when they meet, and this interaction sorts out the relevant branches. But no account of any suitable interaction has ever been given, and also, one can reduce the possible interaction between  Alice and Bob to as little as desired, say by having them exchange their data by email, or some such. Another suggestion has been that since the original particles are entangled, some magic keeps everything straight. I do not find either line of attempted explanation in the least convincing, so I conclude that Everettian QM cannot account for any correlations, much less those that are observed to violate the Bell inequalities.

Attempts to relate Everettian many worlds to computationalism, or theories of everything, are just disingenuous. There is no reason why these many-worlds theories should have anything in common.

Bruce, your assertion that the epistemic interpretation of the wavefunction is compatible with non-locality and capable of addressing Bell inequality violations deserves attention. While it is true that an epistemic interpretation can align with non-local correlations, it struggles to explain the coherence and structure underlying these correlations. If the wavefunction is purely a representation of knowledge, what enforces the observed statistical regularities that persist independently of the observer? These correlations suggest a deeper reality to the wavefunction itself, beyond an epistemic framework.

You critique MWI on the basis of a "branch meet-up" problem, suggesting that the coherence of correlations collapses due to arbitrary branch matching. However, this interpretation mischaracterizes the role of the wavefunction in Everettian QM. The wavefunction evolves unitarily, preserving coherence across all branches. Correlations between Alice and Bob emerge from the shared history of their entangled particles, embedded in the global structure of the wavefunction. The branches are not randomly assigned but are intrinsically connected through their common origin in the unitary evolution. This global coherence ensures the persistence of correlations without requiring post-measurement sorting.

MWI is, at its core, a “local theory” with no faster-than-light action. The violation of Bell’s inequalities becomes a natural consequence of the wavefunction’s structure, serving as confirmation, softer than evidence, of the "other histories" that MWI posits. These violations do not indicate FTL signaling but instead highlight the fundamentally relational nature of quantum mechanics as described by the universal wavefunction. In this way, MWI addresses non-local correlations without the need for external collapse mechanisms or epistemic assumptions. It also provides a cure for what can be termed a form of Cosmo-solipsism—a worldview that limits reality to a single trajectory while dismissing the explanatory power of other branches.

Your argument implies that randomness in branch matching undermines MWI’s explanatory capacity, but this critique relies on a rather superficial misunderstanding of the global coherence of the wavefunction, uncharacteristic of your reasoning. The correlations are not artifacts of randomness but emerge from the mathematical structure of the wavefunction itself. Dismissing MWI on the grounds that it fails to account for these correlations requires evidence of mathematical or empirical failure, yet MWI has consistently matched experimental predictions, including Bell inequality violations.

The connections between computationalism and MWI are not disingenuous; they arise naturally from their shared reliance on universality and formal systems. Both frameworks explore branching realities—MWI through the wavefunction's evolution and computationalism through the interplay of self-reference and arithmetic. These are not disparate domains but overlapping ones, addressing the same fundamental questions of structure, indeterminacy, and coherence.

Your dismissal of computationalism as speculative philosophy overlooks its grounding in formal logic, arithmetic, and modal systems, which are as rigorous and predictive as the mathematical framework of quantum mechanics itself. The scientific method, which studies observable phenomena, is not in opposition to computationalism but is enriched by its insights into the structures that generate those phenomena. Computationalism extends the explanatory scope of science, bridging physical observations with deeper metaphysical questions.

I’ll admit that my perspective on this matter is rooted not only in logic and evidence but in an enduring curiosity shaped by personal experience, not merely by this list. Since childhood, I’ve been struck by the inadequacies of both hard and soft sciences when it comes to reconciling the physical and the subjective. Hard sciences have captivated me with their explanatory precision but often falter when addressing consciousness and first-person experience. Soft sciences offer insight into the subjective but lack the rigor to engage with physical phenomena in a truly predictive way. This bias has shaped my openness to frameworks like computationalism, which strive to bridge these domains instead of the dull compartmentalization that is standard. Who can finally prove some absolute notion of domain-specificity? You're arguments are in constant danger of slipping into ideological certitude here.

Perhaps this is my own version of taste, cultivated not just by logic but by a personal journey through wonder, doubt, and staying globally naive. The notion of “taste” is apt—it underscores the need to engage with these ideas experientially, not dismissively. Whether one prefers beans from an epistemic or Everettian can, the richness lies in savoring the flavor, not in rejecting the dish outright. 

Alan Grayson

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Nov 18, 2024, 4:03:33 PM11/18/24
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Very sophisticated! The bottom line for you is that it's a matter of taste. In the time it took to write this short message, innumerable universes were created by cars turning left or right at stop signs, and other innumerable choices by humans, animals, and microscopic entities. Are you comfortable with this? Does it meet your good taste, or does it seem beyond the pale, way beyond? TY, AG

Bruce Kellett

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Nov 18, 2024, 4:40:31 PM11/18/24
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On Tue, Nov 19, 2024 at 5:11 AM PGC <multipl...@gmail.com> wrote:
On Monday, November 18, 2024 at 7:03:02 AM UTC+1 Bruce Kellett wrote:
On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com> wrote:

Bruce, let’s directly address the epistemic interpretation of the wavefunction. While this view neatly avoids ontological commitments and sidesteps issues like FTL action, it doesn’t fully account for experimentally observed phenomena such as violations of Bell’s inequalities.

The violation of Bell inequalities implies non-locality, and the epistemic interpretation of the wave function is perfectly compatible with non-locality.

These correlations are not just statistical artifacts of knowledge updates; they point to an underlying structure that resists dismissal as mere epistemic bookkeeping. The wavefunction’s role in consistently modeling entanglement and its statistical implications suggests questioning the existence of a deeper reality, challenging the sufficiency of an epistemic-only framework.


Unfortunately, Everettian QM, or MWI, cannot even account for the correlations, much less the violations of the Bell inequalities. I have made this argument before, but failed to make any impact. Let me try again.

The essence of Everett, as I see it, is that every possible outcome is realized on every experiment, albeit on separate branches, or in disjoint worlds. Given this interpretation, when Alice and Bob each separately measure their particles, say spin one-half particles, they split at random on to two branches, one getting spin-up and the other branch seeing spin-down. This happens for both Alice and Bob, independent of their particular polarization orientations. If this were not so, the correlations could be used to send messages at spacelike separations, i.e, FTL.

If N entangled pairs are exchanged, each of Alice and Bob split into 2^N branches, covering all possible combinations of UP and DOWN. When Alice and Bob meet, there is no control over which Alice-branch meets which Bob-branch. If the branch meet-up is random, then in general there will be zero correlation, since out of the 2^N Bob branches for each Alice branch, only one will give the observed correlations -- a 1/2^N chance. In the literature, some attempts have been made to solve this problem: for instance, it is sometimes claimed that Alice and Bob interact when they meet, and this interaction sorts out the relevant branches. But no account of any suitable interaction has ever been given, and also, one can reduce the possible interaction between  Alice and Bob to as little as desired, say by having them exchange their data by email, or some such. Another suggestion has been that since the original particles are entangled, some magic keeps everything straight. I do not find either line of attempted explanation in the least convincing, so I conclude that Everettian QM cannot account for any correlations, much less those that are observed to violate the Bell inequalities.

Attempts to relate Everettian many worlds to computationalism, or theories of everything, are just disingenuous. There is no reason why these many-worlds theories should have anything in common.

Bruce, your assertion that the epistemic interpretation of the wavefunction is compatible with non-locality and capable of addressing Bell inequality violations deserves attention. While it is true that an epistemic interpretation can align with non-local correlations, it struggles to explain the coherence and structure underlying these correlations. If the wavefunction is purely a representation of knowledge, what enforces the observed statistical regularities that persist independently of the observer? These correlations suggest a deeper reality to the wavefunction itself, beyond an epistemic framework.

You critique MWI on the basis of a "branch meet-up" problem, suggesting that the coherence of correlations collapses due to arbitrary branch matching. However, this interpretation mischaracterizes the role of the wavefunction in Everettian QM. The wavefunction evolves unitarily, preserving coherence across all branches. Correlations between Alice and Bob emerge from the shared history of their entangled particles, embedded in the global structure of the wavefunction. The branches are not randomly assigned but are intrinsically connected through their common origin in the unitary evolution. This global coherence ensures the persistence of correlations without requiring post-measurement sorting.


That is not an explanation of how the correlations arise. You are just relying on magic, without giving any coherent account of the process.

Bruce

Brent Meeker

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Nov 18, 2024, 5:37:16 PM11/18/24
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LOL.  You just wrote three paragraphs immediately above each of which referred to "observed".  So if it doesn't need an explanation it must be obvious and have the same meaning as in the neo-Copenhagen interpretation, NCI.  MWI needs to explain how and when the worlds split, presumably due to decoherence although I've not seen an explicit calculation of an instance of the process.  The same when and how is available to NCI if you think it needs one.


, nor does it need to explain exactly, or even approximately, where the Heisenberg cut is.
No, it just assumes there is a point at which the world becomes multiple and measurement is complete.

Brent


And it doesn't need to explain what consciousness is because it has nothing to do with it.  

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

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Nov 18, 2024, 9:38:22 PM11/18/24
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On Monday, November 18, 2024 at 11:37:16 PM UTC+1 Brent Meeker wrote:



On 11/18/2024 5:53 AM, John Clark wrote:
...

The useful role that Many Worlds provides is that it doesn't need to explain what a "measurement" or an "observer" is
LOL.  You just wrote three paragraphs immediately above each of which referred to "observed".  So if it doesn't need an explanation it must be obvious and have the same meaning as in the neo-Copenhagen interpretation, NCI.  MWI needs to explain how and when the worlds split, presumably due to decoherence although I've not seen an explicit calculation of an instance of the process.  The same when and how is available to NCI if you think it needs one.

I find myself seeking clarification regarding your statements, Brent. E.g. about the absence of explicit calculations for the process of branching in MWI. This surprises me, as the phenomenon of decoherence, as you well know, has been extensively studied both theoretically and experimentally. The literature is abundant with models demonstrating how interactions between quantum systems and their environments suppress interference, leading to the emergence of classical behavior. These calculations provide the empirical foundation for many interpretations of quantum mechanics, including MWI.

If your critique is that these calculations do not explicitly prove the branching described by MWI, I would consider that a valid philosophical concern, but not necessarily a deficiency of the calculations themselves, which are separate and agnostic regarding interpretation. In MWI, branching is not an additional mechanism; rather, it is a natural interpretation of decoherence. Each "world" corresponds to a term in the wavefunction that no longer interferes with others due to environmental entanglement. This framework aligns with the unitary dynamics of quantum mechanics, avoiding the need for collapse mechanisms.

While it is true that some explanations use terms like "observed," MWI does not treat observation as a special ontological event. Instead, observation is modeled as a unitary interaction between systems that results in decoherence, creating branches of the wavefunction corresponding to different outcomes. In this sense, "observation" in MWI is a descriptive shorthand for the branching process and not an additional mechanism requiring explanation. Your insistence that MWI needs to explain "how and when worlds split" is strange to me; the splitting is continuous and governed by the dynamics of decoherence.

Decoherence calculations, as I understand them, apply equally to MWI and other interpretations, such as the neo-Copenhagen interpretation (NCI). The question, then, seems here, in this thread, to be whether one views the wavefunction as a real entity describing multiple branches, as in MWI, or as an epistemic tool requiring collapse, as in NCI. From my perspective, MWI avoids introducing additional ad hoc elements, providing a simpler and more frugal, low cost explanation of the same phenomena.

If you find the connection between decoherence and MWI unsatisfactory, it would be helpful to understand where you believe the explanatory gap lies. Scholars like Zeh, Tegmark, and Wallace have elaborated on these connections; and Schlosshauer’s reviews, in particular, provide an agnostic mathematical context for decoherence —a context on which there seems to be broad agreement in the field. And yet, I feel this is all obvious to you. Your perspective on how these studies/literature might then fall short of addressing your concerns would clarify. What am I missing, besides a lifetime of more reading and the beans to sustain the same?

Alan Grayson

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Nov 19, 2024, 4:20:52 AM11/19/24
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IMO, fundamentally, for you the bottom line is "taste". Presumably, you feel the MWI is in good taste so you affirm it. For me, it's the opposite. MWI IMO is in bad taste, very bad taste. Have you ever watched how an ant moves, or flying insects? They zig-zag, back and forth, sometimes in small circles. Presumably, every slight change creates new worlds according to the MWI, and copies of these insects come into being in these worlds. And what about us humans? Are we also in these worlds? If not, where is the cutoff? How does that come to be? It all seems totally ridiculous, indeed UGLY. You write eloquently, with authority, very educated. Probably a professor somwhere, at some prestigious university. So it baffles me how you could arrive at, and support a theory which utterly fails the smell test. But what could I know? After all, I'm just a simple country lawyer. AG

PGC

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Nov 19, 2024, 6:12:55 AM11/19/24
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Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive. Infinite branching, while seeming counterintuitive on the surface, feels consistent with the vastness suggested by math, particularly since I first encountered the real numbers and their uncountable infinity in High School. The idea that there are vastly more real numbers, even between 1 and 2, than natural numbers and that extensions of the set are efficacious tools in various domains, applied and theoretically, makess natural numbers and countable sets the rare exception. 

