PURPOSE: To show that a box with a small hole behaves like a blackbody, that is, the light that exits the hole is independant of the nature of the walls and is only a function of the temperature.
DESCRIPTION: The two equal boxes each have small holes. The holes both appear equally dark. But the inside of one box is white, while the other is black. The radiation emerging from the holes is a function only of temperature.
EQUIPMENT: Two boxes, stored in the modern physics cabinet.
Updated by Jun Qi in 3/22/2000