This document discusses how light travels through different mediums like air, water, and oil. It describes an experiment where the viewer looks at a pencil through an empty glass, a glass filled with water, and a glass filled with oil and water to see how the light bends differently. The document then discusses that white light is made up of the colors of the rainbow and can be split using a prism. It explains how different colored objects reflect different colors of light and how mixing colored paints produces different results than mixing colored lights. The primary colors of light are identified as red, blue, and green and how combining them in different ways produces other colors or white light.