Doppler Effect (Noun)
Meaning
Change in the apparent frequency of a wave as observer and source move toward or away from each other.
Classification
Nouns denoting natural phenomena.
Examples
- The police officer used a radar gun to measure the speed of the car based on the Doppler effect of the returned signal.
- The change in pitch of the siren as the ambulance sped by was an example of the Doppler effect in action.
- Astronomers use the Doppler effect to calculate the velocity of celestial objects moving away from or towards Earth.
- The Doppler effect is commonly observed in the change in tone of a train's whistle as it passes a stationary observer.
- Meteorologists rely on the Doppler effect to measure wind velocity and direction by analyzing the frequency shift of radar signals scattered by particles in the air.