Sci.Physics.Foundations

The differences between ontology and epistemology are crucial to the way we interpret mathematics and logic. Very often statements are made which suggest that these concepts have not been properly understood by even sometimes the most "educated" people discussing the foundations of physics.

I believe it will be found that a lack of proper grounding in philosophy would be one of the main reasons why 20th-century physics failed. "Bell's theorem" would be another one (not entirely unrelated to the former). The 21st century is still young but at the current pace, it may have a similar fate of stagnation and regression.


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

minkwe wrote: ↑Wed Nov 17, 2021 1:26 pm The differences between ontology and epistemology are crucial to the way we interpret mathematics and logic. Very often statements are made which suggest that these concepts have not been properly understood by even sometimes the most "educated" people discussing the foundations of physics.

I believe it will be found that a lack of proper grounding in philosophy would be one of the main reasons why 20th-century physics failed. "Bell's theorem" would be another one (not entirely unrelated to the former). The 21st century is still young but at the current pace, it may have a similar fate of stagnation and regression.


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

Nice talk by Feynman! It was about the difference between mathematics and physics. We need both. We need epistemology and we need ontology.

Feynman agreed with Bell. He heard about Bell’s theorem and came up immediately with his own alternative proof. He preferred to figure things out for himself.

Bell had an excellent grounding both in philosophy and in physics and in mathematics. His work is all about the differences between epistemology and ontology. His work on the foundations of quantum mechanics is high level philosophy. His work at CERN was high level particle physics.

There is a hard mathematical core to Bell’s work. You can express it as a formal sequence of axioms, proposition, lemma, theorem. The application to physics is still a matter of debate. Debate about ontology. It is metaphysics. Philosophy of physics.

You can also apply that mathematical core to certain problems in distributed computing (computer science, classical, not quantum). I think that that application is not controversial at all.

Feynman in 1983 talking about the Bell theorem said: "...It is not a theorem that anybody thinks is of any particular importance. We who use quantum mechanics have been using it all the time. It is not an important theorem. It is simply a statement of something we know is true—a mathematical proof of it.”

Justo wrote: ↑Thu Nov 18, 2021 4:45 am Feynman in 1983 talking about the Bell theorem said: "...It is not a theorem that anybody thinks is of any particular importance. We who use quantum mechanics have been using it all the time. It is not an important theorem. It is simply a statement of something we know is true—a mathematical proof of it.”

Feynman also noted that it can be proved only by assuming incompatible experiments that cannot be physically realized simultaneously.

In other words, physically, the "theorem" of Bell is complete nonsense.

In my view, the so-called "theorem" is a joke.
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Justo wrote: ↑Thu Nov 18, 2021 4:45 am Feynman in 1983 talking about the Bell theorem said: "...It is not a theorem that anybody thinks is of any particular importance. We who use quantum mechanics have been using it all the time. It is not an important theorem. It is simply a statement of something we know is true—a mathematical proof of it.”

Indeed! Everybody who understood quantum mechanics had already ditched local realism. It’s an elementary mathematical proof of something you would expect to be true, anyway. Feynman immediately came up with his own.

Joy, you say

Feynman also noted that it can be proved only by assuming incompatible experiments that cannot be physically realized simultaneously

Please give us the exact Feynman quote. I think you are completely wrong. And I think Feynman was too smart to think what you say he said.

Is the theorem a joke? It certainly is close to a joke. So simple, so obviously true. The joke is that some people still so desperately want it to be untrue.

gill1109 wrote: ↑Thu Nov 18, 2021 5:18 am

Justo wrote: ↑Thu Nov 18, 2021 4:45 am Feynman in 1983 talking about the Bell theorem said: "...It is not a theorem that anybody thinks is of any particular importance. We who use quantum mechanics have been using it all the time. It is not an important theorem. It is simply a statement of something we know is true—a mathematical proof of it.”

Indeed! Everybody who understood quantum mechanics had already ditched local realism. It’s an elementary mathematical proof of something you would expect to be true, anyway. Feynman immediately came up with his own.

Not everybody. Not smart people like Einstein who knew better. Only dumb people ditched local realism.

gill1109 wrote: ↑Thu Nov 18, 2021 5:18 am Joy, you say

Feynman also noted that it can be proved only by assuming incompatible experiments that cannot be physically realized simultaneously

Please give us the exact Feynman quote. I think you are completely wrong. And I think Feynman was too smart to think what you say he said.

Watch the video where Feynman explains Bell's theorem. Find it yourself on YouTube. I am not going to be bothered looking for it.
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Joy Christian wrote: ↑Thu Nov 18, 2021 5:28 am

gill1109 wrote: ↑Thu Nov 18, 2021 5:18 am

Justo wrote: ↑Thu Nov 18, 2021 4:45 am Feynman in 1983 talking about the Bell theorem said: "...It is not a theorem that anybody thinks is of any particular importance. We who use quantum mechanics have been using it all the time. It is not an important theorem. It is simply a statement of something we know is true—a mathematical proof of it.”

