This document discusses how light travels and interacts with matter. It explains that light travels from the sun to earth at a distance of 90 million miles. Light is made up of electric and magnetic waves, and travels faster in a vacuum than in other materials. The document defines transparent, translucent and opaque materials and how they interact with light. It describes the laws of reflection and refraction, and how shadows, mirrors and the bending of light allow us to see objects and images. Color is explained by the different wavelengths of light in the visible spectrum.