Collapse, on the other hand, feels - yes this is personal taste - seem baroque and contrived. It assumes that the wavefunction, universal and deterministic, inexplicably "chooses" one outcome over others at the moment of measurement. This raises unsettling questions: Who or what triggers that collapse? How is this reconciled with spacelike separations? For me, this process seems far more arbitrary and less natural than the branching structure of MWI, which flows directly from the unitary evolution of the wavefunction. The funny thing is that I am always the guy accused of believing in "magic", when - with collapse - the wavefunction just suddenly disappears after we assume it exists. That feels like somebody pulling my leg, and why I prefer the infinities in MWI.

No, I am not an expert in the field. Just a tourist with a notebook, enjoying everybody's contributions here for years, eager to learn, as I know nothing. Regarding your analogy with insects and their zig-zagging: in MWI every possible quantum event contributes to branching, and humans are no exception. There is no "cutoff" because the wavefunction applies universally to all systems. Again, this may seem counterintuitive and even extravagant, but it avoids the need for selective pruning and sudden vanishing of the wave function required by collapse theories, which to me feels more contrived. It feels like an awkward and artificial attempt to fit quantum behavior into classical intuition, demanding far more explanation than it provides. Therefore, I don't find the idea ugly. If it holds, the only ugliness is that I'm just a bit annoyed that I'm not in a branch where I'm making more money. A large set of those versions of "me" seem to be having more fun, which is hard to accept, but better than "woosh - wavefunction is gone, it never really was etc."

Alan Grayson

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Nov 19, 2024, 7:05:29 AM11/19/24
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     1)  IMO, fundamentally, for you the bottom line is "taste". Presumably, you feel the MWI is in good taste so you affirm it. For me, it's the  opposite. MWI IMO is in bad taste, very bad taste. Have you ever watched how an ant moves, or flying insects? They zig-zag, back and forth, sometimes in small circles. Presumably, every slight change creates new worlds according to the MWI, and copies of these insects come into being in these worlds. And what about us humans? Are we also in these worlds? If not, where is the cutoff? How does that come to be? It all seems totally ridiculous, indeed UGLY. You write eloquently, with authority, very educated. Probably a professor somwhere, at some prestigious university. So it baffles me how you could arrive at, and support a theory which utterly fails the smell test. But what could I know? After all, I'm just a simple country lawyer. AG

On Tuesday, November 19, 2024 at 4:12:55 AM UTC-7 PGC wrote:

    2)  Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive. Infinite branching, while seeming counterintuitive on the surface, feels consistent with the vastness suggested by math, particularly since I first encountered the real numbers and their uncountable infinity in High School. The idea that there are vastly more real numbers, even between 1 and 2, than natural numbers and that extensions of the set are efficacious tools in various domains, applied and theoretically, makess natural numbers and countable sets the rare exception. 

Collapse, on the other hand, feels - yes this is personal taste - seem baroque and contrived. It assumes that the wavefunction, universal and deterministic, inexplicably "chooses" one outcome over others at the moment of measurement. This raises unsettling questions: Who or what triggers that collapse? How is this reconciled with spacelike separations? For me, this process seems far more arbitrary and less natural than the branching structure of MWI, which flows directly from the unitary evolution of the wavefunction. The funny thing is that I am always the guy accused of believing in "magic", when - with collapse - the wavefunction just suddenly disappears after we assume it exists. That feels like somebody pulling my leg, and why I prefer the infinities in MWI.

No, I am not an expert in the field. Just a tourist with a notebook, enjoying everybody's contributions here for years, eager to learn, as I know nothing. Regarding your analogy with insects and their zig-zagging: in MWI every possible quantum event contributes to branching, and humans are no exception. There is no "cutoff" because the wavefunction applies universally to all systems. Again, this may seem counterintuitive and even extravagant, but it avoids the need for selective pruning and sudden vanishing of the wave function required by collapse theories, which to me feels more contrived. It feels like an awkward and artificial attempt to fit quantum behavior into classical intuition, demanding far more explanation than it provides. Therefore, I don't find the idea ugly. If it holds, the only ugliness is that I'm just a bit annoyed that I'm not in a branch where I'm making more money. A large set of those versions of "me" seem to be having more fun, which is hard to accept, but better than "woosh - wavefunction is gone, it never really was etc."

3)   If wf collapse is the cause of your problem, IMO it's misplaced. It was a bad choice of words by Bohr. The real underlying problem is that QM is alleged to be irreducibly random. IOW, it's supposed to be random without any rule about what, if anything, governs this randomness. For me, this makes QM, or shall we say the measurement problem, unintelligible for human consciousness. So, when we look at the wf, which generally has many non-zero probabilities, we can think or model the occurrence of a measurement as those probabilities converging to zero, save one of them, which gets progressively larger, becoming exactly one (numerically 1), so the net effect is that the wf converges to a delta function centered on the measured value. I am not claiming any such transformation actually occurs, and I never took the so-called collapse seriously, but rather as a bookkeeping device. You can do the same, and focus on the real problem, which isn't the non-existent collapse, but the fact that QM alleges to be irreducibly random. I don't have an answer to this problem, but I refuse to adopt MWI as the answer since it makes an enigmatic situation hugely worse. AG 

Alan Grayson

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Nov 19, 2024, 7:17:03 AM11/19/24
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4)  Concerning your problem of the wf disappearing when the measurement occurs, consider this; when there's a horse race and each horse has a probability of winning, do you have a problem with these probabilities "disappearing" when the race is over? If not, why not? And why not apply this perspective to the disappearance of the wf? AG 

PGC

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Nov 19, 2024, 7:52:34 AM11/19/24
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The analogy oversimplifies the situation and misses the conceptual challenge of the wavefunction's disappearance in quantum mechanics. In a horse race, probabilities represent our lack of knowledge about the outcome, and when the race concludes, we gain said knowledge, collapsing the uncertainty into a definite result. This process doesn't imply that the probabilities themselves were real entities that ceased to exist—they were merely tools to represent our incomplete knowledge at an earlier point.

In QM, however, the wavefunction is often taken to represent more than just epistemic uncertainty; it is considered an ontological concept describing the state of a quantum system. When the wavefunction "disappears" upon measurement, this raises the question of what happens to the other branches of the superposition; unlike the horse race analogy, where the probabilities were never "real" in the same way as the horses. The wavefunction embodies a more fundamental description of reality in many interpretations. Its abrupt disappearance therefore feels more like invoking "magic" than a natural resolution, as it suggests an unexplained mechanism or process that isn't present in classical probability theory.

This is why some folks find interpretations like MWI appealing—they sidestep this "magic" collapse by maintaining all branches of the wavefunction as physically real, avoiding the need to explain its vanishing act. Call it taste/preference/tendency to find more plausible; not believe literally. This list tends to be more refined than that (mostly). I won't spoon feed you on details. Instead, I propose immersion in the literature or Sean Carroll on why these things are commonly misunderstood, similar to your reasoning on this point. You appear convinced without seeming to have perused the menu of MWI interpretation. Get comfortable, make some orders, and consider trying it for yourself instead of dismissing it outright + with certitude.

Alan Grayson

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Nov 19, 2024, 8:23:19 AM11/19/24
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The branches you discuss don't exist, and the MWI creates hugely more problems than it solves. Maybe you should just accept the fact that the wf is just epistemic (despite what some "experts" like Carroll claim) and the horse racing example applies. As I explained, the wf doesn't disappear, or otherwise by magic. Since we can't predict the outcome of a quantum measurement, there's no reason to consider the wf probabilities as essentially different from those in the horse race model. If probabilities were ontological, you could kick them, and they'd kick back! There likely is an unexplained mechanism in the measurement process, but your imaginary branches are not the answer. AG

Alan Grayson

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Nov 19, 2024, 8:51:54 AM11/19/24
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If the alleged disappearance of the wf bothers you, keep in mind that Bohr means, or models it as evolving into a delta function. That's why I pointed out that calling it a "collapse" might be misleading. You can think of the wf evolving, and the real problem is that QM is irreducibly random, so we don't know at present how that process can exist. AG

Brent Meeker

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Nov 19, 2024, 6:10:36 PM11/19/24
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On 11/18/2024 6:38 PM, PGC wrote:


On Monday, November 18, 2024 at 11:37:16 PM UTC+1 Brent Meeker wrote:



On 11/18/2024 5:53 AM, John Clark wrote:
...

The useful role that Many Worlds provides is that it doesn't need to explain what a "measurement" or an "observer" is
LOL.  You just wrote three paragraphs immediately above each of which referred to "observed".  So if it doesn't need an explanation it must be obvious and have the same meaning as in the neo-Copenhagen interpretation, NCI.  MWI needs to explain how and when the worlds split, presumably due to decoherence although I've not seen an explicit calculation of an instance of the process.  The same when and how is available to NCI if you think it needs one.

I find myself seeking clarification regarding your statements, Brent. E.g. about the absence of explicit calculations for the process of branching in MWI. This surprises me, as the phenomenon of decoherence, as you well know, has been extensively studied both theoretically and experimentally. The literature is abundant with models demonstrating how interactions between quantum systems and their environments suppress interference, leading to the emergence of classical behavior.

Then it will be easy for you to cite a few.  The ones I find like arxiv2406.15577 are not very satisfactory

"Unfortunatey, it seems much more complicated to explain the behaviour for cases (ii) and (iii). Certainly, owing to the extensive number of conserved quantities, the states |ψ(x)⟩ can not explore the available Hilbert space in an unbiased fashion, which causes deviations from the behaviour of typical states. Yet, why the exponent α(T) becomes even smaller for larger T remains a mystery."

These calculations provide the empirical foundation for many interpretations of quantum mechanics, including MWI.

If your critique is that these calculations do not explicitly prove the branching described by MWI, I would consider that a valid philosophical concern, but not necessarily a deficiency of the calculations themselves, which are separate and agnostic regarding interpretation. In MWI, branching is not an additional mechanism; rather, it is a natural interpretation of decoherence. Each "world" corresponds to a term in the wavefunction that no longer interferes with others due to environmental entanglement. This framework aligns with the unitary dynamics of quantum mechanics, avoiding the need for collapse mechanisms.

While it is true that some explanations use terms like "observed," MWI does not treat observation as a special ontological event. Instead, observation is modeled as a unitary interaction between systems that results in decoherence, creating branches of the wavefunction corresponding to different outcomes. In this sense, "observation" in MWI is a descriptive shorthand for the branching process and not an additional mechanism requiring explanation. Your insistence that MWI needs to explain "how and when worlds split" is strange to me; the splitting is continuous and governed by the dynamics of decoherence.

Then does the split propagate from a microscopic event that starts the split?  How  does it propagate?  In a Bell experiment do all four results occur and propagate? 

Decoherence calculations, as I understand them, apply equally to MWI and other interpretations, such as the neo-Copenhagen interpretation (NCI). The question, then, seems here, in this thread, to be whether one views the wavefunction as a real entity describing multiple branches, as in MWI, or as an epistemic tool requiring collapse, as in NCI. From my perspective, MWI avoids introducing additional ad hoc elements, providing a simpler and more frugal, low cost explanation of the same phenomena.

I'm well aware of MWI advocate's claims.  But claims that it entails the Born rule keep failing.  And if you have to add an axiom to provide a probabilistic interpretation of your multiple worlds, then it's just a simple to say only one world exists with the associated probability.

If you find the connection between decoherence and MWI unsatisfactory, it would be helpful to understand where you believe the explanatory gap lies. Scholars like Zeh, Tegmark, and Wallace have elaborated on these connections; and Schlosshauer’s reviews, in particular, provide an agnostic mathematical context for decoherence —a context on which there seems to be broad agreement in the field. And yet, I feel this is all obvious to you. Your perspective on how these studies/literature might then fall short of addressing your concerns would clarify. What am I missing, besides a lifetime of more reading and the beans to sustain the same?

You don't need to explain MWI to me.  I have Schlosshauer's papers and book as well as papers by Zeh, Zurek, Carroll, and others.  What you are missing is a skeptical curiosity.  How is the Born rule realized?  What about Barandes Minimal Modal Interpretation, or Path Integrals, or Invariant Set Theory...which seem to avoid multiple-worlds?

Brent
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Brent Meeker

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On 11/19/2024 3:12 AM, PGC wrote:

Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive.

But the "collapse" is still there for you in MWI.   As far as anything you can observer or experience or measure a single possibility occurs and this is explained by the action of decoherence splitting your world away from the other possibilities.  The only difference is whether you imagine those other worlds as existing or you say that probabilities mean one is realized and the other's are not.  If you don't say that then you will have trouble saying what those probabilities refer to.

Brent

Alan Grayson

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Nov 19, 2024, 8:17:44 PM11/19/24
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PGC doesn't realize that the so-called collapse perfectly describe what happens in a measurement process; except for the measurement which is realized, all other probabilities converge to zero, and the realized measurement converges to 1. IOW, the wf converges to a delta function. So collapse per se, isn't the problem. Rather, the problem is how the measurement process occurs; how it happens; what governs the process? This is the real mystery; not the collapse, which just correctly describes at a top level, what happens. AG

PGC

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Nov 20, 2024, 11:16:43 PM11/20/24
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This requires a bit of disambiguation and clarity indeed. 


