Sean Carroll: Universe a 'tiny sliver' of all there is

[John Clark]

Sean Carroll: Universe a 'tiny sliver' of all there is

John K Clark

[Philip Thrift]

On Monday, September 16, 2019 at 1:41:41 AM UTC-5, John Clark wrote:

Sean Carroll: Universe a 'tiny sliver' of all there is

John K Clark

"Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

@philipthrift 

[John Clark]

On Mon, Sep 16, 2019 at 4:49 AM Philip Thrift <cloud...@gmail.com> wrote:

> "Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

And I think the above demonstrates a lack of courage to face the possibility that reality may be structured in ways you do not like. As Carl Sagan said  "The universe is not required to be in perfect harmony with human ambition".

 John K Clark

[Bruce Kellett]

Perhaps he could usefully have added: "nor to be in perfect harmony with any humanly devised equation."

Bruce

 

[Alan Grayson]

... and one that isn't even covariant. AG 

 

[Alan Grayson]

When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers. So what happened to the (non-covariant) wf after the measurement? Nothing. Like a horserace when it reaches conclusion, it's no longer applicable. That simple! The collapse hypothesis is just a bookkeeping device to get rid of it! AG 

[Philip Thrift]

http://www.math.columbia.edu/~woit/wordpress/?p=11277

An Apology

Posted on September 15, 2019 by woit

I’m afraid I made a serious mistake in this previous posting discussing Sean Carroll’s new book. Since the book was relatively reasonable, while the jacket and promotional material that came with it were nonsense, I assumed that Carroll was just being ill-served by his publisher. It’s now clear I was very wrong. He’s on a book tour, and the nonsense is exactly what he is putting front and center as a revelation to the public about how to understand quantum mechanics. For a couple examples, here’s what was on the PBS News Hour

The “many worlds” theory in quantum mechanics suggests that with every decision you make, a new universe springs into existence containing what amounts to a new version of you. Bestselling author and theoretical physicist Sean Carroll discusses the concept and his new book, “Something Deeply Hidden,” with NewsHour Weekend’s Tom Casciato.

and here’s something from his talk down the street from me.

Using your public platform to tell people that the way to understand quantum mechanics is that the world splits depending on what you decide to do is simply What the Bleep? level stupidity. Those in the physics and science communication communities who care about the public understanding of quantum mechanics should think hard about what they can do to deal with this situation. They may however come to the same conclusion I’ve just reached: best to ignore him, which I’ll try to do from now on.

@philipthrift 

 

[spudb...@aol.com]

So, if we develop AI to come up with new, better, equations, this would be good with you, because, non-human? 

Perhaps he could usefully have added: "nor to be in perfect harmony with any humanly devised equation."

Bruce

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.

[Brent Meeker]

On 9/16/2019 6:22 AM, Alan Grayson wrote:

On Monday, September 16, 2019 at 5:58:58 AM UTC-6, John Clark wrote:

On Mon, Sep 16, 2019 at 4:49 AM Philip Thrift <cloud...@gmail.com> wrote:

> "Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

And I think the above demonstrates a lack of courage to face the possibility that reality may be structured in ways you do not like. As Carl Sagan said  "The universe is not required to be in perfect harmony with human ambition".

 John K Clark

When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers. So what happened to the (non-covariant)

You need to read this: http://www.preposterousuniverse.com/blog/2016/08/15/you-should-love-or-at-least-respect-the-schrodinger-equation/

Brent

[spudb...@aol.com]

Oh My! I'll simply have to delete my un-read download of Carroll's book because Woit disapproves!!!  

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[John Clark]

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

 

> So what happened to the (non-covariant) wf after the measurement? Nothing.

True, and that's what Many Worlds says, nothing happens to the Schrödinger wave of the universe described by his equation, it just keeps on going forever.

 

> Like a horserace when it reaches conclusion, it's no longer applicable. That simple! The collapse hypothesis is just a bookkeeping device to get rid of it!

True again, the collapse hypothesis was tacked on not because it explained observations better but because some people didn't like those many worlds, so they just said some mysterious process makes them disappear even though they can't clearly explain how this process does this or explain exactly what circumstances are needed for it to take effect. In Sean Carroll's new book, which I just started reading, he says Many Worlds could be called Austere Quantum Mechanics because it adds nothing to Schrödinger's Equation because nothing more is needed to explain observations.  Hugh Everett didn't add any new physics, when he came up with Many Worlds, he just followed the Schrödinger Equation as far as it would go and junked a lot of useless gunk (like the collapse hypothesis) that did nothing except make people who were squeamish about the idea there was more than one version of them more comfortable.  

 John K Clark

[Bruce Kellett]

On Tue, Sep 17, 2019 at 6:44 AM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

 

So, if we develop AI to come up with new, better, equations, this would be good with you, because, non-human? 

Perhaps he could usefully have added: "nor to be in perfect harmony with any humanly devised equation."

Bruce

Go for it, man! First develop your super-intelligent AI.......... And then see if the world conforms to its predictions......

Bruce

[Brent Meeker]

On 9/16/2019 2:54 PM, John Clark wrote:

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

 

> So what happened to the (non-covariant) wf after the measurement? Nothing.

True, and that's what Many Worlds says, nothing happens to the Schrödinger wave of the universe described by his equation, it just keeps on going forever.

 

> Like a horserace when it reaches conclusion, it's no longer applicable. That simple! The collapse hypothesis is just a bookkeeping device to get rid of it!

True again, the collapse hypothesis was tacked on not because it explained observations better but because some people didn't like those many worlds, so they just said some mysterious process makes them disappear even though they can't clearly explain how this process does this or explain exactly what circumstances are needed for it to take effect. In Sean Carroll's new book, which I just started reading, he says Many Worlds could be called Austere Quantum Mechanics because it adds nothing to Schrödinger's Equation because nothing more is needed to explain observations. 

You still need the Born rule, including its intepretation as a probability.

Brent

[spudb...@aol.com]

It would be (will be?) interesting when we achieve this. Serious, academic bench computer scientists are actively working on variations of machine intelligence to make this happen, money to be made. Are you stating that making a hyper-smart machine is impossible? Are you a spiritualist? A Cartesian dualist imputing a magic substance? :-) 

-----Original Message-----
From: Bruce Kellett <bhkel...@gmail.com>
To: everything-list <everyth...@googlegroups.com>
Sent: Mon, Sep 16, 2019 7:28 pm
Subject: Re: Sean Carroll: Universe a 'tiny sliver' of all there is

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[Bruce Kellett]

On Tue, Sep 17, 2019 at 10:39 AM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

It would be (will be?) interesting when we achieve this. Serious, academic bench computer scientists are actively working on variations of machine intelligence to make this happen, money to be made. Are you stating that making a hyper-smart machine is impossible?

No, I am agnostic about the possibility. Certainly I am not a Cartesian dualist -- mind-brain identity is the thing.....

Bruce

 

Are you a spiritualist? A Cartesian dualist imputing a magic substance? :-) 

[spudb...@aol.com]

Speaking of the observable being just a sliver, I wonder if this article is worth consideration? It's a consciousness thing, which seems to be in opposition to matter, if I read correctly? There are a few other physicists for the worthies here, to defame, so it might be a bit of fun?

https://dailygalaxy.com/2019/09/the-ultimate-mystery-consciousness-may-exist-in-the-absence-of-matter-weekend-feature/

https://groups.google.com/d/msgid/everything-list/1958873613.8197096.1568666688820%40mail.yahoo.com

.

[spudb...@aol.com]

Agnostic, Mind-Brain thing is good with me. According to a brief article, some theorists have mused about consciousness in the absence of matter. Check it out. It will either be a good laugh for you, but once in a while, the 'lofty' stuff works for me. 

-----Original Message-----
From: Bruce Kellett <bhkel...@gmail.com>
To: everything-list <everyth...@googlegroups.com>
Sent: Mon, Sep 16, 2019 9:08 pm
Subject: Re: Sean Carroll: Universe a 'tiny sliver' of all there is

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[Bruce Kellett]

On Tue, Sep 17, 2019 at 12:19 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

Agnostic, Mind-Brain thing is good with me. According to a brief article, some theorists have mused about consciousness in the absence of matter. Check it out. It will either be a good laugh for you, but once in a while, the 'lofty' stuff works for me. 

As soon as the article mentioned Deepak Chopra I knew that we were deep into woo-woo territory....

