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)

Traces the development of basic radiation physics that underlies much of today's medical physics and looks separately at the historical development of two major subfields of medical physics: radiation therapy and nuclear medicine. Indicates that radiation physics has made important contributions to solving biomedical problems in medical…

Provided are two tables which contain the latest orbital and physical characteristics of the planets and their main satellites. These tables are part of a series of information materials available from the Astronomical Society of the Pacific, 1290 24th Avenue, San Francisco, CA 94122. (JN)

Discusses some lesser known examples of atomic phenomena to illustrate to students that the old quantum theory in its simplest (Bohr) form is not an antiquity but can still make an important contribution to understanding such phenomena. Topics include hydrogenic/non-hydrogenic spectra and atoms in strong electric and magnetic fields. (Author/JN)

A digital electronics course taught on four successive Saturdays is described. Includes comments on course goals, text materials, and hardware. A table summarizing class and laboratory parts of the sessions is also provided. (JN)

The monochromaticity, directionality, and intensity of laser light make possible spectroscopic investigations of previously unimagined precision. Several of these investigations and their applications are discussed. (Author/JN)

Highlights the career and accomplishments of Philip Morrison, one of the most thoughtful advocates of arms control, valued for his scientific contributions to the Manhattan Project, theoretical physics, astrophysics, and the public understanding of science. (Author/JN)