The Doppler Effect

Thursday, October 26, 2011

First, a review from yesterday…

What is visible light?• Visible light is transmitted via waves (radiation)• Wavelength determines the color - each color has its own

characteristic wavelength

Violet & Blue have the shortest wavelengths Red and Orange have the longest wavelengths

What is visible light?

Red light wavelength

Violet light wavelength

What is the Doppler Effect?

=an observed change in the wavelength of a wave when the source of the wave is moving.

• The wavelength appears shorter when moving toward you, longer when moving away.

What is the Doppler Effect?

Waves are scrunched together in front of the moving source, and the pitch sounds higher

Waves are spread out behind the moving source, and the pitch sounds lower

What is the Doppler Effect?This happens with all types of waves, including light. So what would it look like if an object that emitted light (like a star), was moving toward or away from us?

If the object is moving toward you, the waves bunched up are BLUE-SHIFTED

If the object is moving away from you, the waves spreading out are RED-SHIFTED