image credit: Wikimedia Commons; image source; larger image
Polarization and Interference Colors
-- For this photo, the protractor was backlit, and the light passed through two crossed polarizers, one behind the protractor and one in front.
-- Stress within the protractor affects the phase of the polarized light, producing cancellation of some wavelengths and reinforcement of others, and the result is the pattern of colors that you see.
-- Materials like the clear plastic of the protractor are called birefringent. To learn more about them, see the Hyperphysics pages Polarization and Interference Colors and Birefringent Materials.
Login to Comment on this Item
CoolStuff Newsletter: Polarization
Visit CoolStuff Newsletter: Polarization to learn more about polarization and birefringence, and for related activities.