Bruce

[spudb...@aol.com]

Yeah, but despite Chopra there was Linde is seems to be a reliable. physicist. Also, the dismissive crap performed by number crunchers, dismiss it because it merely offends their sense of...conventionality. Outside of  Bruno, and Young, Standish, nobody else here is employed as an academician is there? Sagan, who gets quoted here, offered woo, in Cosmos, and basically. 40 years later what do we know of the universe (currently) save that is a great, expanse of gas, dust, bereft of other civilizations, that we can never, in principle ever reach via probes. I, for one, look for some sort of commercial...intellectual..technological...somehow, some way..ROI. We need a pay out, in some fashion. 

-----Original Message-----
From: Bruce Kellett <bhkel...@gmail.com>
To: everything-list <everyth...@googlegroups.com>
Sent: Mon, Sep 16, 2019 10:23 pm
Subject: Re: Sean Carroll: Universe a 'tiny sliver' of all there is

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[Bruce Kellett]

On Tue, Sep 17, 2019 at 2:41 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

Yeah, but despite Chopra there was Linde is seems to be a reliable. physicist. Also, the dismissive crap performed by number crunchers, dismiss it because it merely offends their sense of...conventionality. Outside of  Bruno, and Young, Standish, nobody else here is employed as an academician is there?

When I was employed (which was some time ago) I was certainly an academic. Besides, it is not who you are, or what your current employment is, that counts. It is whether you talk sense or nonsense.  Linde is not the only professor of physics to go out onto speculative limbs from time to time. Carroll seems to have fallen into the popularity trap of trying to make the physics more sensational than it actually is.

Bruce

[Alan Grayson]

On Monday, September 16, 2019 at 3:54:46 PM UTC-6, John Clark wrote:

 

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

Many "odd" results are now mainstream, but MWI is bridge too far, way too far IMO. Why don't you just accept that the wf is simply irrelevant after the measurement occurs like in the horserace example?. Here, there's no collapse, no many worlds, no need to explain where the energy comes from which defines these worlds, and so forth? AG 

 

> So what happened to the (non-covariant) wf after the measurement? Nothing.

True, and that's what Many Worlds says, nothing happens to the Schrödinger wave of the universe described by his equation, it just keeps on going forever.

MW says that and a hellofalot MORE! I gave you a hugely simpler solution. Why don't you take it and go in peace? AG

[Bruce Kellett]

On Tue, Sep 17, 2019 at 4:51 PM Alan Grayson <agrays...@gmail.com> wrote:

On Monday, September 16, 2019 at 3:54:46 PM UTC-6, John Clark wrote:

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

Many "odd" results are now mainstream, but MWI is bridge too far, way too far IMO. Why don't you just accept that the wf is simply irrelevant after the measurement occurs like in the horserace example?. Here, there's no collapse, no many worlds, no need to explain where the energy comes from which defines these worlds, and so forth? AG

Except that horses and horse races do not interfere (except in Australia, where several jockeys and trainers have recently been suspended for unauthorised interference -- but that is a different matter!)

Bruce

[Alan Grayson]

I know. I was just being illustrative. But note that Carroll says much the same thing when he says worlds are created when you make a left or right turn, or flip a coin (or some equivalent analogy). AG 

[Bruce Kellett]

And that is where Sean slips inevitably into woo-woo.

Bruce 

[John Clark]

On Mon, Sep 16, 2019 at 7:57 PM 'Brent Meeker <everyth...@googlegroups.com> wrote:

 

>> Many Worlds could be called Austere Quantum Mechanics because it adds nothing to Schrödinger's Equation because nothing more is needed to explain observations. 

> You still need the Born rule, including its intepretation as a probability.

Every quantum interpretation needs the Born rule, but it comes pretty naturally. If you square the amplitude of the Schrödinger wave you automatically get numbers that are positive and unitary, that is the always add up to exactly 100%. And those are 2 properties a probability must have, negative probability has no meaning and there is always a 100% chance SOMETHING will happen.

 John K Clark

[John Clark]

On Tue, Sep 17, 2019 at 2:51 AM Alan Grayson <agrays...@gmail.com> wrote:

> Why don't you just accept that the wf is simply irrelevant after the measurement occurs

Because you can't explain exactly what is and what is not a "measurement". And because tacking on complicated mathematical wheels within wheels to make the wave function suddenly vanish would not improve the theories ability to make observable predictions by one bit and would do absolutely nothing except muzzle the Schrödinger Equation which is virtually shouting at us about the nature of reality. The Many Worlds theory didn't tack on all those many worlds, if you take a bare bones approach to quantum mechanics and add nothing not needed to explain observation those worlds come naturally, they can't be avoided.

 John K Clark

[Bruce Kellett]

The fact that the squared amplitudes add up to unity is not particularly surprising when you have normalised the wave function! Showing that this is a probability is a whole other kettle of bananas.

Bruce 

[Bruce Kellett]

So why do all Everettians have to add so many additional assumptions in order to pretend to get out the Born rule?

Bruce 

[Bruno Marchal]

On 16 Sep 2019, at 10:49, Philip Thrift <cloud...@gmail.com> wrote:

On Monday, September 16, 2019 at 1:41:41 AM UTC-5, John Clark wrote:

Sean Carroll: Universe a 'tiny sliver' of all there is

John K Clark

"Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

Why?

Bruno

@philipthrift 

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[John Clark]

On Tue, Sep 17, 2019 at 7:30 AM Bruce Kellett <bhkel...@gmail.com> wrote:

> The fact that the squared amplitudes add up to unity is not particularly surprising when you have normalised the wave function!

True, and it's also not surprising that it always gives you positive numbers, and that's just what you need for a probability.

 

> Showing that this is a probability is a whole other kettle of bananas.

And that other kettle of bananas is seeing if treating the square of the amplitude as a probability is compatible with experimental observation. And it is.

John K Clark

[Philip Thrift]

On Tuesday, September 17, 2019 at 8:20:01 AM UTC-5, Bruno Marchal wrote:

On 16 Sep 2019, at 10:49, Philip Thrift <cloud...@gmail.com> wrote:

On Monday, September 16, 2019 at 1:41:41 AM UTC-5, John Clark wrote:

Sean Carroll: Universe a 'tiny sliver' of all there is

John K Clark

"Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

Why?

Bruno

From a pragmatic perspective, I do not see any Everettian MW (theory, math, ideas, formulations, interpretations or whatever they want to call it) in computational quantum mechanics:

https://www.simonsfoundation.org/flatiron/center-for-computational-quantum-physics/software

If MW were important, it would be there.

@philipthrift

 

[smitra]

On 17-09-2019 09:16, Bruce Kellett wrote:
> On Tue, Sep 17, 2019 at 5:08 PM Alan Grayson <agrays...@gmail.com>
> wrote:
>
>> On Tuesday, September 17, 2019 at 1:02:39 AM UTC-6, Bruce wrote:
>>
>> On Tue, Sep 17, 2019 at 4:51 PM Alan Grayson <agrays...@gmail.com>
>> wrote:
>>
>> On Monday, September 16, 2019 at 3:54:46 PM UTC-6, John Clark wrote:
>>
>> On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com>
>> wrote:
>>

>> _> When physics began to give non-intuitive results, in QM AND

>> Relativity, people when overboard. Now any patently absurd result

>> finds its justification among true believers._

>>
>> And in this context "patently absurd" means odd, not logically
>> contradictory not paradoxical not contrary to experimental results,
>> just odd. But as far as we know there is no law that says nature
>> can't behave in ways that humans find odd.
>
> Many "odd" results are now mainstream, but MWI is bridge too far, way
> too far IMO. Why don't you just accept that the wf is simply
> irrelevant after the measurement occurs like in the horserace
> example?. Here, there's no collapse, no many worlds, no need to
> explain where the energy comes from which defines these worlds, and so
> forth? AG
>
> Except that horses and horse races do not interfere (except in
> Australia, where several jockeys and trainers have recently been
> suspended for unauthorised interference -- but that is a different
> matter!)
>
> Bruce
>
> I know. I was just being illustrative. But note that Carroll says much
> the same thing when he says worlds are created when you make a left or
> right turn, or flip a coin (or some equivalent analogy). AG
>
> And that is where Sean slips inevitably into woo-woo.
>
>

No, this is a rather solid result from assuming the validity of the
Schrodinger equation:

https://arxiv.org/abs/1212.0953

"We argue using simple models that all successful practical uses of
probabilities originate in quantum fluctuations in the microscopic
physical world around us, often propagated to macroscopic scales. Thus
we claim there is no physically verified fully classical theory of
probability. We comment on the general implications of this view, and
specifically question the application of classical probability theory to
cosmology in cases where key questions are known to have no quantum
answer. We argue that the ideas developed here may offer a way out of
the notorious measure problems of eternal inflation."

