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Change in speed of light

  1. Nov 27, 2012 #1
    if a car(A) is moving with a speed 2m/s and another car(B) is moving in opposite direction with speed 3m/s. then velocity of car(A) with respect to (B) is 5 or -5m/s .
    so my question is why the same principle does not follow with speed of light as according to theory of relativity speed of light remains same from every frame of refrence ?
    or i can say that if i move with a speed c/2( c is the velocity of light ) opposite to the direction in which light is propogating the velocity of light w.r.t me will be 3v/2 or -3v/2.
    Isn't this true?
  2. jcsd
  3. Nov 27, 2012 #2


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    Staff: Mentor

  4. Nov 27, 2012 #3


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    Simply put - that's not the way our universe works. Feynman said, "You don't like it? Go somewhere else!"
  5. Nov 27, 2012 #4
    Actually, the law is the same :smile:. It's only that you didn't know which is it:

    V = (v1 + v2)/(1 + v1*v2/c2).

    Now put 2m/s as v1 and 5m/s as v2 and compute V.
    Then do the same with v1 or v2 or both, equal to c = 299,792,458 m/s.

  6. Nov 27, 2012 #5
    thankyou guys
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