Blackboard optics: Light sources with lucite lenses.

Blackboard optics: Light sources with Lucite lenses (and prisms and mirrors). The Blackboard Optics Kit contains Lucite converging and diverging lenses, as well as a semicircular disk, Lucite prisms, and plane, concave and convex mirrors. Two light sources are included. Each light source emits a collimated ray of white light that passes through (or reflects from) the optical components, as well as grazing the chalkboard so that the class can see. The lights have magnetic bases which stick to the steel-backed chalkboards. The lenses (and prisms, etc.) are held against the blackboards by a strip of Plexiglas with magnets at both ends. Light sources can be arranged to show focusing of a converging lens, or the virtual focus of a diverging lens. The other components of the Kit can be used to demonstrate reflection, refraction, internal reflection, critical angle, etc.