Light from a vibrating object can be shown as rays moving in all directions from the source. Light rays moving in only one direction are polarized. Using a beam of light with 2 rays as our example, both rays at right angles to each other, a polarizing lens was shown to allow only one set of rays to exit the backside of the lens. Using a second lens at 90 degrees, the complete blockage of light was shown. The physics behind this was explained with diagrams on the board.