You critique MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap. But I don’t advocate MWI; you confuse a preference with advocacy. I prefer the clarity of histories or computations, which avoid unclear ontological commitments.
With UDA of Bruno it’s difficult to not acknowledge the multiverse as a confirmation of the many-computations (many implying 2^aleph_0 or more iirc) theorem in meta-arithmetic, which is not an interpretation but derivable from the ontology with the smallest ontological entry fee I’ve seen to date.

Collapse postulates, in my view/taste, are conceptually less refined. We all know they assume the wavefunction to be real only to make it vanish upon measurement. This introduces a level of arbitrariness absent in MWI, which maintains coherence between the wavefunction’s status before and after observation. MWI’s probability weights and the Born rule remain open problems but there’s at least room for the possibility, that they do not require the same ontological reversal inherent to collapse and can be smuggled in somehow, a possibility we’ve discussed on this list some years ago.

Your concern about skeptical curiosity is well-taken, and I share your interest in understanding how probabilities arise but with the added standard of acknowledging the possibility and problems of doing so without conflating personal/observer accounts and views with objective descriptions. Gödel did happen. A circumstance that explains why none of the frameworks are satisfactory on their own. Deriving something akin to Gleason’s theorem from within mathematical self-reference assuming Bruno’s UDA is an open problem, one that I suppose computational metaphysics acknowledges as both desirable and difficult; perhaps excessively so. If the latter should continue to hold with nobody making progress, the gap between observer perspectives and objective descriptions increasingly isn’t a bug to fix but a feature of the self-referential structures underlying both observed physics and consciousness of the observer in what I understand to be Bruno’s approach.

In this light, Barandes' MMI, path integrals, and IST are important contributions, but they too must grapple with the problem of these foundational splits by other means than rhetorical dismissal; all frameworks should at least be acknowledge this difference in some way to indeed clarify what the probabilities refer to. By explicitly acknowledging this, UDA clarifies why observer consciousness, its properties and views, and it’s distinction from objective descriptions, isn’t evasion or gobbledygook but an essential part of the inquiry that can't be swept under the rug. If you can reconcile this within a physicalist or collapse framework, I am - without the obligatory clowning around of the list - genuinely interested. Thank you for enriching my reading. Unfortunately too much work atm.


 
Brent

Alan Grayson

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Nov 21, 2024, 2:00:12 AM11/21/24
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On Wednesday, November 20, 2024 at 9:16:43 PM UTC-7 PGC wrote:
On Wednesday, November 20, 2024 at 1:08:36 AM UTC+1 Brent Meeker wrote:



On 11/19/2024 3:12 AM, PGC wrote:

Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive.

But the "collapse" is still there for you in MWI.   As far as anything you can observer or experience or measure a single possibility occurs and this is explained by the action of decoherence splitting your world away from the other possibilities.  The only difference is whether you imagine those other worlds as existing or you say that probabilities mean one is realized and the other's are not.  If you don't say that then you will have trouble saying what those probabilities refer to.


This requires a bit of disambiguation and clarity indeed. 


You critique MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap. But I don’t advocate MWI; you confuse a preference with advocacy. I prefer the clarity of histories or computations, which avoid unclear ontological commitments.
With UDA of Bruno it’s difficult to not acknowledge the multiverse as a confirmation of the many-computations (many implying 2^aleph_0 or more iirc) theorem in meta-arithmetic, which is not an interpretation but derivable from the ontology with the smallest ontological entry fee I’ve seen to date.

Collapse postulates, in my view/taste, are conceptually less refined. We all know they assume the wavefunction to be real only to make it vanish upon measurement. This introduces a level of arbitrariness absent in MWI, which maintains coherence between the wavefunction’s status before and after observation. MWI’s probability weights and the Born rule remain open problems but there’s at least room for the possibility, that they do not require the same ontological reversal inherent to collapse and can be smuggled in somehow, a possibility we’ve discussed on this list some years ago.

What makes you so sure the wf is real? Or that it collapses? It doesn't collapse. Rather, it evolves into a delta function centered on the measured value. And it's much more likely to be epistemic since it gives us probabilities, or information about frequencies for a large number of trials. And what would it mean for the wf to be real? Does it exist in the material world? What's the argument for that? Does its existence in a Hilbert space constitute "real"? I am doubtful. AG

Alan Grayson

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Nov 21, 2024, 3:20:23 AM11/21/24
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On Thursday, November 21, 2024 at 12:00:12 AM UTC-7 Alan Grayson wrote:
On Wednesday, November 20, 2024 at 9:16:43 PM UTC-7 PGC wrote:
On Wednesday, November 20, 2024 at 1:08:36 AM UTC+1 Brent Meeker wrote:



On 11/19/2024 3:12 AM, PGC wrote:

Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive.

But the "collapse" is still there for you in MWI.   As far as anything you can observer or experience or measure a single possibility occurs and this is explained by the action of decoherence splitting your world away from the other possibilities.  The only difference is whether you imagine those other worlds as existing or you say that probabilities mean one is realized and the other's are not.  If you don't say that then you will have trouble saying what those probabilities refer to.


This requires a bit of disambiguation and clarity indeed. 


You critique MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap. But I don’t advocate MWI; you confuse a preference with advocacy. I prefer the clarity of histories or computations, which avoid unclear ontological commitments.
With UDA of Bruno it’s difficult to not acknowledge the multiverse as a confirmation of the many-computations (many implying 2^aleph_0 or more iirc) theorem in meta-arithmetic, which is not an interpretation but derivable from the ontology with the smallest ontological entry fee I’ve seen to date.

Collapse postulates, in my view/taste, are conceptually less refined. We all know they assume the wavefunction to be real only to make it vanish upon measurement. This introduces a level of arbitrariness absent in MWI, which maintains coherence between the wavefunction’s status before and after observation. MWI’s probability weights and the Born rule remain open problems but there’s at least room for the possibility, that they do not require the same ontological reversal inherent to collapse and can be smuggled in somehow, a possibility we’ve discussed on this list some years ago.

What makes you so sure the wf is real? Or that it collapses? It doesn't collapse. Rather, it evolves into a delta function centered on the measured value. And it's much more likely to be epistemic since it gives us probabilities, or information about frequencies for a large number of trials. And what would it mean for the wf to be real? Does it exist in the material world? What's the argument for that? Does its existence in a Hilbert space constitute "real"? I am doubtful. AG

It's useful to keep in mind that wf's are as real as Hilbert Spaces, and they're as real as, say, coordinate systems, which are convenient constructs that exist in the minds of mathematicians. AG 

John Clark

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Nov 21, 2024, 7:37:29 AM11/21/24
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On Wed, Nov 20, 2024 at 11:16 PM PGC <multipl...@gmail.com> wrote:

MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap.

I thought Carroll did a pretty good job showing that during the time interval between the wave function branching, due to decoherence, and an observerregistering the outcome of a measurement, even if "he" knew the wave function of the entire Multiverse "he" still wouldn't know which branch "he" was on because before "he" opened his eyes and looked around all the hes on all the branches would be identical. Only after that do they become unique individuals. To ask, before you have seen, heard, felt, smelled or tasted anything, "which ONE branch am I on?" cannot be answered because during that time interval "you" are on many branches, perhaps infinitely many.



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



smitra

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Nov 21, 2024, 8:12:46 AM11/21/24
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On 18-11-2024 07:02, Bruce Kellett wrote:
> On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com>
> wrote:
>
>> Your response presents strong points but contains some redundancies
>> and overlapping arguments. Here's a revised version with greater
>> focus, while maintaining the original’s precision and accuracy:
>> -------------------------
>>
>> Bruce, let’s directly address the epistemic interpretation of the
>> wavefunction. While this view neatly avoids ontological commitments
>> and sidesteps issues like FTL action, it doesn’t fully account for
>> experimentally observed phenomena such as violations of Bell’s
>> inequalities.
>
> The violation of Bell inequalities implies non-locality, and the
> epistemic interpretation of the wave function is perfectly compatible
> with non-locality.
>

The violation of Bell's inequalities does not imply non-locality. In
fact, the violation of Bell's inequality is a prediction of QM which
when describing the dynamics with a physical Hamiltonian, is a
manifestly local theory. It's only in certain interpretations that there
can be non-local aspects, but then these interpretations make
assumptions that require local dynamics to be violated. But there is
nothing whatsoever non-local about the dynamics of how the wavefunction
evolves over time. This means that in any interpretation where you stick
to only the wavefunction as describing physical reality, that nothing
non-local can occur.





>> These correlations are not just statistical artifacts of knowledge
>> updates; they point to an underlying structure that resists
>> dismissal as mere epistemic bookkeeping. The wavefunction’s role
>> in consistently modeling entanglement and its statistical
>> implications suggests questioning the existence of a deeper reality,
>> challenging the sufficiency of an epistemic-only framework.
>
> Unfortunately, Everettian QM, or MWI, cannot even account for the
> correlations, much less the violations of the Bell inequalities. I
> have made this argument before, but failed to make any impact. Let me
> try again.
>
> The essence of Everett, as I see it, is that every possible outcome is
> realized on every experiment, albeit on separate branches, or in
> disjoint worlds. Given this interpretation, when Alice and Bob each
> separately measure their particles, say spin one-half particles, they
> split at random on to two branches, one getting spin-up and the other
> branch seeing spin-down. This happens for both Alice and Bob,
> independent of their particular polarization orientations. If this
> were not so, the correlations could be used to send messages at
> spacelike separations, i.e, FTL.

It doesn't happen independently, because when Alice makes her
measurement, her state becomes entangled with entangled spin pair. So,
you now have a macroscopic quantum state where Alice plus her
measurement apparatus are entangled with the entangled spin par. And
when Bob makes his measurement, he gets entangled with the spin pair and
as a result with Alice's sector. So, in the end it's because you choose
not to describe Alice and Bob quantum mechanically and treat them as
classical objects that you end up missing an essential element and that
leads to a paradox.

Another example of non-locality arising as an artifact of describing
part of a system classically, is the Aharanmov-Bohm effect:

https://arxiv.org/abs/1906.03440

Here too the fact that within the classical realm, you cannot describe
entanglement causes local dynamics to manifest itself as a seemingly
non-local effect.

Saibal
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Brent Meeker

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Nov 21, 2024, 3:53:39 PM11/21/24
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On 11/21/2024 4:36 AM, John Clark wrote:
On Wed, Nov 20, 2024 at 11:16 PM PGC <multipl...@gmail.com> wrote:

MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap.

I thought Carroll did a pretty good job showing that during the time interval between the wave function branching, due to decoherence, and an observerregistering the outcome of a measurement, even if "he" knew the wave function of the entire Multiverse "he" still wouldn't know which branch "he" was on because before "he" opened his eyes and looked around all the hes on all the branches would be identical. Only after that do they become unique individuals. To ask, before you have seen, heard, felt, smelled or tasted anything, "which ONE branch am I on?" cannot be answered because during that time interval "you" are on many branches, perhaps infinitely many.
So where would he be if he just walked away without ever looking at the result?

Brent

John Clark

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Nov 21, 2024, 4:28:36 PM11/21/24
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On Thu, Nov 21, 2024 at 3:53 PM Brent Meeker <meeke...@gmail.com> wrote:

>> I thought Carroll did a pretty good job showing that during the time interval between the wave function branching, due to decoherence, and an observerregistering the outcome of a measurement, even if "he" knew the wave function of the entire Multiverse "he" still wouldn't know which branch "he" was on because before "he" opened his eyes and looked around all the hes on all the branches would be identical. Only after that do they become unique individuals. To ask, before you have seen, heard, felt, smelled or tasted anything, "which ONE branch am I on?" cannot be answered because during that time interval "you" are on many branches, perhaps infinitely many.
 
So where would he be if he just walked away without ever looking at the result?

Mr.He would remain in every branch until something in the environment interacted with the man in a way that was different from that of every other branch. And that wouldn't take long because even if Mr.He didn't directly look at the results those results would still affect other things in the environment which would soon affect Mr.He. too. That phenomenon is why it's so hard to make a practical Quantum Computer,  and why you need to cool things down to a thousandth of a degree above absolute zero or less and make use of quantum error correction. 
 
John K Clark    See what's on my new list at  Extropolis
.,-
 

Alan Grayson

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Nov 21, 2024, 4:31:48 PM11/21/24
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On Thursday, November 21, 2024 at 1:20:23 AM UTC-7 Alan Grayson wrote:
On Thursday, November 21, 2024 at 12:00:12 AM UTC-7 Alan Grayson wrote:
On Wednesday, November 20, 2024 at 9:16:43 PM UTC-7 PGC wrote:
On Wednesday, November 20, 2024 at 1:08:36 AM UTC+1 Brent Meeker wrote:



On 11/19/2024 3:12 AM, PGC wrote:

Your critique of MWI as "bad taste" because of its proliferation of worlds is understandable, but for me, collapse is far stranger and less intuitive.

