by minkwe » Sun Feb 23, 2020 9:02 pm
Jarek wrote:If you see mathematics we successfully use to model/predict nature as just a "mathematical trickery", so what better do you propose? Let say construct a radio using only wisdom of philosophers?
You are not getting it. I'm not proposing anything "better". I'm proposing that we understand that the models as just that -- "models"! And not deceive ourselves into thinking that our models are nature. I think you need a paradigm shift to see what I'm saying.
Exactly, aren't the current ones mainly Lagrangian formalism I am asking about? - like classical mechanics, electromagnetism, general relativity, QFT.
All of them assume there exists e.g. field (realism) containing all relevant information, evolve it with finite propagation speed (locality) - why Bell theorem do not disprove them?[b]
Yes, by assuming the presence of a field in the model, they can do all kinds of predictions and it appears to work quite well. This absolutely does not mean that the "field" is a thing that exists in nature, or that nature is a field. There are other models that do not use fields and also arrive at the same correct answers. It may be easier to use fields but all that proves is the fact that it is a mathematical trick that works better. You can model a mutli-pendulum with Newton's equations, it will be very complicated but you will get the correct answer. You can do the same using Lagrangian mechanics and it will be much easier to get the correct answer. Does that mean nature is like the Lagrangian mechanics, rather than the other model. Absolutely not. It tells you that Lagrangian mechanics is a better mathematical trick for solving these types of problems. Again, it is humans who are trying to solve the problems, not nature.
Sure, while nature is universal, there is some freedom of details/perspectives for physics/mathematics to describe it.
Descriptions are entirely human activities that live in the realm of epistemology. Of course there is a lot of freedom in how we describe things. In fact, our descriptions have evolved over human history. But the descriptions themselves are not nature, and nature is not bound by how we chose to describe it.
However, there are also objective questions with universal answers - hypothetical aliens would answer in analogous ways, like dependencies between atoms in periodic table.
Give me an example, without using a concept that was invented by humans. How do you know hypothetical aliens will even have periodic tables. All those concepts are human inventions.
Another example for [b]yes/no universal question: "is nature fundamentally time/CPT symmetric", there should be one objective answer - also for hypothetical aliens.Trying to answer 'no', all working theories lead to inequalities violated by nature - contradiction.
That question is meaningless. CPT symmetry applies to theories, not to nature. What ontology do you ascribe to CPT symmetry. Do you know of anyone who has ever observed time symmetry? Or is it sufficient to you that if you can imagine time going backwards, the laws that govern the theories will work just the same. Aren't you projecting what you can imagine in your mind as if it is nature?
How does the particle that is moving, know which path is going to be the one with least action? Is it, as some have suggested, the ridiculous idea that it simultaneously tries out all possible paths?
Great question - let's look at it from perspective of Ising model, in which mathematically we assume that physics "tries out all possible" sequences/configurations - weighting them in Botlzmann instead of Feynman way.
First the statement 'physics "tries out all possible" sequences' is quite unfortunate. What do you mean by "physics", the particle, nature, ..., what exactly? But you admit you are just thinking mathematically, so we may let that one go.
So this is statistical mechanics - in reality physics randomly perturbs the configuration space, leading to Boltzmann ensemble as the safest/statistically dominant for fixed energy - due to mathematically universal (also for aliens) Jaynes maximal uncertainty principle:
https://en.wikipedia.org/wiki/Principle ... um_entropy
There is so much that is troubling about this statement that I don't even know where to start. Statistical mechanics is a method we have invented to reason about physical systems when we are interested in macro properties but do not have sufficient information about the micro properties. Then you say "physics randomly pertubs the configuration space". How can physics do anything? How does this "physics" relate back to the particle we are talking about. You have to be more clear what you mean. A configuration, is a collection of information about something. The configuration space, is a space of various possible configurations. It is a concept that lives entirely in the human mind as we manipulate information. When you "perturb" configuration space, you are manipulating information in your mind or in an equation. A Boltzmann ensemble is a probability distribution, again a concept from statistical mechanics that involves how we organise and manipulate information in our minds or equations. Maximum entropy principle is again an entirely epistemological concept that helps us to pick the probability distribution which best represents our current state of knowledge. Nothing about any of this deals with nature at all. So sorry, there is no way that this even begins to attempt to answer the question of how the particle knows which path has the least action. You are talking about epistemological concepts as if they are real things. But you are not alone in making this blunder. You have good company.
So Boltzmann sequence ensemble in space is effective statistical/mathematical description of some complex behavior.
QM is Feynman path ensemble in time - according to general relativity, we live in spacetime, could transform between space and time e.g. below black hole horizon ... so maybe this is again just analogous effective statistical/mathematical description of some complex behavior.
This makes no sense to me. Sorry.
I am definitely not saying that path ensembles are fundamental description, only that Bell theorem has ruled out asymmetric ways of solving local realistic models like general relativity, leaving the symmetric ways, like: the least action principle, Einstein's equations, path/diagram ensembles, TSVF, meeting of propagators from both time directions.
Bell's theorem has not ruled out anything. But at this point I think you have bigger problems than Bell's theorem. But this is not a personal criticism. In fact, many articles published in so-called top journals suffer from the same problems.