Saibal

[smitra]

On 17-09-2019 13:32, Bruce Kellett wrote:
> On Tue, Sep 17, 2019 at 8:43 PM John Clark <johnk...@gmail.com>
> wrote:
>
>> On Tue, Sep 17, 2019 at 2:51 AM Alan Grayson
>> <agrays...@gmail.com> wrote:
>>

>>>> _Why don't you just accept that the wf is simply irrelevant
>>> after the measurement occurs_

>>
>> Because you can't explain exactly what is and what is not a
>> "measurement". And because tacking on complicated mathematical
>> wheels within wheels to make the wave function suddenly vanish would
>> not improve the theories ability to make observable predictions by
>> one bit and would do absolutely nothing except muzzle the
>> Schrödinger Equation which is virtually shouting at us about the
>> nature of reality. The Many Worlds theory didn't tack on all those
>> many worlds, if you take a bare bones approach to quantum mechanics
>> and add nothing not needed to explain observation those worlds come
>> naturally, they can't be avoided.
>
> So why do all Everettians have to add so many additional assumptions
> in order to pretend to get out the Born rule?
>
>

Simply assuming the special case of the Born rule that measuring a
system in an eigenstate of an observable will yield the eigenvalue of
that eigenstate with certainty, is enough. You can consider the case of
repeatedly preparing and measuring N copies of a system and then
consider the observable that corresponds to the frequency distribution
of the individual measurement outcomes in the limit of N to infinity.
The special case of the Born rule applied to observable for the
frequency distribution then implies the general Born rule.

Saibal

[smitra]

On 17-09-2019 16:04, Philip Thrift wrote:
> On Tuesday, September 17, 2019 at 8:20:01 AM UTC-5, Bruno Marchal
> wrote:
>
>> On 16 Sep 2019, at 10:49, Philip Thrift <cloud...@gmail.com> wrote:
>>
>> On Monday, September 16, 2019 at 1:41:41 AM UTC-5, John Clark wrote:
>>

>> Sean Carroll: Universe a 'tiny sliver' of all there is [1]

>>
>> John K Clark
>>
>> "Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a
>> failure of theoretical physics, or philosophy, or both.
>
> Why?
>
> Bruno
>
> From a pragmatic perspective, I do not see any Everettian MW (theory,
> math, ideas, formulations, interpretations or whatever they want to
> call it) in computational quantum mechanics:
>
> https://www.simonsfoundation.org/flatiron/center-for-computational-quantum-physics/software
>
> If MW were important, it would be there.
>
> @philipthrift

The fact that computational quantum mechanics works at all is very
strong evidence for the MWI. That the MWI in the sense of the idea that
you have copies out there that have experienced different things, has no
practical applications is similar to saying that the idea that you are
ultimately reducible to only chemistry has no practical applications.
The question whether or not biology is merely a branch of chemistry has
been answered and this has some applications, but at the level of human
beings in the way they interact with each other, this is just an
academic question. The same is pretty much true for quantum mechanics
and the MWI, or at least the "Many Words" part of the MWI, as the some
details if the MWI still need to be fleshed out.

Thing is that if the MWI is wrong then that implies new physics in an
area that no one is expecting. Physicists are expecting new physics to
appear at high energies, e.g. supersymmetry may be discovered. But no
one expects that quantum mechanics will fail to hold up. What's
unexpected may still happen, but it's just not plausible given
everything we do know.

Saibal

[Alan Grayson]

To be perfectly candid here, there's a disconnect that borders on insanity. Some worthless asshole can go into a lab, do a double slit experiment, and conjure possibly uncountable universes into existence, replete with possibly many infinite stars, galaxies, and life forms. Can't you see how ridiculous this is, hubris on steroids, and by simply assuming the wf is irrelevant after the measurement occurs, makes it all go away? AG 

[Philip Thrift]

That there is a a different kind of "probability "space" underlying QM does not imply MWI. 

In fact. MWI is a probability ("extended" or not) eliminative theory (or framework, or interpretation, or formulation, or whatever word physicists are happy with).

@philipthrift

[Bruce Kellett]

They can argue this, but that falls far short of a demonstration that new branches split off for every decision we make. In general, decisions are not choices from a set of possibilities in superposition, which would be the only way in which the proposal could make any sense.

Bruce 

[Bruce Kellett]

On Wed, Sep 18, 2019 at 3:01 AM smitra <smi...@zonnet.nl> wrote:

On 17-09-2019 13:32, Bruce Kellett wrote:
>
> So why do all Everettians have to add so many additional assumptions
> in order to pretend to get out the Born rule?
>

Simply assuming the special case of the Born rule that measuring a
system in an eigenstate of an observable will yield the eigenvalue of
that eigenstate with  certainty, is enough.

Where did the concept of an observable as an operator in a Hilbert space, and the idea that measurements correspond to the action of that observable  on the state, giving a result that is the eigenvalue corresponding to the projected eigenvector, come from?

As I said, you have to build an awful lot into the Schrodinger equation in order to get out quantum physics. The Born rule is one of the hardest things to get. And no one has yet produced a convincing argument that the Born rule can be derived in Everettian QM.

Bruce

[Brent Meeker]

On 9/17/2019 3:49 PM, Bruce Kellett wrote:

On Wed, Sep 18, 2019 at 3:01 AM smitra <smi...@zonnet.nl> wrote:

On 17-09-2019 13:32, Bruce Kellett wrote:
>
> So why do all Everettians have to add so many additional assumptions
> in order to pretend to get out the Born rule?
>

Simply assuming the special case of the Born rule that measuring a
system in an eigenstate of an observable will yield the eigenvalue of
that eigenstate with  certainty, is enough.

Where did the concept of an observable as an operator in a Hilbert space, and the idea that measurements correspond to the action of that observable  on the state, giving a result that is the eigenvalue corresponding to the projected eigenvector, come from?

The operator should be expressible in terms of the Hamiltonian of the measuring instrument and its interaction with the system.  But nobody tries to write down the Hamiltonian of the instrument; they just look at what it's supposed to measure classically and then they write an abstract operator that does that.

Brent

As I said, you have to build an awful lot into the Schrodinger equation in order to get out quantum physics. The Born rule is one of the hardest things to get. And no one has yet produced a convincing argument that the Born rule can be derived in Everettian QM.

Bruce

You can consider the case of
repeatedly preparing and measuring N copies of a system and then
consider the observable that corresponds to the frequency distribution
of the individual measurement outcomes in the limit of N to infinity.
The special case of the Born rule applied to observable for the
frequency distribution then implies the general Born rule.

Saibal

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[Bruce Kellett]

On Wed, Sep 18, 2019 at 10:37 AM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:

On 9/17/2019 3:49 PM, Bruce Kellett wrote:

On Wed, Sep 18, 2019 at 3:01 AM smitra <smi...@zonnet.nl> wrote:

On 17-09-2019 13:32, Bruce Kellett wrote:
>
> So why do all Everettians have to add so many additional assumptions
> in order to pretend to get out the Born rule?
>

Simply assuming the special case of the Born rule that measuring a
system in an eigenstate of an observable will yield the eigenvalue of
that eigenstate with  certainty, is enough.

Where did the concept of an observable as an operator in a Hilbert space, and the idea that measurements correspond to the action of that observable  on the state, giving a result that is the eigenvalue corresponding to the projected eigenvector, come from?

The operator should be expressible in terms of the Hamiltonian of the measuring instrument and its interaction with the system.  But nobody tries to write down the Hamiltonian of the instrument; they just look at what it's supposed to measure classically and then they write an abstract operator that does that.

So it is something added to the supposed "minimal QM" of the Schrodinger equation. The eigenvector/eigenvalue link is pretty well established. Zurek has a good argument to derive this. 

Bruce

[Alan Grayson]

But suppose you flip a coin and while it's in the air, you write its wf. Since the prevailing belief is that all objects are quantum objects, why can't one suppose that the two terms in the superposition, head and tail, manifest quantum interference? AG 

[Bruce Kellett]

Why can't one observe a superposition of a live cat and a dead cat? The problem is decoherence, and coin tosses are totally decohered -- no quantum superpositions left. So one is reduced to standard classical ignorance probability .

