The first proof of the Doppler Effect

The Doppler Effect is physics that is so ingrained in our brain that even the movies get it right. Any time some character is walking down a street and a car or train rushes past, the sound of the horn drops down a few notes as it passes by. Anything else would be jarring. We all hear it, all the time. But how was it… » 1/10/13 7:40am 1/10/13 7:40am