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)

A teacher of junior high hearing impaired students describes learning experiences in which wildlife (mice, garden snakes, grasshoppers, etc.) were used to develop understanding in life cycle concepts and stimulated language development. (CL)

Suggests using Play Doh to mold models of the nucleus, mitochondria, and inner cellular structures. Students can conceptualize the cell's structures as three-dimensional even though they appear two-dimensional under a microscope. Includes instructions for preparing homemade dough. (Author/JN)

At the end of a secondary school science study of mechanics, a summary lab uses a motorcycle to provide students with the chance to apply some of the concepts they have studied. Exercises from this motorcycle physics lab are discussed. (Author/JN)

Suggests science activities using amaryllis plants. Includes information on growing the plant and its annual growth cycle. (SK)

Described is the observation of the moon with binoculars. Descriptions of the thin crescent moon, three-day-old moon, five-day-old moon, first quarter moon, 10-day-old moon and the full moon are presented and characteristics of each phase are included. (DS)