But the "collapse" is still there for you in MWI.   As far as anything you can observer or experience or measure a single possibility occurs and this is explained by the action of decoherence splitting your world away from the other possibilities.  The only difference is whether you imagine those other worlds as existing or you say that probabilities mean one is realized and the other's are not.  If you don't say that then you will have trouble saying what those probabilities refer to.


This requires a bit of disambiguation and clarity indeed. 


You critique MWI for not deriving Born’s rule from the Schrödinger equation. I agree this is an unresolved challenge for MWI advocates, but I would note that it does not fundamentally undermine MWI. It’s open and I actually share the skepticism towards attempts by Carroll and Co. to bridge that gap. But I don’t advocate MWI; you confuse a preference with advocacy. I prefer the clarity of histories or computations, which avoid unclear ontological commitments.
With UDA of Bruno it’s difficult to not acknowledge the multiverse as a confirmation of the many-computations (many implying 2^aleph_0 or more iirc) theorem in meta-arithmetic, which is not an interpretation but derivable from the ontology with the smallest ontological entry fee I’ve seen to date.

Collapse postulates, in my view/taste, are conceptually less refined. We all know they assume the wavefunction to be real only to make it vanish upon measurement. This introduces a level of arbitrariness absent in MWI, which maintains coherence between the wavefunction’s status before and after observation. MWI’s probability weights and the Born rule remain open problems but there’s at least room for the possibility, that they do not require the same ontological reversal inherent to collapse and can be smuggled in somehow, a possibility we’ve discussed on this list some years ago.

What makes you so sure the wf is real? Or that it collapses? It doesn't collapse. Rather, it evolves into a delta function centered on the measured value. And it's much more likely to be epistemic since it gives us probabilities, or information about frequencies for a large number of trials. And what would it mean for the wf to be real? Does it exist in the material world? What's the argument for that? Does its existence in a Hilbert space constitute "real"? I am doubtful. AG

It's useful to keep in mind that wf's are as real as Hilbert Spaces, and they're as real as, say, coordinate systems, which are convenient constructs that exist in the minds of mathematicians. AG 

How come no one claims that Einstein's Field Equation in GR is "real", even though it keeps making accurate predictions? ISTM, that all the laws of physics, expressed in mathematical terms, are epistemic. They just describe reality, and hence are informational in nature. AG
 

Bruce Kellett

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Nov 21, 2024, 4:54:04 PM11/21/24
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On Fri, Nov 22, 2024 at 12:12 AM smitra <smi...@zonnet.nl> wrote:
On 18-11-2024 07:02, Bruce Kellett wrote:
> On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com>
> wrote:
>
>> Your response presents strong points but contains some redundancies
>> and overlapping arguments. Here's a revised version with greater
>> focus, while maintaining the original’s precision and accuracy:
>> -------------------------
>>
>> Bruce, let’s directly address the epistemic interpretation of the
>> wavefunction. While this view neatly avoids ontological commitments
>> and sidesteps issues like FTL action, it doesn’t fully account for
>> experimentally observed phenomena such as violations of Bell’s
>> inequalities.
>
> The violation of Bell inequalities implies non-locality, and the
> epistemic interpretation of the wave function is perfectly compatible
> with non-locality.
>

The violation of Bell's inequalities does not imply non-locality. In
fact, the violation of Bell's inequality is a prediction of QM which
when describing the dynamics with a physical Hamiltonian, is a
manifestly local theory. It's only in certain interpretations that there
can be non-local aspects, but then these interpretations make
assumptions that require local dynamics to be violated.

And what might these assumptions be?

But there is
nothing whatsoever non-local about the dynamics of how the wavefunction
evolves over time.

Not for an isolated non-interacting system. But the Bell inequalities refer to entangled particles, which do not evolve independently. In that case, non-local effects are required to explain the observed correlations.
According to Everett, Alice splits into two branches, one for each possible result of the spin measurement. That is how the entanglement is manifested. There is nothing particularly classical about this situation.

And when Bob makes his measurement, he gets entangled with the spin pair and
as a result with Alice's sector.

When Bob is spacelike separated from Alice and her measurement, he also splits into two independent branches.

So, in the end it's because you choose
not to describe Alice and Bob quantum mechanically and treat them as
classical objects

That is not the case. Everettian quantum mechanics says that they both split on to two branches, and there is no clear way in the formalism to see how the branches for the two individuals are related. In any model, in which both outcomes are necessarily realized for every measurement, there is no way to relate the outcomes.

that you end up missing an essential element and that
leads to a paradox.

Nothing has been missed in my analysis. As usual, you are unable to actually spell out how the correlations are preserved in the many-worlds scenario.

Bruce

Alan Grayson

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Nov 21, 2024, 5:07:15 PM11/21/24
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On Thursday, November 21, 2024 at 2:54:04 PM UTC-7 Bruce Kellett wrote:
On Fri, Nov 22, 2024 at 12:12 AM smitra <smi...@zonnet.nl> wrote:
On 18-11-2024 07:02, Bruce Kellett wrote:
> On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com>
> wrote:
>
>> Your response presents strong points but contains some redundancies
>> and overlapping arguments. Here's a revised version with greater
>> focus, while maintaining the original’s precision and accuracy:
>> -------------------------
>>
>> Bruce, let’s directly address the epistemic interpretation of the
>> wavefunction. While this view neatly avoids ontological commitments
>> and sidesteps issues like FTL action, it doesn’t fully account for
>> experimentally observed phenomena such as violations of Bell’s
>> inequalities.
>
> The violation of Bell inequalities implies non-locality, and the
> epistemic interpretation of the wave function is perfectly compatible
> with non-locality.
>

The violation of Bell's inequalities does not imply non-locality. In
fact, the violation of Bell's inequality is a prediction of QM which
when describing the dynamics with a physical Hamiltonian, is a
manifestly local theory. It's only in cerPeleliutain interpretations that there
can be non-local aspects, but then these interpretations make
assumptions that require local dynamics to be violated.
And what might these assumptions be?

But there is
nothing whatsoever non-local about the dynamics of how the wavefunction
evolves over time.

Not for an isolated non-interacting system. But the Bell inequalities refer to entangled particles, which do not evolve independently. In that case, non-local effects are required to explain the observed correlations.

Even without entangled particles, ISTM that QM is a non-local theory since the wf extends to infinity in all directions, while the probabilities continue to change throughout as time increases. How could that occur without instantaneous action at a distance, aka non-locality?  AG 

Brent Meeker

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Nov 21, 2024, 5:27:27 PM11/21/24
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On 11/21/2024 5:12 AM, smitra wrote:
> On 18-11-2024 07:02, Bruce Kellett wrote:
>> On Mon, Nov 18, 2024 at 4:17 PM PGC <multipl...@gmail.com>
>> wrote:
>>
>>> Your response presents strong points but contains some redundancies
>>> and overlapping arguments. Here's a revised version with greater
>>> focus, while maintaining the original’s precision and accuracy:
>>> -------------------------
>>>
>>> Bruce, let’s directly address the epistemic interpretation of the
>>> wavefunction. While this view neatly avoids ontological commitments
>>> and sidesteps issues like FTL action, it doesn’t fully account for
>>> experimentally observed phenomena such as violations of Bell’s
>>> inequalities.
>>
>> The violation of Bell inequalities implies non-locality, and the
>> epistemic interpretation of the wave function is perfectly compatible
>> with non-locality.
>>
>
> The violation of Bell's inequalities does not imply non-locality. In
> fact, the violation of Bell's inequality is a prediction of QM which
> when describing the dynamics with a physical Hamiltonian, is a
> manifestly local theory.
But it has a state which shares the polarization of the two particles,
|x1 x2>+|y1 y2>  The particles are at different places when they are
measured but are sharing a variable...that's the non-locality. That's
why Bell's theorem can't be violated by a shared hidden variable.

Brent
So what is this essential element?  and why is it local?

Brent

John Clark

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Nov 21, 2024, 5:33:23 PM11/21/24
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On Mon, Nov 18, 2024 at 1:03 AM Bruce Kellett <bhkel...@gmail.com> wrote:

The violation of Bell inequalities implies non-locality,

No, that's an oversimplification. The violation of Bell's Inequalitie implies that things are either non-local and realistic, or local and unrealistic. Many Worlds is local and unrealistic. 

and the epistemic interpretation of the wave function is perfectly compatible with non-locality.

True, there could still be hidden variables, but they would be non-local hidden variables.  

Unfortunately, Everettian QM, or MWI, cannot even account for the correlations, much less the violations of the Bell inequalities.

The spin of 2 electrons has been quantum mechanically entangled.  One electron is given to Alice and the other to Bob.  Alice and her electron stay on earth but Bob takes his electron and gets in a near light speed spaceship and after 4 years is on Alpha Centauri. And after 4 years Alice picks a direction at random, calls that "up" and measures the spin of her electron in that direction with a Stern Gerlach magnet.

At that instant the universe splits into two, in one Alice has the spin up electron and Bob has spin down, and in the other universe Alice has spin down and Bob has spin up. So in both universes, because she knows the laws of quantum mechanics, Alice not only knows what her spin is she also knows what Bob's spin must be, but if she wanted to tell Bob what his spin is it would take another 4 years for the message to reach him.  If Bob picked the same direction for "up" as Alice did there would be a perfect anti-correlation, if he picked some other direction the degree of correlation would depend on how different his direction was from Alice's.  

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

Bruce Kellett

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Nov 21, 2024, 6:01:55 PM11/21/24
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On Fri, Nov 22, 2024 at 9:33 AM John Clark <johnk...@gmail.com> wrote:
On Mon, Nov 18, 2024 at 1:03 AM Bruce Kellett <bhkel...@gmail.com> wrote:

The violation of Bell inequalities implies non-locality,

No, that's an oversimplification. The violation of Bell's Inequalitie implies that things are either non-local and realistic, or local and unrealistic. Many Worlds is local and unrealistic. 

and the epistemic interpretation of the wave function is perfectly compatible with non-locality.

True, there could still be hidden variables, but they would be non-local hidden variables.  

Unfortunately, Everettian QM, or MWI, cannot even account for the correlations, much less the violations of the Bell inequalities.

The spin of 2 electrons has been quantum mechanically entangled.  One electron is given to Alice and the other to Bob.  Alice and her electron stay on earth but Bob takes his electron and gets in a near light speed spaceship and after 4 years is on Alpha Centauri. And after 4 years Alice picks a direction at random, calls that "up" and measures the spin of her electron in that direction with a Stern Gerlach magnet.

At that instant the universe splits into two, in one Alice has the spin up electron and Bob has spin down, and in the other universe Alice has spin down and Bob has spin up.

How does that happen, exactly? At the time Alice makes her measurement, Bob is at a spacelike separation, and does not know either the angle of Alice's measurement, or her result. In the absence of any such relevant information, Everett says that when Bob makes his measurement he splits into a branch where he sees UP, and a branch in which he sees Down. There is no possible correlation with Alice's result.

Actually, this is not directly related to the violation of the Bell inequalities. This 4-way split, two branches for Alice and two for Bob, happens in every case, so their results for spacelike separations are always independent, and no correlation can ever be observed.

Bruce

smitra

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Nov 21, 2024, 11:23:46 PM11/21/24
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Bell's theorem says that no local deterministic hidden variable theory
can explain the correlations that QM predicts. So, Bell's theorem
doesn't say anything about QM itself, it says something about hidden
variable theories that seek to explain the correlations observed in QM
experiments. So, you modify QM and assume that QM is explained by a
classical deterministic hidden variable theory and then you obliged to
take non-locality on board, or else your hidden variable theory will
fail to reproduce at least some of the correlations predicted by QM.

Nothing in here implies that QM is non-local.
Everett introduces the splits as an effective description appropriate
for describing macroscopic observers. He introduces density matrices so
it should be clear that this isnt an exact qjuantum emchancial
description and it will certainly fail to correctly describe subtle
effects due to entanglement.

>> And when Bob makes his measurement, he gets entangled with the spin
>> pair and
>> as a result with Alice's sector.
>
> When Bob is spacelike separated from Alice and her measurement, he
> also splits into two independent branches.

There are no independent branches.


>
>> So, in the end it's because you choose
>> not to describe Alice and Bob quantum mechanically and treat them as
>>
>> classical objects
>
> That is not the case. Everettian quantum mechanics says that they both
> split on to two branches, and there is no clear way in the formalism
> to see how the branches for the two individuals are related. In any
> model, in which both outcomes are necessarily realized for every
> measurement, there is no way to relate the outcomes.
>

Everettian QM says that this is what effectively happens, but it's
obviously not an exact description and will fail to take into account
subtle effects due to entanglement.


>> that you end up missing an essential element and that
>> leads to a paradox.
>
> Nothing has been missed in my analysis. As usual, you are unable to
> actually spell out how the correlations are preserved in the
> many-worlds scenario.

