Why are laws of physics stable?

[Tomas Pales]

Recently I've been thinking about why we live in a world with stable laws of physics, out of the plethora of all possible worlds. Why does the sun rise every day, why is the intensity of the Earth's gravitational field constant, why do causal relations ("the constant conjunction between causes and effects", as Hume put it) persist in time?

While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future. In fact, it may seem that such a stability is very unlikely because there are many ways our world could be in the future but only one way in which it would be a deterministic extension of the world it has been until now.

But in the book Theory of Nothing by Russell Standish I have found an argument that seems to claim the opposite (if I understand it correctly): given the way our world has been until now, this world is more simple if its regularities (such as laws of physics) continue than if they are discontinued, and simple worlds are more likely (more frequent in the collection of all possible worlds) than more complex worlds. (A simpler property is instantiated in a greater number of possible worlds than a more complex property.) Such a deterministic world is fully defined by some initial conditions and laws of physics, while a world whose regularity is discontinued at some point would need an additional property that would define the discontinuation and thereby make the world more complex.

Can it work like that? If so, I guess the probability that the laws remain stable is growing with the time that they have actually been stable. So now, after more than 13 billion years of stable laws of physics in our universe, is the probability that they remain stable overwhelmingly high (practically 100%)?

Here is a link to the book:

https://www.hpcoders.com.au/theory-of-nothing.pdf

(the persistence of laws of physics is discussed in chapter 4, parts 4.1 and 4.2)

[John Clark]

On Sat, Jun 26, 2021 at 7:43 AM Tomas Pales <litew...@gmail.com> wrote:

> While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future.

But the world is not stable. The universe looked very different 13 billion years ago than it does now because space is not only expanding, it's accelerating; and Black Holes evaporate eventually, they are not stable, and there are theoretical reasons to suspect protons are not stable either, although that has never been experimentally verified.  

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

aoz

[Jason Resch]

Hi Tomas,

The origin of laws, and why the universe follows them are great mysteries, but I think there's been some recent progess. I link to done other sources, in addition to Standish, that have worked towards an answer here:

https://alwaysasking.com/why-does-anything-exist/#Why_Laws

Jason

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[Brent Meeker]

On 6/26/2021 9:15 AM, John Clark wrote:

On Sat, Jun 26, 2021 at 7:43 AM Tomas Pales <litew...@gmail.com> wrote:

> While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future.

But the world is not stable.

But presumably the laws are stable.  Why?  Because that's the way we want them.  If they weren't stable (or even time invariant) we wouldn't call them laws of physics.  They'd be initial conditions or historical accidents.

Brent

The universe looked very different 13 billion years ago than it does now because space is not only expanding, it's accelerating; and Black Holes evaporate eventually, they are not stable, and there are theoretical reasons to suspect protons are not stable either, although that has never been experimentally verified.  

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

aoz

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[Tomas Pales]

On Saturday, June 26, 2021 at 6:16:06 PM UTC+2 johnk...@gmail.com wrote:

But the world is not stable. The universe looked very different 13 billion years ago than it does now because space is not only expanding, it's accelerating; and Black Holes evaporate eventually, they are not stable, and there are theoretical reasons to suspect protons are not stable either, although that has never been experimentally verified. 

But the laws of physics are apparently the same as they were 13 billion years ago: law of gravity, quantum mechanics, constants of nature.

[Tomas Pales]

On Saturday, June 26, 2021 at 7:26:01 PM UTC+2 Jason wrote:

Hi Tomas,

The origin of laws, and why the universe follows them are great mysteries, but I think there's been some recent progess. I link to done other sources, in addition to Standish, that have worked towards an answer here:

https://alwaysasking.com/why-does-anything-exist/#Why_Laws

Hi Jason,

Markus Muller seems to be making the same argument as Russell Standish: given the history of our universe it is more likely that we live in a universe where the past regularities will continue in the future because that makes the universe more simple. I am wondering what would be the probability (approximately) that the laws will remain the same as they have been?

[Tomas Pales]

On Saturday, June 26, 2021 at 11:36:47 PM UTC+2 Brent wrote:

But presumably the laws are stable.  Why?  Because that's the way we want them.  If they weren't stable (or even time invariant) we wouldn't call them laws of physics.  They'd be initial conditions or historical accidents.

But why do stable laws exist in our universe and what is the guarantee that they will continue to exist?

[Bruce Kellett]

Why should the universe be simple?

Bruce

[Tomas Pales]

On Sunday, June 27, 2021 at 1:44:32 AM UTC+2 Bruce wrote: 

 

Why should the universe be simple?

 Because simpler universes are more frequent and hence likely.

[Bruce Kellett]

How do you know that? Or is it just an arbitrary assumption? If it is just an assumption, your initial question is without content.

Bruce

[Tomas Pales]

On Sunday, June 27, 2021 at 1:54:29 AM UTC+2 Bruce wrote:

How do you know that? Or is it just an arbitrary assumption? If it is just an assumption, your initial question is without content.

It is in Russell's book on page 58 (universal prior), with reference to equation 2.1 (complexity).

[Bruce Kellett]

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Bruce

[Brent Meeker]

Notice that they don't exist in the sense you mean.  Newton's laws aren't around anymore.  Determinism is gone.  Space and time aren't separate.  So why do you think the laws are stable?  Because when we invent/discover a new law we necessarily demand that it also apply in all of the past.  We ignore the fact that we thought Newton's laws were stable before 1905. 

So there's no guarantee they will continue without change, but they will apply to the past.  How do we know?  We don't, but it's supported by induction.  Induction is a self-supporting form of inference.  If there is any effective form of empirical inference, then induction will do as well.

Brent

[Tomas Pales]

On Sunday, June 27, 2021 at 2:36:38 AM UTC+2 Bruce wrote:

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Note that the relation between simplicity and frequency is not Russell's speculation but a fact following from Kolmogorov's definition of complexity: simpler objects are more frequent than more complex objects because the same simpler object is contained in less simple objects. This fact is then used in Solomonoff's theory of induction:

"Solomonoff induction is an ideal answer to questions like "What probably comes next in the sequence 1, 1, 2, 3, 5, 8?" or "Given the last three years of visual data from this webcam, what will this robot probably see next?" or "Will the sun rise tomorrow?" Solomonoff induction requires infinite computing power, and is defined by taking every computable algorithm for giving a probability distribution over future data given past data, weighted by their algorithmic simplicity, and updating those weights by comparison to the actual data."

https://arbital.com/p/solomonoff_induction

[Tomas Pales]

On Sunday, June 27, 2021 at 3:53:18 AM UTC+2 Brent wrote:

Notice that they don't exist in the sense you mean.  Newton's laws aren't around anymore.

By laws I mean regularities in nature. The apple still falls down and not up or in random directions, so the regularity exists like it did in the days of Newton although Einstein's theory can describe this regularity more accurately than Newton's theory.

 

So there's no guarantee they will continue without change, but they will apply to the past.  How do we know?  We don't, but it's supported by induction.  Induction is a self-supporting form of inference.  If there is any effective form of empirical inference, then induction will do as well.

The problem is, why does induction work? Solomonoff tried to explain it with his theory of induction and that's what Russell's book refers to.

 

[Bruce Kellett]

On Sun, Jun 27, 2021 at 7:38 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:36:38 AM UTC+2 Bruce wrote:

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Note that the relation between simplicity and frequency is not Russell's speculation but a fact following from Kolmogorov's definition of complexity: simpler objects are more frequent than more complex objects because the same simpler object is contained in less simple objects.

This is only if everything is considered to be a bit string. There is no reason to suppose that this is true.

 

This fact is then used in Solomonoff's theory of induction:

"Solomonoff induction is an ideal answer to questions like "What probably comes next in the sequence 1, 1, 2, 3, 5, 8?" or "Given the last three years of visual data from this webcam, what will this robot probably see next?" or "Will the sun rise tomorrow?" Solomonoff induction requires infinite computing power, and is defined by taking every computable algorithm for giving a probability distribution over future data given past data, weighted by their algorithmic simplicity, and updating those weights by comparison to the actual data."

What a load of garbage! Science is not a matter of induction from observed data. Goodman's grue/bleen paradox puts paid to that idea. Algorithmic simplicity has nothing to do with real world data.

Bruce

https://arbital.com/p/solomonoff_induction

[Bruce Kellett]

On Sun, Jun 27, 2021 at 7:49 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 3:53:18 AM UTC+2 Brent wrote:

Notice that they don't exist in the sense you mean.  Newton's laws aren't around anymore.

By laws I mean regularities in nature. The apple still falls down and not up or in random directions, so the regularity exists like it did in the days of Newton although Einstein's theory can describe this regularity more accurately than Newton's theory.

 

So there's no guarantee they will continue without change, but they will apply to the past.  How do we know?  We don't, but it's supported by induction.  Induction is a self-supporting form of inference.  If there is any effective form of empirical inference, then induction will do as well.

The problem is, why does induction work?

Induction does not work.

Bruce

[Tomas Pales]

On Sunday, June 27, 2021 at 1:21:32 PM UTC+2 Bruce wrote:

On Sun, Jun 27, 2021 at 7:38 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:36:38 AM UTC+2 Bruce wrote:

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Note that the relation between simplicity and frequency is not Russell's speculation but a fact following from Kolmogorov's definition of complexity: simpler objects are more frequent than more complex objects because the same simpler object is contained in less simple objects.

This is only if everything is considered to be a bit string. There is no reason to suppose that this is true.

No, atoms are more simple than ducks, and atoms are also more frequent than ducks because there are atoms in every duck but there is no duck in an atom. However, it seems that every object can be represented as a binary string, which is a useful representation in computer science.

 

What a load of garbage! Science is not a matter of induction from observed data.

What is science a matter of then?

 

Goodman's grue/bleen paradox puts paid to that idea. Algorithmic simplicity has nothing to do with real world data.

But the property of "grue" is more complex than the property of "green". "Grue" means "green before time t (for example year 2030) and blue after time t". More complex properties are less frequent than simpler properties. For this reason, and given the way the world has been until now, objects that have been observed as remaining green in the past are more likely to remain green in the future, instead of becoming blue at some time.

[Tomas Pales]

On Sunday, June 27, 2021 at 1:24:41 PM UTC+2 Bruce wrote:

Induction does not work.

So there is no reason to expect that the sun will rise tomorrow?

[John Clark]

On Sat, Jun 26, 2021 at 7:31 PM Tomas Pales <litew...@gmail.com> wrote:

>> But the world is not stable. The universe looked very different 13 billion years ago than it does now because space is not only expanding, it's accelerating; and Black Holes evaporate eventually, they are not stable, and there are theoretical reasons to suspect protons are not stable either, although that has never been experimentally verified. 

> But the laws of physics are apparently the same as they were 13 billion years ago: law of gravity, quantum mechanics, constants of nature.

If scientist existed 13 billion years ago they never would've discovered Dark Energy because back then it would've made an undetectably tiny effect on the way things were, the scientists would've found that the expansion of the universe was decelerating just is Newton and Einstein said it would, the universe only started to accelerate about 5 billion years ago, but today it's accelerating so much that Dark Energy makes up 70% of the mass/energy of the entire universe, and in the future it will make up even more. That's because Dark Energy seems to be a property of space itself, so as more space comes into existence from the expansion all matter, even Dark Matter, gets diluted but Dark Energy does not. And that expansion and acceleration means that the law of conservation of mass/energy is only approximately and locally true. And of course the Hubble "constant" is not a constant at all, it changes with time.  And that's not all, the universe may have a preferred direction.

