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Problem with G?

  1. Dec 29, 2004 #1
    Problem with G??

    This tickled my fancy... anyone else heard anything like this before??

    http://www.npl.washington.edu/eotwash/gconst.html [Broken]

    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. Jan 3, 2005 #2
    Is this just really new or just too far out there to comment on?
  4. Jan 3, 2005 #3

    Just like any empirical constant (like 'little' g), G is the attempt of humans to fit a value to a quantity that has no real significance. G is just the empirical constant Newton needed to describe the effects of gravity. On a macro scale, knowing a 'constant' to within 1% is pretty damn good. Since Newton's equation for gravity is a macro scale equation, that's fine for me.

    For example, when calculating the gravitational attraction between Sol and Earth, the masses of the bodies is less well known than 1%, so the error added in by G is marginal at best.
  5. Jan 3, 2005 #4


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    Most of the constants of nature are known to much better precision than G, it has been notoriously difficult to measure accurately. It's not really a scandal, just a well-known difficulty. It doesn't affect the truth or falsity of any theories.
  6. Jan 3, 2005 #5
    Wouldn't it effect many of our accepted astronomical measurements though? I realize the formulas remain unchanged but the output seems like it might be significantly different.
  7. Jan 3, 2005 #6


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    Cosmological constraints on variation of G over time are much tighter than those established based on solar system experiments. Here is an example based on WMAP data:
    "WMAP constraints on scalar-tensor cosmology and the variation of the gravitational constant"
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