Briefly outlines the theoretical basis of the phenomenon of photoconductivity and describes a simple experiment which demonstrates the photoconductive properties of cadmium sulfide. (JR)

Describes a number of activities designed to assist student understanding of the phenomenon of light bending when it passes from one meduim to another. (JR)

Describes the construction of a simple apparatus capable of converting solar energy into mechanical energy. Construction of the engine'' is inexpensive, and should stimulate student interest in the idea of producing power directly from the sun. (JR)

Describes two experiments in physics, using the same inexpensive apparatus, that may be performed as projects by high ability secondary science students. (JR)

Directions are given for student learning activities on illusions, shadows, the spectrum, and colors. (DT)

Presents experiments with polarized light for grades 8-12 which can produce colorful effects with a minimum of equipment and can illustrate many principles of physics, chemistry, and geology. (MKR)

Presents three experiments exploring aspects of the greenhouse effect. Topics and discussion includes radiation in energy transfer, emissivity and absorptivity, the irrelevance of reflectivity, a digression on insulators and convection, climate change, and radiative energy balance. (MCO)

Discusses the nature of virtual images and how they can be plotted and used to reveal important relationships between objects and their mirror reflections. Describes some applications of virtual images in the theater and classroom. (JR)

Applications of wheels are shown to be an invaluable tool in teaching the processes and technology of science. (DF)