A new study has found a spatial variation in the Fine Structure Constant (a pure number approximately equal to 1/137) with a 3.9 sigma level of confidence, that means there is a 0.8% chance it's just a statistical fluke. It's not good enough to claim a discovery, that requires 5 sigma or only 0.023% chance of it being bogus, but it's good enough to be interesting. The detected variation has a dipole structure, the laws of physics that govern electromagnetism seem to get stronger in one direction, and the further we look the stronger it gets, and it gets weaker when we look in the opposite direction, with no change in the perpendicular direction. In other words it has a dipole shape.

If this turns out to be true then Noether's theorem tells us that the Law Of Conservation Of Angular Momentum is also only approximately and locally true.

Four direct measurements of the fine-structure constant 13 billion years ago

This new optical work is consistent with a different study that used X rays instead of optical light, they also found a variation, and along the same axis.

Rethinking cosmology: Universe expansion may not be uniform

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

v5n

[Bruce Kellett]

On Sun, Jun 27, 2021 at 10:18 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 1:21:32 PM UTC+2 Bruce wrote:

On Sun, Jun 27, 2021 at 7:38 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:36:38 AM UTC+2 Bruce wrote:

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Note that the relation between simplicity and frequency is not Russell's speculation but a fact following from Kolmogorov's definition of complexity: simpler objects are more frequent than more complex objects because the same simpler object is contained in less simple objects.

This is only if everything is considered to be a bit string. There is no reason to suppose that this is true.

No, atoms are more simple than ducks, and atoms are also more frequent than ducks because there are atoms in every duck but there is no duck in an atom. However, it seems that every object can be represented as a binary string, which is a useful representation in computer science.

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

What a load of garbage! Science is not a matter of induction from observed data.

What is science a matter of then?

Maybe it is a matter of finding laws. And laws are not just empirical generalizations obtained by induction.

Goodman's grue/bleen paradox puts paid to that idea. Algorithmic simplicity has nothing to do with real world data.

But the property of "grue" is more complex than the property of "green". "Grue" means "green before time t (for example year 2030) and blue after time t".

But that is the fundamental mistake. 'green and 'blue' are not simpler than 'grue' and 'bleen'. If grue and bleen are the common language, then green is defined as grue before time t and  bleen thereafter. The complexity of the terms depends on the language, so complexity does not distinguiah between them.

More complex properties are less frequent than simpler properties.

Only in your dreams. Because complexity is language dependent, relative frequencies cannot be uniquely defined.

Bruce

[Bruce Kellett]

Our confidence that the sun will rise tomorrow is not based on any induction from a large number of previously observed sunrises.

Bruce

[Jason Resch]

I think that calculation must be subjective rather than objective. It depends on how closely tied an observer's brain/mind/memories are to the universe they inhabit.

See for example: 

https://arxiv.org/abs/0902.3825

I think a complete memory reset provides the opportunity to end up in a different universe with other laws.

Hans Moravec writes about this as well:

https://frc.ri.cmu.edu/~hpm/project.archive/general.articles/1998/SimConEx.98.html

"The regularities we observe may be merely a self-reflection: we must perceive the world as compatible with our own existence---with a strong arrow of time, dependable probabilities, where complexity can evolve and persist, where experiences can accumulate in reliable memories, and the results of actions are predictable. Our mind children, able to manipulate their own substance and structure at the finest levels, will probably greatly transcend our narrow notions of what is."

[...]

"Physical quantities like the speed of light, the attraction of electric charges, and the strength of gravity are, for us, the unchanging foundation on which everything is built. But if our existence is a product of self-interpretation in the space of all possible worlds, this stability may simply reflect the delicacy of our own construction---our biochemistry malfunctions in worlds where the physical constants vary, and we would cease to be there. Thus, we always find ourselves in a world where the constants are just what is needed to keep us functioning. For the same reason, we find the rules have held steady over a long period, so evolution could accumulate our many intricate, interlocking internal mechanisms.

Our engineered descendants will be more flexible. Perhaps mind-hosting bodies can be constructed that are adjustable for small changes in, say, the speed of light. An individual who installed itself in such a body, and then adjusted it for a slightly higher lightspeed, should then find itself in a physical universe appropriately altered, since it could then exist in no other. It would be a one-way trip."

Jason

[John Clark]

On Sat, Jun 26, 2021 at 7:43 AM Tomas Pales <litew...@gmail.com> wrote:

 

> this world is more simple if its regularities (such as laws of physics) continue than if they are discontinued, and simple worlds are more likely (more frequent in the collection of all possible worlds) than more complex worlds. (A simpler property is instantiated in a greater number of possible worlds than a more complex property.)

If everything in the universe was completely random then there would be no laws of physics, so to describe the universe you'd not only have to describe exactly what every single particle and photon in it was doing now but what they would be doing in every instance in the future; in such a world inductive logic would be of no help in figuring this out. I suppose in that way the fundamental laws of physics can be thought of as data compression algorithms, and since we know that induction is very useful in figuring things out such laws must exist, but the question is, are any of the laws of physics that we call fundamental really fundamental?  

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

u2x 

[Jason Resch]

It's not just Russell, and it's no longer just rampant speculation. The assumption of our existence within an infinite ensemble of computations distributed according to the precepts algorithmic information theory makes many predictions for the properties of physical universes.

So far, of the predictions we can and have tested, all such predictions have been experimentally/observationally confirmed:

For an overview of this evidence see:

https://alwaysasking.com/why-does-anything-exist/#Confirming_Evidence

We can now say: why we have laws, where laws come from, why they're stable, why they're maximally simple (while suited for us), why they're quantum mechanical, and why we inhabit a universe that evolves over time and which has a point of maximal simplicity in it's past.

Wheeler, Hawking, Davies, etc. were also all working down this same path of tying together the observer with the observed in a tightly coupled mutual interrelation and interdependence. See Eheeler's participatory universe, Hawking's top down physics, and Davies's Flexi-Laws.

Jason

[Jason Resch]

We could still ask: why does empiricism tend to work here? Which I think is the crux if Tomas's question.

Jason

Brent

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[Tomas Pales]

On Sunday, June 27, 2021 at 2:29:38 PM UTC+2 Bruce wrote:

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

Complexity is a property of structure, so if we want to explore complexity of real-world objects indirectly, that is, in representations of the real-world objects rather than in the real-world objects themselves, we must make sure that the representations preserve the structure and thus the complexity of the real-world objects. So there must be some systematic, isomorphic mapping between the real-world objects and their representations - a common language for describing (representing) the real world objects. It seems that one such language could be binary strings of 0s and 1s, at least this approach has been very successful in digital technology.

Another way of isomorphic representation of the structure of real-world objects that is even more similar to the structure of real-world objects is set theory since real-world objects are collections of collections of collections etc.

What is science a matter of then?

Maybe it is a matter of finding laws. And laws are not just empirical generalizations obtained by induction.

Sure, but how do we know that our world has laws that will hold in the future when it seems possible and even likely that they will not (because there are many ways that the world could deviate from the past laws in the future)?

[Tomas Pales]

On Sunday, June 27, 2021 at 2:30:56 PM UTC+2 Bruce wrote:

Our confidence that the sun will rise tomorrow is not based on any induction from a large number of previously observed sunrises.

What is it based on then?

[Tomas Pales]

On Sunday, June 27, 2021 at 2:44:31 PM UTC+2 johnk...@gmail.com wrote:

I suppose in that way the fundamental laws of physics can be thought of as data compression algorithms

Yes, and this makes a universe more simple and therefore more likely than a universe without laws.

[Philip Benjamin]

[Philip Benjamin]

  A representation of reality is not REALITY itself. Atoms are complex structures. “Positive” protons do not repel each other within the nucleus, nor areelectrons drawn into nucleus. How did that “highly informed” complexity arise? Moreover the question of “aseity” of atomic constituents remain unsolvable. How can dead atoms produce a live duck! As far as observations go, only life produces life. The “aseity” of “LIFE” is more reasonable than “aseity” of dead MATTER. Only a degree of rationality, not absolutism,  can be established here.  The only law that is stable for a duck is DEATH! The Sentence of Death is universal (Law of Entropy). Only the Sentencer can cancel that. That is the difference between pan-Gaian-ism (earth veneration) and the Reverence of the Self-Existent who in Patriarchal, Prophetic and Apostolic revelation is Adonai (plural) YHWH (singular) Elohim (uni-plural). That is what Augustinianism is all about (or Neo-Platonism which he eventually gave up for Scripturalism).  https://www.midwestaugustinians.org/conversion-of-st-augustine;    https://www.puritanboard.com/threads/was-augustine-a-scripturalist-by-drake.64956/   This is TRUE Western History of Transformation of individual life and collective culture—which pagan politicians under the control of the WAMP with un-awakened consciousness reject with fury!!!!

Philip Benjamin

 

 

From: everyth...@googlegroups.com <everyth...@googlegroups.com> On Behalf Of Bruce Kellett
Sent: Sunday, June 27, 2021 7:29 AM
To: Everything List <everyth...@googlegroups.com>
Subject: Re: Why are laws of physics stable?

 

“No, atoms are more simple than ducks, and atoms are also more frequent than ducks because there are atoms in every duck but there is no duck in an atom. However, it seems that every object can be represented as a binary string, which is a useful representation in computer science.

[Brent Meeker]

Yes, I've read Russell's book.  Solomonoff's idea is interesting but whether his assumptions are more fundamental or believable than just saying induction works and we know that by induction, is questionable.

Brent

[Brent Meeker]

On 6/27/2021 5:18 AM, Tomas Pales wrote:

On Sunday, June 27, 2021 at 1:21:32 PM UTC+2 Bruce wrote:

On Sun, Jun 27, 2021 at 7:38 PM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:36:38 AM UTC+2 Bruce wrote:

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Note that the relation between simplicity and frequency is not Russell's speculation but a fact following from Kolmogorov's definition of complexity: simpler objects are more frequent than more complex objects because the same simpler object is contained in less simple objects.

This is only if everything is considered to be a bit string. There is no reason to suppose that this is true.

No, atoms are more simple than ducks, and atoms are also more frequent than ducks because there are atoms in every duck but there is no duck in an atom. However, it seems that every object can be represented as a binary string, which is a useful representation in computer science.

Actually that's doubtful.  You're idealizing "object" into a class.  A specific duck or atom may require and infinite string to define it's relation to the rest of the universe.  But you've tried to pull a switch from "being" to "represented"; a common move for those enamored of language, description, computers,...

 

What a load of garbage! Science is not a matter of induction from observed data.

What is science a matter of then?

 

Goodman's grue/bleen paradox puts paid to that idea. Algorithmic simplicity has nothing to do with real world data.

But the property of "grue" is more complex than the property of "green". "Grue" means "green before time t (for example year 2030) and blue after time t". More complex properties are less frequent than simpler properties.

A supposition on the same order as nature has regularities.  Remember you're talking about "properties" within theories...not necessarily the same as within objects.

Brent

For this reason, and given the way the world has been until now, objects that have been observed as remaining green in the past are more likely to remain green in the future, instead of becoming blue at some time.

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[Jason Resch]

By chance I was just reading this: https://www.researchgate.net/publication/286624424_My_8_Big_Ideas by Zuboff, and in it he shows how to justify induction through a priori reasoning:

"By the same reasoning

as above, if all the first beads randomly drawn are blue, it is becoming more and more
probable that the beads in the urn are generally blue. (Otherwise something improbable
would be happening in another colour not appearing; and what’s improbable is improbable.)
It is therefore probable also that the next bead drawn will be blue. This is induction. As Hume
would have said, we could not know a priori, given this evidence, that the next bead will be
blue. But, as he overlooked, we can know a priori, given this evidence, that it is probable that
the next bead will be blue. In neither urn example has the belief regarding the beads been
formed as a Humean habit of expectation after many observations of beads. (In the first case
there is only one observation. The second could be modified to have all the beads drawn out

at once.) Rather the belief is a product of a priori reasoning about probability." 

