Summary
- The Doppler effect…
- is the apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer.
- applies to all types of waves.
- increases the frequency of a wave when the source moves toward the observer.
- This is also known as a blue shift since it shifts the color of a monochromatic light wave toward the blue end of the spectrum. (Blue light is on the high frequency end of the visible spectrum.)
- decreases the frequency of a wave when the source moves away from the observer.
- This is also known as a red shift since it shifts the color of a monochromatic light wave toward the red end of the spectrum. (Red light is on the low frequency end of the visible spectrum.)
