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Replies: 6   Last Post: Apr 21, 2013 1:58 PM

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Pentcho Valev

Posts: 6,212
Registered: 12/13/04
Posted: Apr 21, 2013 1:58 PM
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Bingo the Einsteiniano: "The Doppler effect, or Doppler shift, describes the changes in frequency of any kind of sound or light wave produced by a moving source with respect to an observer. Waves emitted by an object traveling toward an observer get compressed ? prompting a higher frequency ? as the source approaches the observer. In contrast, waves emitted by a source traveling away from an observer get stretched out."

For SOUND waves, when the observer starts moving, the waves get neither compressed nor stretched out - rather, the speed of the waves relative to the observer shifts from c to c'=c±u:
"Sound waves have speed c, and f and L are related by c=Lf. For an observer moving relative to medium with speed u, apparent propagation speed c' will be different: c'=c±u. Wavelength cannot change - it's a constant length in the medium, and same length in moving coordinate system (motion does not change lengths). Observed frequency has to change, to match apparent speed and fixed wavelength: f'=c'/L."

How about LIGHT waves? Bingo? The analogy with sound waves still holds? If the observer starts moving towards the light source with speed v, does the speed of the waves relative to him shift from c to c'=c+v? No? Why, Bingo? The motion of the observer does not compress or stretch out sound waves but does compress or stretch out light waves? But, Bingo, the following video does not show anything like that - rather, it clearly shows that the speed of the light waves relative to the observer varies with the speed of the observer:

Did you see the video, Bingo? Yes? So you saw how the speed of the light waves (relative to the observer) decreased as the observer started moving away from the light source? No? Why are you lying so blatantly, Bingo? That's the way ahah ahah you like it, ahah ahah?

Pentcho Valev

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