|MadSci Network: Physics|
If 2 bodies 'A' & 'B' are moving at half the speed of light (0.5c) relative to a common frame of reference 'E'. The velocity of 'A' RELATIVE to 'B' is given by: (a + b )/(1 + ab/c*c) where a = velocity of 'A' w.r.t. E b = velocity of 'B' w.r.t. E c = the speed of light. -> (0.5c+0.5c)/(1 + (0.5c*0.5c/c*c)) = 0.8c No matter how fast 2 bodies approach one other their relative speed can never exceed the speed of light. 'Lorentz Transformations' describe the phenomena of time dilation and length contraction. Differentiating them gives rise to the expression above.
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