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Is 299,792,458 m/s really the max speed of light

  1. Sep 6, 2014 #1
    I have read that the speed of light is 299,792,458 m/s in a vacum, and is the Max speed of light. But if the speed of light can be reduced once it is removed from that vacum, and we now propose that Dark energy and Dark matter may exisist.

    If Dark mater and energy are everywhere that humans currently have access to in the universe, does creating a vacum infer that dark energy and dark matter are also removed from the experiment?
     
  2. jcsd
  3. Sep 6, 2014 #2
    Dark matter and dark energy don't interact with light (that's why they're "dark!") so they don't affect its speed.
     
  4. Sep 6, 2014 #3

    Drakkith

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    Staff: Mentor

    No, creating a vacuum does not infer that dark energy and dark matter are removed. Since they barely interact with normal matter, we can simply ignore them at our scale without worrying that they will affect our experiments.
     
  5. Sep 9, 2014 #4
    so then would the speed of light be greater when traveling in the vacum of space, where no dark energy or dark matter existed?
     
  6. Sep 9, 2014 #5

    Drakkith

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    Staff: Mentor

    No, it would be exactly the same.
     
  7. Sep 10, 2014 #6
    So then as The_Duck indicated, Dark Matter and Dark Energy do not interact with light at all?
     
  8. Sep 10, 2014 #7

    Drakkith

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    Staff: Mentor

    Dark matter interacts with light via gravity, and dark energy acts on light by causing the acceleration of the expansion of space that light travels through.
     
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