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LAGEOS confirms frame dragging.

  1. Dec 8, 2004 #1


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    I haven't seen it posted anywhere, but unsurprisingly LAGEOS 1 and LAGEOS 2 have confirmed the frame dragging predicted by GR in the solar system within 99% of the predicted value. The margin of error was +/- 5%.

  2. jcsd
  3. Dec 13, 2004 #2


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    Dearly Missed

    I finally came across some links to journal articles about this
    and posted something in relativity forum

    your link points to this:

    and also to the Nature article (but unfortunately I dont have a subscription)

    glad you called attention to this, Willecke, and my intention is, if I find any more on it, to add it to the thread in relativity forum
  4. Dec 14, 2004 #3


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  5. Dec 14, 2004 #4


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    A little more info on first quoted paper.

    Dr. John Ries, an expert in satellite geodesy at the
    University of Texas at Austin, cautions that it is very
    challenging to remove the much larger effects of tidal changes and
    small zonal influences in the Earth's gravitational field, so that
    estimating the possible errors in the measurement of the Lense-
    Thirring effect is itself uncertain.
    Last edited: Dec 14, 2004
  6. Dec 14, 2004 #5


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    A snip from Wikipidia,

    The 20 October 2004 online edition of Nature reports an updated analysis by Ciufolini and Pavlis of the LAGEOS data, now enhanced by using NASA's GRACE gravity model. They claim to have measured an effect which is 99% ± 5% of the value for the Earth's frame-dragging effect predicted by relativity theory, which they have revised to a ±10% error term to allow for errors not taken account of in their analysis.
  7. Dec 14, 2004 #6
    The thing with this is the method used has a huge effect on the sattelites' positions due just to the fact that the earth isn't a sphere. They're looking for a very small deviation in the sattelites' orbits when they have already been perturbed greatly by other factors. The accuracy of their measurements hinges on knowing these other factors very precisely.
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