"YBM" wrote in message ...
The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/

Nice one.
An excellent opportunity for Androcles to finally grasp it, but it will
not work. Let's hope he will finally lose whatever is left of his mind
over the abundant (but never named or even conceived) closing
speeds/velocities in there ;-)

Dirk Vdm