The Doppler Effect Refers to the frequency change in waves as objects move toward you or away from you. As things move toward you – waves become compressed, making the wavelength shorter- if wavelength is shorter than frequency is higher As things move away – the waves stretch out, increasing the wavelength and decreasing the frequency Doppler effect car horn

The Doppler Effect and Stars The same thing happens with light waves from stars. Blue Shift Light waves moving toward you become compressed and have a higher frequency/ shorter wavelength Red Shift Light waves moving away from you are stretched and have a longer wavelength/lower frequency

How can we see this? The spectrum tell us what is happening. Red light has a lower frequency/longer wavelength than blue light. So shifting the normal spectrum towards the red means it is moving away because wavelength has shifted to a region with a longer wavelength.

You can also tell if something is further or closer to the earth by looking at how far the spectrum is shifted. The further to the red, the further the galaxy

9/25/14 Page # The Doppler Effect and Motion of Galaxies LT: To explain the Doppler effect and Red shift in terms of shifting wavelengths and frequencies. EVIDENCE: Cornell Notes What is the Doppler Effect? What is Red Shift? What is Blue Shift? How can we use Doppler shift to Detect movement in stars?