What is the DOPPLER EFFECT Doppler and Sound
- Slides: 8
What is the DOPPLER EFFECT?
Doppler and Sound Ø When sound waves are made they spread out evenly in all directions like ripples on a pool of water Ø A stationary train sounds the same from all directions.
Ø When the train making the sound or the listener are moving there is an apparent change in frequency. Ø Higher frequency when moving towards each other. Ø Lower frequency when moving apart.
Doppler and Light Ø The Doppler effect occurs with light waves and other energy wave types. Ø In the area of astronomy the Doppler effect helps explain the red shift in stellar objects.
Red Shift Stars emit light in specific patterns called spectral lines. Ø Stellar objects found outside of our galaxy all had spectral lines that had shifted towards the red end of the spectrum. Ø
ØRed light has lower wave frequency which means the objects are moving away from the earth.
Big Bang Ø The red shift shows every galaxy is moving away from the Earth. Ø This supports the concept of an expanding universe. This in turn supports the Big Bang theory.
Links Ø www. pbs. org/wnet/hawking/strange/html/untitled_14_stuff. html webphysics. davidson. edu/Applets/Doppler. html www. colorado. edu/physics/2000/applets/doppler 2. html lectureonline. cl. msu. edu/~mmp/applist/doppler/d. htm
