Discusses refraction in terms of the deviation of light. Points out that in physics courses where very little mathematics is used, it might be more suitable to describe refraction entirely in terms of the deviation, rather than by introducing Snell's law. (DH)

Describes a convenient method of displaying color effects (colors of the blue sky, white clouds, and red sunsets) of Rayleigh and Mie scattering. (ZWH)

Describes several demonstrations that can be easily reproduced to help students understand optical polarization. Displays and supplement text include polarization by reflection; polarization by scattering; liquid crystals; optical activity; calcite; birefringent plastics; retardation plates; photoelasticity; and the "Optical Barber…

Presents and analyzes excerpts from an interview with one student to determine his conceptions of light (including the nature of light and of optical systems). Implications for instruction include taking students' initial beliefs seriously, approaching issues through actual experiences, and using intelligible, plausible, and fruitful…

Measurement of the brightness of moonlight by comparison with lamp-light from a low wattage light bulb is an elementary project in astronomy which illustrates scientific principles for the freshman level. Two methods used for the comparison (shadow brightness method and grease spot method) are explained, with suggestions and expected answers. (DH)

Suggests several techniques for using large parabolic detectors (radio and television dishes) to reinforce principles of physics. Includes discussions of: (1) electromagnetic rays, (2) angles of incidence/reflection, and (3) mathematical derivation of focus location. (DH)

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)

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

Describes a method of making simple transmission gratings by photographing the interference fringes generated by an interferometer. (SL)

Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

Presents the Night Spectra Quest, a pocket-sized chart that identifies in color the spectra of all the common night lights and has an integrally mounted, holographic diffraction grating to look through. (JRH)

Introduces the method of ray tracing to analyze the refraction or reflection of real or virtual images from multiple optical devices. Discusses ray-tracing techniques for locating images using convex and concave lenses or mirrors. (MDH)

Discusses the following questions based on the assumption that students' personal experiences and prior beliefs about plane mirrors can promote interesting discussions: (1) How mirror images are formed? (2) Why doesn't paper behave like a mirror? (3) Does a mirror left-right reverse objects? and (4) Why are corner images of two perpendicular…

Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

Presents a design for constructing a colorimeter as an alternative to the more expensive spectrophotometer. The materials cost less than $25.00. (PR)