[quote="Jarek"]If you see mathematics we successfully use to model/predict nature as just a "mathematical trickery", so what better do you propose? Let say construct a radio using only wisdom of philosophers?[/quote]
You are not getting it. I'm not proposing anything "better". I'm proposing that we understand that the models as just that -- "models"! And not deceive ourselves into thinking that our models are nature. I think you need a paradigm shift to see what I'm saying.
[quote]Exactly, aren't the current ones mainly Lagrangian formalism I am asking about? - like classical mechanics, electromagnetism, general relativity, QFT.
[b]All of them assume there exists e.g. field (realism) containing all relevant information, evolve it with finite propagation speed (locality) - why Bell theorem do not disprove them?[b][/quote]
Yes, by assuming the presence of a field in the model, they can do all kinds of predictions and it appears to work quite well. This absolutely does not mean that the "field" is a thing that exists in nature, or that nature is a field. There are other models that do not use fields and also arrive at the same correct answers. It may be easier to use fields but all that proves is the fact that it is a mathematical trick that works better. You can model a mutli-pendulum with Newton's equations, it will be very complicated but you will get the correct answer. You can do the same using Lagrangian mechanics and it will be much easier to get the correct answer. Does that mean nature is like the Lagrangian mechanics, rather than the other model. Absolutely not. It tells you that Lagrangian mechanics is a better mathematical trick for solving these types of problems. Again, it is humans who are trying to solve the problems, not nature.
[quote]Sure, while nature is universal, there is some freedom of details/perspectives for physics/mathematics to describe it.[/quote]
Descriptions are entirely human activities that live in the realm of epistemology. Of course there is a lot of freedom in how we describe things. In fact, our descriptions have evolved over human history. But the descriptions themselves are not nature, and nature is not bound by how we chose to describe it.
[quote]However, there are also objective questions with universal answers - hypothetical aliens would answer in analogous ways, like dependencies between atoms in periodic table.[/quote]
Give me an example, without using a concept that was invented by humans. How do you know hypothetical aliens will even have periodic tables. All those concepts are human inventions.
[quote]Another example for [b]yes/no universal question: "is nature fundamentally time/CPT symmetric", there should be one objective answer[/b] - also for hypothetical aliens.Trying to answer 'no', all working theories lead to inequalities violated by nature - contradiction.[/quote]
That question is meaningless. CPT symmetry applies to theories, not to nature. What ontology do you ascribe to CPT symmetry. Do you know of anyone who has ever observed time symmetry? Or is it sufficient to you that if you can imagine time going backwards, the laws that govern the theories will work just the same. Aren't you projecting what you can imagine in your mind as if it is nature?
[quote][quote]How does the particle that is moving, know which path is going to be the one with least action? Is it, as some have suggested, the ridiculous idea that it simultaneously tries out all possible paths?[/quote]
Great question - let's look at it from perspective of Ising model, in which mathematically we assume that physics "tries out all possible" sequences/configurations - weighting them in Botlzmann instead of Feynman way.[/quote]
First the statement 'physics "tries out all possible" sequences' is quite unfortunate. What do you mean by "physics", the particle, nature, ..., what exactly? But you admit you are just thinking mathematically, so we may let that one go.
[quote]So this is statistical mechanics - in reality physics randomly perturbs the configuration space, leading to Boltzmann ensemble as the safest/statistically dominant for fixed energy - due to mathematically universal (also for aliens) Jaynes maximal uncertainty principle: https://en.wikipedia.org/wiki/Principle_of_maximum_entropy
[/quote]
There is so much that is troubling about this statement that I don't even know where to start. Statistical mechanics is a method we have invented to reason about physical systems when we are interested in macro properties but do not have sufficient information about the micro properties. Then you say "physics randomly pertubs the configuration space". How can physics do anything? How does this "physics" relate back to the particle we are talking about. You have to be more clear what you mean. A configuration, is a collection of information about something. The configuration space, is a space of various possible configurations. It is a concept that lives entirely in the human mind as we manipulate information. When you "perturb" configuration space, you are manipulating information in your mind or in an equation. A Boltzmann ensemble is a probability distribution, again a concept from statistical mechanics that involves how we organise and manipulate information in our minds or equations. Maximum entropy principle is again an entirely epistemological concept that helps us to pick the probability distribution which best represents our current state of knowledge. Nothing about any of this deals with nature at all. So sorry, there is no way that this even begins to attempt to answer the question of how the particle knows which path has the least action. You are talking about epistemological concepts as if they are real things. But you are not alone in making this blunder. You have good company.
[quote]So [b]Boltzmann sequence ensemble in space[/b] is effective statistical/mathematical description of some complex behavior.
QM is [b]Feynman path ensemble in time[/b] - according to general relativity, we live in spacetime, could transform between space and time e.g. below black hole horizon ... so maybe this is again just analogous effective statistical/mathematical description of some complex behavior.[/quote]
This makes no sense to me. Sorry.
[quote]I am definitely not saying that path ensembles are fundamental description, only that [b]Bell theorem has ruled out asymmetric ways of solving local realistic models like general relativity, leaving the symmetric ways, like: the least action principle, Einstein's equations, path/diagram ensembles[/b], TSVF, meeting of propagators from both time directions.[/quote]
Bell's theorem has not ruled out anything. But at this point I think you have bigger problems than Bell's theorem. But this is not a personal criticism. In fact, many articles published in so-called top journals suffer from the same problems.