Jason

[Bruce Kellett]

On Mon, Jun 28, 2021 at 12:08 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:29:38 PM UTC+2 Bruce wrote:

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

Complexity is a property of structure, so if we want to explore complexity of real-world objects indirectly, that is, in representations of the real-world objects rather than in the real-world objects themselves, we must make sure that the representations preserve the structure and thus the complexity of the real-world objects.

That's known as begging the question.

 

So there must be some systematic, isomorphic mapping between the real-world objects and their representations - a common language for describing (representing) the real world objects. It seems that one such language could be binary strings of 0s and 1s, at least this approach has been very successful in digital technology.

Digital technology is not fundamental physics.

Another way of isomorphic representation of the structure of real-world objects that is even more similar to the structure of real-world objects is set theory since real-world objects are collections of collections of collections etc.

Is there a set that contains all sets?

What is science a matter of then?

Maybe it is a matter of finding laws. And laws are not just empirical generalizations obtained by induction.

Sure, but how do we know that our world has laws that will hold in the future when it seems possible and even likely that they will not (because there are many ways that the world could deviate from the past laws in the future)?

The evidence points to the fact that the world is not just a random collection of objects. So there are not a large number of ways in which the dynamics could evolve into the future.

Bruce

[Bruce Kellett]

Essentially on the law of conservation of angular momentum, coupled with our detailed knowledge of the structure and dynamics of the solar system. Besides, the sun will not rise tomorrow in Antarctica.

Bruce

[Brent Meeker]

But notice that this depends on an assumption that there are only a finite number of beads and that the drawing is random (which is hard to even define).  In considering regularities of nature I find those plausible, but not really any more compelling that just saying nature has regularities because we've observed regularities in the past.  It's just a kind of "just so" story to make regularities seem be explained.

Brent

[Jason Resch]

What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?

Jason

Bruce

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[Jason Resch]

On Sun, Jun 27, 2021, 5:34 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 12:08 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:29:38 PM UTC+2 Bruce wrote:

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

Complexity is a property of structure, so if we want to explore complexity of real-world objects indirectly, that is, in representations of the real-world objects rather than in the real-world objects themselves, we must make sure that the representations preserve the structure and thus the complexity of the real-world objects.

That's known as begging the question.

 

So there must be some systematic, isomorphic mapping between the real-world objects and their representations - a common language for describing (representing) the real world objects. It seems that one such language could be binary strings of 0s and 1s, at least this approach has been very successful in digital technology.

Digital technology is not fundamental physics.

Another way of isomorphic representation of the structure of real-world objects that is even more similar to the structure of real-world objects is set theory since real-world objects are collections of collections of collections etc.

Is there a set that contains all sets?

There's is a short computer program that executes all other computer programs: 

https://youtu.be/T1Ogwa76yQo

It's distribution will be of a type where shorter programs are exponentially more frequent the shorter the description is. This accounts for the law of parsimony (assuming we belong to such an ensemble).

Jason

What is science a matter of then?

Maybe it is a matter of finding laws. And laws are not just empirical generalizations obtained by induction.

Sure, but how do we know that our world has laws that will hold in the future when it seems possible and even likely that they will not (because there are many ways that the world could deviate from the past laws in the future)?

The evidence points to the fact that the world is not just a random collection of objects. So there are not a large number of ways in which the dynamics could evolve into the future.

Bruce

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[Bruce Kellett]

On Mon, Jun 28, 2021 at 8:50 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 5:38 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 12:10 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:30:56 PM UTC+2 Bruce wrote:

Our confidence that the sun will rise tomorrow is not based on any induction from a large number of previously observed sunrises.

What is it based on then?

Essentially on the law of conservation of angular momentum, coupled with our detailed knowledge of the structure and dynamics of the solar system. Besides, the sun will not rise tomorrow in Antarctica.

What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?

Largely on symmetry. The conservation of angular momentum is related, by Noether's theorem, to the isotropy of space -- largely its rotational symmetry. One can have confidence in the continuation of angular momentum conservation because there is nothing in prospect that will spoil this symmetry -- the rotational invariance of space.

You cannot, of course, rule out the idea that the universe will suddenly become random, and symmetries will no longer obtain. If you want to worry about that possibility, feel free, but don't bother me with your paranoia.

Bruce

[Bruce Kellett]

On Mon, Jun 28, 2021 at 8:58 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 5:34 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 12:08 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:29:38 PM UTC+2 Bruce wrote:

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

Complexity is a property of structure, so if we want to explore complexity of real-world objects indirectly, that is, in representations of the real-world objects rather than in the real-world objects themselves, we must make sure that the representations preserve the structure and thus the complexity of the real-world objects.

That's known as begging the question.

 

So there must be some systematic, isomorphic mapping between the real-world objects and their representations - a common language for describing (representing) the real world objects. It seems that one such language could be binary strings of 0s and 1s, at least this approach has been very successful in digital technology.

Digital technology is not fundamental physics.

Another way of isomorphic representation of the structure of real-world objects that is even more similar to the structure of real-world objects is set theory since real-world objects are collections of collections of collections etc.

Is there a set that contains all sets?

There's is a short computer program that executes all other computer programs: 

https://youtu.be/T1Ogwa76yQo

It's distribution will be of a type where shorter programs are exponentially more frequent the shorter the description is. This accounts for the law of parsimony (assuming we belong to such an ensemble).

As I said, that is known as begging the question.

Bruce

[Jason Resch]

I don't fear it suddenly changing, but it's valid to ask why we should not fear it, or: why is the probability deemed low that the laws will stop working?

Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.

I admire Tomas for questioning something many scientists might take as a given.

Jason

Bruce

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[Jason Resch]

To offer a theory that gives an explanation/answer to some question is how science progresses. The theory may be right or wrong.

It only becomes a logical fallacy when one says the predictions are necessary true because the theory is necessarily true.

Otherwise Newton was begging the question when he offered a theory of universal gravitation.

Jason

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[Tomas Pales]

On Sunday, June 27, 2021 at 10:12:23 PM UTC+2 Brent wrote:

On 6/27/2021 5:18 AM, Tomas Pales wrote:

No, atoms are more simple than ducks, and atoms are also more frequent than ducks because there are atoms in every duck but there is no duck in an atom. However, it seems that every object can be represented as a binary string, which is a useful representation in computer science.

Actually that's doubtful.  You're idealizing "object" into a class.  A specific duck or atom may require and infinite string to define it's relation to the rest of the universe.  But you've tried to pull a switch from "being" to "represented"; a common move for those enamored of language, description, computers,...

I meant a structure-preserving, complexity-preserving representation, at least in principle. So the binary string would completely represent the structure of the real object. But there may be a problem with calculating probability if there is an infinite number of objects. For example, it may seem that there are more natural numbers than even numbers but actually they are both infinite numbers. I don't know how Solomonoff got around the problem with infinity. 

A supposition on the same order as nature has regularities.  Remember you're talking about "properties" within theories...not necessarily the same as within objects.

I am talking about properties of objects - atoms, ducks, worlds...

[Tomas Pales]

On Sunday, June 27, 2021 at 10:56:33 PM UTC+2 Jason wrote:

By chance I was just reading this: https://www.researchgate.net/publication/286624424_My_8_Big_Ideas by Zuboff, and in it he shows how to justify induction through a priori reasoning:

"By the same reasoning

as above, if all the first beads randomly drawn are blue, it is becoming more and more
probable that the beads in the urn are generally blue. (Otherwise something improbable
would be happening in another colour not appearing; and what’s improbable is improbable.)
It is therefore probable also that the next bead drawn will be blue. This is induction. As Hume
would have said, we could not know a priori, given this evidence, that the next bead will be
blue. But, as he overlooked, we can know a priori, given this evidence, that it is probable that
the next bead will be blue.

That makes sense. I am wondering, if this idea was worked out in more detail maybe it would end up being the same as Solomonoff's theory of induction?

[Tomas Pales]

On Monday, June 28, 2021 at 1:01:14 AM UTC+2 Bruce wrote:

One can have confidence in the continuation of angular momentum conservation because there is nothing in prospect that will spoil this symmetry -- the rotational invariance of space.

And there is nothing in prospect to maintain the symmetry either.

[Brent Meeker]

On 6/27/2021 4:13 PM, Jason Resch wrote:

On Sun, Jun 27, 2021, 6:03 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 8:58 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 5:34 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 12:08 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 2:29:38 PM UTC+2 Bruce wrote:

The problem with that is that it is dependent on the language in which you express things. The string 'amcjdhapihrib;f' is quite comples. But I can define Z = amcjdhapihrib;f', and Z is algorithmically much simpler. Kolmogorov complexity is a useful concept only if you compare things in the same language. And there is no  unique language in which to describe nature.

Complexity is a property of structure, so if we want to explore complexity of real-world objects indirectly, that is, in representations of the real-world objects rather than in the real-world objects themselves, we must make sure that the representations preserve the structure and thus the complexity of the real-world objects.

That's known as begging the question.

 

So there must be some systematic, isomorphic mapping between the real-world objects and their representations - a common language for describing (representing) the real world objects. It seems that one such language could be binary strings of 0s and 1s, at least this approach has been very successful in digital technology.

Digital technology is not fundamental physics.

Another way of isomorphic representation of the structure of real-world objects that is even more similar to the structure of real-world objects is set theory since real-world objects are collections of collections of collections etc.

Is there a set that contains all sets?

There's is a short computer program that executes all other computer programs: 

https://youtu.be/T1Ogwa76yQo

It's distribution will be of a type where shorter programs are exponentially more frequent the shorter the description is. This accounts for the law of parsimony (assuming we belong to such an ensemble).

As I said, that is known as begging the question.

Bruce

To offer a theory that gives an explanation/answer to some question is how science progresses. The theory may be right or wrong.

It only becomes a logical fallacy when one says the predictions are necessary true because the theory is necessarily true.

Otherwise Newton was begging the question when he offered a theory of universal gravitation.

The proof is in the pudding though.  Bruno's proposed the same theory, but he's not been able to make any predictions...only retrodictions in which he fits the interpretation of number theoretic theorems to "observations" about consciousness.

Newton calculated the measured orbits of planets.

Brent

[Brent Meeker]

But the regularities of nature are in the theories.  The explain how a duck flies, but they don't explain why this duck flies while that one swims.  Physics leaves to particularities to historians.

Brent

[Jason Resch]

Many theories succeeded by explaining a previously unexplained phenomena, rather than predicting new, previously unknown phenomena.

Bruno's theory answers Feynman's question about why it should take infinite logical operations to figure out what's going on in no matter how tiny a bit of time or space.

What do you think about Standish's derivation of quantum postulates from an ensemble theory?

Jason

Brent

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[Jason Resch]

That's a good question. I think it might, if you presume observer states are computationally generated, and assume all program descriptions have a uniform likelihood. Markus Mueller has a derivation in his paper where he shows "consistent laws" are the rule rather than the exception for observers. Then the repeated tests of stable laws acts like drawing 🔵 over and over. No test is guaranteed to be affirm consistency, but the likelihood increases as the compressed (lawful) description becomes more likely.

As an aside, I also wonder whether less significant, unmeasured decimal places if fundamental constants are in a sense "undefined."

Jason

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[Bruce Kellett]

On Mon, Jun 28, 2021 at 9:06 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 6:01 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 8:50 AM Jason Resch <jason...@gmail.com> wrote:

What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?

