The Speed of Causality vs Speed of Light

Discussion in 'Techforge' started by Bickendan, Apr 17, 2017.

  1. Bickendan

    Bickendan Custom Title Administrator Faceless Mook Writer

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    They're the same value, but light is irrelevant in the matter.

    :rimshot:

    PBS did a pretty nice presentation on the subject:

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  2. Paladin

    Paladin Overjoyed Man of Liberty

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    Yep, those PBS SpaceTime videos are excellent, and that one is especially good.

    Photons are massless, and would travel infinitely fast if not for the universal speed limit. As it is, because photons travel at c, they are timeless from our point of view, meaning they can't undergo change, meaning they never decay. That's why photons emitted at the beginning of the universe can still be reaching us after having traveled 13.8 billion years through space.
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  3. Lanzman

    Lanzman Vast, Cool and Unsympathetic Formerly Important

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    So . . . photons are disconnected from the Higgs field? And yet can still be influenced by gravity. Hmm . . .
  4. Ebeneezer Goode

    Ebeneezer Goode Gobshite

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    IIRC, gravity interacts with energy-momentum, not mass (E=MC^2 links mass to energy-momentum). So a particle needn't be associated with a Higgs field for gravity to exert an influence on it.

    That's pretty much the remote edge of my physics-fu though...
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