doppler effect

     

The Doppler effect, name after Christian Doppler, is the change in frequency and wavelength of a wave for an observer moving relative to the source of the waves. For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source are relative to the medium in which the waves are transmitted. The total Doppler effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analysed separately. For waves which do not require a medium, such as light or gravity in special relativity, only the relative difference in velocity between the observer and the source needs to be considered.

Trivia about doppler effect

  • In this "effect" first described in 1842, the pitch of a train whistle seems to change as it moves
  • The apparent change in the pitch of the whistle from a moving train is due to this effect
  • The red shift of galaxies & the change in the pitch of a train whistle are examples of this man's effect
  • (Cheryl of the Clue Crew at the Franklin Institute in Philadelphia) Weather forecasting radar uses this effect because radio waves change frequency like sound waves

Found pages about doppler effect