Bruce

[Philip Thrift]

The Zurek (QD) theory is a very good (in my view) framework to consider. A useful antidote to MWI.

https://arxiv.org/abs/1807.02092

Quantum Theory of the Classical: Quantum Jumps, Born's Rule, and Objective Classical Reality via Quantum Darwinism

Wojciech Hubert Zurek

(Submitted on 5 Jul 2018)

Emergence of the classical world from the quantum substrate of our Universe is a long-standing conundrum. I describe three insights into the transition from quantum to classical that are based on the recognition of the role of the environment. I begin with derivation of preferred sets of states that help define what exists - our everyday classical reality. They emerge as a result of breaking of the unitary symmetry of the Hilbert space which happens when the unitarity of quantum evolutions encounters nonlinearities inherent in the process of amplification - of replicating information. This derivation is accomplished without the usual tools of decoherence, and accounts for the appearance of quantum jumps and emergence of preferred pointer states consistent with those obtained via environment-induced superselection, or einselection. Pointer states obtained this way determine what can happen - define events - without appealing to Born's rule for probabilities. Therefore, Born's rule can be now deduced from the entanglement-assisted invariance, or envariance - a symmetry of entangled quantum states. With probabilities at hand one also gains new insights into foundations of quantum statistical physics. Moreover, one can now analyze information flows responsible for decoherence. These information flows explain how perception of objective classical reality arises from the quantum substrate: Effective amplification they represent accounts for the objective existence of the einselected states of macroscopic quantum systems through the redundancy of pointer state records in their environment - through quantum Darwinism.

@philipthrift 

[Brent Meeker]

On 9/18/2019 1:33 AM, Alan Grayson wrote:
> But suppose you flip a coin and while it's in the air, you write its
> wf. Since the prevailing belief is that all objects are quantum
> objects, why can't one suppose that the two terms in the
> superposition, head and tail, manifest quantum interference? AG

One clue that you can't is that magicians teach themselves to flip a
coin so that can always catch it the same way it started.  That shows
it's not quantum randomness.

Brent

[Alan Grayson]

Yes, you're getting to the core of the issue, and there's more here then (than?) meets the eye, at least mine. It seems that quantum superpositions depend on isolation and are destroyed by entanglements, but exactly why that's the case remains obscure. And these entanglements also connect the micro to the macro. AG

[smitra]

That only shows that in some cases its not random. But when it is
random, it can only be due to quantum fluctuations as there is no other
form of randomness in nature.

Saibal

[Bruno Marchal]

Our decision are classical, so (even in the Everett quantum world) they do not "create new worlds”. 

I suspect Sean Carroll is quoted out of context, as indeed that is a mistake (a common one).

Bruno

On 16 Sep 2019, at 15:28, Philip Thrift <cloud...@gmail.com> wrote:

On Monday, September 16, 2019 at 7:11:30 AM UTC-5, Bruce wrote:

On Mon, Sep 16, 2019 at 9:58 PM John Clark <johnk...@gmail.com> wrote:

On Mon, Sep 16, 2019 at 4:49 AM Philip Thrift <cloud...@gmail.com> wrote:

> "Many Worlds" (as demonstrated via Sean Carroll here) demonstrates a failure of theoretical physics, or philosophy, or both.

And I think the above demonstrates a lack of courage to face the possibility that reality may be structured in ways you do not like. As Carl Sagan said  "The universe is not required to be in perfect harmony with human ambition".

 

Perhaps he could usefully have added: "nor to be in perfect harmony with any humanly devised equation."

Bruce

http://www.math.columbia.edu/~woit/wordpress/?p=11277

An Apology

Posted on September 15, 2019 by woit

I’m afraid I made a serious mistake in this previous posting discussing Sean Carroll’s new book. Since the book was relatively reasonable, while the jacket and promotional material that came with it were nonsense, I assumed that Carroll was just being ill-served by his publisher. It’s now clear I was very wrong. He’s on a book tour, and the nonsense is exactly what he is putting front and center as a revelation to the public about how to understand quantum mechanics. For a couple examples, here’s what was on the PBS News Hour

The “many worlds” theory in quantum mechanics suggests that with every decision you make, a new universe springs into existence containing what amounts to a new version of you. Bestselling author and theoretical physicist Sean Carroll discusses the concept and his new book, “Something Deeply Hidden,” with NewsHour Weekend’s Tom Casciato.

and here’s something from his talk down the street from me.

Using your public platform to tell people that the way to understand quantum mechanics is that the world splits depending on what you decide to do is simply What the Bleep? level stupidity. Those in the physics and science communication communities who care about the public understanding of quantum mechanics should think hard about what they can do to deal with this situation. They may however come to the same conclusion I’ve just reached: best to ignore him, which I’ll try to do from now on.

@philipthrift 

 

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[Bruno Marchal]

On 17 Sep 2019, at 04:22, Bruce Kellett <bhkel...@gmail.com> wrote:

On Tue, Sep 17, 2019 at 12:19 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

Agnostic, Mind-Brain thing is good with me. According to a brief article, some theorists have mused about consciousness in the absence of matter. Check it out. It will either be a good laugh for you, but once in a while, the 'lofty' stuff works for me. 

As soon as the article mentioned Deepak Chopra I knew that we were deep into woo-woo territory….

I agree.

Yet, to identify mind and brain is still a sort of Woo-Woo act, needing some ontological substance, and making Mechanism false (and thus Darwin, Molecular biology, etc, unless you add non Turing emulable things there, just to save an ontological substance, which is a bit of wishful thinking). 

But consciousness, like numbers are not made of quark, and biology favours strongly mechanism on non-mechanism. Driesch defended the élan vital due to Descartes inability to solve the reproduction of machine problem, but this has been solved technically by Molecular Biology, and conceptually by Kleene’s second recursion theorem. No matter or substance involved there.

Bruno

Bruce

 

From: Bruce Kellett <bhkel...@gmail.com>

On Tue, Sep 17, 2019 at 10:39 AM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

It would be (will be?) interesting when we achieve this. Serious, academic bench computer scientists are actively working on variations of machine intelligence to make this happen, money to be made. Are you stating that making a hyper-smart machine is impossible?

No, I am agnostic about the possibility. Certainly I am not a Cartesian dualist -- mind-brain identity is the thing.....

Bruce

 

Are you a spiritualist? A Cartesian dualist imputing a magic substance? :-) 

From: Bruce Kellett <bhkel...@gmail.com>

On Tue, Sep 17, 2019 at 6:44 AM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

 

So, if we develop AI to come up with new, better, equations, this would be good with you, because, non-human? 

Perhaps he could usefully have added: "nor to be in perfect harmony with any humanly devised equation."

Bruce

Go for it, man! First develop your super-intelligent AI.......... And then see if the world conforms to its predictions......

Bruce

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[Bruno Marchal]

Not if you shake the coin long enough. The Heisenberg uncertainties can add up, and eventually you can the two (times aleph_1) histories/worlds.

But if you flip the coin without shaking much, that will not lead to any superposition.

You don’t need to isolate the coin, note. (Just to prevent a common mistake here too).

Bruno

Bruce 

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[Brent Meeker]

There's no other source of inherent randomness.  There's plenty of randomness from ignorance and there's randomness from the past light cone.

Brent

[Lawrence Crowell]

Event horizons may play a randomizing role. Quantum gravitation is likely a nonlocal field theory, whereas other gauge fields are localized as oscillators on spatial surfaces. Of course this is probably a manifestation of how spacetime is emergent from large Qu-Nit entanglements.

LC 

[Philip Thrift]

That 

       Quantum gravitation is likely a nonlocal field theory

shows how physics has become like a religion (as Feyerabend criticized).

@philipthrift

[Bruno Marchal]

Which one precisely? Gleason theorem is enough, and it requires only that the Hilbert space is not too much low dimensional (>= 3).

Then, with Mechanism, the “many” is as natural than “many numbers” or “many computations”. “Many” is conceptually simpler that any particular non trivial thing, usually.

And then, the collapse needed to avoid the MWI (or the many histories) reintroduce dualism, and asks for a non mechanist theory of mind, which nobody has found yet, except for the usual fairy tales.

Bruno

Bruce 

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[Bruno Marchal]

All computational theory (quantum or not) implies the "Many Computations”. 

Bruno

@philipthrift

 

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[Bruno Marchal]

That is the argument of incredulity. But is it so ridiculous? The very starting motto of this list was that “all things” is simpler than one thing, or a finite number of things. There are many people, many planets, many solar (star) systems, many galaxies, … so why not many physical universes/histories?

and by simply assuming the wf is irrelevant after the measurement occurs, makes it all go away? AG 

This makes sense for all practical purposes, but we can’t dispose so easily from what the theory tells us when we search to understand instead of merely applying tools.

