We have all noticed how the horn of a speeding car changes as it approaches: each wave-peak is emitted from a closer point, so the wave is “squeezed” and the pitch increases. As the car recedes, the ...

The Doppler shift of sound or light waves from a moving source is familiar to physicists and non-physicists alike. Now, researchers in China and Australia have seen the more exotic inverse Doppler ...

Today's Google Doodle celebrates the 214th birthday of Christian Doppler, whose discovery of the Doppler Effect now helps us track thunderstorms, study distant galaxies, and much more. Doppler was an ...