Pentcho Valev
2015-07-02 20:41:34 UTC
"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://farside.ph.utexas.edu/teaching/315/Waveshtml/node41.html
"Thus, the moving observer sees a wave possessing the same wavelength (...) but a different frequency (...) to that seen by the stationary observer."
http://physics.bu.edu/~redner/211-sp06/class19/class19_doppler.html
"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'/λ=(v+vO)/λ."
Bingo the Einsteiniano: No! The moving observer does not see a wave possessing the same wavelength, and relative to him the waves do not travel at a higher speed v'=v+vO, Divine Einstein, yes we all believe in relativity, relativity, relativity:
http://www.lp2i-poitiers.fr/doc/aps/albatros/uk/pages/doppleffet.html
Bingo the Einsteiniano: "The observer moves closer to the source. The wave received has a shorter wavelength (higher frequency) than that emitted by the source. The observer moves away from the source. The wave received has a longer wavelength (lower frequency) than that emitted by the source. Divine Einstein! Yes we all believe in relativity, relativity, relativity!"
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/big_bang_observed/index.html
Bingo the Einsteiniano: "Every sound or light wave has a particular frequency and wavelength. In sound, they determine the pitch; in light they determine the color. Here's a light wave and an observer. If the observer were to hurry towards the source of the light, the observer would now pass wavecrests more frequently than the resting observer. That would mean that moving observer would find the frequency of the light to have increased (and correspondingly for the wavelength - the distance between crests - to have decreased). Divine Einstein! Yes we all believe in relativity, relativity, relativity!"
http://astro.berkeley.edu/~mwhite/darkmatter/dopplershift.html
Bingo the Einsteiniano: "...the sound waves have a fixed wavelength (distance between two crests or two troughs) only if you're not moving relative to the source of the sound. If you are moving away from the source (or equivalently it is receding from you) then each crest will take a little longer to reach you, and so you'll perceive a longer wavelength. Similarly if you're approaching the source, then you'll be meeting each crest a little earlier, and so you'll perceive a shorter wavelength. (...) The same principle applies for light as well as for sound. In detail the amount of shift depends a little differently on the speed, since we have to do the calculation in the context of special relativity. But in general it's just the same: if you're approaching a light source you see shorter wavelengths (a blue-shift), while if you're moving away you see longer wavelengths (a red-shift). Divine Einstein! Yes we all believe in relativity, relativity, relativity!"
Bingo the Clowno
Pentcho Valev