> 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.
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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
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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.
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:
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.
Why should the universe be simple?
How do you know that? Or is it just an arbitrary assumption? If it is just an assumption, your initial question is without content.
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.
Notice that they don't exist in the sense you mean. Newton's laws aren't around anymore.
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.
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."
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?
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.
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.
Induction does not work.
>> 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.
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.
> 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.)
Brent
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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 is science a matter of then?Maybe it is a matter of finding laws. And laws are not just empirical generalizations obtained by induction.
Our confidence that the sun will rise tomorrow is not based on any induction from a large number of previously observed sunrises.
I suppose in that way the fundamental laws of physics can be thought of as data compression algorithms
[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.
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.
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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)?
Bruce
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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
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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?
On Sun, Jun 27, 2021, 5:34 PM Bruce Kellett <bhkel...@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: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).
--Bruce
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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,...
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.
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 reasoningas 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.
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.
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 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:
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.
Brent
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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?
Since empiricism is not logically required in the set of logically possible worlds, it is then a phenomenon we should try to explain.
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.
BruceI admire Tomas for questioning something many scientists might take as a given.Jason
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"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?”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.
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.
> > What is your assumption that the conservation of angular momentum will continue to hold throughout the night based on?
> Largely on symmetry.
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.
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.
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.
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.
> 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
> 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,
> 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.
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.
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:(the persistence of laws of physics is discussed in chapter 4, parts 4.1 and 4.2)
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
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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
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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
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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
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>>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"?
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.
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.
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.
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.
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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.
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.
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?
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.
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.
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.
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.
Used to seeing the difference between possibility and existence.
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.
> 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.
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
> 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
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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.BruceIt 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.
> 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
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 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.
>> "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?
>> "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.
>>>> "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.