The correlations are preserved because Alice's and Bob's sectors get
entangled. Suppose Alice, Bob, and Charlie measure x or y components of
the spins of the state:

1/sqrt(2) [|up, up, up> - |down, down, down>]

and two of them measure the y-component and 1 measures the x-component
and we multiply together the 3 results (plus or minus 1), then the
product will always be 1. If you then assume local huidden variables,
then you can argue that both the results of x and y had predetermined
results independently of what was actually measured and independently of
what the other observes choose to measure. Therefore, we can multiply
the 3 potential measurement results where the kth observer measures the
x-component with each other for k = 1, 2, 3. Each experiment would yield
1, and in the product over the 3 spin measurements there are then for
each observer 2 factors for the y-component and 1 or the x-component,
and with the square of a spin being 1, this leads to the conclusion that
the product of the 3 x-components for the 3 observers should equal 1.

However, from the above state you can see that measuring the x
components of all three spins and multiplying the results will always
yield -1. What is then non-local about this result? it's not in the QM,
it's in the fact that the classical reasoning about the measurement
results existing independent of the actual measurement in a local way,
yields a result that QM is in conflict with. So, the non-locality is
squarely in any classical model that is consistent with what QM
predicts.

It's not a problem that the results are correlated per se. Otherwise,
Bell could have saved all the efforts derving his inequalities and just
say that measuring any entangled spin state leads to correlated results.
In the above example one could simply stop at the measurement results of
2 y-components and 1 x-component and say that the results of the 3
observers are correlated. But that
does not demonstrate the necessity of non-local dynamics in an
underlying deterministic hidden variable theory, let alone that QM
requires non-local dynamics.

Saibal
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smitra

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Nov 21, 2024, 11:28:35 PM11/21/24
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One can create such non-local states but that doesn't require anything
non-local in the dynamical laws, and indeed, the known dynamical laws
are of a local nature. So, all the non-local effects are due to common
cause effects.

Saibal

Bruce Kellett

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Nov 21, 2024, 11:45:52 PM11/21/24
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On Fri, Nov 22, 2024 at 3:23 PM smitra <smi...@zonnet.nl> wrote:

Bell's theorem says that no local deterministic hidden variable theory
can explain the correlations that QM predicts. So, Bell's theorem
doesn't say anything about QM itself, it says something about hidden
variable theories that seek to explain the correlations observed in QM
experiments. So, you modify QM and assume that QM is explained by a
classical deterministic hidden variable theory and then you obliged to
take non-locality on board, or else your hidden variable theory will
fail to reproduce at least some of the correlations predicted by QM.

Nothing in here implies that QM is non-local.

The results of Bell's theorem imply exactly that. Bell assumes that the theory is local, and shows that the QM results violate particular inequalities. The theorem is NOT about non-local theories since Bell does not assume a non-local theory.


Everett introduces the splits as an effective description appropriate
for describing macroscopic observers. He introduces density matrices so
it should be clear that this isnt an exact qjuantum emchancial
description and it will certainly fail to correctly describe subtle
effects due to entanglement.

Density matrices are not an approximate form of QM.

There are no independent branches.

That is what decoherence is supposed to give you.


> That is not the case. Everettian quantum mechanics says that they both
> split on to two branches, and there is no clear way in the formalism
> to see how the branches for the two individuals are related. In any
> model, in which both outcomes are necessarily realized for every
> measurement, there is no way to relate the outcomes.
>

Everettian QM says that this is what effectively happens, but it's
obviously not an exact description and will fail to take into account
subtle effects due to entanglement.

In other words, Everettian QM, or many-worlds, is not able to give an account of the correlations. You are saying that that is because it is not an exact theory. This is a pretty extreme way of getting out of the difficulty that I have pointed out. If Everett is not just a version of exact QM, it is of no use for anything. My claim is that it cannot reproduce the observed correlations, therefore it is not a version of standard QM, and is of no use for anything.

Bruce

Brent Meeker

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Nov 21, 2024, 11:57:44 PM11/21/24
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It's quite easy to isolate mr. he from the result.  Quantum computers are hard to isolate from the environment affecting them, not vice versa and not from the result.

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

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Nov 22, 2024, 12:40:22 AM11/22/24
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That's what is ruled out by violation of Bell's inequality.

Brent

smitra

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Nov 22, 2024, 2:55:19 AM11/22/24
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On 22-11-2024 05:45, Bruce Kellett wrote:
> On Fri, Nov 22, 2024 at 3:23 PM smitra <smi...@zonnet.nl> wrote:
>
>> Bell's theorem says that no local deterministic hidden variable
>> theory
>> can explain the correlations that QM predicts. So, Bell's theorem
>> doesn't say anything about QM itself, it says something about hidden
>>
>> variable theories that seek to explain the correlations observed in
>> QM
>> experiments. So, you modify QM and assume that QM is explained by a
>> classical deterministic hidden variable theory and then you obliged
>> to
>> take non-locality on board, or else your hidden variable theory will
>>
>> fail to reproduce at least some of the correlations predicted by QM.
>>
>> Nothing in here implies that QM is non-local.
>
> The results of Bell's theorem imply exactly that. Bell assumes that
> the theory is local, and shows that the QM results violate particular
> inequalities. The theorem is NOT about non-local theories since Bell
> does not assume a non-local theory.

Bell assumes a hidden variable theory and then shows that the hidden
variable theory must be non-local. So, it's about hidden variable
theories, not about QM. The relevance t QM is that it implies that
quantum mechanics cannot have an underlying local hidden variable
theory, not that QM itself is non-local.

Saibal
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smitra

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Nov 22, 2024, 3:05:42 AM11/22/24
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Bells' theorem doesn't apply to QM, it's a theorem about deterministic
hidden variable theories that says that certain correlations like some
of those of QM cannot be reproduced by any local hidden variable theory.
The relevance of Bell's theorem to QM is only that it rules out that if
QM is not fundamental and has an underlying hidden variable theory, then
that hidden variable theory cannot be local.

So, if we then assume that QM is fundamental, then there is no objection
against QM being local. Getting to non-local states via local dynamics
isn't a problem as this is routinely done in experiments where entangled
spin pairs are created. Nothing non-local goes on as far as the dynamics
is concerned in such experiments.

Saibal

>
> Brent

Bruce Kellett

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Nov 22, 2024, 3:30:27 AM11/22/24
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On Fri, Nov 22, 2024 at 7:05 PM smitra <smi...@zonnet.nl> wrote:
On 22-11-2024 06:40, Brent Meeker wrote:

> That's what is ruled out by violation of Bell's inequality.

Bells' theorem doesn't apply to QM,

I think it is about time that you read Bell's papers.  His theorem is not about hidden variable theories, or non-local theories. He assumes, for the purposes of argument, a local theory. He then derives a series of inequalities that such a local theory must satisfy. Experimentally, these inequalities are violated. Inspection of standard QM gives results that agree with experiment, but these results also require non-locality. The conclusion drawn from these experiments is that quantum mechanics, itself, is non-local.

Bruce

John Clark

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Nov 22, 2024, 7:59:10 AM11/22/24
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On Thu, Nov 21, 2024 at 6:01 PM Bruce Kellett <bhkel...@gmail.com> wrote:

>> The spin of 2 electrons has been quantum mechanically entangled.  One electron is given to Alice and the other to Bob.  Alice and her electron stay on earth but Bob takes his electron and gets in a near light speed spaceship and after 4 years is on Alpha Centauri. And after 4 years Alice picks a direction at random, calls that "up" and measures the spin of her electron in that direction with a Stern Gerlach magnet.
At that instant the universe splits into two, in one Alice has the spin up electron and Bob has spin down, and in the other universe Alice has spin down and Bob has spin up.

Bob is at a spacelike separation, and does not know either the angle of Alice's measurement, or her result. 

And that's why the resulting correlation is so weird, not paradoxical but definitely very weird.  

 This 4-way split, two branches for Alice and two for Bob [...]

That is incorrect. There is only a two-way split:
1) Alice sees up and Bob sees down.
2) Alice sees down and Bob sees up.
There is no universe in which both electrons are spin-up, and there is no universe in which both electrons are spin-down. This is because the laws of physics (a.k.a. Schrodinger's Quantum Wave) forbids it. As soon as Alice measures her electron and sees what her spin is she knows for certain that she will be in the same universe where Bob sees that his electron has the opposite spin. And a similar statement could be said about Bob and his electron.  

How does that happen, exactly? 

Are you sure you really want to know EXACTLY? The short answer is it happens because of the  [COS (x)]^2 polarization rule, but you said you wanted all the details about how that apparently innocent sounding rule could lead to a violation of Bell's inequality and put philosophers in a panic. I'm not sure you really want all the details but about two weeks ago somebody else asked the same question you did and I went into much more detail. I'm not going to rephrase what I wrote then I'm just gonna repeat it because I don't think anybody actually read it the first time:
== 

 
If you want all the details this is going to be a long post, you asked for it. First I'm gonna have to show that any theory (except for super determinism which is idiotic) that is deterministic, local and realistic cannot possibly explain the violation of Bell's Inequality that we see in our experiments, and then show why a theory like Many Worlds which is deterministic and local but NOT realistic can.

The hidden variable concept was Einstein's idea, he thought there was a local reason all events happened, even quantum mechanical events, but we just can't see what they are. It was a reasonable guess at the time but today experiments have shown that Einstein was wrong, to do that I'm gonna illustrate some of the details of Bell's inequality with an example.

When a photon of undetermined polarization hits a polarizing filter there is a 50% chance it will make it through. For many years physicists like Einstein who disliked the idea that God played dice with the universe figured there must be a hidden variable inside the photon that told it what to do. By "hidden variable" they meant something different about that particular photon that we just don't know about. They meant something equivalent to a look-up table inside the photon that for one reason or another we are unable to access but the photon can when it wants to know if it should go through a filter or be stopped by one. We now understand that is impossible. In 1964 (but not published until 1967) John Bell showed that correlations that work by hidden variables must be less than or equal to a certain value, this is called Bell's Inequality. In experiment it was found that some correlations are actually greater than that value. Quantum Mechanics can explain this, classical physics or even classical logic can not.

Even if Quantum Mechanics is someday proven to be untrue Bell's argument is still valid, in fact his original paper had no Quantum Mechanics in it and can be derived with high school algebra; his point was that any successful theory about how the world works must explain why his inequality is violated, and today we know for a fact from experiments that it is indeed violated. Nature just refuses to be sensible and doesn't work the way you'd think it should.            

I have a black box, it has a red light and a blue light on it, it also has a rotary switch with 6 connections at the 12,2,4,6,8 and 10 o'clock positions. The red and blue light blink in a manner that passes all known tests for being completely random, this is true regardless of what position the rotary switch is in. Such a box could be made and still be completely deterministic by just pre-computing 6 different random sequences and recording them as a look-up table in the box. Now the box would know which light to flash.

I have another black box. When both boxes have the same setting on their rotary switch they both produce the same random sequence of light flashes. This would also be easy to reproduce in a classical physics world, just record the same 6 random sequences in both boxes. 

The set of boxes has another property, if the switches on the 2 boxes are set to opposite positions, 12 and 6 o'clock for example, there is a total negative correlation; when one flashes red the other box flashes blue and when one box flashes blue the other flashes red. This just makes it all the easier to make the boxes because now you only need to pre-calculate 3 random sequences, then just change every 1 to 0 and every 0 to 1 to get the other 3 sequences and record all 6 in both boxes.

The boxes have one more feature that makes things very interesting, if the rotary switch on a box is one notch different from the setting on the other box then the sequence of light flashes will on average be different 1 time in 4. How on Earth could I make the boxes behave like that? Well, I could change on average one entry in 4 of the 12 o'clock look-up table (hidden variable) sequence and make that the 2 o'clock table. Then change 1 in 4 of the 2 o'clock and make that the 4 o'clock, and change 1 in 4 of the 4 o'clock and make that the 6 o'clock. So now the light flashes on the box set at 2 o'clock is different from the box set at 12 o'clock on average by 1 flash in 4. The box set at 4 o'clock differs from the one set at 12 by 2 flashes in 4, and the one set at 6 differs from the one set at 12 by 3 flashes in 4.

BUT I said before that boxes with opposite settings should have a 100% anti-correlation, the flashes on the box set at 12 o'clock should differ from the box set at 6 o'clock by 4 flashes in 4 NOT 3 flashes in 4. Thus if the boxes work by hidden variables then when one is set to 12 o'clock and the other to 2 there MUST be a 2/3 correlation, at 4 a 1/3 correlation, and of course at 6 no correlation at all.  A correlation greater than 2/3, such as 3/4, for adjacent settings produces paradoxes, at least it would if you expected everything to work mechanistically because of some local hidden variable involved.

Does this mean it's impossible to make two boxes that have those specifications? Nope, but it does mean hidden variables can not be involved and that means something very weird is going on. Actually it would be quite easy to make a couple of boxes that behave like that, it's just not easy to understand how that could be. 

Photons behave in just this spooky manner, so to make the boxes all you need it 4 things:

1) A glorified light bulb, something that will make two photons of unspecified but identical polarizations moving in opposite directions so you can send one to each box. An excited calcium atom would do the trick, or you could turn a green photon into two identical lower energy red photons with a crystal of potassium dihydrogen phosphate.

2) A light detector sensitive enough to observe just one photon. Incidentally the human eye is not quite good enough to do that but frogs can, for frogs when light gets very weak it must stop getting dimmer and appears to flash instead. 

3) A polarizing filter, we've had these for well over a century.

