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About the origen of the fundamental theories

  1. Apr 21, 2008 #1
    Hi , i have this question - it's not an idea , and it's not a theory indeed , it's merely a question - we all know that the theory of relativity is inspired by maxwell theory of electromagnetism , from which the constancy of speed of light in any frame of reference is derived . and we know that the quantum theory in certain aspects make use of S.R , QED - for instance - incorporates S.R in quantum mechanics to arrive to its predictions . and we know that our understanding of the electromagnetic phenomena is modified by QED . now here is the question : if Q.M modifies the classical picture of electromagnetism , and the theory of relativity depends on a result of classical electromagnetism , and Q.M in some aspects depends on S.R , how on god's earth a consistent understanding - theory - is claimed to be achieved ?
  2. jcsd
  3. Apr 21, 2008 #2
    All of the later theories aim to be more general versions of the earlier theories and remain experimentally consistent with them under certain coniditons, i.e., special relativity and newtonian mechanics are virtually the same at slow speeds but diverge at high speeds
  4. Apr 21, 2008 #3
    what i meant is this : what if Q.M - yet to be found "new" Q.M that depends on the yet to be found "new" S.R that depends on the yet to be found "mew" maxwell equations - modifies maxwell equations in a certain way that the speed of light is more constant in all frames of reference , then our version of S.R must be modified , hence Q.M is to be modified . see , here is my question exactly : is it possible for a certain theory that looks like Q.M - with little modifications- along with a theory that looks like S.R - with little modifications - ; is it possible for such theories to modify maxwell equations in such a way our version of S.R is no more accurate ? if yes , then the consequences are huge !!!! both relativity and Q.M are to be revised .
  5. Apr 21, 2008 #4
    Well, both (general) relativity and QM need to be improved anyway, because there are inconsistencies where they meet.

    The special theory of relativity was inspired by classical electromagnetism, but does not follow from it. It is more general, whereas electromagnetism applies only to light. So once you have a more complete theory, namely SR, it turns out that you can do quantum mechanics, or quantum field theory ontop of that. Now QFT indeed corrects electromagnetism, but those corrections are still in keeping with special relativity, and so that doesn't need modification.

    All hell breaks loose when you try to treat gravity and quantum mechanics on the same level. But you can do QFT "on top" of gravity, in the same way you can do QFT on top of special relativity.
  6. Apr 21, 2008 #5
    thanks a lot , but for some reason i'm not satisfied , i'll think of what you have just written , and i will come back to you later .
  7. Apr 21, 2008 #6
    It might be useful to know that quantum field theory may be thought of as quantum mechanics with the Poincare group (symmetries of special relativity) as it's symmetry group.

    Maxwell equations aren't that fundamental, really. There are many more systems out there than just electromagnetism. In any case, it is possible that we might find corrections to our theories but those corrections are likely to be improvements. Just as special relativity is an improvement of Newtonian mechanics and doesn't invalidate it at low velocities, another theory might be an improvement of QFT and won't invalidate it at low energies.
  8. Apr 21, 2008 #7
    first of all excuse my technical terms , physics was my major before switching to electrical engineering .
    you know , this is exactly what i had in mind : poincare group !! i know that maxwell equations aren't that fundamental , but still any lorentzian transformation should leave them invariant , if not , then we expect a modification !! just like schrodinger's equation was modified to G.K and later to Dirac equations . the same applies for yang-mills generalization , but in this case things went the other way : poincare group was taken into consideration when the Y-M equations where put . until now i reason things perfectly , but - and it's a big fat but - the modifications that QFT implied on electromagnetism were consistent with S.R 'cause the latter was a "given" in the formulation of QFT , right ?? so what if we adapt another technique : generalize maxwell equations - lets say Y-M picture - without poincare group being the symmetry group , but rather an "unknown" symmetry which is to be revealed , now S.R derived from this new theory is certainly different from einstein's S.R !!! . a QFT ontop of this new S.R would modify -say - Y-M equations in a different way , and we end up with a new "degree of freedom" : the symmetry group we chose .. i know i'm being obsered and all , but it just hit me right now .
    Last edited: Apr 21, 2008
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