Largely on symmetry. The conservation of angular momentum is related, by Noether's theorem, to the isotropy of space -- largely its rotational symmetry. One can have confidence in the continuation of angular momentum conservation because there is nothing in prospect that will spoil this symmetry -- the rotational invariance of space.

You cannot, of course, rule out the idea that the universe will suddenly become random, and symmetries will no longer obtain. If you want to worry about that possibility, feel free, but don't bother me with your paranoia.

I don't fear it suddenly changing, but it's valid to ask why we should not fear it, or: why is the probability deemed low that the laws will stop working?

It is not really possible to give a probability estimate for things like this because we have no data on which we could base such an estimate. The general working assumption is that things will continue as they are unless there is some underlying instability or some external cause of change. We have no evidence for any such instability in the nature of space, or of the conservation laws. This is essentially Newton's first law writ large.

Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.

Why should we ever be led to consider the set of all logically possible worlds? I doubt that such a set can ever be well-defined. Current evidence is against the existence of these other worlds -- we have evidence only for our world.

Bruce

[Bruce Kellett]

Why should you think that symmetry requires maintenance? Unless you take a medieval religious view and hold that God is necessary in order to hold the universe in order -- to hold the heavens in place. I think Galileo and Newton successfully dispelled such a notion.

Bruce

[Jason Resch]

On Sun, Jun 27, 2021, 10:30 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 9:06 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 6:01 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 8:50 AM Jason Resch <jason...@gmail.com> wrote:

What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?

Largely on symmetry. The conservation of angular momentum is related, by Noether's theorem, to the isotropy of space -- largely its rotational symmetry. One can have confidence in the continuation of angular momentum conservation because there is nothing in prospect that will spoil this symmetry -- the rotational invariance of space.

You cannot, of course, rule out the idea that the universe will suddenly become random, and symmetries will no longer obtain. If you want to worry about that possibility, feel free, but don't bother me with your paranoia.

I don't fear it suddenly changing, but it's valid to ask why we should not fear it, or: why is the probability deemed low that the laws will stop working?

It is not really possible to give a probability estimate for things like this because we have no data on which we could base such an estimate.

We can propose distributions and test them by comparing the predictions against current observations.

The general working assumption is that things will continue as they are unless there is some underlying instability or some external cause of change. We have no evidence for any such instability in the nature of space, or of the conservation laws.

This stability is what we should try to explain. You spoke of begging the question earlier. Here you are saying we should believe it is that way because we assume it is that way.

This is essentially Newton's first law writ large.

Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.

Why should we ever be led to consider the set of all logically possible worlds? I doubt that such a set can ever be well-defined. Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What evidence is there that this is the only universe? I can think of many theories and findings that suggest there are many, but I don't know if one piece of evidence suggesting there's only one.

Jason

Bruce

I admire Tomas for questioning something many scientists might take as a given.

Jason

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[Jason Resch]

"For each law-governed world, there are countless variants that would fail in different ways to be wholly law-governed."

-- Derek Parfit in “Why Anything? Why This?”

Jason

[Bruce Kellett]

What does Derek Parfit know about it? That is just his unevidenced opinion.

Bruce

[Bruce Kellett]

On Mon, Jun 28, 2021 at 2:30 PM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 10:30 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 9:06 AM Jason Resch <jason...@gmail.com> wrote:

I don't fear it suddenly changing, but it's valid to ask why we should not fear it, or: why is the probability deemed low that the laws will stop working?

It is not really possible to give a probability estimate for things like this because we have no data on which we could base such an estimate.

We can propose distributions and test them by comparing the predictions against current observations.

One data point does not test a proposed distribution.

The general working assumption is that things will continue as they are unless there is some underlying instability or some external cause of change. We have no evidence for any such instability in the nature of space, or of the conservation laws.

This stability is what we should try to explain. You spoke of begging the question earlier. Here you are saying we should believe it is that way because we assume it is that way.

It is not begging the question because I am not using the assumption to prove that the assumption is correct.  It is merely an observation that the usual assumption is that things do not change without reason or cause. Science is based on just this assumption. Without it science would not be possible.

This is essentially Newton's first law writ large.

Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.

Why should we ever be led to consider the set of all logically possible worlds? I doubt that such a set can ever be well-defined. Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What evidence is there that this is the only universe?

There is evidence that there is this one universe. There is no evidence that other universes exist. There might be theories and speculations to that effect, but these are not evidence.

I can think of many theories and findings that suggest there are many, but I don't know if one piece of evidence suggesting there's only one.

There is certainly evidence that there is this one universe. Other universes are always merely theoretical conjectures. And those theories are generally wrong.

Bruce

[Brent Meeker]

It seems to me there's an immediate failure of prediction.  You write:

In this paper I show why, in an ensemble theory of the universe, we should be inhabiting one of the elements of that ensemble with least information content that satisfies the anthropic principle. This explains the effectiveness of aesthetic principles such as Occam’s razor in predicting usefulness of scientific theories.

Russell Standish in “Why Occam’s Razor” (2004)
And indeed, this is what we find when we examine our physics:

But it's not what we observe.  We observe an enormous, possibly infinite universe that is many orders of magnitude more complicated than necessary for us to exist in it.

Brent

[John Clark]

On Sun, Jun 27, 2021 at 7:01 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> > What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?

> Largely on symmetry. 

But the only way you know something is symmetrical is by making  measurements, but it's impossible to make a measurement in every direction because there are a infinite number of them, so you make only a few measurements and then you must use induction, the idea that things usually continue, to fill in the blanks and thus make an inductive conclusion from just a finite number of measurements. Induction will not always give you the correct answer, if you wait long enough it will almost always fail, but in the meantime it will give you a long string of correct answers and so is an extremely useful rule of thumb, in fact I'd say inductive reasoning is even more important than deductive reasoning.

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

dfp

[Tomas Pales]

The regularities of nature are in nature. The apple falls down regardless of any theories anyone might have about it. Whether a particular duck flies or swims is a joint consequence of regularities, initial conditions of the universe and randomness.

[Tomas Pales]

On Monday, June 28, 2021 at 5:30:43 AM UTC+2 Bruce wrote:

Why should we ever be led to consider the set of all logically possible worlds?

Because why does this particular world exist instead of some other? And what is the difference between a possible world that exists and a possible world that doesn't, anyway? What does it mean "to exist"? I see no difference between possibility and existence.

 

I doubt that such a set can ever be well-defined.

Maybe it can't. All possible concrete worlds might be identical to all possible pure sets, which would need uncountably many axioms to define, as per Godel's first incompleteness theorem. But there are some more limited sets of possible worlds that are closely connected to known physics that might be easier to define: possible worlds beyond the horizon of our observable universe (but still in our universe), possible worlds of inflationary multiverse, of string theory multiverse and of quantum mechanical multiverse.

 

Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What about worlds beyond the horizon of our observable universe (but still in our universe)? By definition, we don't have direct observational evidence for them. We do have indirect observational evidence that they exist because they seem to be predicted by known physics. One might argue that known physics also predicts some types of multiverse, although the matters are not so clear there.

[Tomas Pales]

On Monday, June 28, 2021 at 5:35:32 AM UTC+2 Bruce wrote:

Why should you think that symmetry requires maintenance? Unless you take a medieval religious view and hold that God is necessary in order to hold the universe in order -- to hold the heavens in place. I think Galileo and Newton successfully dispelled such a notion.

Why should you think that a broken symmetry needs something to break it? Sometimes there is a cause that breaks it and sometimes it breaks without a cause. Reality as a whole doesn't need a cause to have symmetries or asymmetries; they exist because they are logically possible.

[Bruce Kellett]

On Mon, Jun 28, 2021 at 9:54 PM Tomas Pales <litew...@gmail.com> wrote:

On Monday, June 28, 2021 at 5:30:43 AM UTC+2 Bruce wrote:

Why should we ever be led to consider the set of all logically possible worlds?

Because why does this particular world exist instead of some other?

It would seem that this is merely a philosophical issue, outside the domain of standard physics. For example, Lewis's analysis of counterfactuals in terms of possible worlds. As far as I can see, that is merely a linguistic trick.

And what is the difference between a possible world that exists and a possible world that doesn't, anyway? What does it mean "to exist"? I see no difference between possibility and existence.

That is a serious conceptual shortcoming on your part. It is possible that there exists a horse-like creature with a single horn (unicorn), but that does not mean that unicorns exist anywhere outside the realms of the secret forest in Harry Potter novels.

 

I doubt that such a set can ever be well-defined.

Maybe it can't. All possible concrete worlds might be identical to all possible pure sets, which would need uncountably many axioms to define, as per Godel's first incompleteness theorem. But there are some more limited sets of possible worlds that are closely connected to known physics that might be easier to define: possible worlds beyond the horizon of our observable universe (but still in our universe), possible worlds of inflationary multiverse, of string theory multiverse and of quantum mechanical multiverse.

That is the set of worlds that have been suggested by some physical theories. The only one that really makes any sense is the existence of domains of space-time beyond our current Hubble horizon. There is reason to think that the initial singularity from which our universe evolved was of infinite (or at least unbounded) spatial extent. As the universe expands, galaxies and so on vanish over our Hubble horizon. We can never communicate with them again, but that does not mean that they cease to exist -- they are asimply in the greater regions of spacetime. But, at the same time, they necessarily have the same laws of physics as we do, so they do not constitute counterfactual "possible worlds" in that sense.

There is no well-defined theory of eternal inflation, so other worlds from this source are purely speculative. String theory and its "landscape" is a failed attempt at a physical theory, and no credence can be placed in any supposed prediction of that theory. The quantum mechanical multiverse, arisong in the multi-worlds interpretation, must necessarily involve the same physics as we observe. And there is no reason to suppose that such worlds exist. MWI is not a well-worked out theory, despite several well-known attempts.

Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What about worlds beyond the horizon of our observable universe (but still in our universe)? By definition, we don't have direct observational evidence for them. We do have indirect observational evidence that they exist because they seem to be predicted by known physics. One might argue that known physics also predicts some types of multiverse, although the matters are not so clear there.

See the discussion of the various proposed multiverses above. Regions beyond our Hubble horizon which have the same physics as we observe constitute the only well-evidenced "other worlds" (if you want to call them that.)

Bruce

[Bruce Kellett]

On Mon, Jun 28, 2021 at 10:10 PM Tomas Pales <litew...@gmail.com> wrote:

On Monday, June 28, 2021 at 5:35:32 AM UTC+2 Bruce wrote:

Why should you think that symmetry requires maintenance? Unless you take a medieval religious view and hold that God is necessary in order to hold the universe in order -- to hold the heavens in place. I think Galileo and Newton successfully dispelled such a notion.

Why should you think that a broken symmetry needs something to break it?

Spontaneously broken symmetries are a very special class of physical theories. Spontaneous symmetry breaking does not apply to all symmetries - particularly not the space-time symmetries.

Sometimes there is a cause that breaks it and sometimes it breaks without a cause. Reality as a whole doesn't need a cause to have symmetries or asymmetries; they exist because they are logically possible.

Maybe they are just brute facts. Not all possible symmetries occur in nature.

Bruce

[John Clark]

On Mon, Jun 28, 2021 at 8:24 AM Bruce Kellett <bhkel...@gmail.com> wrote:

> As the universe expands, galaxies and so on vanish over our Hubble horizon. We can never communicate with them again, but that does not mean that they cease to exist 

I agree, but that is the very reason some people reject Everett's Many Worlds interpretation of Quantum Mechanics. I think an equation, such as Schrodinger's Wave Equation, that can make all sorts of testable predictions that it passes with flying colors, but also makes predictions that have not been tested and perhaps can never be tested even in theory,  then those additional predictions should not be immediately embraced but they should not be immediately rejected as pure nonsense either.  And Schrodinger's equation says absolutely positively nothing about wave collapse, that part was just thrown in by the Copenhagen interpretation people because they didn't like those other worlds and needed collapse to get rid of them, although they were never clear or consistent in explaining exactly when, how, or why the collapse occurred. William of Ockham must be spinning in his grave.

