21
Doppler
effect
•Effect similar in light and sound
–Waves compressed with source moving toward
you
•Sound pitch is higher, light wavelength is
smaller (bluer)
–Waves stretched with source moving away
from you
•Sound pitch is lower, light wavelength is
longer (redder)
•v
= velocity of source
•c
= velocity of light (or
sound)
•l
= apparent wavelength of
light
•lo =
original wavelength of light
