The Amazing Vulnerability of Einstein's Relativity
Dr Ricardo Eusebi: "f'=f(1+v/c). Light frequency is relative to the observer. The velocity is not though. The velocity is the same in all the reference frames."
The video shows a light source and an (initially) stationary observer measuring the frequency to be f=c/d, where d is the distance between the wavecrests.
When the observer starts moving with speed v away from the light source, the videowatcher clearly sees that the speed of the wavecrests relative to the observer shifts from c to c'=c-v, and that this causes the frequency the observer measures to shift from f=c/d to f'=(c-v)/d=f(1-v/c).
Yet Dr. Ricardo Eusebi explains to the videowatcher that the picture is partly illusory. The frequency shift the videowatcher sees (from f=c/d to f'=(c-v)/d) is true, but the cause, the shift in the speed of the wavecrests relative to the observer (from c to c'=c-v) is not real. The videowatcher may see it but it is not there. If the source emitted sound waves, then - OK - the frequency would shift from f=c/d to f'=(c-v)/d, and the cause would be none other than the shift in the speed of the waves relative to the observer, from c to c'=c-v. For light waves, however, the effect, the frequency shift, still exists, but the cause, the shift in the speed of the waves relative to the observer, is absent, or at least some other cause must have produced exactly the same effect.
Needless to say, not all scientists suffer from the above schizophrenia. Many admit, explicitly or implicitly, that the speed of the light waves relative to the observer does vary with the speed of the observer:
Sidney Redner: "The Doppler effect is the shift in frequency of a wave that occurs when the wave source, or the detector of the wave, is moving. Applications of the Doppler effect range from medical tests using ultrasound to radar detectors and astronomy (with electromagnetic waves). (...) We will focus on sound waves in describing the Doppler effect, but it works for other waves too. (...) Let's say you, the observer, now move toward the source with velocity vO. You encounter more waves per unit time than you did before. Relative to you, the waves travel at a higher speed: v'=v+vO. The frequency of the waves you detect is higher, and is given by: f'=v'/(lambda)=(v+vO)/(lambda)."
Tony Harker, University College London: "The Doppler Effect: Moving sources and receivers. The phenomena which occur when a source of sound is in motion are well known. The example which is usually cited is the change in pitch of the engine of a moving vehicle as it approaches. In our treatment we shall not specify the type of wave motion involved, and our results will be applicable to sound or to light. (...) Now suppose that the observer is moving with a velocity Vo away from the source. (....) If the observer moves with a speed Vo away from the source (...), then in a time t the number of waves which reach the observer are those in a distance (c-Vo)t, so the number of waves observed is (c-Vo)t/lambda, giving an observed frequency f'=f(1-Vo/c) when the observer is moving away from the source at a speed Vo."
Tony Harker: "In a time t the number of waves which reach the observer are those in a distance (c-Vo)t."
Consequence: The speed of the light waves relative to the moving observer is:
c' = distance/time = (c - Vo)t/t = c - Vo,
in violation of Einstein's relativity.
Pentcho Valev