Bruno

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[Bruno Marchal]

On 18 Sep 2019, at 00:45, Bruce Kellett <bhkel...@gmail.com> wrote:

On Wed, Sep 18, 2019 at 2:52 AM smitra <smi...@zonnet.nl> wrote:

On 17-09-2019 09:16, Bruce Kellett wrote:
> On Tue, Sep 17, 2019 at 5:08 PM Alan Grayson <agrays...@gmail.com>
> wrote:
>
> I know. I was just being illustrative. But note that Carroll says much
> the same thing when he says worlds are created when you make a left or
> right turn, or flip a coin (or some equivalent analogy). AG
>
> And that is where Sean slips inevitably into woo-woo.
>
No, this is a rather solid result from assuming the validity of the
Schrodinger equation:

https://arxiv.org/abs/1212.0953

"We argue using simple models that all successful practical uses of
probabilities originate in quantum fluctuations in the microscopic
physical world around us, often propagated to macroscopic scales. Thus
we claim there is no physically verified fully classical theory of
probability. We comment on the general implications of this view, and
specifically question the application of classical probability theory to
cosmology in cases where key questions are known to have no quantum
answer. We argue that the ideas developed here may offer a way out of
the notorious measure problems of eternal inflation."

They can argue this, but that falls far short of a demonstration that new branches split off for every decision we make.

I agree with you. Decision are very plausibly classical. Actually, even more so if the brain was a quantum computer, as we would use quantum effect to enhance the classical probabilities of getting what we search. 

In general, decisions are not choices from a set of possibilities in superposition, which would be the only way in which the proposal could make any sense.

OK.

Bruno

Bruce 

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[Bruno Marchal]

That is meaningful …. only in the MW.

Bruno

@philipthrift 

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[Bruno Marchal]

Yes. As I said, you need to shaken the coin a lot to get the tail + head superpositions. But there is no need to isolate the coin at all. It will decohere, but the observers too, and this leads to the MW or Many histories.

Bruno



>
> Brent

>
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[Bruno Marchal]

How could ever something destroyed an entanglement? 

On the contrary, the entailment with an observer will just put the observer in a superposition state himself, and then assuming mechanism, you get the “illusion” of a collapse, without any need of collapse.

Everett “many-worlds” is just the rather natural (for monist at least) idea that a physicist obeys to the laws of physics.

Bruno

but exactly why that's the case remains obscure. And these entanglements also connect the micro to the macro. AG

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[Bruno Marchal]

Hmm… The classical division of the amoeba provides an example of first person randomness in nature, without the quantum, and indeed the quantum randomness becomes such first person randomness in the superposition (weighted by the amplitude of the wave, using Born rule (added or derived from Gleason’s theorem).

Bruno



>
> Saibal

>
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[Philip Thrift]

On Friday, September 20, 2019 at 7:39:14 AM UTC-5, Philip Thrift wrote:

On Friday, September 20, 2019 at 6:31:15 AM UTC-5, Bruno Marchal wrote:

On 17 Sep 2019, at 16:04, Philip Thrift <cloud...@gmail.com> wrote:

From a pragmatic perspective, I do not see any Everettian MW (theory, math, ideas, formulations, interpretations or whatever they want to call it) in computational quantum mechanics:

https://www.simonsfoundation.org/flatiron/center-for-computational-quantum-physics/software

If MW were important, it would be there.

All computational theory (quantum or not) implies the "Many Computations”. 

Bruno

I guess. But I was looking at the actual libraries of computational QM programming repositories, and there is a lot of Monte Carlo for example but nothing explicitly Many Worlds. 

In Sean Carroll's advocacy of Many Worlds:

https://www.preposterousuniverse.com/blog/2015/02/19/the-wrong-objections-to-the-many-worlds-interpretation-of-quantum-mechanics/

The people who object to MWI because of all those unobservable worlds aren’t really objecting to MWI at all; they just don’t like and/or understand quantum mechanics. Hilbert space is big, regardless of one’s personal feelings on the matter.

So in Sean's presentation, if you object to Many Worlds then you don't like/understand quantum mechanics.

[ But one could start instead with a (quantum) measure space: https://arxiv.org/abs/1002.0589 ]

When scientists proceed from the mathematics of any theory to an ontology of nature, they are being more of a religious guru than a scientific one.

@philipthrift

 

[Alan Grayson]

On Friday, September 20, 2019 at 6:01:41 AM UTC-6, Bruno Marchal wrote:

On 18 Sep 2019, at 21:15, Alan Grayson <agrays...@gmail.com> wrote:

On Wednesday, September 18, 2019 at 3:01:23 AM UTC-6, Bruce wrote:

On Wed, Sep 18, 2019 at 6:33 PM Alan Grayson <agrays...@gmail.com> wrote:

On Tuesday, September 17, 2019 at 1:08:16 AM UTC-6, Alan Grayson wrote:

On Tuesday, September 17, 2019 at 1:02:39 AM UTC-6, Bruce wrote:

On Tue, Sep 17, 2019 at 4:51 PM Alan Grayson <agrays...@gmail.com> wrote:

On Monday, September 16, 2019 at 3:54:46 PM UTC-6, John Clark wrote:

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

Many "odd" results are now mainstream, but MWI is bridge too far, way too far IMO. Why don't you just accept that the wf is simply irrelevant after the measurement occurs like in the horserace example?. Here, there's no collapse, no many worlds, no need to explain where the energy comes from which defines these worlds, and so forth? AG

Except that horses and horse races do not interfere (except in Australia, where several jockeys and trainers have recently been suspended for unauthorised interference -- but that is a different matter!)

Bruce

I know. I was just being illustrative. But note that Carroll says much the same thing when he says worlds are created when you make a left or right turn, or flip a coin (or some equivalent analogy). AG 

But suppose you flip a coin and while it's in the air, you write its wf. Since the prevailing belief is that all objects are quantum objects, why can't one suppose that the two terms in the superposition, head and tail, manifest quantum interference? AG 

Why can't one observe a superposition of a live cat and a dead cat? The problem is decoherence, and coin tosses are totally decohered -- no quantum superpositions left. So one is reduced to standard classical ignorance probability .

Bruce

Yes, you're getting to the core of the issue, and there's more here then (than?) meets the eye, at least mine. It seems that quantum superpositions depend on isolation and are destroyed by entanglements,

How could ever something destroyed an entanglement? 

I think any entanglement can be destroyed, or undone, by isolating a system. AG 

On the contrary, the entailment with an observer will just put the observer in a superposition state himself, and then assuming mechanism, you get the “illusion” of a collapse, without any need of collapse.

Everett “many-worlds” is just the rather natural (for monist at least) idea that a physicist obeys to the laws of physics.

Bruno

but exactly why that's the case remains obscure. And these entanglements also connect the micro to the macro. AG

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[John Clark]

On Thu, Sep 19, 2019 at 12:07 PM Bruno Marchal <mar...@ulb.ac.be> wrote:

> Our decision are classical, so (even in the Everett quantum world) they do not "create new worlds”.
I suspect Sean Carroll is quoted out of context, as indeed that is a mistake (a common one).

If there is one theme running through Sean Carroll's new book it's that nothing is classical and everything is  Quantum Mechanical, and the deterministic wavefunction of the Multiverse can be thought of as a wavefunction of wavefunctions not of worlds because even the concept of a world is just a human approximation. He suggests our current difficulties in finding a theory that goes beyond General Relativity is that we're trying to find something to stick onto it to make it Quantum Mechanical but nature didn't start classical, it was Quantum Mechanical from day one, if there was a day one and there may not have been.

John K Clark

 

[Bruce Kellett]

Has Carroll forgotten about effective theories? Even QFT is just an "effective theory". We use classical approximations to quantum mechanics because they work -- not for ideological or philosophical reasons.

Bruce 

[John Clark]

On Sat, Sep 21, 2019 at 7:29 AM Bruce Kellett <bhkel...@gmail.com> wrote:

> Has Carroll forgotten about effective theories? Even QFT is just an "effective theory". We use classical approximations to quantum mechanics because they work -- not for ideological or philosophical reasons.

Read the book, Carroll devote several chapters to those exact topics.

 John k Clark

[Alan Grayson]

On Monday, September 16, 2019 at 12:41:41 AM UTC-6, John Clark wrote:

Sean Carroll: Universe a 'tiny sliver' of all there is

John K Clark

I think the enforcers of "right speech" deleted my post which stated that the MWI was "hubris on steroids", since it means that any fool can go into a lab, do a double slit experiment, and create possibly uncountable worlds replete with stars, galaxies and life forms. This idea is probably worse than the egregeous overestimate, by 120 orders of magnitude. of the EM vacuum energy.  AG

[Philip Thrift]

I doubt Sean has any better "approach" that combines QM and GR than any of the many others. 

But if you go on a well-marketed book tour with a well-written book (and fiction can be well-written) then you gan get the science-interested public to think that it is the best approach that exists today.