> There is no well-defined theory of eternal inflation, so other worlds from this source are purely speculative.

There is a pretty well-defined theory of eternal inflation, there just is not any strong confirming observational evidence for it, at least not yet. But that is true of a lot of current cosmology and, with one exception, all quantum interpretations that attempt to make sense of the weird world of the quantum, including the vanilla Copenhagen Interpretation. The one exception is SUAC, the Shut Up And Calculate quantum interpretation.   

> String theory and its "landscape" is a failed attempt at a physical theory,

That assessment is, I think, a little harsh, String Theory has already produced some interesting mathematics and maybe someday it will produce some interesting and testable physics too. But right now, as far as physics is concerned, it's not even a theory, it's an embryo theory, it's a theory for a theory. And after all there aren't a lot of alternative ideas for linking General Relativity and Quantum Mechanics, Loop Quantum Gravity is the main competitor to String Theory but it hasn't been able to come up with anything physically testable either.

 

> The quantum mechanical multiverse, arisong in the multi-worlds interpretation, must necessarily involve the same physics as we observe. And there is no reason to suppose that such worlds exist.

If the human mind wishes to make sense  of the weird quantum realm then those other worlds must exist, or at least that's true for my particular human mind. I don't deny the possibility that in the future somebody might come up with an idea even better than Everett's and doesn't need all those other worlds, but as of today there's not even a hint of such a superior interpretation.  

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

be8

 

[Tomas Pales]

On Monday, June 28, 2021 at 2:24:08 PM UTC+2 Bruce wrote:

On Mon, Jun 28, 2021 at 9:54 PM Tomas Pales <litew...@gmail.com> wrote:

And what is the difference between a possible world that exists and a possible world that doesn't, anyway? What does it mean "to exist"? I see no difference between possibility and existence.

That is a serious conceptual shortcoming on your part. It is possible that there exists a horse-like creature with a single horn (unicorn), but that does not mean that unicorns exist anywhere outside the realms of the secret forest in Harry Potter novels.

If unicorns are defined logically consistently with the whole reality, I don't see why they wouldn't exist, though apparently not on this planet. So what is the difference between a possible world that exists and a possible world that doesn't?

[Lawrence Crowell]

The de Sitter vacuum is not eternally stable. In fact the disagreement between the Hubble parameter of expansion may point to the prospect the vacuum is a phantom energy vacuum and the observable universe is heading towards a big rip in a few trillion years. The dS vacuum may be even less stable than thought.

LC

On Saturday, June 26, 2021 at 6:43:23 AM UTC-5 Tomas Pales wrote:

Recently I've been thinking about why we live in a world with stable laws of physics, out of the plethora of all possible worlds. Why does the sun rise every day, why is the intensity of the Earth's gravitational field constant, why do causal relations ("the constant conjunction between causes and effects", as Hume put it) persist in time?

While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future. In fact, it may seem that such a stability is very unlikely because there are many ways our world could be in the future but only one way in which it would be a deterministic extension of the world it has been until now.

But in the book Theory of Nothing by Russell Standish I have found an argument that seems to claim the opposite (if I understand it correctly): given the way our world has been until now, this world is more simple if its regularities (such as laws of physics) continue than if they are discontinued, and simple worlds are more likely (more frequent in the collection of all possible worlds) than more complex worlds. (A simpler property is instantiated in a greater number of possible worlds than a more complex property.) Such a deterministic world is fully defined by some initial conditions and laws of physics, while a world whose regularity is discontinued at some point would need an additional property that would define the discontinuation and thereby make the world more complex.

Can it work like that? If so, I guess the probability that the laws remain stable is growing with the time that they have actually been stable. So now, after more than 13 billion years of stable laws of physics in our universe, is the probability that they remain stable overwhelmingly high (practically 100%)?

Here is a link to the book:

https://www.hpcoders.com.au/theory-of-nothing.pdf

(the persistence of laws of physics is discussed in chapter 4, parts 4.1 and 4.2)

[Lawrence Crowell]

On Saturday, June 26, 2021 at 4:36:47 PM UTC-5 Brent wrote:

On 6/26/2021 9:15 AM, John Clark wrote:

On Sat, Jun 26, 2021 at 7:43 AM Tomas Pales <litew...@gmail.com> wrote:

> While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future.

But the world is not stable.

But presumably the laws are stable.  Why?  Because that's the way we want them.  If they weren't stable (or even time invariant) we wouldn't call them laws of physics.  They'd be initial conditions or historical accidents.

Brent

The instability of the deSitter vacuum means gauge theories are not stable, and in fact are just local gauge redundancies that are not global in space or time.

LC

 

The universe looked very different 13 billion years ago than it does now because space is not only expanding, it's accelerating; and Black Holes evaporate eventually, they are not stable, and there are theoretical reasons to suspect protons are not stable either, although that has never been experimentally verified.  

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

aoz

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[Lawrence Crowell]

On Saturday, June 26, 2021 at 7:36:38 PM UTC-5 Bruce wrote:

On Sun, Jun 27, 2021 at 10:20 AM Tomas Pales <litew...@gmail.com> wrote:

On Sunday, June 27, 2021 at 1:54:29 AM UTC+2 Bruce wrote:

How do you know that? Or is it just an arbitrary assumption? If it is just an assumption, your initial question is without content.

It is in Russell's book on page 58 (universal prior), with reference to equation 2.1 (complexity).

Much as I respect Russell, his book is not an authoritative source for anything. It is all rampant speculation.

On the matter of the stability of laws and the connection with simplicity, I refer you to the 'grue/bleen' paradox introduced by Nelson Goodman. That shows that the idea of simplicity as an explanation for anything is misplaced.

Bruce

Hey, but at least we are not getting the psychotic missives of you know who on this list.

The simplicity idea has troubles. The dS spacetime is a broken vacuum structure, and the QFT principles we observe are a set of redundancies. QCD can be obtained from CFT_4, but with broken conformal group and a reduction in dimension. It is then a messy bundle of gauge redundancies that are NOT stable. We live in something similar to Cumrun Vafa's swampland. This instability is far more grave then the stability of the proton. It means the stability of spacetime itself is local and temporary.

LC

[Jason Resch]

He's just using reasoning according to math and logic. Do you see a flaw in his reasoning? If so, what is it?

Jason

Bruce

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[Jason Resch]

On Sun, Jun 27, 2021, 11:59 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 2:30 PM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 10:30 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 9:06 AM Jason Resch <jason...@gmail.com> wrote:

I don't fear it suddenly changing, but it's valid to ask why we should not fear it, or: why is the probability deemed low that the laws will stop working?

It is not really possible to give a probability estimate for things like this because we have no data on which we could base such an estimate.

We can propose distributions and test them by comparing the predictions against current observations.

One data point does not test a proposed distribution.

One data point can rule out many possibilities.

Also, our universe provides many data points in terms of the many dimensionless constants. Tegmark has analyzed their distribution and found a statistically uniform distribution in their values.

The general working assumption is that things will continue as they are unless there is some underlying instability or some external cause of change. We have no evidence for any such instability in the nature of space, or of the conservation laws.

This stability is what we should try to explain. You spoke of begging the question earlier. Here you are saying we should believe it is that way because we assume it is that way.

It is not begging the question because I am not using the assumption to prove that the assumption is correct.  It is merely an observation that the usual assumption is that things do not change without reason or cause. Science is based on just this assumption. Without it science would not be possible.

No disagreement there, but if we can explain it rather than assume it, all the better.

This is essentially Newton's first law writ large.

Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.

Why should we ever be led to consider the set of all logically possible worlds? I doubt that such a set can ever be well-defined. Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What evidence is there that this is the only universe?

There is evidence that there is this one universe. There is no evidence that other universes exist. There might be theories and speculations to that effect, but these are not evidence.

Evidence for theories that predict other universes is evidence of other universes.

We've never tested the idea that 2-ton diamonds fall in gravitational fields, but because we accept the theory of gravity, we believe they would fall. If we don't accept consequences of theories when we haven't tested some outcome directly, then what's the point of having theories?

I can think of many theories and findings that suggest there are many, but I don't know if one piece of evidence suggesting there's only one.

There is certainly evidence that there is this one universe. Other universes are always merely theoretical conjectures. And those theories are generally wrong.

Many of them are well supported by evidence.

Jason

Bruce

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[Jason Resch]

Can you name a property of the universe that's more complicated than it needs to be for us to be here? Tegmark said he isn't aware of any such thing in physics.

You say it's too big, but it's large size is related to the amount of time it has taken for life to evolve.

Jason

Brent

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[Jason Resch]

On Mon, Jun 28, 2021, 7:24 AM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 9:54 PM Tomas Pales <litew...@gmail.com> wrote:

On Monday, June 28, 2021 at 5:30:43 AM UTC+2 Bruce wrote:

Why should we ever be led to consider the set of all logically possible worlds?

Because why does this particular world exist instead of some other?

It would seem that this is merely a philosophical issue, outside the domain of standard physics. For example, Lewis's analysis of counterfactuals in terms of possible worlds. As far as I can see, that is merely a linguistic trick.

And what is the difference between a possible world that exists and a possible world that doesn't, anyway? What does it mean "to exist"? I see no difference between possibility and existence.

That is a serious conceptual shortcoming on your part. It is possible that there exists a horse-like creature with a single horn (unicorn), but that does not mean that unicorns exist anywhere outside the realms of the secret forest in Harry Potter novels.

 

I doubt that such a set can ever be well-defined.

Maybe it can't. All possible concrete worlds might be identical to all possible pure sets, which would need uncountably many axioms to define, as per Godel's first incompleteness theorem. But there are some more limited sets of possible worlds that are closely connected to known physics that might be easier to define: possible worlds beyond the horizon of our observable universe (but still in our universe), possible worlds of inflationary multiverse, of string theory multiverse and of quantum mechanical multiverse.

That is the set of worlds that have been suggested by some physical theories. The only one that really makes any sense is the existence of domains of space-time beyond our current Hubble horizon. There is reason to think that the initial singularity from which our universe evolved was of infinite (or at least unbounded) spatial extent. As the universe expands, galaxies and so on vanish over our Hubble horizon. We can never communicate with them again, but that does not mean that they cease to exist -- they are asimply in the greater regions of spacetime. But, at the same time, they necessarily have the same laws of physics as we do, so they do not constitute counterfactual "possible worlds" in that sense.

There is no well-defined theory of eternal inflation, so other worlds from this source are purely speculative.

Inflation, in its simplest and most general forms is eternal. You need to work to make a version that's not eternal. Eternal inflation is preferable under Occam's razor.

String theory and its "landscape" is a failed attempt at a physical theory, and no credence can be placed in any supposed prediction of that theory.

What's your opinion of the fine tuning coincidences? Do you think it is a genuine mystery that calls for an explanation?

The quantum mechanical multiverse, arisong in the multi-worlds interpretation, must necessarily involve the same physics as we observe.

Not necessarily. There are recent speculations that the laws of physics themselves are determined by a quantum process:

"Cosmic bio-friendliness is therefore the result of a sort of quantum post-selection effect extended to the very laws of physics themselves."

-- Paul Davies in “The flexi-laws of physics” (2007)

And there is no reason to suppose that such worlds exist.

There is: how do quantum computers work unless the wave function, and all its superpositional states, are "really real"?

