Einstein:

If we place x'=x-vt, it is clear that a point at rest in the system k must

have a system of values x', y, z, independent of time.

xi = (x-vt) / sqrt(1-v^2/c^2)

xi = x' * beta where beta = 1/sqrt(1-v^2/c^2)

http://www.fourmilab.ch/etexts/einst...ures/img53.gif
http://www.fourmilab.ch/etexts/einst...ures/img54.gif
He [Einstein] wrote the lowercase greek letter Xi instead of x', -- Sylvia

Else

Ref , Jan 1st, 2013

What a way to begin a new year - change Einstein's notation and then change

its meaning.

Poor sick sad Sylvia the psychopathic bigot.

-- This message is brought to you from the keyboard of

Lord Androcles, Zeroth Earl of Medway.

When I get my O.B.E. I'll be an earlobe.