Presents a ray-tracing procedure based on some ideas of Herzberger and the matrix approach to geometrical optics. This method, which can be implemented on a programmable pocket calculator, applies to any conic surface, including paraboloids, spheres, and planes. (Author/GA)

Reviews the theories and fundamental principles of physics as they relate to the comprehensibility of the cosmos. (DKM)

Describes procedures for a demonstration of the focal length of spherical lenses and mirrors using an aquarium, a flashlight, and nondairy creamer. Enables nonquantitative three-dimensional observation of these phenomena. (DDR)

Explains why transparency film demonstrates biaxial optical properties. Provides detailed descriptions of the procedure and equipment needed for large-scale optics demonstrations of the polarization interference pattern produced by biaxial crystals. (DDR)

Presents an effective way to demonstrate the difference between direct current and alternating current using red and green LEDs. Describes how to make a tool that shows how an AC voltage changes with time using the afterimage effect of the LEDs. (Author/NB)

Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

Involves students in a study designed to examine the interaction between children's observations of light and shadows and their developing theories in the context of a series of lessons in a third-grade classroom. Results suggest that student's observation of light led to the development of a limited theory about light that was largely useful in…

Describes simple inexpensive modifications to existing equipment that facilitate the computerization of interference and diffraction experiments done in introductory laboratory courses. (JRH)

Provides instructions to make a device able to simulate the typical light pulses seen by a photomultiplier tube. Comments on circuit theory, circuit operation, and pedagogical value. (MVL)

Discusses and provides an example of reflectivity approximation to determine whether reflection will occur. Provides a method to show thin-film interference on a projection screen. Also applies the reflectivity concepts to electromagnetic wave systems. (MVL)

Discusses the production of hundreds of pinhole images of a recent eclipse of the sun through the leaf canopy. Provides photograph of the images. (MVL)

Describes construction and operation of an inexpensive and portable educational hallway exhibit on color mixing. (JRH)

The interrelationship between the various forms of the Planck radiation equation is discussed. A differential equation that gives intensity or energy density of radiation per unit wavelength or per unit frequency is emphasized. The Stefan-Boltzmann Law and the change in the glow of a hot body with temperature are also discussed. (KR)

A procedure for measuring the speed of light using the assumption that the frequency of light remains unchanged as it moves from one medium to another is presented. A laser with a known wavelength and frequency in air was used as a light source. (KR)

The discovery of radio waves, infrared, and x-rays and their importance in describing the universe and its origins is discussed. Topics include radio waves from space, the radio pioneers of World War II, radio telescopes, infrared radiation, satellites, space missions, and x-ray telescopes. (KR)