This paper provides examples of naturally radioactive items that are likely to be found in most communities. Additionally, there is information provided on how to acquire many of these items inexpensively. I have found that the presence of these materials in the classroom is not only useful for teaching about nuclear radiation and debunking the…

Discusses the events surrounding a famous picture of Albert Einstein in which he poses near a blackboard containing a tensor form of his 10 field equations for pure gravity with a question mark after it. Speculates as to the content of Einstein's lecture and the questions he might have had about the equation. (Contains over 30 references.) (WRM)

Four questions related to rain concerning aerodynamic drag force, pressure from the impact of raindrops, impact of wind on the pressure, and stopping force extended on the car by the water are proposed. (YP)

Listed are the 19 artificial elements and the meanings of the terms "natural" and "artificial" when applied to elements are discussed. Describes some commercial uses of each. (YP)

Describes how the authors used portions of popular movies to help students review concepts related to electromagnetism. Movies used and concepts covered in the review are listed, and a sample activity is described. (WRM)

Argues that the study of refraction of sound waves, although usually neglected, is an excellent ancillary to the normal optical approach in physics courses. Discusses the historical context of interest in the science behind outdoor sound propagation, particularly during the Civil War in the United States. (WRM)

Examines the design and construction of a mini-sextant and its use in demonstrating Fresnel reflection, geometric optics, and several common optical techniques. A sidebar explains the basic use of the mini-sextant as a navigational tool. (WRM)

Explains the scientific concepts, technical designs, and materials that make up incandescent light sources. (WRM)

Explains how students can perform a refutation of the ether theory using information from the Global Positioning System (GPS). Discusses the functioning of the GPS, qualitatively describes how position determination would be affected by an ether wind, and illustrates the pertinent ideas with a simple quantitative model. (WRM)