@philipthrift

[smitra]

On 21-09-2019 14:50, Philip Thrift wrote:
> On Saturday, September 21, 2019 at 7:32:43 AM UTC-5, John Clark wrote:
>
>> On Sat, Sep 21, 2019 at 7:29 AM Bruce Kellett <bhkel...@gmail.com>
>> wrote:
>>

>>> _> Has Carroll forgotten about effective theories? Even QFT is

>>> just an "effective theory". We use classical approximations to
>>> quantum mechanics because they work -- not for ideological or

>>> philosophical reasons._

>>
>> Read the book, Carroll devote several chapters to those exact
>> topics.
>>
>> John k Clark
>
> I doubt Sean has any better "approach" that combines QM and GR than
> any of the many others.
>
> But if you go on a well-marketed book tour with a well-written book
> (and fiction can be well-written) then you gan get the
> science-interested public to think that it is the best approach that
> exists today.
>

Combining QM with GR is trivial, there is no problem here. The problem
is with regularizing quantum gravity. A non-renormalizable theory is not
per se wrong, just inconvenient for physicists who want to do
computations with it. If you write down some arbitrary field theory
formulated on a lattice and you consider the effective field theory at
some large length scale, the non-renormalizable terms become very small.
So, the fact that gravity is very weak could well be due to it being
non-renormalizable. This is a point that's sometimes made in books on
renormalization group methods as applied in statistical physics. In that
context non-renormalizable terms are a normal occurrence.

Saibal

[spudb...@aol.com]

I downloaded Carroll's book a few days ago. Will read it this weekend. Current physics research indicates that everything is entangled, which of course is the quantum, but the thinking of physicists is that every law emerged from a basic soup of entanglement. 

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.

[spudb...@aol.com]

QFT is an effective theory that explain neural activity too. Yes, to Penrose's microtubules, no, to Tegmark's objection that all quantum processes need to be done via sub-zero temps. What the implications for life are using this way of thinking, if anything, are, as always open to speculation. 

-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: everything-list <everyth...@googlegroups.com>
Sent: Sat, Sep 21, 2019 8:32 am
Subject: Re: Sean Carroll: Universe a 'tiny sliver' of all there is

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[Bruno Marchal]

On 20 Sep 2019, at 14:57, Philip Thrift <cloud...@gmail.com> wrote:

On Friday, September 20, 2019 at 7:39:14 AM UTC-5, Philip Thrift wrote:

On Friday, September 20, 2019 at 6:31:15 AM UTC-5, Bruno Marchal wrote:

On 17 Sep 2019, at 16:04, Philip Thrift <cloud...@gmail.com> wrote:

From a pragmatic perspective, I do not see any Everettian MW (theory, math, ideas, formulations, interpretations or whatever they want to call it) in computational quantum mechanics:

https://www.simonsfoundation.org/flatiron/center-for-computational-quantum-physics/software

If MW were important, it would be there.

All computational theory (quantum or not) implies the "Many Computations”. 

Bruno

I guess. But I was looking at the actual libraries of computational QM programming repositories, and there is a lot of Monte Carlo for example but nothing explicitly Many Worlds. 

In Sean Carroll's advocacy of Many Worlds:

https://www.preposterousuniverse.com/blog/2015/02/19/the-wrong-objections-to-the-many-worlds-interpretation-of-quantum-mechanics/

The people who object to MWI because of all those unobservable worlds aren’t really objecting to MWI at all; they just don’t like and/or understand quantum mechanics. Hilbert space is big, regardless of one’s personal feelings on the matter.

So in Sean's presentation, if you object to Many Worlds then you don't like/understand quantum mechanics.

Quantum Mechanics is “many-world” right at the start, (like Mechanism). That is why the founders have add the collapse postulate, but that leads all the time to non-sense, or to proposal that quantum mechanics is wrong.

[ But one could start instead with a (quantum) measure space: https://arxiv.org/abs/1002.0589 ]

When scientists proceed from the mathematics of any theory to an ontology of nature, they are being more of a religious guru than a scientific one.

That is correct. Even a theorem in the theology of the machine, ironically perhaps.

But that is valid for a universes, whatever the cardinal a is, from zero to the cardinal of Laver …

Now when doing metaphysics seriously, the number of universe and histories become a subject of matter, and we can try different theories, but with mechanism, it always multiplied the observers, which is annoying or pleasing according to our taste, but have no voice in the matter of searching the truth. 

As we cannot observe any “universe”, the consequence of the metaphysical cardinal of universes must be indirect, of course. With mechanism, we get 0 universes, even 0 token, but infinitely many types, and when universal type meet universal type, they multiply innumerably. 

Bruno

@philipthrift

 

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[Bruno Marchal]

On 20 Sep 2019, at 22:43, Alan Grayson <agrays...@gmail.com> wrote:

On Friday, September 20, 2019 at 6:01:41 AM UTC-6, Bruno Marchal wrote:

On 18 Sep 2019, at 21:15, Alan Grayson <agrays...@gmail.com> wrote:

On Wednesday, September 18, 2019 at 3:01:23 AM UTC-6, Bruce wrote:

On Wed, Sep 18, 2019 at 6:33 PM Alan Grayson <agrays...@gmail.com> wrote:

On Tuesday, September 17, 2019 at 1:08:16 AM UTC-6, Alan Grayson wrote:

On Tuesday, September 17, 2019 at 1:02:39 AM UTC-6, Bruce wrote:

On Tue, Sep 17, 2019 at 4:51 PM Alan Grayson <agrays...@gmail.com> wrote:

On Monday, September 16, 2019 at 3:54:46 PM UTC-6, John Clark wrote:

On Mon, Sep 16, 2019 at 9:22 AM Alan Grayson <agrays...@gmail.com> wrote:

> When physics began to give non-intuitive results, in QM and Relativity, people when overboard. Now any patently absurd result finds its justification among true believers.

And in this context "patently absurd" means odd, not logically contradictory not paradoxical not contrary to experimental results, just odd. But as far as we know there is no law that says nature can't behave in ways that humans find odd.

Many "odd" results are now mainstream, but MWI is bridge too far, way too far IMO. Why don't you just accept that the wf is simply irrelevant after the measurement occurs like in the horserace example?. Here, there's no collapse, no many worlds, no need to explain where the energy comes from which defines these worlds, and so forth? AG

Except that horses and horse races do not interfere (except in Australia, where several jockeys and trainers have recently been suspended for unauthorised interference -- but that is a different matter!)

Bruce

I know. I was just being illustrative. But note that Carroll says much the same thing when he says worlds are created when you make a left or right turn, or flip a coin (or some equivalent analogy). AG 

But suppose you flip a coin and while it's in the air, you write its wf. Since the prevailing belief is that all objects are quantum objects, why can't one suppose that the two terms in the superposition, head and tail, manifest quantum interference? AG 

Why can't one observe a superposition of a live cat and a dead cat? The problem is decoherence, and coin tosses are totally decohered -- no quantum superpositions left. So one is reduced to standard classical ignorance probability .

Bruce

Yes, you're getting to the core of the issue, and there's more here then (than?) meets the eye, at least mine. It seems that quantum superpositions depend on isolation and are destroyed by entanglements,

How could ever something destroyed an entanglement? 

I think any entanglement can be destroyed, or undone, by isolating a system. AG 

By isolating the system, you can avoid “future entanglement”, and dismiss older, but when an entanglement is made, without collapse, by linearity of both the evolution and the tensor product, it is will last forever.

Bruno

On the contrary, the entailment with an observer will just put the observer in a superposition state himself, and then assuming mechanism, you get the “illusion” of a collapse, without any need of collapse.

Everett “many-worlds” is just the rather natural (for monist at least) idea that a physicist obeys to the laws of physics.

Bruno

but exactly why that's the case remains obscure. And these entanglements also connect the micro to the macro. AG

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[Bruno Marchal]

And that is one hundred percent coherent with the quantum physics of the unievsdral Turing machine. Gold you like the relativisation of the concept of world (which for a logician is only an element of a set).

Bruno

John K Clark

 

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[Bruno Marchal]

On 21 Sep 2019, at 19:22, spudboy100 via Everything List <everyth...@googlegroups.com> wrote:

I downloaded Carroll's book a few days ago. Will read it this weekend. Current physics research indicates that everything is entangled, which of course is the quantum,

Or any universal machinery seen from inside (up to some unsolved problem, to be honest)

but the thinking of physicists is that every law emerged from a basic soup of entanglement. 

They get nearer the first person plural phenomenological physics as implied by mechanism, with a simple notion of entanglement (sharing the annihilation box).

