http://www.pitt.edu/~jdnorton/teachi...ods/index.html
"An immediate consequence of the light postulate is that observers in the inertially moving spaceship will not judge the light signal to have slowed, no matter how fast they are moving past us. That is impossible according to classical Newtonian physics."

They will judge the frequency to have decreased, in accordance with classical Newtonian physics:

f' = f(1-v/c) = (c-v)/L

where v is the speed of the spaceship (relative to us), f=c/L is the original frequency and L is the wavelength. Clearly the light signal is slower in the spaceship (c'=c-v):

http://www.youtube.com/watch?feature...&v=EVzUyE2oD1w

Since the "immediate consequence of the light postulate" is false, the light postulate is false as well. That is, the speed of light does depend on the speed of the light source.

Pentcho Valev