MWI is not a well-worked out theory, despite several well-known attempts.

It is the most worked out quantum theory of all. It's just the Schrodinger equation. It's the theories that propose collapse which aren't worked out, nor even properly defined in many cases.

Jason

Current evidence is against the existence of these other worlds -- we have evidence only for our world.

What about worlds beyond the horizon of our observable universe (but still in our universe)? By definition, we don't have direct observational evidence for them. We do have indirect observational evidence that they exist because they seem to be predicted by known physics. One might argue that known physics also predicts some types of multiverse, although the matters are not so clear there.

See the discussion of the various proposed multiverses above. Regions beyond our Hubble horizon which have the same physics as we observe constitute the only well-evidenced "other worlds" (if you want to call them that.)

Bruce

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[John Clark]

On Mon, Jun 28, 2021 at 11:13 AM Jason Resch <jason...@gmail.com> wrote:

>>And there is no reason to suppose that such worlds exist.

> There is: how do quantum computers work unless the wave function, and all its superpositional states, are "really real"?

Forget Quantum Computers, I can't even understand how the 2 slit experiment could work as it does if those other Everett worlds didn't exist.  

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

qrpp

[Brent Meeker]

On 6/28/2021 4:54 AM, Tomas Pales wrote:

On Monday, June 28, 2021 at 5:30:43 AM UTC+2 Bruce wrote:

Why should we ever be led to consider the set of all logically possible worlds?

Because why does this particular world exist instead of some other? And what is the difference between a possible world that exists and a possible world that doesn't, anyway? What does it mean "to exist"? I see no difference between possibility and existence.

Then it must seem curious to you that you only have one head today and have two arms.

Brent

[Brent Meeker]

Are you saying it would entail a logical contradiction for a unicorn to exist on this planet?  I don't think "logical possibility" means what you think it means.

Brent

[Brent Meeker]

Now you're moving the goal posts.  Tegmark is talking about what's nomologically possible...given physics.  You're trying derive physics supposing that everything not contradictory is possible.

Anyway there are three families of elementary particles.  Only one is needed. 

You say it's too big, but it's large size is related to the amount of time it has taken for life to evolve.

It's too old by at least a factor of two.  And there's no reason is could not be small and old.  Just adjust the cosmological constant. 

Brent

[Brent Meeker]

On 6/28/2021 8:13 AM, Jason Resch wrote:

There is no well-defined theory of eternal inflation, so other worlds from this source are purely speculative.

Inflation, in its simplest and most general forms is eternal. You need to work to make a version that's not eternal. Eternal inflation is preferable under Occam's razor.

So is zero cosmological constant.

Brent

[Brent Meeker]

On 6/28/2021 9:27 AM, John Clark wrote:

On Mon, Jun 28, 2021 at 11:13 AM Jason Resch <jason...@gmail.com> wrote:

>>And there is no reason to suppose that such worlds exist.

> There is: how do quantum computers work unless the wave function, and all its superpositional states, are "really real"?

Forget Quantum Computers, I can't even understand how the 2 slit experiment could work as it does if those other Everett worlds didn't exist. 

The photons can't go thru slits in different worlds and still interfere is this one.

Brent

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

qrpp

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[Tomas Pales]

Why, I guess I'm used to it.

[Bruce Kellett]

On Tue, Jun 29, 2021 at 12:12 AM Lawrence Crowell <goldenfield...@gmail.com> wrote:

On Saturday, June 26, 2021 at 4:36:47 PM UTC-5 Brent wrote:

On 6/26/2021 9:15 AM, John Clark wrote:

On Sat, Jun 26, 2021 at 7:43 AM Tomas Pales <litew...@gmail.com> wrote:

> While the anthropic principle might be used to explain why the laws have been stable in the past (because this stability is probably necessary for the evolution of living or conscious organisms such as humans), it doesn't seem to explain why we should expect that the laws will continue to be stable in the future.

But the world is not stable.

But presumably the laws are stable.  Why?  Because that's the way we want them.  If they weren't stable (or even time invariant) we wouldn't call them laws of physics.  They'd be initial conditions or historical accidents.

Brent

The instability of the deSitter vacuum means gauge theories are not stable, and in fact are just local gauge redundancies that are not global in space or time.

Do you have any actual evidence that the deSitter vacuum is unstable? Or is this just a speculative idea based on the idea of a string theory landscape?

Bruce

[Tomas Pales]

On Tuesday, June 29, 2021 at 12:02:04 AM UTC+2 Brent wrote:

Are you saying it would entail a logical contradiction for a unicorn to exist on this planet?  I don't think "logical possibility" means what you think it means.

It would be a contradiction if a unicorn existed where it doesn't exist. Or if a triangle existed in a set of all circles.

[Bruce Kellett]

On Tue, Jun 29, 2021 at 12:48 AM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 11:51 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 2:34 PM Jason Resch <jason...@gmail.com> wrote:

On Sun, Jun 27, 2021, 10:35 PM Bruce Kellett <bhkel...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 10:11 AM Tomas Pales <litew...@gmail.com> wrote:

On Monday, June 28, 2021 at 1:01:14 AM UTC+2 Bruce wrote:

One can have confidence in the continuation of angular momentum conservation because there is nothing in prospect that will spoil this symmetry -- the rotational invariance of space.

And there is nothing in prospect to maintain the symmetry either.

Why should you think that symmetry requires maintenance? Unless you take a medieval religious view and hold that God is necessary in order to hold the universe in order -- to hold the heavens in place. I think Galileo and Newton successfully dispelled such a notion.

"For each law-governed world, there are countless variants that would fail in different ways to be wholly law-governed."

-- Derek Parfit in “Why Anything? Why This?”

What does Derek Parfit know about it? That is just his unevidenced opinion.

He's just using reasoning according to math and logic. Do you see a flaw in his reasoning? If so, what is it?

I have no idea what his reasoning might be. With a conclusion like this, I see no reason to actually try to find out. But all conclusions depend on premises, and even if the reasoning from these premises is flawless, the conclusions are not valid if the premises are flawed.

Bruce

[Brent Meeker]

Just like it would be a contradiction if natural laws were unstable where they are stable.  Ain't it wonderful what you can prove with logic.

Brent

[Bruce Kellett]

On Tue, Jun 29, 2021 at 1:13 AM Jason Resch <jason...@gmail.com> wrote:

On Mon, Jun 28, 2021, 7:24 AM Bruce Kellett <bhkel...@gmail.com> wrote:

There is no well-defined theory of eternal inflation, so other worlds from this source are purely speculative.

Inflation, in its simplest and most general forms is eternal. You need to work to make a version that's not eternal. Eternal inflation is preferable under Occam's razor.

You obviously know very little about inflation theory. If you take a simple inflaton potential, such as phi^2, then the inflation is eternal. But that simple potential does not fit the cosmological data. The best fits to the data require a single slow-roll potential with sensitively adjusted parameters. Such a potential does not give eternal inflation.

String theory and its "landscape" is a failed attempt at a physical theory, and no credence can be placed in any supposed prediction of that theory.

What's your opinion of the fine tuning coincidences? Do you think it is a genuine mystery that calls for an explanation?

No.

The quantum mechanical multiverse, arisong in the multi-worlds interpretation, must necessarily involve the same physics as we observe.

Not necessarily. There are recent speculations that the laws of physics themselves are determined by a quantum process:

"Cosmic bio-friendliness is therefore the result of a sort of quantum post-selection effect extended to the very laws of physics themselves."

-- Paul Davies in “The flexi-laws of physics” (2007)

Recent speculations are not established scientific facts. Besides, even if Davies is right, that does not show that the other worlds of MWI involve different physics. Application of the Schrodinger equation would demonstrate that they must have the same physics.

 

And there is no reason to suppose that such worlds exist.

There is: how do quantum computers work unless the wave function, and all its superpositional states, are "really real"?

Quantum computers, since they rely on interference between quantum amplitudes, must operate in one world. There can be no interference between separate worlds. The old idea that quantum computer speed-up is due to all calculations being performed in parallel in other worlds has long been discarded as misguided. The idea has not even been fruitful in suggesting possible algorithms for quantum calculations. I refer you to Scott Aaronson for details.

MWI is not a well-worked out theory, despite several well-known attempts.

It is the most worked out quantum theory of all. It's just the Schrodinger equation.

The trouble with that idea is that it does not work. You cannot get probabilities or the Born rule from just the Schrodinger equation. If you like, I can go through the demonstration that the Zurek derivation of the Born rule, the derivation taken up by Sean Carroll for example, is fatally circular. Similar problems exist with the Deutsch-Wallace approach using Decision Theory.

It's the theories that propose collapse which aren't worked out, nor even properly defined in many cases.

 The Flash GRW theory is well worked out.. And it gives an excellent account of quantum physics. As with all other approaches to quantum theory, the Born rule has to be added as an additional postulate. But that is inevitable. fGRW has the great advantage that it is an inherently stochastic theory, so there is no problem introducing probabilities.

Bruce

[Bruce Kellett]

On Tue, Jun 29, 2021 at 8:16 AM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:

On 6/28/2021 9:27 AM, John Clark wrote:

On Mon, Jun 28, 2021 at 11:13 AM Jason Resch <jason...@gmail.com> wrote:

>>And there is no reason to suppose that such worlds exist.

> There is: how do quantum computers work unless the wave function, and all its superpositional states, are "really real"?

Forget Quantum Computers, I can't even understand how the 2 slit experiment could work as it does if those other Everett worlds didn't exist. 

The photons can't go thru slits in different worlds and still interfere is this one.

I think John's trouble here is that he still adheres to David Deutsch's concept of worlds. Deutch talks as though every component of a superposition is a separate world. This leaves Deutsch no language to talk about decohered worlds, pointer states, and all the other usual apparatus of quantum interpretations. The trouble with taking every component of a superposition as a separate world is that in Hilbert space  (as in any vector space) you can define an infinite number of different sets of basis vectors, so any vector in the space is represented by an infinity of different worlds, and there is no way to distinguish between these.

I think Bruno has flirted with this idea as well. Deutsch, through his popular writings, has done an immense amount of harm to the cause of quantum interpretations.

Bruce

[Tomas Pales]

On Tuesday, June 29, 2021 at 12:55:45 AM UTC+2 Brent wrote:

Just like it would be a contradiction if natural laws were unstable where they are stable.

Sure, that would be a contradiction.

 

Ain't it wonderful what you can prove with logic.

I just proved some trivial stuff.

[Brent Meeker]

Used to seeing the difference between possibility and existence.

Brent

[Tomas Pales]

On Tuesday, June 29, 2021 at 5:56:25 AM UTC+2 Brent 

Used to seeing the difference between possibility and existence.

What difference? 

[Lawrence Crowell]

The argument is a bit difficult, but the dS vacuum has positive energy and there is some probability of it tunneling to a lower value. It may do this "drip by drip" with Gibbon-Hawking radiation. It could also transition into an anti-de Sitter vacuum. In that case the vacuum energy is negative, but there are conditions for regular eigenvalued orbits that define a minimum. That is a difficult subject involving the moduli of hyperbolic geometries. So string theory is not needed to understand this. In fact the de Sitter vacuum is "anti-string," and string theory has nothing directly to do with the spectra of elementary particles or the vacuum in the observable universe, That is except with colliding black holes.

LC

[Bruce Kellett]

On Wed, Jun 30, 2021 at 4:50 AM Lawrence Crowell <goldenfield...@gmail.com> wrote:

The argument is a bit difficult, but the dS vacuum has positive energy and there is some probability of it tunneling to a lower value.

