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Gravitational radiation

  1. Jun 29, 2007 #1

    wolram

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    Please excuse the naivety of the question, i guess the whole of cosmology hinges on the finding of G Radiation, is this a proper assumption?
     
  2. jcsd
  3. Jun 29, 2007 #2
    Of course not.

    Cosmology is a field of science not a theory. Even if we assume for a moment that no gravitational radiation will be found were we would expect it, then that does not mean cosmology is dead. As long as there is a cosmos and humans to ponder it there will be cosmology.

    However, if we would not find gravitational radiation where we logically expect it then the general theory of relativity would become a questionable theory since this theory predicts the existence of gravitational radiation.
     
    Last edited: Jun 29, 2007
  4. Jun 29, 2007 #3

    wolram

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    OOps, i did not want feathers to fly, of course cosmology will continue, but without GR?
     
  5. Jun 29, 2007 #4
    Why not? No theory is sacred in science.
     
  6. Jun 29, 2007 #5

    wolram

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    Oh my, give me one the other.
     
  7. Jun 29, 2007 #6

    marcus

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    Hi wolram, I interpret your question differently from how Jennifer hears it, so I answer differently (without contradicting any of J's facts)

    I think the whole of mainstream cosmology is built on a foundation of classic Gen Rel.

    To verify Gen Rel, gravity waves must be detected. Otherwise the theory is falsified.

    So I would say in answer to you YES finding waves in geometry is crucial.

    If it turned out there were no waves, then GR would be out and the theory of spacetime geometry would have to be rebuilt and then standard cosmology would have to be rebuilt on the new foundation.

    So it is fair to say, I think, that standard cosmology hinges on the wave issue.

    It would not necessrily be BAD to have to rebuild our model of the universe on a drastically changed foundation, however :smile:
     
  8. Jun 30, 2007 #7

    wolram

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    Thank you Marcus.
     
  9. Jun 30, 2007 #8

    jimgraber

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    Two searches for gravitational radiation

    Wolram,
    There are two radically different efforts to detect gravitational waves going on. One is direct detection ala LIGO, VIRGO, GEO, TAMA and later LISA in space. If these gravitational waves are not found it would be a very big surprise and seriously challenge GR, which is fundamental to cosmology (and a lot of other things).
    There is another effort to detect gravitational waves from the time of inflation near the beginning of the universe indirectly by the effect of the tensor gravitational waves on the B mode of the polarization of the CMB. See the last paragraph of http://xxx.lanl.gov/PS_cache/astro-ph/pdf/9706/9706147v1.pdf for example.
    This indirect detection is much more directly related to choosing between different cosmological models.
    Best,
    Jim Graber
     
  10. Jun 30, 2007 #9

    wolram

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    I have read some of the papers, i do not under stand all the maths, but
    can under stand the idea, these tests are far more exciting to me than GPB.
     
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