Answer to Question #290580 in Physics for Jez

Question

What is the Doppler effect? How does it work? If a star looks bluer to us than it should, is the start moving away from us or toward us? Explain.

Answer 1

Doppler effect is the apparent increase or decrease in wavelength due to relative speed of the source to the observer. A blue star is moving toward us because the wave length shortens and shorter wavelengths are blue.