Orodruin said:
No, this is just wrong (demonstrably). The justification for studying quantum gravity is that we expect that GR and quantum mechanics to break down in particular limits.
And why would this be a reason to develop some completely unnecessary theory of QG? It would not be better than GR and QT, because everything we can test is covered either by GR or by QT. Some minor issues where both are necessary are covered by QFT on curved background. Which is internally inconsistent, but once it makes all the accurate predictions, it is not wrong too. So, everything is fine.
Orodruin said:
So, in other words, you are using a different nomenclature than others have used in this thread and in linked references. That is no basis for a discussion.
I use the standard meaning of the words, as established over centuries. This standard meaning tells, uniquely, that classical mechanics is wrong, and this was established by the first experiment which has experimentally falsified classical mechanics.
Orodruin said:
What do you base this on. Again, please provide references because this is just pure speculation. You do realize that many people thought everything had been discovered in the early 20th century, right?
We have the SM of particle physics, and actually nothing in particle physics is in contradiction to the SM. We have GR, and a model of cosmology in agreement with GR. Dark energy may be described by the cosmological term of GR, dark matter with a simple massive scalar field not interacting with other fields, so that
all what is not covered by the SM is covered by GR. Both the SM and GR are quite similar theories, namely effective field theories. Of course, every expectation about the future remains in some sense pure speculation, but all I need is the hypothesis that two effective field theories may be unified into a single one.
Given that I do not at all claim that everything has been already discovered, why do you think your remark is relevant? (BTW, how it makes sense to claim, at a time when people have learned to see the spectral lines of various materials, without having an explanation for them, that everything has been already found is something I have never understood.)
Orodruin said:
(My emphasis) This is very very different from attaining a theory with some higher form of "truth". I hope you see the difference.
I do not care about "higher forms of truth" (religious?) at all. What I care about is the standard, everyday form of truth, which rejects something as false if it is falsified by observation, internally inconsistent, or in conflict with other things considered to be true. The definition is the simple straightforward correspondence to reality. I recognize very well that there may be theories which are consistent and compatible with everything we have observed up to now but are nonetheless wrong, so that we can never be sure that we have found the truth, even if in reality we have found it. This does not make truth something higher, it is simply a consequence of our very restricted human abilities to identify false theories as false.
Orodruin said:
But that is not how people stating it puts it. The argument is typically presented in the manner described in the text. If you have not read the text and/or not understood it, I do not think you should enter the discussion after just reading the title.
I have read the text and understood it. It does not prove at all what is claimed in the title '"Classical Physics Is Wrong" Fallacy'. Instead, it created a strawman "There is somehow a notion that SR, GR, and QM have shown that classical physics is wrong, and so, it shouldn’t be used." and then attacked and killed the "it shouldn’t be used" part of it. I criticize this. (If I had read somewhere only the title, I would have ignored it as I ignore the usual "logical errors made by Einstien" nonsense, but given that I don't think that PF insights is a place for such nonsense, I have taken a look at it.)
Orodruin said:
To answer your second sentence: If you had been around for any amount of time you would have realized that this is indeed a fallacy that appears in new posters from time to time.
Maybe, ok. Then what I have named "the only objection imaginable" would be wrong or weak. And the suggestion to name the insight appropriately, '"Classical Physics should not be used because it is wrong" fallacy' remains.
Orodruin said:
No, your case is not finished because your argument is not valid. Again, this is how the fallacy presents itself. Instead of reading and understanding this, you have chosen to start a strawman argument, which is never a good thing to do.
If a fallacy hides itself behind a true statement, this does not make the true statement a fallacy.
In this case, 'The "Classical Physics is wrong" cover for the "Classical Physics should not be used" fallacy' would be the appropriate title.
"Classical Mechanics is wrong" is not a fallacy, but a simple well-known truth.
What has surprised me are the open attacks against the very idea of truth, and the defense of the misleading title, and all this not from a single freak, but consistently from many participants:
Orodruin: "Any talk of a ”true” theory is useless and ultimately not constructive or scientific as you can never prove that your theory is ”true” in some deeper meaning."
PeterDonis: "The whole point is that "correct" and "wrong", binary categories, are not useful categories to use when talking about scientific theories and approximations."
Dale: "The experimental results are the relevant demonstration, and in the classical domain the approximation is experimentally valid. You can call it an approximation, a limit, or a flubnubitz, and what you call it does not change the experimental facts that validate it."
russ_watters: "Which - again - means you may as well use "wrong" in a relative sense so that the word is useful. Otherwise a statement like "that theory is wrong" is pointless/redundant."
Please note also that I would not have a problem with a philosophical discussion about various theories of truth, where the (classical and Popperian) correspondence theory of truth is questioned, and various alternatives like relative theories or consent theories of truth are defended. There are reasonable, scientific ways to discuss such things. But what is common to them is that they would not try to question the use of words used in the other theory of truth. If the same word, here "truth", would be given a different meaning in different theories, fine, the standard scientific way would be to introduce add a qualification to the word, say, "consent theory truth" vs. "correspondence theory truth", and this would be necessary only if the same word is used in a different meaning in the own preferred theory. If the word is not used at all in the own theory, one would leave it to the other theory which has a use for it. And the only aim which makes it useful is the Orwellian one - the evil theory will be left without the words necessary even to think about it.
Maybe I'm wrong if I see such an Orwellian element in the quotes above? I hope so.