Describes a technique that uses a helium neon laser, a steel rule, a wooden rule, and a piece of paper to measure the diameter of a hair using the diffraction of light. Details on technique, mathematics, and sources of error are provided. (DDR)

Presents an experiment to demonstrate the diurnal and seasonal motions of the sun, which can be used in different grade levels, depending on the degree of difficulty required for the analysis, as an effort to generate student interest in the scientific method. Includes an activity to teach students elementary concepts of the sun's apparent motion…