Have students use a textbook or an encyclopedia to build a timeline of the history of theories about the nature of light since the 1600s. Working either as a class or individually, have students place the following individuals on the timeline, together with a 2-3 sentence summary of each theory about the nature of light. Philipp Lenard 2. Explain that light is an electromagnetic phenomenon, part of the electromagnetic spectrum. The spectrum is made up of waves of different wavelengths and frequencies.
Light is the range of the electromagnetic spectrum that stimulates the retina and enables sight.
If students have already studied waves, ask them to name some general characteristics of waves. Physics students can do the Riverdeep SimLibrary activity, Two Slits , which explores interference patterns for Young's double slits. Students examine the effects of the separation distance between slits and the wavelength of the light. They are asked to identify the wavelength of a given pattern. Light as Rays 1.