Doppler effect

Doppler effect

noun

Definition of DOPPLER EFFECT

: a change in the frequency with which waves (as of sound or light) from a given source reach an observer when the source and the observer are in motion with respect to each other so that the frequency increases or decreases according to the speed at which the distance is decreasing or increasing

Origin of DOPPLER EFFECT

Christian J. Doppler

First Known Use: 1905

Rhymes with DOPPLER EFFECT

aftereffect, benign neglect, bioprospect, halo effect, hypercorrect, idiolect, interconnect, megaproject, ripple effect, semierect

Doppler effect

noun    (Medical Dictionary)

Medical Definition of DOPPLER EFFECT

: a change in the frequency with which waves (as sound, light, or radio waves) from a given source reach an observer when the source and the observer are in motion with respect to each other so that the frequency increases or decreases according to the speed at which the distance is decreasing or increasing—compare shift a

Doppler effect

noun    (Concise Encyclopedia)

Apparent difference between the frequency at which waves—including light, sound, and radio waves—leave a source and that at which they reach an observer. The effect, first described by the Austrian physicist Christian Doppler (1803–1853), is caused by the relative motion of the observer and the wave source. It can be observed by listening to the blowing horn or siren of an approaching vehicle, whose pitch rises as the vehicle approaches the observer and falls as it recedes. It is used in radar and to calculate the speed of stars by observing the change in frequency of their light.