4) Some gears and pulleys so that each time the rotary switch is advanced one position the filter is advanced by 30 degrees. This is because it's been known for many years that the amount of light polarized at 0 degrees that will make it through a polarizing filter set at X is [COS (x)]^2; and if X = 30 DEGREES (π/6 radians) then the value is .75; if the light is so dim that only one photon is sent at a time then that translates to the probability that any individual photon will make it through the filter is 75%.

The bottom line of all this is that there can not be something special about a specific photon, some internal difference, some hidden local variable that determines if it makes it through a filter or not. Thus if we ignore a superdeterministic conspiracy, as we should, then one of two things MUST be true:

1) The universe is not realistic, that is, things do NOT exist in one and only one state both before and after they are observed. In the case of Many Worlds it means the very look up table as described in the above cannot be printed in indelible ink but, because Many Worlds assumes that Schrodinger's Equation means what it says, the look up table itself not only can but must exist in many different versions both before and after a measurement is made.

2) The universe is non-local, that is, everything influences everything else and does so without regard for the distances involved or amount of time involved or even if the events happen in the past or the future; the future could influence the past. But because Many Worlds is non-realistic, and thus doesn't have a static lookup table, it has no need to resort to any of these non-local influences to explain experimental results.

Einstein liked non-locality even less than nondeterminism, I'm not sure how he'd feel about non-realistic theories like Many Worlds, the idea wasn't discovered until about 10 years after his death.
 John K Clark    See what's on my new list at  Extropolis
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PGC

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Nov 22, 2024, 9:19:10 AM11/22/24
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These discussions around Bell's theorem, the Many-Worlds Interpretation (MWI), and the challenges of deriving the Born rule continue invoking the interplay between epistemic frameworks and ontological commitments. A significant point of contention is whether MWI can account for the correlations observed in entangled systems without additional postulates, such as collapse, and how these correlations map onto the observer accounts and global description perspectives. There are interpretational gaps that persist.

John’s description of branching in the Many-Worlds Interpretation (MWI) assumes that decoherence ensures each branch corresponds to a distinct outcome of a quantum measurement. This can be expressed using the density matrix in a composite system-environment state:

Decoherence suppresses off-diagonal terms in , effectively yielding a mixed state:

Consider the correlations in entangled systems that violate Bell's inequality. These correlations are quantitatively expressed as deviations from the CHSH inequality:

where represents the expectation value of measurements along directions and . Experimental results consistently show that , as predicted by quantum mechanics but inconsistent with local hidden variable theories (Bell, 1964, p.195). In MWI, these results follow from the unitary evolution of the wavefunction. The wavefunction for an entangled pair,

evolves unitarily under the Schrödinger equation. Decoherence ensures that interference terms vanish in the density matrix describing macroscopic observers, giving the appearance of distinct "branches."

However, Bruce keeps raising the critical challenge: how do these branches remain correlated across spacelike separations? In MWI, the correlations are not post-measurement artifacts but inherent to the global wavefunction. The key is the consistency enforced by the universal wf's structure, which ensures that for any measurement basis, the resulting "branches" respect the original entanglement. The reduced density matrix formalism explicitly demonstrates this:

yielding probabilities consistent with the Born rule. Yet, the Born rule itself remains elusive within MWI's framework and demands further clarification, as acknowledged by Carroll (2014, p.18).

Critics like Brent and Bruce argue that without an explicit derivation of the Born rule, MWI fails to fully account for observed probabilities. This is valid but reflects a broader epistemological gap. Probabilities, as noted, have different interpretations: frequentist, Bayesian, and, uniquely in computational contexts, "objective" probabilities derived from "subjective probabilities" (Everett used "subjective probabilities" iirc, and Bruno's refinement was terming them "objective" in this sense). In this framework, probabilities emerge not as axioms but as limits of frequency operators over the ensemble of computations or histories:

Something akin to:

where . This connects subjective perspectives (what the observer experiences) to 3p descriptions (what the formalism predicts), which is insufficiently addressed/incomplete in MWI or collapse approaches and open with Bruno's approach iirc (correct me, if otherwise). The merit of this kind of approach is that observer experience is no longer outside the scope of the clearest ontology.

Now, consider the Gödelian critique. All frameworks—whether MWI, collapse postulates, or alternatives like Invariant Set Theory (Palmer, 2009)—assume arithmetical or stronger foundations. Gödel's incompleteness theorems (Gödel, 1931) demonstrate that within any sufficiently rich formal system , there exist true statements that are unprovable within . Explicitly:

Applied to quantum mechanics and ontology, this indicates that any framework aiming for ontological finality will inevitably encounter unprovable truths if it includes arithmetic or its use in its formulations. For example, the observer's role versus the formalism's predictions remains a gap that cannot be fully bridged within any single system. Collapse postulates introduce "magic" by assuming the wavefunction's reality only to dismiss it post-measurement, while MWI faces the unresolved challenge of deriving probabilities without external axioms.

The whack-a-mole nature of these discussions therefore may find an explanation in this incompleteness. Every attempt to resolve one gap (e.g., deriving Born within MWI) introduces others (e.g., defining the observer). As Saibal notes, local hidden variables fail due to Bell's theorem, but Bruce counters that this implies non-locality within standard QM. Both points reflect the limits of purely formal reasoning without acknowledging the epistemic/ontological split.

In conclusion, these discussions risk circularity if participants prioritize defending their preferred interpretations over collaborative inquiry. Recognizing the limitations imposed by Gödelian constraints and the potential irreducibility of observer perspectives relative to global descriptions is essential. While frameworks like MWI or collapse postulates have epistemic value, they are better seen as tools for exploring the boundaries of what can be explained or inspiration for developing new problems and possible application, rather than as definitive ontological inquiry. The quest for consensus may remain elusive, but acknowledging these limits instead of giving in to the whack-a-mole discourse may mitigate circularity risk. Work has to be done from all sides. Have a great weekend, whether collapse or in some world, or while riding computations. 

Brent Meeker

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Nov 22, 2024, 8:21:18 PM11/22/24
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I recommend the lectures of Jacob Barandes.  He has developed an interpretation of QM which shows how QM is related to classical stochastic processes and which avoids the problems I see in other interpretations.  He makes a distinction between ontic and epistemic layers in the interpretations which I think clarifies things a lot.

"A New Formulation of Quantum Theory" https://www.youtube.com/watch?v=sshJyD0aWXg

"New Foundations for Quantum Theory"  https://www.youtube.com/watch?v=dB16TzHFvj0

"Why We Shouldn't Believe in Hilbert Spaces Anymore"
https://www.youtube.com/watch?v=OmaSAG4J6nw

Of course there are also papers on the same topic:

The Stochastic-Quantum Theorem  arXiv:2309.03085

The Stochastic-Quantum Correspondence  arxiv:2302.10778
 
The Minimal Modal Interpretation of Quantum Theory  arXiv:1405.6755

Brent
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Alan Grayson

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Nov 22, 2024, 9:37:59 PM11/22/24
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On Friday, November 22, 2024 at 7:19:10 AM UTC-7 PGC wrote:

These discussions around Bell's theorem, the Many-Worlds Interpretation (MWI), and the challenges of deriving the Born rule continue invoking the interplay between epistemic frameworks and ontological commitments. A significant point of contention is whether MWI can account for the correlations observed in entangled systems without additional postulates, such as collapse, and how these correlations map onto the observer accounts and global description perspectives. There are interpretational gaps that persist.

John’s description of branching in the Many-Worlds Interpretation (MWI) assumes that decoherence ensures each branch corresponds to a distinct outcome of a quantum measurement. This can be expressed using the density matrix in a composite system-environment state:

Decoherence suppresses off-diagonal terms in , effectively yielding a mixed state:

Consider the correlations in entangled systems that violate Bell's inequality. These correlations are quantitatively expressed as deviations from the CHSH inequality:

where represents the expectation value of measurements along directions and . Experimental results consistently show that , as predicted by quantum mechanics but inconsistent with local hidden variable theories (Bell, 1964, p.195). In MWI, these results follow from the unitary evolution of the wavefunction. The wavefunction for an entangled pair,

evolves unitarily under the Schrödinger equation. Decoherence ensures that interference terms vanish in the density matrix describing macroscopic observers, giving the appearance of distinct "branches."

However, Bruce keeps raising the critical challenge: how do these branches remain correlated across spacelike separations? In MWI, the correlations are not post-measurement artifacts but inherent to the global wavefunction. The key is the consistency enforced by the universal wf's structure, which ensures that for any measurement basis, the resulting "branches" respect the original entanglement. The reduced density matrix formalism explicitly demonstrates this:

yielding probabilities consistent with the Born rule. Yet, the Born rule itself remains elusive within MWI's framework and demands further clarification, as acknowledged by Carroll (2014, p.18).

Critics like Brent and Bruce argue that without an explicit derivation of the Born rule, MWI fails to fully account for observed probabilities. This is valid but reflects a broader epistemological gap. Probabilities, as noted, have different interpretations: frequentist, Bayesian, and, uniquely in computational contexts, "objective" probabilities derived from "subjective probabilities" (Everett used "subjective probabilities" iirc, and Bruno's refinement was terming them "objective" in this sense). In this framework, probabilities emerge not as axioms but as limits of frequency operators over the ensemble of computations or histories:

Something akin to:

where . This connects subjective perspectives (what the observer experiences) to 3p descriptions (what the formalism predicts), which is insufficiently addressed/incomplete in MWI or collapse approaches and open with Bruno's approach iirc (correct me, if otherwise). The merit of this kind of approach is that observer experience is no longer outside the scope of the clearest ontology.

Now, consider the Gödelian critique. All frameworks—whether MWI, collapse postulates, or alternatives like Invariant Set Theory (Palmer, 2009)—assume arithmetical or stronger foundations. Gödel's incompleteness theorems (Gödel, 1931) demonstrate that within any sufficiently rich formal system , there exist true statements that are unprovable within . Explicitly:

Applied to quantum mechanics and ontology, this indicates that any framework aiming for ontological finality will inevitably encounter unprovable truths if it includes arithmetic or its use in its formulations. For example, the observer's role versus the formalism's predictions remains a gap that cannot be fully bridged within any single system. Collapse postulates introduce "magic" by assuming the wavefunction's reality only to dismiss it post-measurement, while MWI faces the unresolved challenge of deriving probabilities without external axioms.

The whack-a-mole nature of these discussions therefore may find an explanation in this incompleteness. Every attempt to resolve one gap (e.g., deriving Born within MWI) introduces others (e.g., defining the observer). As Saibal notes, local hidden variables fail due to Bell's theorem, but Bruce counters that this implies non-locality within standard QM. Both points reflect the limits of purely formal reasoning without acknowledging the epistemic/ontological split.

In conclusion, these discussions risk circularity if participants prioritize defending their preferred interpretations over collaborative inquiry. Recognizing the limitations imposed by Gödelian constraints and the potential irreducibility of observer perspectives relative to global descriptions is essential. While frameworks like MWI or collapse postulates have epistemic value, they are better seen as tools for exploring the boundaries of what can be explained or inspiration for developing new problems and possible application, rather than as definitive ontological inquiry. The quest for consensus may remain elusive, but acknowledging these limits instead of giving in to the whack-a-mole discourse may mitigate circularity risk. Work has to be done from all sides. Have a great weekend, whether collapse or in some world, or while riding computations. 

Let's go beyond the sophisticated rhetoric. Remember; I'm just a simple country lawyer. Admit it. At the end of the day, what do you have, or aspire to have? Even if you resolve Born's Rule for the MWI, what do you have, or aspire to have? Answer; nothing! Your presumed branches are non-interacting, so there's no way to confirm the MWI. It's all speculation, or to be more precise, philosophy, and there's no way to go beyond this. It all a disservice to real science. Physics has taken a turn to the foolish. AG 

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Alan Grayson

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Nov 22, 2024, 9:55:12 PM11/22/24
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On Friday, November 22, 2024 at 6:21:18 PM UTC-7 Brent Meeker wrote:
I recommend the lectures of Jacob Barandes.  He has developed an interpretation of QM which shows how QM is related to classical stochastic processes and which avoids the problems I see in other interpretations.  He makes a distinction between ontic and epistemic layers in the interpretations which I think clarifies things a lot.

Ontic? Is any equation ontic? Have you tried to kick one? AG

"A New Formulation of Quantum Theory" https://www.youtube.com/watch?v=sshJyD0aWXg

"New Foundations for Quantum Theory"  https://www.youtube.com/watch?v=dB16TzHFvj0

"Why We Shouldn't Believe in Hilbert Spaces Anymore"
https://www.youtube.com/watch?v=OmaSAG4J6nw

This seems promising. AG 

Of course there are also papers on the same topic:

The Stochastic-Quantum Theorem  arXiv:2309.03085

Doesn't "stochastic" imply the classical theory where ignorance is assumed of individual members of an ensemble, so when applied to quantum theory wouldn't it imply the Ignorance Interpretation of the superposed wf? AG

Russell Standish

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Nov 22, 2024, 9:56:31 PM11/22/24
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On Fri, Nov 22, 2024 at 05:21:14PM -0800, Brent Meeker wrote:
>
> The Stochastic-Quantum Theorem  arXiv:2309.03085
>
> The Stochastic-Quantum Correspondence  arxiv:2302.10778
>  
> The Minimal Modal Interpretation of Quantum Theory  arXiv:1405.6755
>

Thanks - these look interesting! I've downloaded them for later study.