In order for this to be possible, there must be some  "landscape" of possible values for the vacuum energy. There is no evidence for any such thing. The data are best described by a cosmological constant -- that is, a fixed constant function. In order for there to be some "landscape", or some lower possible value for the vacuum energy, there must be some function that describes this. That would require a dynamical origin for vacuum energy, and be the opposite of a simple constant. 

Any theory that goes in this direction is necessarily unevidenced speculation, no matter how arcane the mathematics might be.

It may do this "drip by drip" with Gibbon-Hawking radiation.

I think Gibbon-Hawking radiation is rather like Unruh radiation. -- a test body in the expanding universe will experience radiation, but the vacuum energy does not decay, since the whole of spacetime is not filled with such radiation -- it is only in the presence of a test body that it is observable. Just like with Unruh radiation. The spacetime surrounding the accelerating body is not filled with radiation since the inertial observer does not see radiation. All he sees is the accelerated body emitting the occasional thermal particle.

Bruce

[John Clark]

On Mon, Jun 28, 2021 at 7:46 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> I think John's trouble here is that he still adheres to David Deutsch's concept of worlds. Deutch talks as though every component of a superposition is a separate world. This leaves Deutsch no language to talk about decohered worlds, pointer states, and all the other usual apparatus of quantum interpretations.

Not so, "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time, in other words it's a word that people like to use when they just don't want to say that the universe has split.  In Many Worlds if the mathematics says that 2 things could happen then 2 things do happen. Usually when a universe splits the two never recombine again, that's why we usually don't see weird quantum effects in our everyday lives, and that's why making a Quantum Computer is hard. But If the difference between universes is very very small then a skilled experimenter can make them become identical again and recombine, and that produces interference. However the difference between the universes rapidly grows larger and the task of making them identical again rapidly becomes more difficult, so when the difference becomes larger than the microscopic level the possibility of them becoming identical again becomes ridiculously small, like in classical physics and the possibility that by pure random chance all the air molecules in the room you're in right now will go to the other side of the room and you'll suffocate to death. That's why you never see somebody as large as a human being use quantum tunneling to walk through a brick wall even though such a thing is theoretically possible.
 

We don't always see a superposition of states, in fact usually we don't. If you flip a coin and it comes out heads then you are NOT living in the world where it came out tails. In a roughly similar  way if you do the two slit experiment and see that the photon goes through slit A then you are not living in the world where the photon went through slot B. But the 2 slit experiment can be a little different from the simple coin toss example.

If after the universe splits and the photon goes through both slits they then hits a photographic plate (or a brick wall) then both photons in both universes are destroyed and thus there is no longer any difference between the two, so the universes will merge back together. Then and only then you will see evidence that the photon went through both slits (aka. Interference) on the photographic plate even if you send the photos through one at a time.

If you got rid of the film (or the brick wall) and let the photon head out into infinite space after it passes the slits then the two universes will never recombine, and so of course you will never see a interference effect. The beautiful part of the theory is that it doesn't have to explain what an observer is and that's why a brick wall will work just as well as a photographic plate.

A measurement, if for some reason you'd like to use that word, is a change made in the universe, and it doesn't matter if that change is made in a conscious being or not. In one universe the photon hits the screen at point X, and in another universe the photon hits the screen at point Y, and in yet another universe the photon doesn't hit the screen at all because it doesn't pass through either slit. If there happens to be an observer watching all this he splits too, and they all have different memories about what happened.  And it doesn't matter if nobody is watching, the universe splits anyway. In Many Worlds if you like you could replace the word "measurement" with the word "change" and you don't need to use the word "observer" at all, so you don't need to ponder the question of if a cockroach can observe things and make the universe split.

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

v42

[smitra]

On 29-06-2021 01:46, Bruce Kellett wrote:
> On Tue, Jun 29, 2021 at 8:16 AM 'Brent Meeker' via Everything List
> <everyth...@googlegroups.com> wrote:
>
>> On 6/28/2021 9:27 AM, John Clark wrote:
>>
>> On Mon, Jun 28, 2021 at 11:13 AM Jason Resch <jason...@gmail.com>
>> wrote:
>>
>>>> And there is no reason to suppose that such worlds exist.
>>

>> _> There is: how do quantum computers work unless the wave function,
>> and all its superpositional states, are "really real"?_

>
> Forget Quantum Computers, I can't even understand how the 2 slit
> experiment could work as it does if those other Everett worlds didn't
> exist.
>
> The photons can't go thru slits in different worlds and still
> interfere is this one.
>
> I think John's trouble here is that he still adheres to David
> Deutsch's concept of worlds. Deutch talks as though every component of
> a superposition is a separate world. This leaves Deutsch no language
> to talk about decohered worlds, pointer states, and all the other
> usual apparatus of quantum interpretations. The trouble with taking
> every component of a superposition as a separate world is that in
> Hilbert space (as in any vector space) you can define an infinite
> number of different sets of basis vectors, so any vector in the space
> is represented by an infinity of different worlds, and there is no way
> to distinguish between these.
>
> I think Bruno has flirted with this idea as well. Deutsch, through his
> popular writings, has done an immense amount of harm to the cause of
> quantum interpretations.
>
> Bruce

There ids a large body of rigorous work in this field, it's not that you
have just a handful of advocates who are defending the MWI based on
dodgy nonrigorous arguments. Of course, you can't just take nay
component of a superposition as a separate world. But given that Worlds
do exist and given that time evolution is given as a linear operator, it
follows that if QM is a fundamental theory that also describes
observers, that you inevitably end up with superpositions of entire
Worlds.

This conclusion does not depend on any assumptions of how observers
should be defined rigorously, how experiments and ultimately
observations arise out of the physics. These issues that are not yet
100% solved, are totally irrelevant provided QM is indeed a fundamental
theory.

It's not any different from someone claiming that conservation of
momentum may not be true. How do we convince this person that it is
true? We can appeal to fundamental laws of physics and argue on the
basis of symmetries, Noether's theorem and then say that this rigorously
establishes conservation of momentum. But the skeptic can then take
issue with the assumption about the validity of the fundamental laws,
he will insist that it's still possible for momentum to get lost. If he
does an experiment involving many particles, then he'll say that unless
you measure the momentum of each particle to infinite accuracy, you
can't really tell that momentum is conserved. He'll then turn the logic
about the fundamental laws upside down by arguing that because you can't
really be sure about momentum conservation, you can't therefore say that
the fundamental laws have been all that well established.

Of course, there is then a lot to argue about this reasoning suggesting
that there is room for momentum nonconservation. But the arguments
against MWI (regardless of whether or not you need to add Born's rule as
a postulate and if so, regardless about any discussions about this then
invalidating the original goals of some MWI advocates), are of the same
nature. Here you have a supposedly fundamental theory, QM and it implies
in a rather straightforward way the existence of parallel Worlds, and
because people don't like that conclusion, you have arguments against it
that can only work if QM is not true as a fundamental theory. The
problem with those arguments is then that it's invoked as a standalone
argument against the MWI. If these arguments were well motivated on
their own merits, then they would form the basis of a lot of physics
research in many different fields ranging from condensed matter,
particle physics etc. But that's not the case.

Saibal

[Lawrence Crowell]

On Tuesday, June 29, 2021 at 5:24:06 PM UTC-5 Bruce wrote:

On Wed, Jun 30, 2021 at 4:50 AM Lawrence Crowell <goldenfield...@gmail.com> wrote:

The argument is a bit difficult, but the dS vacuum has positive energy and there is some probability of it tunneling to a lower value.

In order for this to be possible, there must be some  "landscape" of possible values for the vacuum energy. There is no evidence for any such thing. The data are best described by a cosmological constant -- that is, a fixed constant function. In order for there to be some "landscape", or some lower possible value for the vacuum energy, there must be some function that describes this. That would require a dynamical origin for vacuum energy, and be the opposite of a simple constant. 

Any theory that goes in this direction is necessarily unevidenced speculation, no matter how arcane the mathematics might be.

It is tied to inflationary cosmology, which has some empirical support. It does give predictions on the CMB and ΛCDM, which has a fair amount of empirical support. The B-modes for gravitational waves induced by inflation seemed a good bet back in 2015, but the problem is that polarization from galactic dust leaves a similar signature. So the data fell from 6-sigma to 3-sigma. The situation though is improving. It is turning into a very difficult signal processing issue.

Inflationary cosmology implies the sort of multi-cosmogony or multiverse (I never liked that term) model. If B-modes are found this will gives some support for that. In that case we will have some data to support work on different vacua for cosmogonies. Where things go from there is uncertain. I tend to think that alternate cosmologies with Λ >> Λ_obs may in fact be a form of off-shell condition. These may then not in fact be real worlds as such. I also think this might be a way to do radiative corrections in general, not just cosmology, that avoids a lot of redundancies in Feynman diagram approaches and that further avoids confusions over virtual states. 

 

It may do this "drip by drip" with Gibbon-Hawking radiation.

I think Gibbon-Hawking radiation is rather like Unruh radiation. -- a test body in the expanding universe will experience radiation, but the vacuum energy does not decay, since the whole of spacetime is not filled with such radiation -- it is only in the presence of a test body that it is observable. Just like with Unruh radiation. The spacetime surrounding the accelerating body is not filled with radiation since the inertial observer does not see radiation. All he sees is the accelerated body emitting the occasional thermal particle.

Bruce

It is similar to Unruh radiation in that the cosmological horizon is a particle horizon. It is though also similar to Hawking radiation, and an inertial observer in principle can observe it. The practical problem of course is the quanta emitted have wavelength that is comparable to the horizon distance L = √(3/Λ). If one wants hold to the analogue with Unruh radiation then the cosmological constant does induce an accelerated frame dragging of particles.

I ponder whether in this multiple cosmogony perspective that all other vacua have transition amplitudes to the lowest energy vacuum. These other vacua the correspond to what we might call virtual cosmogonies or off-shell states. The vacuum we are in would then be the lowest with the Λ_obs the physical vacuum that has a fundamental mass-gap with zero energy or T^{00} = 0. The internal emission of Gibbon-Hawking radiation might be the only way the vacuum can transition to zero. If so there would be a restriction on the number of physical cosmogonies, maybe down to just the one we observe.

LC

[Brent Meeker]

On 6/30/2021 8:07 AM, John Clark wrote:

On Mon, Jun 28, 2021 at 7:46 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> I think John's trouble here is that he still adheres to David Deutsch's concept of worlds. Deutch talks as though every component of a superposition is a separate world. This leaves Deutsch no language to talk about decohered worlds, pointer states, and all the other usual apparatus of quantum interpretations.

Not so, "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time,

It's more that a particle or a system of particles exist in a single physical state, which is represented by different components in our basis for the Hilbert space.  A particle that is spin UP is in a coherent superposition of spin LEFT and spin RIGHT, relative to a Stern-Gerlach measurement.  Aside from measurement, any pure system is just some vector in Hilbert space.  I has components relative to whatever basis we choose for its representation...and it's a "superposition" of those components.  The only reason this is at all different from classical mechanics is that in the quantum case we can't just measure the all the components of the vector.  In general we can at most measure/prepare half of them (c.f. Holevo's theorem).  So measurement results are determined by what instruments we can devise and we usually write Hilbert space vectors in terms of components we can measure/prepare.

in other words it's a word that people like to use when they just don't want to say that the universe has split. 

MWI doesn't split worlds until some measurement-like interaction decoheres the coherent superposition.  So making a LEFT/RIGHT measurement on a spin UP atom in an SG decoheres the state into a mixture of LEFT or RIGHT which Everett takes to define different worlds.

