For 10 points, name this effect that explains the change in the frequency of waves as they move by an observer, typically demonstrated by a moving train.
This effect's transverse form was detected by the Ives-Stillwell experiment, and Hubble used this effect to prove the expansion of the universe. This effect is used in astronomy to measure the speed of moving galaxies because the light they produce may blue shift or red shift, which are both examples of this effect. For 10 points, name this effect that explains the change in the frequency of waves as they move by an observer, typically demonstrated by a moving train.
This effect's transverse form was detected by the Ives-Stillwell experiment, and Hubble used this effect to prove the expansion of the universe.
{Doppler} effect