Doppler effect


Doppler effect
/dop"leuhr/, Physics.
(often l.c.) the shift in frequency (Doppler shift) of acoustic or electromagnetic radiation emitted by a source moving relative to an observer as perceived by the observer: the shift is to higher frequencies when the source approaches and to lower frequencies when it recedes.
[1900-05; named after C. J. Doppler (1803-53), Austrian physicist]

* * *

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.

* * *

      the apparent difference between the frequency at which sound or light waves leave a source and that at which they reach an observer, caused by relative motion of the observer and the wave source. This phenomenon is used in astronomical measurements, in Mössbauer effect studies, and in radar and modern navigation. It was first described (1842) by Austrian physicist Christian Doppler (Doppler, Christian).

      The following is an example of the Doppler effect: as one approaches a blowing horn, the perceived pitch is higher until the horn is reached and then becomes lower as the horn is passed. Similarly, the light from a star, observed from the Earth, shifts toward the red end of the spectrum (lower frequency or longer wavelength) if the Earth and star are receding from each other and toward the violet (higher frequency or shorter wavelength) if they are approaching each other. The Doppler effect is used in studying the motion of stars and to search for double stars and is an integral part of modern theories of the universe. See also red shift.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Doppler effect — Doppler io efektas statusas T sritis automatika atitikmenys: angl. Doppler effect vok. Doppler Effekt, m rus. доплеровский эффект, m; эффект Доплера, m pranc. effet Doppler, m ryšiai: sinonimas – Doplerio efektas …   Automatikos terminų žodynas

  • Doppler effect — Doppler io reiškinys statusas T sritis automatika atitikmenys: angl. Doppler effect vok. Doppler Effekt, m rus. доплеровский эффект, m pranc. effet Doppler, m ryšiai: sinonimas – Doplerio reiškinys …   Automatikos terminų žodynas

  • Doppler effect — (also Doppler shift) ► NOUN Physics ▪ an increase (or decrease) in the apparent frequency of sound, light, or other waves as the source and the observer move towards (or away from) each other. ORIGIN named after the Austrian physicist Johann… …   English terms dictionary

  • Doppler effect — [däp′lər] n. [after C. Doppler (1803 53), Austrian mathematician and physicist] the apparent change of frequency of sound waves or light waves, varying with the relative velocity of the source and the observer: if the source and observer are… …   English World dictionary

  • Doppler effect — n 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… …   Medical dictionary

  • Doppler effect — Change of wavelength caused by motion of the source. An animation illustrating how the Doppler effect causes a car engine or siren to soun …   Wikipedia

  • Doppler effect —    Also known as Doppler shift. Both eponyms refer to the Austrian mathematician and physicist Christian Andreas Doppler (1803 1853), who first described the effect in or shortly before 1842. In perceptual neuroscience, they are used to denote an …   Dictionary of Hallucinations

  • Doppler effect — Doplerio efektas statusas T sritis Standartizacija ir metrologija apibrėžtis Matuojamosios spinduliuotės dažnio pokytis, atsirandantis dėl reliatyviojo judesio tarp pirminio ar antrinio šaltinio ir stebėtojo. atitikmenys: angl. Doppler effect vok …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • Doppler effect — Doplerio efektas statusas T sritis fizika atitikmenys: angl. Doppler effect vok. Doppler Effekt, m rus. эффект Доплера, m pranc. effet Doppler, m …   Fizikos terminų žodynas

  • Doppler effect — Doplerio reiškinys statusas T sritis fizika atitikmenys: angl. Doppler effect vok. Doppler Effekt, m rus. эффект Доплера, m; явление Доплера, n pranc. effet Doppler, m …   Fizikos terminų žodynas


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.