Examines aspects of competitive exclusion, which develops when two species jointly utilize a vital resource that is in short supply. When this occurs, one of the species will eventually eliminate the other from the habitat where their distributions overlap, unless one or both species evolve differences that reduce competition. (JR)

Presents a quiz on Copernicus' life, work, and impact on human thought for the purpose of sharpening some of the prevalent ideas about Copernicus. Includes the answers with detailed discussions. (CC)

Describes various parts of a mini car and their chemical composition. Useful information is included for science teachers to relate basic chemistry concepts and techniques with their application in automobile industry. (PS)

Discusses the historical rod contraction-block retardation (RC-CR) ether theory to illustrate its relationship to the special theory of relativity and the possibility of experimental differences between them. Indicates that the RC-CR theory is worthy of the attention of both physicists and science philosophers. (CC)

Contributions made by UNESCO are evaluated and a plan of action is presented. Accomplishments as measured by publications, conferences and workshops, and technical services are discussed, along with future plans. (DF)

Explains vast applications of simple harmonic motion in many fields of physics. With examples of 16 phenomena governed by the law, the author points out in conclusion that phenomena which may look like simple harmonic motion may not be in reality. (PS)

Describes reasons for radically reducing topics usually included in freshman chemistry courses, and stresses historical, philosophical, and sociological aspects in the course presentation. (CC)

Ten hypothetical problems are described which should enable students to understand fundamental concepts of the solar system. (PS)