PURPOSE: To demonstrate polarization of light.
DESCRIPTION: The first polaroid polarizes the light. Rotating the front polaroid causes the light to become alternately brighter (polaroids aligned) and dimmer (polaroids crossed).
Insert a third polaroid between the two crossed polaroids at a 45 degree angle to show that the electric field is a vector, and to demonstrate a component of a component. Argue with your students about what happens in this experiment when the light passes one photon at a time.
REFERENCES: (PIRA 6H10.10)
EQUIPMENT: Goose neck lamp, large round polaroids on base, extra square polaroid.
SETUP TIME: None.
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