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Time, Space and Light

  1. Mar 31, 2013 #1
    A physics person told me that

    1. According to Einstein time is 'frozen' for light.

    2. According to Einstein space is infinitely contracted (i.e. it does not exist) for light.

    Are these two points true?

    If yes,

    How come light from a distant star 'travel' to us?:cry:
  2. jcsd
  3. Mar 31, 2013 #2


    Staff: Mentor


    Special Relativity says that for any observer the speed of light is the same. So if you as an observer are traveling at near the speed of light relative to another observer, you will still witness light traveling by you at the speed of light.

    Special Relativity also says that as you attempt to travel at speeds close to light you will require all the energy of the universe to do so which means no material object that we know today will travel that fast.

    The time it takes light to travel from a distant star is not infinitely fast we observe to travel at the speed of light and use that a form of measurement for how far away it is: 5 lightyears, 10 lightyears... which means it took light 5 or 10 years respectively to get here.
  4. Mar 31, 2013 #3
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