Indeed! Everybody who understood quantum mechanics had already ditched local realism. It’s an elementary mathematical proof of something you would expect to be true, anyway. Feynman immediately came up with his own.

Not everybody. Not smart people like Einstein who knew better. Only dumb people ditched local realism.

gill1109 wrote: ↑Thu Nov 18, 2021 5:18 am Joy, you say

Feynman also noted that it can be proved only by assuming incompatible experiments that cannot be physically realized simultaneously

Please give us the exact Feynman quote. I think you are completely wrong. And I think Feynman was too smart to think what you say he said.

Watch the video where Feynman explains Bell's theorem. Find it yourself on YouTube. I am not going to be bothered looking for it.
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I’ve watched the video. Feynman agrees entirely with Bell’s theorem. He says everybody already knew it was true. It didn’t change anything. Bell just write out a formal proof. Feynman agrees that Bell’s proof is correct and agrees that Bell’s theorem is correct.

Feynman explicitly ditches local realism. He is absolutely explicit that if you don’t measure something, the value which it would have if you had measured it, simply isn’t there. Can’t be there. You only get into trouble by imagining that it does.

Feynman nowhere says what you say he says. (I’m sure he was far too smart to say something like that!) You picked up some words somewhere about incompatible experiments, and put your own meaning on them.

Here’s a nice reference to Feynman’s views on Bell’s theorem and link to the relevant YouTube video.
https://aapt.scitation.org/doi/pdf/10.1119/1.4948268

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Feynman on Bell's theorem: "It is not a theorem that anybody thinks is of any particular importance."

https://aapt.scitation.org/doi/full/10.1119/1.4948268
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Joy Christian wrote: ↑Thu Nov 18, 2021 6:30 am .
Feynman on Bell's theorem: "It is not a theorem that anybody thinks is of any particular importance."

https://aapt.scitation.org/doi/full/10.1119/1.4948268
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Yes, because (Feynman says) everybody already knew it was true! Nobody (at least, nobody smart) had any need of it! Bell just wrote out the math properly.

What did everyone already know? Not the CHSH inequality, obviously. What everyone who knew anything about QM already knew was that local realism had to be abandoned.

Watch the video!

gill1109 wrote: ↑Thu Nov 18, 2021 6:34 am

Joy Christian wrote: ↑Thu Nov 18, 2021 6:30 am .
Feynman on Bell's theorem: "It is not a theorem that anybody thinks is of any particular importance."

https://aapt.scitation.org/doi/full/10.1119/1.4948268
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Yes, because (Feynman says) everybody already knew it was true! Nobody (at least, nobody smart) had any need of it! Bell just wrote out the math properly.

What did everyone already know? Not the CHSH inequality, obviously. What everyone who knew anything about QM already knew was that local realism had to be abandoned.

Watch the video!

Only really dumb people thought that "local realism had to be abandoned." Smart people like Einstein knew better.
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Einstein didn’t give up on local realism. But he didn’t get anywhere.

Superdeterminism is popular. Retrocausality is popular. Non-locality has few supporters, but very good arguments. A lot of people go for “shut up and calculate”. Feynman argued for that. He didn’t mean that one should do it in a mindless way. He argued that that was the only option, and Bell’s theorem was a supporting argument.

gill1109 wrote: ↑Thu Nov 18, 2021 7:34 pm Einstein didn’t give up on local realism. But he didn’t get anywhere.

Superdeterminism is popular. Retrocausality is popular. Non-locality has few supporters, but very good arguments. A lot of people go for “shut up and calculate”. Feynman argued for that. He didn’t mean that one should do it in a mindless way. He argued that that was the only option, and Bell’s theorem was a supporting argument.

Unbelievable that even Feynman got hoodwinked by Bell's junk physics theory.
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Feynman on Bell's theorem: "It is not a theorem that anybody thinks is of any particular importance."
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Joy Christian wrote: ↑Fri Nov 19, 2021 2:30 am .
Feynman on Bell's theorem: "It is not a theorem that anybody thinks is of any particular importance."

Ah... figures that Gill would be stretching the truth as usual.
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I am not stretching the truth.

Feynman says it is a theorem of no particular importance, because everyone (who knew about QM) already knew it.

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Bell's theorem is just a bad joke.
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Joy Christian wrote: ↑Fri Nov 19, 2021 3:33 am .
Bell's theorem is just a bad joke.

Yeah, if you say, "Bell's junk physics theory", then the theory is just a joke. But using "theorem" makes it a really really bad joke.
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Here is where Feynman makes that claim: https://www.youtube.com/watch?v=hWTbtXgqYMo&t=1500s

From Feynman's actual comments it is very clear that Richard D. Gill is lying again, as he frequently does.
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