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Brent Meeker

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Nov 22, 2024, 11:01:23 PM11/22/24
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On 11/22/2024 6:42 PM, Alan Grayson wrote:
On Friday, November 22, 2024 at 6:21:18 PM UTC-7 Brent Meeker wrote:
I recommend the lectures of Jacob Barandes.  He has developed an interpretation of QM which shows how QM is related to classical stochastic processes and which avoids the problems I see in other interpretations.  He makes a distinction between ontic and epistemic layers in the interpretations which I think clarifies things a lot.

"A New Formulation of Quantum Theory" https://www.youtube.com/watch?v=sshJyD0aWXg

"New Foundations for Quantum Theory"  https://www.youtube.com/watch?v=dB16TzHFvj0

"Why We Shouldn't Believe in Hilbert Spaces Anymore"
https://www.youtube.com/watch?v=OmaSAG4J6nw

Of course there are also papers on the same topic:

The Stochastic-Quantum Theorem  arXiv:2309.03085

The Stochastic-Quantum Correspondence  arxiv:2302.10778
 
The Minimal Modal Interpretation of Quantum Theory  arXiv:1405.6755

Brent
 
Ontic? Is any equation ontic? Have you tried to kick one? AG
Where did I say an equation was ontic?  Check your eye sight.

Brent

Brent Meeker

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Nov 22, 2024, 11:19:12 PM11/22/24
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On 11/22/2024 6:19 AM, PGC wrote:
>
First, that's only relative to a fix set of axioms.  Physics isn't an
axiomatic game.  Second, the Goedel proposition that is true but
unprovable may be no more that "This is not provable." expressed within
the theory...not necessarily some deep truth.
>
> or its use in its formulations. For example, the observer's role
> versus the formalism's predictions remains a gap that cannot be fully
> bridged within any single system.
>
"Observer" is a carryover from Bohr.  A measurement can be performed by
a system that is diagonalized by decoherence.  Decoherence isn't magic. 
See the formulation of QM by Barandes that I posted.

Brent

Alan Grayson

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Nov 22, 2024, 11:24:16 PM11/22/24
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I meant to write equation or theory. What's your favorite ontic theory if you have one? AG 

Alan Grayson

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Nov 22, 2024, 11:30:15 PM11/22/24
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More interesting to me is the question about stochastics. Why do you choose to answer my relatively trivial question? AG 

Alan Grayson

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Nov 22, 2024, 11:37:14 PM11/22/24
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I suppose Faraday's Law or Coulumb's Law could be considered ontic since they describe real things. But this criterion could be applied to all the Laws of Physics (and their interpretations), so, AFAICT, "ontic" doesn't have much, if any, meaning. AG 

Brent Meeker

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Nov 23, 2024, 12:08:36 AM11/23/24
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The phrase was "ontic layer" which is just the things you take to exist, e.g. charged particles and photons in QED.  It's prior to equations and theories.

Brent
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Alan Grayson

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Nov 23, 2024, 12:14:52 AM11/23/24
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Don't worry. I forgive you for you snide remark. After all, you might not be the real Brent, but a copy of some original, more polite Brent, resident on some other branch who conducted some experiment, or was accidentally included in a branch induced by an ant who turned left of a dung hill. lol. AG 

Alan Grayson

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Nov 23, 2024, 12:20:49 AM11/23/24
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On Friday, November 22, 2024 at 10:08:36 PM UTC-7 Brent Meeker wrote:
On 11/22/2024 8:24 PM, Alan Grayson wrote:
 
On Friday, November 22, 2024 at 9:01:23 PM UTC-7 Brent Meeker wrote:
 
On 11/22/2024 6:42 PM, Alan Grayson wrote:
On Friday, November 22, 2024 at 6:21:18 PM UTC-7 Brent Meeker wrote:
I recommend the lectures of Jacob Barandes.  He has developed an interpretation of QM which shows how QM is related to classical stochastic processes and which avoids the problems I see in other interpretations.  He makes a distinction between ontic and epistemic layers in the interpretations which I think clarifies things a lot.

"A New Formulation of Quantum Theory" https://www.youtube.com/watch?v=sshJyD0aWXg

"New Foundations for Quantum Theory"  https://www.youtube.com/watch?v=dB16TzHFvj0

"Why We Shouldn't Believe in Hilbert Spaces Anymore"
https://www.youtube.com/watch?v=OmaSAG4J6nw

Of course there are also papers on the same topic:

The Stochastic-Quantum Theorem  arXiv:2309.03085

The Stochastic-Quantum Correspondence  arxiv:2302.10778
 
The Minimal Modal Interpretation of Quantum Theory  arXiv:1405.6755

Brent
 
Ontic? Is any equation ontic? Have you tried to kick one? AG
Where did I say an equation was ontic?  Check your eye sight.

Brent

I meant to write equation or theory. What's your favorite ontic theory if you have one? AG
The phrase was "ontic layer" which is just the things you take to exist, e.g. charged particles and photons in QED.  It's prior to equations and theories.

Brent

You'd have to include things which might exist, such as gravitons or tachyons, which is why, IMO, the concept is vacuous and therefore meaningless, and just adds to our confusion. But that's just my opinion and we know what that's worth. AG

John Clark

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Nov 23, 2024, 8:47:52 AM11/23/24
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On Fri, Nov 22, 2024 at 9:19 AM PGC <multipl...@gmail.com> wrote:

[the Gödelian critique] Applied to quantum mechanics and ontology indicates that any framework aiming for ontological finality will inevitably encounter unprovable truths if it includes arithmetic or its use in its formulations. 

But Physics is not mathematics. In physics you don't need to prove experimental results, you need to demonstrate them. Theory is used to predict and explain those experimental results, which Objective Collapse and Pilot Wave and Many Worlds all can do. The best theory is the one that can do so with the fewest assumptions; and in that regard Many Worlds is the clear winner. But even if you knew for a fact that Objective Collapse, or Pilot Wave, or Many Worlds was 100% correct, you still couldn't claim to have reached ontological finality

You may have noticed I didn't include Copenhagen or Quantum Bayesianism, that's because they don't even claim to have anything to do with ontology, final or otherwise, and they don't even pretend to explain anything, they're for people who only care about predicting what value they're going to get on their voltmeter.

 Collapse postulates introduce "magic" by assuming the wavefunction's reality only to dismiss it post-measurement, 

It's even worse than that because they can't tell you exactly, or even approximately, what a "measurement" is.  


while MWI faces the unresolved challenge of deriving probabilities without external axioms.

Well, MWI can clearly explain why you need probabilities even though Schrodinger's Equation is 100% deterministic. And mathematically we know that taking the square of absolute value of an equation that contains complex numbers, like Schrodinger's does, is the only way to get a set of real numbers between zero and one that add up to exactly one, which is exactly what we need for probability. And we know that if your eyes are closed and you bet on which world you're in and you want to win then you should bet you're in the world that has the largest quantum magnitude, if you keep repeating that you will make more money with that strategy than with any other.  And MWI can do all that without introducing any assumptions except that Schrodinger's Equation means what it says.

While frameworks like MWI or collapse postulates have epistemic value, they are better seen as tools for exploring the boundaries of what can be explained or inspiration for developing new problems and possible application, rather than as definitive ontological inquiry.

If one is interested in exploring the fundamental boundaries of what we can know, I can't think of a better way than trying to figure out what quantum mechanics means; we will never reach the goal of ontological certainty but I think we can go further than we are right now. 
John K Clark    See what's on my new list at  Extropolis

='/ 
 



Alan Grayson

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Nov 23, 2024, 1:30:09 PM11/23/24
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On Saturday, November 23, 2024 at 6:47:52 AM UTC-7 John Clark wrote:
On Fri, Nov 22, 2024 at 9:19 AM PGC <multipl...@gmail.com> wrote:

[the Gödelian critique] Applied to quantum mechanics and ontology indicates that any framework aiming for ontological finality will inevitably encounter unprovable truths if it includes arithmetic or its use in its formulations. 

But Physics is not mathematics. In physics you don't need to prove experimental results, you need to demonstrate them. Theory is used to predict and explain those experimental results, which Objective Collapse and Pilot Wave and Many Worlds all can do. The best theory is the one that can do so with the fewest assumptions; and in that regard Many Worlds is the clear winner. But even if you knew for a fact that Objective Collapse, or Pilot Wave, or Many Worlds was 100% correct, you still couldn't claim to have reached ontological finality

You may have noticed I didn't include Copenhagen or Quantum Bayesianism, that's because they don't even claim to have anything to do with ontology, final or otherwise, and they don't even pretend to explain anything, they're for people who only care about predicting what value they're going to get on their voltmeter.

 Collapse postulates introduce "magic" by assuming the wavefunction's reality only to dismiss it post-measurement, 

It's even worse than that because they can't tell you exactly, or even approximately, what a "measurement" is.  

Only true in the context of Trump physics, whereas, for example, in normal physics we can measure spin using an SG apparutus, and we know we're measuring spin. AG 

while MWI faces the unresolved challenge of deriving probabilities without external axioms.

Well, MWI can clearly explain why you need probabilities even though Schrodinger's Equation is 100% deterministic. And mathematically we know that taking the square of absolute value of an equation that contains complex numbers, like Schrodinger's does, is the only way to get a set of real numbers between zero and one that add up to exactly one, which is exactly what we need for probability. And we know that if your eyes are closed and you bet on which world you're in and you want to win then you should bet you're in the world that has the largest quantum magnitude, if you keep repeating that you will make more money with that strategy than with any other.  And MWI can do all that without introducing any assumptions except that Schrodinger's Equation means what it says.

In fact you've added immensely to the assumptions of S's equation, such as the departure from the frequency interpretation of probability, and the creation of many worlds without knowing the frequency and boundaries of these worlds. When will you admit this fact and stop with the misleading BS? AG  

While frameworks like MWI or collapse postulates have epistemic value, they are better seen as tools for exploring the boundaries of what can be explained or inspiration for developing new problems and possible application, rather than as definitive ontological inquiry.

If one is interested in exploring the fundamental boundaries of what we can know, I can't think of a better way than trying to figure out what quantum mechanics means; we will never reach the goal of ontological certainty but I think we can go further than we are right now.2

John Clark

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Nov 23, 2024, 1:36:02 PM11/23/24
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On Sat, Nov 23, 2024 at 1:30 PM Alan Grayson <agrays...@gmail.com> wrote:

Only true in the context of Trump physics,

Wow, calling a guy known for disliking Trump a Trump supporter, what a witty and original insult!  I've never heard that one before, except for the 19 dozen +1 times I've heard it from you. 

John K Clark    See what's on my new list at  Extropolis
91t


Alan Grayson

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Nov 23, 2024, 4:56:12 PM11/23/24
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On Saturday, November 23, 2024 at 11:36:02 AM UTC-7 John Clark wrote:
On Sat, Nov 23, 2024 at 1:30 PM Alan Grayson <agrays...@gmail.com> wrote:

Only true in the context of Trump physics,

Wow, calling a guy known for disliking Trump a Trump supporter, what a witty and original insult!  I've never heard that one before, except for the 19 dozen +1 times I've heard it from you. 

John K Clark  
91t
I didn't write you were a Trump supporter; rather that your reasoning on the MWI resembles the way Trump thinks. How about dealing with the substance of my reply? AG

Brent Meeker

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Nov 23, 2024, 8:24:56 PM11/23/24
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On 11/23/2024 5:47 AM, John Clark wrote:
On Fri, Nov 22, 2024 at 9:19 AM PGC <multipl...@gmail.com> wrote:

[the Gödelian critique] Applied to quantum mechanics and ontology indicates that any framework aiming for ontological finality will inevitably encounter unprovable truths if it includes arithmetic or its use in its formulations. 

But Physics is not mathematics. In physics you don't need to prove experimental results, you need to demonstrate them. Theory is used to predict and explain those experimental results, which Objective Collapse and Pilot Wave and Many Worlds all can do.
So do the more instrumentalist interpretations


The best theory is the one that can do so with the fewest assumptions; and in that regard Many Worlds is the clear winner.

You only think so because you close your eyes to it's shortcomings.  Try this lecture by Jacob Barandes.

https://www.youtube.com/watch?v=n9RhoQVxuwQ

And Barandes is not only a critic; he has a one-world formulation that is still conventional, non-instrumentalist QM.

https://www.youtube.com/watch?v=sshJyD0aWXg&t=49s

Brent

smitra

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Nov 23, 2024, 10:25:47 PM11/23/24
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On 22-11-2024 09:30, Bruce Kellett wrote:
> On Fri, Nov 22, 2024 at 7:05 PM smitra <smi...@zonnet.nl> wrote:
>
>> On 22-11-2024 06:40, Brent Meeker wrote:
>>
>>> That's what is ruled out by violation of Bell's inequality.
>>
>> Bells' theorem doesn't apply to QM,
>
> I think it is about time that you read Bell's papers. His theorem is
> not about hidden variable theories, or non-local theories. He assumes,
> for the purposes of argument, a local theory.

