Describes an experiment demonstrating Lenz's law by measuring a magnet falling through a copper tube compared to a nonmagnet falling. Presents diagrams and pictures showing the apparatus. (YP)

Discusses the nature, resolution, focal length, and angle of a pinhole camera. Describes the development and some applications of the camera. Nineteen references are listed. (YP)

Described are the history, formation, and observing techniques of meteors and comets. Provided are several pictures, diagrams, meteor organizations and publications, and meteor shower observation tables. (YP)

Describes a model for generating solution features, or karren, on gypsum blocks within 24-48 hours in order to illustrate terrain-forming processes. This method for replicating landforms provides hands-on experience for students, and can be varied to demonstrate a number of principles. (LS)

Highlights semantic links and shows how the semantic content of hypertext links can be used for information retrieval. Discussion includes indexing and retrieval algorithms that exploit link content and node content; retrieval strategies exploiting semantic links, including conventional retrieval and constrained spreading activation techniques;…

Presents a science experiment to demonstrate the emergence of a snake from an "egg" and illustrates the necessity of heat to induce the hatching process. (MKR)

Describes experiments designed to investigate the cooling rate of microwave-boiled water as compared to that of stove-boiled water. Concludes that within experimental limits, microwave-boiled water and stove-boiled water cool at the same rate. (JRH)

Explores strategies in the situation of a runner trying to evade a tackler on a football field. Enables the student to test intuitive strategies in a familiar situation using simple graphical and numerical methods or direct experimentation. (JRH)

Shows that the conventional wisdom about the extreme inaccuracy of stopwatch measurements during the acceleration and free fall of objects is mistaken. (ZWH)

Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

Using the movie Star Wars as inspiration, an activity is presented to introduce students to water's cohesiveness and how the surface tension of water can be disrupted. (MKR)

Describes a simple, inexpensive system that allows students to have hands-on contact with simple experiments involving forces generated by induced currents. Discusses the use of a dynamic force sensor in making quantitative measurements of the forces generated. (JRH)