Brent

In Many Worlds if the mathematics says that 2 things could happen then 2 things do happen. Usually when a universe splits the two never recombine again, that's why we usually don't see weird quantum effects in our everyday lives, and that's why making a Quantum Computer is hard. But If the difference between universes is very very small then a skilled experimenter can make them become identical again and recombine, and that produces interference. However the difference between the universes rapidly grows larger and the task of making them identical again rapidly becomes more difficult, so when the difference becomes larger than the microscopic level the possibility of them becoming identical again becomes ridiculously small, like in classical physics and the possibility that by pure random chance all the air molecules in the room you're in right now will go to the other side of the room and you'll suffocate to death. That's why you never see somebody as large as a human being use quantum tunneling to walk through a brick wall even though such a thing is theoretically possible.
 

We don't always see a superposition of states, in fact usually we don't. If you flip a coin and it comes out heads then you are NOT living in the world where it came out tails. In a roughly similar  way if you do the two slit experiment and see that the photon goes through slit A then you are not living in the world where the photon went through slot B. But the 2 slit experiment can be a little different from the simple coin toss example.

If after the universe splits and the photon goes through both slits they then hits a photographic plate (or a brick wall) then both photons in both universes are destroyed and thus there is no longer any difference between the two, so the universes will merge back together. Then and only then you will see evidence that the photon went through both slits (aka. Interference) on the photographic plate even if you send the photos through one at a time.

If you got rid of the film (or the brick wall) and let the photon head out into infinite space after it passes the slits then the two universes will never recombine, and so of course you will never see a interference effect. The beautiful part of the theory is that it doesn't have to explain what an observer is and that's why a brick wall will work just as well as a photographic plate.

A measurement, if for some reason you'd like to use that word, is a change made in the universe, and it doesn't matter if that change is made in a conscious being or not. In one universe the photon hits the screen at point X, and in another universe the photon hits the screen at point Y, and in yet another universe the photon doesn't hit the screen at all because it doesn't pass through either slit. If there happens to be an observer watching all this he splits too, and they all have different memories about what happened.  And it doesn't matter if nobody is watching, the universe splits anyway. In Many Worlds if you like you could replace the word "measurement" with the word "change" and you don't need to use the word "observer" at all, so you don't need to ponder the question of if a cockroach can observe things and make the universe split.

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

v42

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[Bruce Kellett]

On Thu, Jul 1, 2021 at 7:13 AM Lawrence Crowell <goldenfield...@gmail.com> wrote:

On Tuesday, June 29, 2021 at 5:24:06 PM UTC-5 Bruce wrote:

On Wed, Jun 30, 2021 at 4:50 AM Lawrence Crowell <goldenfield...@gmail.com> wrote:

The argument is a bit difficult, but the dS vacuum has positive energy and there is some probability of it tunneling to a lower value.

In order for this to be possible, there must be some  "landscape" of possible values for the vacuum energy. There is no evidence for any such thing. The data are best described by a cosmological constant -- that is, a fixed constant function. In order for there to be some "landscape", or some lower possible value for the vacuum energy, there must be some function that describes this. That would require a dynamical origin for vacuum energy, and be the opposite of a simple constant. 

Any theory that goes in this direction is necessarily unevidenced speculation, no matter how arcane the mathematics might be.

It is tied to inflationary cosmology, which has some empirical support.

Eternal inflation is not a generic prediction of inflationary cosmology. It all depends on the inflaton potential. The best fits to the cosmological data come from slow roll potential models with finely adjusted parameters. These do no give eternal inflation.

It does give predictions on the CMB and ΛCDM, which has a fair amount of empirical support. The B-modes for gravitational waves induced by inflation seemed a good bet back in 2015, but the problem is that polarization from galactic dust leaves a similar signature. So the data fell from 6-sigma to 3-sigma. The situation though is improving. It is turning into a very difficult signal processing issue.

Whether inflation occurred or not is not the issue. The problem is with the assumption that inflation is eternal.

Inflationary cosmology implies the sort of multi-cosmogony or multiverse (I never liked that term) model. If B-modes are found this will gives some support for that. In that case we will have some data to support work on different vacua for cosmogonies.

The question of multiple vacua is like that of eternal inflation. It all depends on the inflaton potential, and we have no direct way of determining that.

Where things go from there is uncertain. I tend to think that alternate cosmologies with Λ >> Λ_obs may in fact be a form of off-shell condition. These may then not in fact be real worlds as such. I also think this might be a way to do radiative corrections in general, not just cosmology, that avoids a lot of redundancies in Feynman diagram approaches and that further avoids confusions over virtual states. 

 

It may do this "drip by drip" with Gibbon-Hawking radiation.

I think Gibbon-Hawking radiation is rather like Unruh radiation. -- a test body in the expanding universe will experience radiation, but the vacuum energy does not decay, since the whole of spacetime is not filled with such radiation -- it is only in the presence of a test body that it is observable. Just like with Unruh radiation. The spacetime surrounding the accelerating body is not filled with radiation since the inertial observer does not see radiation. All he sees is the accelerated body emitting the occasional thermal particle.

Bruce

It is similar to Unruh radiation in that the cosmological horizon is a particle horizon. It is though also similar to Hawking radiation, and an inertial observer in principle can observe it.

Any observer in deSitter space can observe the radiation because they constitute a test particle. However, the space is not filled with such radiation in such a way that the cosmological constant itself decays.

Bruce

[Bruce Kellett]

On Thu, Jul 1, 2021 at 1:07 AM John Clark <johnk...@gmail.com> wrote:

On Mon, Jun 28, 2021 at 7:46 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> I think John's trouble here is that he still adheres to David Deutsch's concept of worlds. Deutch talks as though every component of a superposition is a separate world. This leaves Deutsch no language to talk about decohered worlds, pointer states, and all the other usual apparatus of quantum interpretations.

Not so, "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time, in other words it's a word that people like to use when they just don't want to say that the universe has split.  In Many Worlds if the mathematics says that 2 things could happen then 2 things do happen. Usually when a universe splits the two never recombine again, that's why we usually don't see weird quantum effects in our everyday lives, and that's why making a Quantum Computer is hard. But If the difference between universes is very very small

That seems a bit arbitrary. Exactly how is this "very very small difference" quantified? It all looks much more like an arbitrary "just so" story rather than a well-defined physical theory.

Bruce

[Bruce Kellett]

On Thu, Jul 1, 2021 at 2:29 AM smitra <smi...@zonnet.nl> wrote:

On 29-06-2021 01:46, Bruce Kellett wrote:
>
> I think John's trouble here is that he still adheres to David
> Deutsch's concept of worlds. Deutch talks as though every component of
> a superposition is a separate world. This leaves Deutsch no language
> to talk about decohered worlds, pointer states, and all the other
> usual apparatus of quantum interpretations. The trouble with taking
> every component of a superposition as a separate world is that in
> Hilbert space  (as in any vector space) you can define an infinite
> number of different sets of basis vectors, so any vector in the space
> is represented by an infinity of different worlds, and there is no way
> to distinguish between these.
>
> I think Bruno has flirted with this idea as well. Deutsch, through his
> popular writings, has done an immense amount of harm to the cause of
> quantum interpretations.
>
> Bruce

There ids a large body of rigorous work in this field, it's not that you
have just a handful of advocates who are defending  the MWI based on
dodgy nonrigorous arguments. Of course, you can't just take nay
component of a superposition as a separate world.

But that is precisely what people like John, Deutsch, and Bruno do.

But given that Worlds
do exist

A world exists. That is all that we can be sure of.

and given that time evolution is given as a linear operator, it
follows that if QM is a fundamental theory that also describes
observers, that you inevitably end up with superpositions of entire
Worlds.

Worlds have to be carefully defined. According to decoherence theory (which is also a consequence of the linearity of the Schrodinger equation), decohered worlds are truly separate and do not recombine. Non-decohered elements of a superposition do not constitute separate worlds.

This conclusion does not depend on any assumptions of how observers
should be defined rigorously, how experiments and ultimately
observations arise out of the physics. These issues that are not yet
100% solved, are totally irrelevant provided QM is indeed a fundamental
theory.

It's not any different from someone claiming that conservation of
momentum may not be true. How do we convince this person that it is
true? We can appeal to fundamental laws of physics and argue on the
basis of symmetries, Noether's theorem and then say that this rigorously
establishes conservation of momentum. But the skeptic can then take
issue with the assumption  about the validity of the fundamental laws,
he will insist that it's still possible for momentum to get lost. If he
does an experiment involving many particles, then he'll say that unless
you measure the momentum of each particle to infinite accuracy, you
can't really tell that momentum is conserved. He'll then turn the logic
about the fundamental laws upside down by arguing that because you can't
really be sure about momentum conservation, you can't therefore say that
the fundamental laws have been all that well established.

Of course, there is then a lot to argue about this reasoning suggesting
that there is room for momentum nonconservation. But the arguments
against MWI (regardless of whether or not you need to add Born's rule as
a postulate and if so, regardless about any discussions about this then
invalidating the original goals of some MWI advocates), are of the same
nature.

Not really. You can accept the Schrodinger equation as fundamental without agreeing to MWI. The fact that you can't derive the Born rule from the Schrodinger equation in a non-circular fashion is quite telling. It means that the Schrodinger equation is more naturally seen as a way of calculating the time evolution of probabilities. QM is a probabilistic theory, so its fundamental laws give probabilities. And probabilities are not worlds.

Bruce

[John Clark]

On Wed, Jun 30, 2021 at 7:48 PM Bruce Kellett <bhkel...@gmail.com> wrote:

 >> "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time, in other words it's a word that people like to use when they just don't want to say that the universe has split.  In Many Worlds if the mathematics says that 2 things could happen then 2 things do happen. Usually when a universe splits the two never recombine again, that's why we usually don't see weird quantum effects in our everyday lives, and that's why making a Quantum Computer is hard. But If the difference between universes is very very small

>That seems a bit arbitrary. Exactly how is this "very very small difference" quantified?

Exactly what is the definition of "quantified" and exactly what does that question mean?

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

v4

wxs

[John Clark]

On Wed, Jun 30, 2021 at 5:55 PM 'Brent Meeker' via Everything List <everyth...@googlegroups.com> wrote:

 >> "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time,

> It's more that a particle or a system of particles exist in a single physical state, which is represented by different components in our basis for the Hilbert space. 

To me that sounds like a basically correct but needlessly convoluted euphemism for saying the universe splits. I mean… How would things be different if instead of the "a particle or a system of particles exist in a single physical state, which is represented by different components in our basis for the Hilbert space", the universe just split?  Seems to me that if one thing needs two "different components in our basis for the Hilbert space" then you don't have 1 thing, you have 2 things.

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

o06

[Bruce Kellett]

Don't play silly bugger games. You know perfectly well what I mean. Your response indicates that you have no sensible answer to the question.

Bruce

[John Clark]

On Thu, Jul 1, 2021 at 7:38 AM Bruce Kellett <bhkel...@gmail.com> wrote:

 >>>> "superposition" is just a word that means a collection of particles that exist in very different physical states at exactly the same time, in other words it's a word that people like to use when they just don't want to say that the universe has split.  In Many Worlds if the mathematics says that 2 things could happen then 2 things do happen. Usually when a universe splits the two never recombine again, that's why we usually don't see weird quantum effects in our everyday lives, and that's why making a Quantum Computer is hard. But If the difference between universes is very very small

>>>That seems a bit arbitrary. Exactly how is this "very very small difference" quantified?

>> Exactly what is the definition of "quantified" and exactly what does that question mean?

> Don't play silly bugger games. You know perfectly well what I mean.

And you know perfectly well what the difference is between "the same" and "different "! Or at least I think you do. I learned the difference sometime ago by watching Sesame Street, 

One of these things is not like the other

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

qba