Bruno

-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: everything-list <everyth...@googlegroups.com>
Sent: Sat, Sep 21, 2019 7:10 am
Subject: Re: Sean Carroll: Universe a 'tiny sliver' of all there is

On Thu, Sep 19, 2019 at 12:07 PM Bruno Marchal <mar...@ulb.ac.be> wrote:

> Our decision are classical, so (even in the Everett quantum world) they do not "create new worlds”.
I suspect Sean Carroll is quoted out of context, as indeed that is a mistake (a common one).

If there is one theme running through Sean Carroll's new book it's that nothing is classical and everything is  Quantum Mechanical, and the deterministic wavefunction of the Multiverse can be thought of as a wavefunction of wavefunctions not of worlds because even the concept of a world is just a human approximation. He suggests our current difficulties in finding a theory that goes beyond General Relativity is that we're trying to find something to stick onto it to make it Quantum Mechanical but nature didn't start classical, it was Quantum Mechanical from day one, if there was a day one and there may not have been.

John K Clark

 

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[Philip Thrift]

On Monday, September 23, 2019 at 1:30:35 PM UTC-5, Bruno Marchal wrote:

On 20 Sep 2019, at 14:57, Philip Thrift <cloud...@gmail.com> wrote:

On Friday, September 20, 2019 at 7:39:14 AM UTC-5, Philip Thrift wrote:

On Friday, September 20, 2019 at 6:31:15 AM UTC-5, Bruno Marchal wrote:

On 17 Sep 2019, at 16:04, Philip Thrift <cloud...@gmail.com> wrote:

From a pragmatic perspective, I do not see any Everettian MW (theory, math, ideas, formulations, interpretations or whatever they want to call it) in computational quantum mechanics:

https://www.simonsfoundation.org/flatiron/center-for-computational-quantum-physics/software

If MW were important, it would be there.

All computational theory (quantum or not) implies the "Many Computations”. 

Bruno

I guess. But I was looking at the actual libraries of computational QM programming repositories, and there is a lot of Monte Carlo for example but nothing explicitly Many Worlds. 

In Sean Carroll's advocacy of Many Worlds:

https://www.preposterousuniverse.com/blog/2015/02/19/the-wrong-objections-to-the-many-worlds-interpretation-of-quantum-mechanics/

The people who object to MWI because of all those unobservable worlds aren’t really objecting to MWI at all; they just don’t like and/or understand quantum mechanics. Hilbert space is big, regardless of one’s personal feelings on the matter.

So in Sean's presentation, if you object to Many Worlds then you don't like/understand quantum mechanics.

Quantum Mechanics is “many-world” right at the start, (like Mechanism). That is why the founders have add the collapse postulate, but that leads all the time to non-sense, or to proposal that quantum mechanics is wrong.

[ But one could start instead with a (quantum) measure space: https://arxiv.org/abs/1002.0589 ]

When scientists proceed from the mathematics of any theory to an ontology of nature, they are being more of a religious guru than a scientific one.

That is correct. Even a theorem in the theology of the machine, ironically perhaps.

But that is valid for a universes, whatever the cardinal a is, from zero to the cardinal of Laver …

Now when doing metaphysics seriously, the number of universe and histories become a subject of matter, and we can try different theories, but with mechanism, it always multiplied the observers, which is annoying or pleasing according to our taste, but have no voice in the matter of searching the truth. 

As we cannot observe any “universe”, the consequence of the metaphysical cardinal of universes must be indirect, of course. With mechanism, we get 0 universes, even 0 token, but infinitely many types, and when universal type meet universal type, they multiply innumerably. 

Bruno

A review just out by Tom Siegfried on Carroll's Many Worlds book

 https://www.sciencenews.org/article/sean-carroll-something-deeply-hidden-quantum-physics-many-worlds

has this: 

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes. And as Carroll admits, the decoherence process does not require belief in the reality of the other branches. It just seems to him (and many others) to be the most elegant explanation for quantum mysteries.

This is sad and funny. The others don't have a big book tour.

I'm pretty much in agreement now more than ever with Alan G. here. The Many Worlds advocates are in some sort of "world" of reality denial. 

@philipthrift

[Brent Meeker]

On 9/23/2019 11:32 AM, Bruno Marchal wrote:
> By isolating the system, you can avoid “future entanglement”, and
> dismiss older, but when an entanglement is made, without collapse, by
> linearity of both the evolution and the tensor product, it is will
> last forever.

Did you read Carroll's explication of the quantum erasure experiment. 
He's showing that it works by erasing the entanglement.

http://www.preposterousuniverse.com/blog/2019/09/21/the-notorious-delayed-choice-quantum-eraser/

Brent

[Brent Meeker]

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying".  If you're only interested in saving the phenomenon you can explain the apparent collapse by decoherence and not say anything about the other results that were predicted.  Chris Fuchs explains quantum phenomenon without either collapse or multiple universes. 

Brent

[Philip Thrift]

This is better?

https://www.wired.com/2015/06/private-view-quantum-reality/

Quantum Bayesianism, or QBism as Fuchs now calls it, solves many of quantum theory’s deepest mysteries. Take, for instance, the infamous “collapse of the wave function,” wherein the quantum system inexplicably transitions from multiple simultaneous states to a single actuality. According to QBism, the wave function’s “collapse” is simply the observer updating his or her beliefs after making a measurement. Spooky action at a distance, wherein one observer’s measurement of a particle right here collapses the wave function of a particle way over there, turns out not to be so spooky—the measurement here simply provides information that the observer can use to bet on the state of the distant particle, should she come into contact with it. But how, we might ask, does her measurement here affect the outcome of a measurement a second observer will make over there? In fact, it doesn’t. Since the wavefunction doesn’t belong to the system itself, each observer has her own. My wavefunction doesn’t have to align with yours.

@philipthrift 

[Alan Grayson]

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG 

[Brent Meeker]

On 9/23/2019 6:24 PM, Alan Grayson wrote:

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG

True.  But I'm still waiting for pt to quote this expert saying he explains quantum phenomena without MW.  He keeps implying it's Zurek, but I just read Zurek's paper on quantum Darwinism again and ISTM Zurek is assuming MWI throughout.  QD is just his solution to the basis problem.

Brent

If you're only interested in saving the phenomenon you can explain the apparent collapse by decoherence and not say anything about the other results that were predicted.  Chris Fuchs explains quantum phenomenon without either collapse or multiple universes. 

Brent

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[Philip Thrift]

On Monday, September 23, 2019 at 8:44:39 PM UTC-5, Brent wrote:

On 9/23/2019 6:24 PM, Alan Grayson wrote:

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG

True.  But I'm still waiting for pt to quote this expert saying he explains quantum phenomena without MW.  He keeps implying it's Zurek, but I just read Zurek's paper on quantum Darwinism again and ISTM Zurek is assuming MWI throughout.  QD is just his solution to the basis problem.

Brent

Zurek is not on a book tour, nor does he tweet, but after the rollout of Carroll's book, one can only conclude:

          Many Worlds is religion, not science.

@philipthrift 

[Alan Grayson]

 Right. You'll notice how my comment that the MWI is tantamount to "hubris on steroids" was never responded to. Hopefully, he'll be denied tenure, and his book and personage can go into the dustbin of history, where it belongs. AG 

[Philip Thrift]

I can't believe (well, I guess I can believe) the number of physicist who think MWI is a valuable contribution to science.  If you tell them otherwise they they you that you don't understand physics. Many Worlds is "in the math" (as Sean Carroll claims) so it must be true.

They engage in magical thinking, but think they are doing science. Amazing.

@philipthrift

[Bruno Marchal]

The term “universe” is not well defined, and I have no clue how we can assume QM, and claim that decoherence eliminate the “mutiple histories”. That seems like pure magic to me.

Also, I don’t need quantum mechanics to believe in all computations, just Church’s thesis to be sure to get really *all* of them by the universal dovetailing or the true sigma_1 sentence.

Arithmetic, or any combinatorial algebra, admits canonical “multiple histories” interpretation, that no universal machine can miss, except for a finite time (number of steps).

It just seems to him (and many others) to be the most elegant explanation for quantum mysteries.

This is sad and funny. The others don't have a big book tour.

I'm pretty much in agreement now more than ever with Alan G. here. The Many Worlds advocates are in some sort of "world" of reality denial. 

Not sure what you mean here.

Bruno

@philipthrift

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[Bruno Marchal]

I might take more time, but I don’t see any erasure of entanglement, once there is no collapse. There is only a local or relative erasure of entanglement, like in entanglement swapping. But I hope I will find some time to read that text more carefully.

Bruno




> Brent

>
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[Bruno Marchal]

On 24 Sep 2019, at 03:24, Alan Grayson <agrays...@gmail.com> wrote:

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG 

… if you believe in the “ontological Occam’s Razor” i.e. simplest reality (OK, but then reality is just arithmetic)

Then if you believe in the conceptual Occam razor (i.e. simplest theory, less axioms), then that favours both arithmetic and, in physics, no-collapse.

