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Vectors in Special Relativity

  1. Oct 28, 2013 #1

    MrBillyShears

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    So for finding the magnitude of a vector, velocity for example, we use v=√(vx2+vy2+vz2), but in special relativity, velocities can not exceed c. Is their a different formula for magnitude in SR, or could a velocity like(in natural units) v=(.9,.9,.9) not exist, since the magnitude comes out to be about 1.5588c, which obviously exceeds c?
     
  2. jcsd
  3. Oct 28, 2013 #2

    UltrafastPED

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  4. Oct 28, 2013 #3

    clem

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    That vector could not be a velocity. Velocity is limited by v_x^2+v_y^2+v_z^2<1.
     
  5. Oct 28, 2013 #4

    MrBillyShears

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    Ok, thanks I get it now.
     
  6. Oct 28, 2013 #5
    In special relativity, all vectors should really be regarded as 4 dimensional. UltrafastPED's reference give the method for how to get the magnitude of a 4D vector.

    Chet
     
  7. Oct 28, 2013 #6

    WannabeNewton

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    How much about 4-vectors do you already know?
     
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