Doppler effect is a change in frequency and wavelength of a wave. It is caused by the change in distance between the thing creating the wave (causer) and whatever is measuring seeing or hearing the wave (watcher or observer).
Similarly, it is asked, how was the Doppler effect discovered?
The Doppler effect, or shift, was named after Christian Doppler, who first discovered it in 1842. The Doppler effect is the change in wavelength of light, radiation or sound from a source due to its relative motion. In the same way, the sound waves from a receding police car sound as though they have a lower frequency.
How does the Doppler effect happen?
A similar change in observed frequency occurs if the source is still and the observer is moving towards or away from it. In fact, any relative motion between the two will cause a Doppler shift/ effect in the frequency observed. A high frequency corresponds to a high pitch.
How does the Doppler effect?
Besides sound and radio waves, the Doppler effect also affects the light emitted by other bodies in space. If a body in space is "blue shifted," its light waves are compacted and it is coming towards us. If it is "red shifted" the light waves are spread apart, and it is traveling away from us.