reilly said:
I guess you somehow did not get the gist of my comment (#9), which plainly says that all do not subscribe to treating all three names interchangeably. Perhaps the problem that my language is too subtle.
As the philosophers have noted: a name is not the same thing as the thing named. If you look through the literature you will indeed find many instances of quantum theory, quantum mechanics, and quantum physics used interchangeably. (Note; that does not mean that some do not attempt to be more precise than others.) And, for goodness sake, what's the big deal if the three terms form an equivalence class? It's the subject matter, that to which the name is applied that is important.
In a similar, earlier post in a similar thread i noted that many physicists use quantum theory and quantum mechanics quite interchangeably. I always have, as have many physicists far more celebrated than I. This can be demonstrated simply by looking at different texts and books. It's no big deal.
The problem is not with your language, the problem is with your attitude. You are not doing math-ph and therefore for you there is no difference. The three terms do not form an equivalence class, similarly as the Newtonian mechanics vs EM vs GR. The vector derivative (rot, curl) does not exist within the classical analysis. The vector analysis is a different math framework; GR curvature does not exist within the vector analysis. In QM the situation is very similar. You can’t describe spin (Pauli-Schrödinger) within complex Hilbert space framework, you need 4-dim C2 algebra of the Pauli matrices. The spin coupled with the magnetic field says that you are already in relativistic QM.
reilly said:
Of course it's all semantics; last I knew, semantics is the study of meanings, which is clearly what this thread is about (sorry about ending a sentence with a preposition, for which I apologize).
I do not agree that this thread is about semantics or meanings. It reminds me slightly the discussion in “Einstein and the Physics of the Future” (“Some Strangeness in the Proportions”, Addison-Wesley (1980)).
Your position seems to me close to S. Weinberg concluding comment (p.506):”I think the theoretical physicist is like the drunk in the story who has lost a quarter. He has no idea of where he lost it, but he’s looking under a lamp post because that is where the light is good.”
I was educated on other version of that story:”The man has lost a quarter and he’s looking under a lamp post. One would like to help him. “Where you lost it?” Over there, about 20m from here.” If so, why you are looking here?” “Because no light there!” (“Physicists jokes”; compare SU(5) and all GUT's).
Then S. Weinberg continues:”However, I always sympathize with the drunk. Because it is true. He doesn’t really know where he lost the quarter, but if he looks for it anywhere else but where the light is good, he is sure not going to find it.”
I do not sympathize with that man. He lost his quarter where the light was obscure; he never was in the area of the absolute darkness. He doesn’t need a good light, since the quarter always just in front of his eyes. As an example what I have in mind, I suggest reading two pages paper by F.J. Dyson “Feynman’s proof of the Maxwell equations”, Am. J. Phys.,
58, 209 (1990).
Regards, Dany.
Wow! I feel like an spy in a strange new land! I'm a Literature buff writing a health and diet book desperately trying to comprehend Quantum Physics so I can sum it up and googled Quantum Physics Vs Quantum Mechanics and most of this is going over my head! Most? Who am I kidding?! All of it! Can I ask someone - in Penrose's book 'Shadows of the Mind' - he talks about Quantum mechanics showing that our concept of matter has suffered a similar fate to that of our old concepts of the nature of time and space since Einstein's general relativity discovery. (*big breath in*) Can I use the term Quantum Physics here, or does it have to be quantum mechanics? And is the lay person going to know/care?!
