Another collection of columns from The Magazine of Fantasy and Science Fiction: 17 pieces, 1982-83--in the usual amiable, faintly soporific Asimov mold. His first topic is electromagnetic radiation--from Newton's discovery of the visible spectrum, through Maxwell's field equations, to cosmic rays (which are actually particles, not radiation). Next: silicon, an element closely related to carbon, and why there are no silicon lifeforms (the main reason is that silicon compounds are insoluble in water)--although, Asimov notes, computers based on silicon chips may one day challenge this assumption. In the section on astronomy: Halley's comet, due to reappear in 1986, and its historical reputation for foretelling dire events; the idea of the geostationary orbit, invented by Arthur C. Clarke; novas and supernovas; the slow realization, over the last few centuries, that Earth is not the center of the universe or, indeed, of any cosmic importance at all. Also on the agenda: the Fibonacci numerical series and the "golden section" of the ancients; Biblical cosmology; an examination of irrationality-in-general, and irrationality in science. Mildly informative, rather complacent, altogether bland: an average outing overall.