There is a Galois connection between theories and models (like in algebra). 

The more axioms you have, the less models satisfied the theory, the less axioms you have, the more models satisfy the theory. Axioms are just logical equation, and you can see a model like if it was a sort of variety obeying equations, there too, the more equation you have, the less variety obeys to them taken together, and vice versa.

The original Occam’s razor is about the axioms, not the models. If I remember correctly.

Note that once a theory is Turing universal, it has an infinity of non isomorphic models, but their relative measure can be different.

Bruno

If you're only interested in saving the phenomenon you can explain the apparent collapse by decoherence and not say anything about the other results that were predicted.  Chris Fuchs explains quantum phenomenon without either collapse or multiple universes. 

Brent

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[Bruno Marchal]

On 24 Sep 2019, at 03:44, 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:

On 9/23/2019 6:24 PM, Alan Grayson wrote:

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG

True.  But I'm still waiting for pt to quote this expert saying he explains quantum phenomena without MW.  He keeps implying it's Zurek, but I just read Zurek's paper on quantum Darwinism again and ISTM Zurek is assuming MWI throughout.  QD is just his solution to the basis problem.

I agree. The very idea of decoherence is already in Everett, and Zurek used it to solve the basis problem (rather successfully Imo).

Bruno

Brent

If you're only interested in saving the phenomenon you can explain the apparent collapse by decoherence and not say anything about the other results that were predicted.  Chris Fuchs explains quantum phenomenon without either collapse or multiple universes. 

Brent

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[Bruno Marchal]

The statement that Many-Worlds is true is pseudo-religion/science, OK. But the statement asserting that it is true that there is one unique world, or k worlds (any k cardinal), is pseudo-religion/science as much,  too.

Bruno

@philipthrift 

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[Bruno Marchal]

The many-histories is a logical consequence of the theory. To assume a theory without accepting its consequence is just wrong, or irrational.

Bruno

@philipthrift

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[Philip Thrift]

On Tuesday, September 24, 2019 at 6:23:10 AM UTC-5, Bruno Marchal wrote:

On 24 Sep 2019, at 10:22, Philip Thrift <cloud...@gmail.com> wrote:

On Tuesday, September 24, 2019 at 3:05:39 AM UTC-5, Alan Grayson wrote:

On Tuesday, September 24, 2019 at 1:36:42 AM UTC-6, Philip Thrift wrote:

On Monday, September 23, 2019 at 8:44:39 PM UTC-5, Brent wrote:

On 9/23/2019 6:24 PM, Alan Grayson wrote:

On Monday, September 23, 2019 at 3:44:49 PM UTC-6, Brent wrote:

On 9/23/2019 11:59 AM, Philip Thrift wrote:

But other quantum experts use decoherence to explain quantum phenomena without invoking multiple universes.

"Without invoking" doesn't mean "denying". 

It does if you believe in applying Occam's Razor. AG

True.  But I'm still waiting for pt to quote this expert saying he explains quantum phenomena without MW.  He keeps implying it's Zurek, but I just read Zurek's paper on quantum Darwinism again and ISTM Zurek is assuming MWI throughout.  QD is just his solution to the basis problem.

Brent

Zurek is not on a book tour, nor does he tweet, but after the rollout of Carroll's book, one can only conclude:

          Many Worlds is religion, not science.

@philipthrift 

 Right. You'll notice how my comment that the MWI is tantamount to "hubris on steroids" was never responded to. Hopefully, he'll be denied tenure, and his book and personage can go into the dustbin of history, where it belongs. AG 

I can't believe (well, I guess I can believe) the number of physicist who think MWI is a valuable contribution to science.  If you tell them otherwise they they you that you don't understand physics. Many Worlds is "in the math" (as Sean Carroll claims) so it must be true.

They engage in magical thinking, but think they are doing science. Amazing.

The many-histories is a logical consequence of the theory. To assume a theory without accepting its consequence is just wrong, or irrational.

Bruno

Which specific theory formulation are you talking about?

There's quantum measure theory:

Axioms in section 2: https://arxiv.org/pdf/1002.0589.pdf

But I don't see where Many Worlds as Carroll presents them are necessarily implied by these axioms.

@philipthrift

 

[Brent Meeker]

But he writes papers.  "Quantum Theory of the Classical: Quantum Jumps, Born’s Rule, and Objective Classical Reality via Quantum Darwinism" He seems ambivalent about multiple worlds, using Everett's relative state, but saying the branches need not be equally real:

Existential interpretation of quantum theory assigns “relatively objective existence” (Zurek, 1998b) – key to effective classicality – to widely broadcast quantum states. It is obviously consistent with the relative state interpretation: Redundancy of records disseminated throughout the environment supplies a natural definition of branches that are classical in the sense that an observer can find out macroscopic features of his branch and stay on it, rather than “cut off the branch he is sitting on” with his measurement.

Zurek takes an operational view of what is "real" and so many quantum states are not real, because they cannot be determined.  He apparently thinks that all the branches of MWI cannot be real because there is not enough information capacity in the universe to determine them all.  But in his examples he is always concerned with the density matrix: objectively determining what the pointer variables can be and showing how einselection implies a probability measure.  So his attitude is like Omnes...once you have a diagonal density matrix you have a probabilistic theory and so it predicts probabilities.

So maybe I was wrong about whether Zurek would say there was a branch on which Neanderthals still existed.  He might say there's not enough room for the universe to carry that information.

Brent

          Many Worlds is religion, not science.

@philipthrift 

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[Brent Meeker]

Sounds like the evangelicals of one religion attacking another.

Brent

[Brent Meeker]

On 9/24/2019 8:44 AM, Philip Thrift wrote:
> The many-histories is a logical consequence of the theory. To assume a
> theory without accepting its consequence is just wrong, or irrational.

The theory, quantum mechanics, is probabilistic.

Brent

[Philip Thrift]

I didn't write that. Obviously.

I would write pretty much its contradiction. 

@philipthrift

[Brent Meeker]

Sorry, that was Bruno.

Brent

[John Clark]

On Mon, Sep 23, 2019 at 6:47 PM Philip Thrift <cloud...@gmail.com> wrote:

> Quantum Bayesianism, or QBism as Fuchs now calls it, solves many of quantum theory’s deepest mysteries.

It seems to me the Copenhagen Interpretation of Quantum Mechanics is just the Shut Up And Calculate interpretation with a few superficial cosmetic tweaks thrown in, and Quantum Bayesianism is just a new name for the Copenhagen Interpretation with a few more superficial cosmetic tweaks; none of them even try to provide any sort of ontology. 

> Since the wavefunction doesn’t belong to the system itself, each observer has her own. My wavefunction doesn’t have to align with yours.

If you and I do the 2 slit experiment we both calculate the same wavefunction so when we square the absolute value we both get the same probability and both either see or don't see an interference pattern depending on how the experiment is setup. 

 John K Clark

[Bruno Marchal]

Any formulation without physical wave reduction. Everett’s one, for example. With our without the Born rules (the fact that they are derivable or not is not much relevant, as you know I do think that Gleason theorem makes them derivable, but that is not relevant here).

There's quantum measure theory:

Axioms in section 2: https://arxiv.org/pdf/1002.0589.pdf

That is a very interesting paper.

But I don't see where Many Worlds as Carroll presents them are necessarily implied by these axioms.

They are implied by the SWE, or Dirac. May be the best argument is that the founder have invented the notion of collapse because that is the only way to avoid them.

QM predict that I f I put cat in the state dead + alive, and if I look at the cat living/dead state, I will put myself in the state seeing-the-cat-dead + seeing the cat-alive, and without a wave reduction postulate, no branche of that superposition can be made more real or less real than the other. 

I don’t need quantum mechanics to bet on many-world: like Deutsch I consider that the two slit experiment is enough.

And, as you know, I don’t need this either. I don’t assume any worlds, I do prove that arithmetic entails the existence of all computation, and that the many-worlds aspect of the physical reality is the “natural” way the universal machine/number see arithmetic from “inside arithmetic” (i.e. inside the standard model of arithmetic).

Bruno

@philipthrift

 

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[Bruno Marchal]

Yes. And your comment is OK. If a theory is probabilistic, and if the probability are not drivable by classical ignorance in a unique computation, then it has to use classical ignorance on some classical extension of its domain, and that is what happens when we accept all the terms in the superposition have a physical role, although negligible if the amplitude is (relatively) small.

Bruno

Brent

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[Brent Meeker]

But if I know that the "which way" has been measured and you don't, we get different answers.

Brent