Exploratorium
Exploratorium: Science Snacks: Physics/light
Here is a large collection of simple science class activities for understanding the physics of light.
Other
Guidance/the Alphabet of Art/value
An informative site that explains Value as an element of art using examples of Rembrandt's work. This is a good juxtaposition between the works "Night Watch," and "The Anatomy Lesson," by Rembrandt.