Clocks and Rhythms (Science Concepts)

Grade 5 Up-This well-written, well-researched title is part of a series designed to introduce key concepts by exploring their development, applications, and relationships to science knowledge as a whole. The authors cover such topics as keeping time with man-made clocks and calendars; the rhythms of planet Earth; and the daily, monthly, and seasonal rhythms of plants and animals. They also discuss society-produced disturbances to natural rhythms (jet lag, late-night shifts, and daylight savings time) and "Biological Clocks and the Future," including the effects of space travel and the possibilities of turning back the aging clock. The format is inviting for both general interest reading and research. Related topics appear as brief, boxed items. Scientific terms that are defined in the glossary are highlighted throughout in boldface type. The color photographs have informative captions, and the annotated listing of Internet resources will be useful to teachers as well as to students.
Carolyn Angus, The Claremont Graduate School, CA
Copyright 1999 Reed Business Information, Inc.

Despite the title, the focus of this introduction is the natural rhythms of humans, animals, and the environment: daily or circadian rhythms, monthly cycles, and seasonal patterns. The chapter on early clocks and ancient calendars seems out of place, and although the chapters on society's manipulation of time and the effects on the body are pertinent, the very brief inclusion of cloning doesn't fit the topic, even if the tie-in is "turning back the aging clock." The text, which will require a capable reader, is well organized and the explanations are clear; boxed facts and diagrams add interesting bits. The pictures vary in quality; several of the color photographs are so dark they're difficult to distinguish. A glossary and Internet and print resources are appended. Linda Perkins