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The Gravitational Constant

  1. Apr 1, 2004 #1
    When I took physics I learned that cavendish measured the gravitational constant G (a so-called, “non-derivable constant”), by using a torsion balance to measure the attraction of two bodies. However, what exactly is G? Is it just there to make things "fit" or what? So some time ago I read a paper stating that G can be derived using plank units as a form of the quantum vacuum. Opinions? :biggrin:

    [tex]\delta_{ZP} = \frac{m_P}{l^3_P} [/tex] = (2.177 x 10^(-8) kg) / (4.22 x 10^(-105) m^3 = 5.159 x 10^(96) kgm^(-3)
    Where [tex]\delta_{ZP}[/tex] = vacuum mass-density equivalent, [tex]m_P[/tex] = Plank mass, and l^3 = [tex]V_P[/tex] (Plank Volume).

    By substituting G by the corresponding Plank unites, we get:

    G = [tex]\frac{1}{\delta_{ZP} t^2_P} [/tex]= 6.67 x 10^(-11) m^3 kg^(-1) s^(-2) !

    Consequently, Newton's equation of gravitation adopts the following form by susbtituting G.

    F = [tex]\frac{1}{\delta_{ZP} t^2_P} \frac{m_1 m_2}{d^2}[/tex]

    The paper can be found here http://www.journaloftheoretics.com/Articles/4-2/UGC-QE-final.pdf
    Last edited: Apr 1, 2004
  2. jcsd
  3. Apr 1, 2004 #2


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    G basically encodes the relation between the units we have chosen for mass, distance and the gravitational attraction between two masses. You can choose your units in such a way that the numerical value of G is one (say, using a "gravitational meter").

    As for the "journal of theoretics", take a quick look at their website. Not a reliable reference, to say the least.

    It is exciting to look for revolutionary theories, and there are very exciting new ideas out there, but to get to play with them (and appreciate them in all their boldness or elegance), you first need to learn the "normal" stuff, from the best sources you can find.
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