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Relativity question

  1. Dec 5, 2004 #1
    If a spaceship is travelling at c and a beam of light is emitted through it. The beam of light would be travelling at c relative to the object. Correct?

    How about if there's an observer, what would the speed of the beam of light be relative to him. c?

    And if the spaceship was instead travelling at 0.6c, would the speed of light relative to it still be c?
     
  2. jcsd
  3. Dec 5, 2004 #2

    Doc Al

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    Staff: Mentor

    Yes to all: The speed of light with respect to any object or observer will be c.
     
  4. Dec 5, 2004 #3
    Great. Thanks. :)
     
  5. Dec 5, 2004 #4

    pervect

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    A spaceship can't travel at c, though it can get arbitrarily close.
     
  6. Dec 6, 2004 #5
    Well... there is that whole Alcubierre warp drive thingy.

    E.g. see Fundamental limitations on "warp drive" spacetimes, Francisco S. N. Lobo, Matt Visser, Class.Quant.Grav. 21 (2004) 5871-5892

    Online at - http://xxx.lanl.gov/abs/gr-qc/0406083

    Pete
     
  7. Dec 6, 2004 #6

    Doc Al

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    Staff: Mentor

    Oops... I must have missed that statement by devious_ in my quick reading. Good catch, pervect.
     
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