He assumes a deterministic local hidden variable theory.

> He then derives a series
> of inequalities that such a local theory must satisfy. Experimentally,
> these inequalities are violated. Inspection of standard QM gives
> results that agree with experiment, but these results also require
> non-locality.

No, non-locality is not required.

> The conclusion drawn from these experiments is that
> quantum mechanics, itself, is non-local.

No, that's not the conclusion. If there were any truth in what you are
saying, then you wouldn't have Sidney Coleman saying things like this:

https://youtu.be/EtyNMlXN-sw?t=2023

And Prof. Marletto wouldn't have put point nr. 2 on her slide:

https://youtu.be/DT61eSiOs50?t=299

Saibal





> Bruce
>
>> it's a theorem about deterministic
>> hidden variable theories that says that certain correlations like
>> some
>> of those of QM cannot be reproduced by any local hidden variable
>> theory.
>> The relevance of Bell's theorem to QM is only that it rules out that
>> if
>> QM is not fundamental and has an underlying hidden variable theory,
>> then
>> that hidden variable theory cannot be local.
>>
>> So, if we then assume that QM is fundamental, then there is no
>> objection
>> against QM being local. Getting to non-local states via local
>> dynamics
>> isn't a problem as this is routinely done in experiments where
>> entangled
>> spin pairs are created. Nothing non-local goes on as far as the
>> dynamics
>> is concerned in such experiments.
>>
>> Saibal
>
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Bruce Kellett

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Nov 23, 2024, 11:04:19 PM11/23/24
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On Sun, Nov 24, 2024 at 2:25 PM smitra <smi...@zonnet.nl> wrote:
On 22-11-2024 09:30, Bruce Kellett wrote:
> On Fri, Nov 22, 2024 at 7:05 PM smitra <smi...@zonnet.nl> wrote:
>
>> On 22-11-2024 06:40, Brent Meeker wrote:
>>
>>> That's what is ruled out by violation of Bell's inequality.
>>
>> Bells' theorem doesn't apply to QM,
>
> I think it is about time that you read Bell's papers.  His theorem is
> not about hidden variable theories, or non-local theories. He assumes,
> for the purposes of argument, a local theory.

He assumes a deterministic local hidden variable theory.

Which theory is that, then?

> He then derives a series
> of inequalities that such a local theory must satisfy. Experimentally,
> these inequalities are violated. Inspection of standard QM gives
> results that agree with experiment, but these results also require
> non-locality.

No, non-locality is not required.

> The conclusion drawn from these experiments is that
> quantum mechanics, itself, is non-local.

No, that's not the conclusion.

If QM were intrinsically local, then you would be able to give this local account of the correlations.
You are manifestly unable to do this.

 
If there were any truth in what you are
saying, then you wouldn't have Sidney Coleman saying things like this:

https://youtu.be/EtyNMlXN-sw?t=2023

And Prof. Marletto wouldn't have put point nr. 2 on her slide:

https://youtu.be/DT61eSiOs50?t=299

I think it is better to rely on the mathematics rather than on so-called authorities.

Bruce

Alan Grayson

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Nov 24, 2024, 1:28:04 AM11/24/24
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On Saturday, November 23, 2024 at 9:04:19 PM UTC-7 Bruce Kellett wrote:
On Sun, Nov 24, 2024 at 2:25 PM smitra <smi...@zonnet.nl> wrote:
On 22-11-2024 09:30, Bruce Kellett wrote:
> On Fri, Nov 22, 2024 at 7:05 PM smitra <smi...@zonnet.nl> wrote:
>
>> On 22-11-2024 06:40, Brent Meeker wrote:
>>
>>> That's what is ruled out by violation of Bell's inequality.
>>
>> Bells' theorem doesn't apply to QM,
>
> I think it is about time that you read Bell's papers.  His theorem is
> not about hidden variable theories, or non-local theories. He assumes,
> for the purposes of argument, a local theory.

He assumes a deterministic local hidden variable theory.

Which theory is that, then?

> He then derives a series
> of inequalities that such a local theory must satisfy. Experimentally,
> these inequalities are violated. Inspection of standard QM gives
> results that agree with experiment, but these results also require
> non-locality.

No, non-locality is not required.

> The conclusion drawn from these experiments is that
> quantum mechanics, itself, is non-local.

No, that's not the conclusion.

If QM were intrinsically local, then you would be able to give this local account of the correlations.
You are manifestly unable to do this.

What exactly do you mean by "local account of the correlations"? Would you
agree that the fact the wf extends infinitely in all directions and changes in
time infinitely in all directions sufficiently establishes that QM is non-local? AG  

scerir

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Nov 24, 2024, 5:18:20 AM11/24/24
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https://plato.stanford.edu/entries/qm-everett/

<In identifying Everett’s theory with Graham’s many-world reconstruction there is good reason to believe that DeWitt simply failed to understand Everett. We know what Everett thought of DeWitt and Graham’s formulation of the theory. In his personal copy of DeWitt’s description of the many-worlds interpretation, Everett wrote the word “bullshit” next to the passage where DeWitt presented Graham’s discussion of the branching process and Everett’s typicality measure. See Barrett and Byrne 2012, 364–6 for scans of Everett’s handwritten marginal notes.>

Was Everett right?

.

John Clark

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Nov 24, 2024, 7:28:20 AM11/24/24
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On Sat, Nov 23, 2024 at 11:04 PM Bruce Kellett <bhkel...@gmail.com> wrote:
 
>> He [Bell] assumes a deterministic local hidden variable theory.

Which theory is that, then?

Ironically that was Erwin Schrödinger's quantum interpretation, and Albert Einstein's, but it turned out they were both wrong. They thought the universe was local, deterministic and realistic, but if it was then it would be impossible to violate Bell's Inequality, and if it was then quantum mechanics would make incorrect predictions in experiments set up the way that Bell described. But the experimental results are clear, Bell's Inequality IS violated and the predictions of quantum mechanics are correct. 

So the only way the universe could be deterministic, local and realistic is with Superdeterminism, but that theory is idiotic because it requires you to make quite literally an INFINITE number of assumptions. It's not even a scientific theory because if it's true then the scientific method itself would be of no help whatsoever in increasing your ontological or even epistemological knowledge. It sort of reminds me of Christian fundamentalists who say that the universe was created in 4004 BC  and God made dinosaur bones, buried them, and made them look like they were hundreds of millions of years old in order to test our faith. It's impossible to disprove that idea because God is omnipotent so He certainly has the power to fool us if He wants to. But a God like that would be a real prick! 

 John K Clark    See what's on my new list at  Extropolis
3sq 

Alan Grayson

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Nov 24, 2024, 4:21:50 PM11/24/24
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Recently you, JC, wrote, referring to those who adopt the Copenhagen Interpretation of collapse:  It's even worse than that because they can't tell you exactly, or even approximately, what a "measurement" is.  

Really? This, of course, is false, the SG experiment being an obvious counter-example, and like Trump, you lie to defend the theory you're in love with. And in the same context, you seem to rely on, and believe the results of Bell experiments. Do you know what you're doing? AG

Brent Meeker

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Nov 24, 2024, 11:01:13 PM11/24/24
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On 11/24/2024 4:27 AM, John Clark wrote:
On Sat, Nov 23, 2024 at 11:04 PM Bruce Kellett <bhkel...@gmail.com> wrote:
 
>> He [Bell] assumes a deterministic local hidden variable theory.

Which theory is that, then?

Ironically that was Erwin Schrödinger's quantum interpretation, and Albert Einstein's, but it turned out they were both wrong. They thought the universe was local, deterministic and realistic, but if it was then it would be impossible to violate Bell's Inequality, and if it was then quantum mechanics would make incorrect predictions in experiments set up the way that Bell described. But the experimental results are clear, Bell's Inequality IS violated and the predictions of quantum mechanics are correct. 

So the only way the universe could be deterministic, local and realistic is with Superdeterminism, but that theory is idiotic because it requires you to make quite literally an INFINITE number of assumptions.
It only requires that there be some initial condition and deterministic evolution thereafter.  Sounds just like Newtonian cosmology.


It's not even a scientific theory because if it's true then the scientific method itself would be of no help whatsoever in increasing your ontological or even epistemological knowledge.
There would still be deterministic law-like evolution.  Does the existence of randomness help increase your ontological or epistemological knowledge?  According your favorite interpretation, observing a binary event like ++++..., consistent with a Born probability of 0.01, will leave almost all physicists with the wrong conclusion because they will see something like ++-+--+---+-++... with roughly equal numbers of + and -.

Brent

It sort of reminds me of Christian fundamentalists who say that the universe was created in 4004 BC  and God made dinosaur bones, buried them, and made them look like they were hundreds of millions of years old in order to test our faith. It's impossible to disprove that idea because God is omnipotent so He certainly has the power to fool us if He wants to. But a God like that would be a real prick! 

 John K Clark    See what's on my new list at  Extropolis
3sq 

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PGC

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Nov 24, 2024, 11:34:01 PM11/24/24
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Barandes' work on non-Markovian quantum dynamics is undeniably sophisticated and offers potential applications (I appreciate the post, thanks), but it exemplifies a recurring issue in alleged foundational inquiry. In "A New Formulation of Quantum Theory," for instance, his "kinematical axiom", that he states as a physical axiom on the slide, assumes natural numbers and sets—abstract or metaphysical concepts, not physical concepts—while presenting them as part of a physical ontology (see minute 11 of the video). This conflation risks undermining the rigor and clarity required in foundational inquiry.

Quantum mechanics, in any interpretation (digital mechanism aside), cannot fully explain why it appears as it does to specific subjects without a precise account of what a subject is and how their interaction with the system is modeled. Questions like "Why collapse?" or "Why Many Worlds?" demand assumptions about the subject, their properties, and their relationship to both the physical and mathematical structures they interpret. Without this clarity, foundational reasoning risks either circularity or ambiguity.

Foundational work should strive for clarity and honesty in its assumptions before reaching for elegance. It’s not enough to say "this works, it's sophisticated"—we have to address and state why it works for a subject with specific properties xyz in relation to the precise quantum or classical frameworks in play. Without this, we risk getting lost in the weeds of sophistication, leaving foundational gaps open and unexamined.

Barandes is right: examine the obvious things we take for granted; too bad he didn't apply that to his axiom mentioned above. If Bruno's digital mechanism strikes you as an implausible foundation, then what exactly are the assumptions underlying your stance  regarding existence of a subject, with which properties, experiencing which kind of physics and why; how QM, randomness, classicality, consciousness or lack thereof, qualia or not etc. manifest and emerge or don't? 

Alan Grayson

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Nov 25, 2024, 1:44:36 AM11/25/24
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On Sunday, November 24, 2024 at 9:34:01 PM UTC-7 PGC wrote:

Barandes' work on non-Markovian quantum dynamics is undeniably sophisticated and offers potential applications (I appreciate the post, thanks), but it exemplifies a recurring issue in alleged foundational inquiry. In "A New Formulation of Quantum Theory," for instance, his "kinematical axiom", that he states as a physical axiom on the slide, assumes natural numbers and sets—abstract or metaphysical concepts, not physical concepts—while presenting them as part of a physical ontology (see minute 11 of the video). This conflation risks undermining the rigor and clarity required in foundational inquiry.

Quantum mechanics, in any interpretation (digital mechanism aside), cannot fully explain why it appears as it does to specific subjects without a precise account of what a subject is and how their interaction with the system is modeled. Questions like "Why collapse?" or "Why Many Worlds?" demand assumptions about the subject, their properties, and their relationship to both the physical and mathematical structures they interpret. Without this clarity, foundational reasoning risks either circularity or ambiguity.

Foundational work should strive for clarity and honesty in its assumptions before reaching for elegance. It’s not enough to say "this works, it's sophisticated"—we have to address and state why it works for a subject with specific properties xyz in relation to the precise quantum or classical frameworks in play. Without this, we risk getting lost in the weeds of sophistication, leaving foundational gaps open and unexamined.

Barandes is right: examine the obvious things we take for granted; too bad he didn't apply that to his axiom mentioned above. If Bruno's digital mechanism strikes you as an implausible foundation, then what exactly are the assumptions underlying your stance  regarding existence of a subject, with which properties, experiencing which kind of physics and why; how QM, randomness, classicality, consciousness or lack thereof, qualia or not etc. manifest and emerge or don't? 

Your philosophy, or shall we say point of view, is an example of the perfect as the enemy of the good. If Euclid had waited to satisfy your criteria, we wouldn't have plane geometry, and we'd still be waiting for the theorem of Pythagoras. Based on a voluminous catalog of passed experience, every successful theory begins with some undefined concepts. AG

John Clark

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Nov 25, 2024, 7:33:40 AM11/25/24
to everyth...@googlegroups.com

On Sun, Nov 24, 2024 at 4:21 PM Alan Grayson <agrays...@gmail.com> wrote:

like Trump, you lie 


Wow, calling a guy known for disliking Trump a Trump supporter, what a witty and original insult!  I've never heard that one before, except for the 19 dozen +2 times I've heard it from you. 

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





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