 > Yes, he's right and you are wrong.  > Reference :  > http://www.fourmilab.ch/etexts/einstein/specrel/www/  > "But the ray moves relatively to the initial point of k, when measured  > in the stationary system, with the velocity cv, so that x'/(cv) = t."  > Since x' is defined as x'=xvt, and v = x/t, it follows that x' = xx = 0,  > and hence t = 0.  > Einstein has a divide by zero in  >  > 1/2 [1/(cv) + 1/(c+v)]dtau/dt = dtau/dx' + 1/(cv) dtau/dt  >  > at dtau/dx' and the Lorentz transforms cannot be derived.    And just where is there a division by zero here? At the term dtau/dx', because x' = 0. Sheesh... if x' is already zero, how can you have a small part of it? f'(x) = [f(x+h)  f(x)]/h as h tends to zero. You can't do that if h is already zero! Androcles. 

Fumble Index  Original post & context: gHXNc.10505$EZ7.105817118@newstext.cableinet.net 