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At the beginning of the universe

  1. Apr 20, 2005 #1
    at the beginning of the universe, is light's speed faster than nowadays?
  2. jcsd
  3. Apr 20, 2005 #2


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    there are a few threads about the concpet of a varying speed of light (VSL), and to expand, the meaningfulness of any other varying dimensionful "constant".


    i might recommend reading this:
    http://arxiv.org/PS_cache/hep-th/pdf/0208/0208093.pdf [Broken]

    bottom line: every physical measurement we make is ultimately measuring a dimensionless number or numbers. if we measure a dimensionful quantity (say, length), we measure it against another like dimensioned quantity (say, a ruler) called a standard or a unit. we count tick marks. we mortals cannot measure a dimensionful quantity in and of itself and cannot measure a change in such a quantity in and of itself. we can only measure such a change against some other like dimensioned quantity, and the only salient measure is that ratio (of say, the speed of light against some other measure of speed), not either of the quantities being compared.

    r b-j
    Last edited by a moderator: May 2, 2017
  4. Apr 20, 2005 #3


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    Staff Emeritus
    Science Advisor

    The short answer is "no".

    The middle length answer is another question - "how could you tell?"
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