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Schroedinger's theory of hydrogen atom and his wave mechanics (1926). It explained positions of emission lines of excited hydrogen, but it didn't explain how th

• pdonis 11y ago
  > Schroedinger's theory of hydrogen atom and his wave mechanics (1926). This was not a "new theory" that was competing with any "old theories". It was a tentative model in a regime where no previous theory existed, and it was never claimed to cover anything outside that limited regime. It wasn't competing with any other theories, because there were no other theories to compete with. The question of whether or not Schrodinger's model reproduced the predictions of the "old" theory never arose, because there was no "old" theory. (Technically, there was a sort of "old" theory of the hydrogen atom--Bohr's model--but Schrodinger's model did reproduce all of its correct predictions, plus it added more correct predictions of things that the Bohr model got wrong.) The position with regard to gravitational waves is very different; we already have a comprehensive, fundamental theory--General Relativity--that explains them. Any alternative theory that only explained GWs, and didn't also explain all the other experimental results that GR explains, would be a nonstarter. > Larmor's older theory (1897) This wasn't a separate "theory" at all; it was just a derivation of a particular formula using an already known theory, Maxwell's Equations.
  • effie 11y ago
    Schroedinger theory certainly was a new theory of the atom and later of molecules at that time, successfully competing and largely replacing classical EM models of atoms and molecules such as Larmor's theory of molecules, although it didn't cover the EM radiation aspect and EM theory needs to be used in parallel with Schroedinger's to get, say, intensities of emission lines. I think this is a good example of what I was saying in the first post. It is the new benefit that the theory brings, not reproduction of every single result of the previous theories, that makes the new theory interesting and helps its adoption. Cases where the new theory completely replaces the old theory and reproduces all of its positive results happen too, but are not the only way how new knowledge is adopted.
    • pdonis 11y ago
      > I think this is a good example of what I was saying in the first post. It is the new benefit that the theory brings, not reproduction of every single result of the previous theories Of course Schrodinger's model didn't reproduce the results of classical EM with regard to the atom. It wasn't supposed to, because those results of classical EM were wrong. In other words, there wasn't a correct "old theory" that covered the regime the Schrodinger model covered (the atom)--there was only a wrong "old theory". As far as using Schrodinger's model plus classical EM theory to get results like emission line intensities, there also there was no correct "old theory"; there was only a wrong "old theory" (classical EM by itself, which did not predict emission lines at all, let alone their intensities--it predicted a continuous emission spectrum). Also, this hybrid classical-quantum model was known to be incomplete at the time; it was only used because nobody had yet figured out how to quantize the EM field. > It is the new benefit that the theory brings, not reproduction of every single result of the previous theories Once again, this is not the situation under discussion in this thread (gravitational waves). In the case you describe, the results of the previous theories were wrong in the regime the new model covered, so there was nothing to reproduce; there was no correct "old theory" for the new theory to compete with. In the case of gravitational waves, we have a correct "old theory"--General Relativity--so any new theory that did not match that correct old theory would be a nonstarter. I am not aware of any case where a new theory was accepted as interesting when there was a correct old theory covering the same regime and the new theory did not reproduce its results.
      • effie 11y ago
        > It wasn't supposed to, because those results of classical EM were wrong. You're badly mistaken. Although nobody succeeded in obtaining the emission line frequencies of gases out of the classical EM theory, the theory did correctly give other results consistent with observations. One of them is the formula for emission intensity that connects energy radiated with second derivative of electric moment; it goes back to Larmor's work. This was the result the new theory would preferably reproduce or at least be consistent with. Wave mechanics wasn't consistent with it - the hydrogen atom oscillates indefinitely in wave mechanics. Schroedinger himself viewed this as a deficiency and planned to get back to it - check the ending part of his seminal papers on wave mechanics. The classical formula is taught to this day both in macroscopic EM theory and quantum optics courses, although there are some deficiencies and problems about the formula that Larmor did not know. > In the case of gravitational waves, we have a correct "old theory"--General Relativity--so any new theory that did not match that correct old theory would be a nonstarter. I do not think any physics theory could even be "correct" in the sense of Platonic ideals, but I do not know what you mean by "correct". I do not claim a new theory could completely replace the old one before it could deliver the same or better results. I claim theory has value and is accepted based on its new benefits, not its superiority in every aspect the old theory was superior before. Calling incomplete theory non-starter makes no sense to me, as all theories, including General Relativity, are incomplete.