There is a change in the observed frequency (color) of light as a very fast source of light moves toward or away from an observer

 

 

 

 

Doppler Shift

Observed in
fast moving stars

 

 

Memory Trick   "BLUE TO", "RED AWAY"

 

 

 

 

Doppler Effect
St. Mary's H.S.

 

 

 

 

Summary