Date: Jun 1, 2010 1:30 PM
Author: stargene@sbcglobal.net
Subject: Re: Is there a compact form for n-tuple relativistic additions of <br>	velocities?


>
> iirc, the addition formula for the inverse hyperbolic tangent is the
> same as the addition formula for velocities in SR.
> i.e., atanh(x)+atanh(y) = atanh((x+y)/(1+xy)).
> Take tanh of both sides and have fun.


Thanks for your response.

Indeed, I looked it up and you are right. However, as I am
often preternaturally dense, I don't understand how knowing
that makes my task of adding, say, n = 10^6 identical little
velocities, where each one is v = Co / 10^6, (identically one
millionth the velocity of light) any easier without steam
shooting out of my ears.

Eg: How would taking the tanh of both sides of your relation
help me, and how does that take into account the totality of
all my n= 10^6 additions? And when n = 10^9 or more? :-(

Can you please enlighten me?
Gene