Describes the application of an inexpensive relaxation oscillator circuit which uses a thermistor or a cadmium-sulfide photocell to affect the rate of an audio pulse output. It is especially well suited for qualitative and quantitative measurement of heat or light in classroom situations because of its clearly audible output. (Author/JR)

Three physics experiments are described, minimizing difficulties for amateur experimenters. One experiment demonstrates the Doppler shift of light, converting the phenomenon into sound. The second measures Planck's constant. The third measures the universal gravitational constant, which does the same in Newton's theory of gravitation. (Author/JN)

Discusses Barkla's part in the controversy around the J-phenomenon, and the different factors that contributed to the refutation of the phenomenon. (GA)

Guides students through the process of designing a window. Allows them to use technology and a variety of representations while maximizing and minimizing the dimensions based on cost and light. Includes activity sheets. (Author/NB)

Presented are directions for making a flexible lens that can be used by students to show the bending of light rays. Diagrams are included for supplementing the activities. (KR)

Included are nine science activities and questions to be used in the physics classroom. Topics include light, sound, force, radio waves, inertia, friction, and levers. (KR)

Discusses making a computer-simulated rainbow using principles of physics, such as reflection and refraction. Provides BASIC program for the simulation. Appends a program illustrating the effects of dispersion of the colors. (YP)

Discusses a demonstration of interference phenomena using three sheets of polaroid material, a light source, and a light meter. Describes instructional procedures with mathematical expressions and a diagram. (YP)

Provides simple techniques for demonstrating and recording the effect of the changing shapes of moving objects when viewed through a moving slot. Includes a puzzle. A computer shareware program (IBM compatible) that simulates the distortions is available from the author. (MVL)

Describes a method to create holograms for use in different interferometry techniques. Students utilize these techniques in experiments to study the structural integrity of a clarinet reed and the effects of temperature on objects. (MDH)

Describes a homemade experimental chamber constructed to accurately measure the refractive index of a transparent liquid. (MDH)

The model for color vision put forward by Edwin Land is explained. The aspects of the theory that can be demonstrated within the classroom are described. A random arrangement of straight-edged colored areas mounted on a screen, called a Mondrian, projectors, and a computer are used to calculate reflectance. (KR)