Color and Light

Bridge Light

This exhibit is illuminated with pure yellow (mono-chromatic) light from a sodium vapor lamp. This light passes through two glass plates on top of each other. Light reflected from the two surfaces in the "inside" of the glass sandwich interfere with each other. The thickness of the air between the plates determines the interference pattern. Pressing on the plates changes the pattern. Colored prints look black and white under the sodium lamp and full color under a white light.