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2nd Law of Thermodynamics question

  1. Dec 17, 2008 #1
    I stand on the outermost planet orbiting the outermost star of the outermost galaxy of our universe. I turn on my flash-light and I can be sure that the beam of light will not hit any object. After I turn it on, I cannot recover the photons or prove they ever existed, so does it mean I decreased the entropy of the universe, in a sense? 2nd law violation?
  2. jcsd
  3. Dec 17, 2008 #2
    Nah, the entropy of the universe still increased as the energy in the battery used to power your flashlight was dissipated as heat.
  4. Dec 17, 2008 #3
    If the universe has no boundary, then this experiment may be impossible. Not completely sure though. See http://en.wikipedia.org/wiki/Shape_of_the_Universe#Local_geometry_.28spatial_curvature.29".

    This scenario is very similar to the problem of http://en.wikipedia.org/wiki/Holographic_principle#Black_Hole_entropy".
    Last edited by a moderator: Apr 24, 2017
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