Presented is an alternative approach to teaching the Physical Science Study Committee (PSSC) wave model of light, using microwaves. Effectiveness of the alternate approach was determined by student achievement of six objectives. Both experimental and conventional PSSC methods were satisfactory for reaching the objectives. (DS)

The diffraction of a full thermal atomic potassium beam by a single slit was observed. Four experimental diffraction patterns were compared with that predicted by de Brogtie's hypothesis and simple scalar Fresnel diffraction theory. Possible reasons for the differences were discussed. (LC)

Describes the computer generation of random and regular arrays of apertures on photographic film and their applications for classroom demonstrations of the Fraunhofer patterns produced by simple and complex apertures, Babinet's principle, resolution according to the Rayleigh criterion, and many other aspects of diffraction. (LC)