Producing light -- Light as a form of energy -- Propagation of light -- Speed of light -- Reflection and refraction of light -- Prisms and lenses -- Light and color -- The human eye -- Uses of light -- Sound waves -- Properties of sound waves -- Vibrating strings -- Vibrating columns of air -- Vibrating skins and solids -- Speed of sound -- Supersonic and subsonic vibrations -- Reflection and refraction of sound -- The human ear -- The human voice -- Sound recording and reproduction.