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)

Discusses the use of a balance assembled from standard laboratory components to conduct an experiment on the repulsion between two bar magnets. Includes an analysis of data on the two-pole and four-pole models. (CC)

An attempt to empirically test conflicting hypotheses on whether scientific discoveries are the result of research by many or few scientists. The data, drawn from physics, supports the hypothesis that physicists making important discoveries depend on the research of a relatively small number of scientists. (Author/JB)

The history of the short film and the single concept film loop is presented. Lists fourteen reasons why it may be necessary to make and use a film loop. Film loop projectors are analyzed according to present features and deficiencies with predictions on future improvements. (DS)