Re: unattainable speed of light?

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.