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Length contraction occurs infront of AND behind you?

  1. Apr 3, 2013 #1
    If I am moving through space, things in front of me contract in the direction parallel to my movement. Does this also occur to objects behind me? For example, I look behind me, would things be contracted?

    As always, thanks.
  2. jcsd
  3. Apr 3, 2013 #2

    Doc Al

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    Staff: Mentor

    Length contraction has nothing to do with where you look or where an object is with respect to you. Any object moving with respect to you will be measured by your frame to be contracted along its direction of motion.

    This is different from the visual appearance of moving objects, if that's what you are interested in.
  4. Apr 3, 2013 #3


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    Yes, the length contraction happens on both sides. However, that's not necessarily what you will SEE with your eyes if you turn around and look backwards because your eyes are responding to the light that hits them where you are, and that light left the object you're looking some time ago.

    The thing to remember here is that length contraction and time dilation are what's left over after you've corrected for light travel time.
  5. Apr 3, 2013 #4
    Thank you. I'm not too interested in the visual appearance (at least in this thread), but more about whether if I am moving towards vs away from an object makes a difference in length contraction. From your post, I gather that wether I am moving towards or away from an object is irrelevant, and what matters is the relative velocity between myself and the object?

    Edit: I posted this before I saw Nugatory's reply. Thank you to both of you!
    Last edited: Apr 3, 2013
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