http://farside.ph.utexas.edu/teachin...ml/node41.html
University of Texas: "Thus, the moving observer sees a wave possessing the same wavelength (...) but a different frequency (...) to that seen by the stationary observer. This phenomenon is known as the Doppler effect."

That is, in accordance with the formula

(frequency) = (speed of light)/(wavelength),

the speed of light waves (relative to the observer) varies with the speed of the observer, in violation of Einstein's relativity.

http://researcher.nsc.gov.tw/public/...1016202571.pdf
Fang-Yuh Lo, Department of Physics, National Taiwan Normal University: "Observer moves toward source: frequency becomes higher. Observer moves away from source: frequency becomes lower. How much higher (lower)? Wavelength does not change. Change in velocity: Vnew=Vwave±Vobs. (...) Examples: sirens of a traveling vehicle; speed radar of police; red shift in light - astronomical observation."

That is, if the observer starts moving towards / away from the light source with (small) speed v, the speed of the light relative to him shifts from c to c'=c±v, and this shift causes the frequency measured by him to shift from f=c/L to f'=c'/L, where L is the wavelength:

http://www.youtube.com/watch?v=bg7O4rtlwEE
"Doppler effect - when an observer moves towards a stationary source. ...the velocity of the wave relative to the observer is faster than that when it is still."

http://www.youtube.com/watch?v=SC0Q6-xt-Xs
"Doppler effect - when an observer moves away from a stationary source. ....the velocity of the wave relative to the observer is slower than that when it is still."

Pentcho Valev