Describes the use of a laser pointer to measure the speed of light by incorporating the phase delay between a modulated split beam of light. (JRH)

Describes a measurement lab that introduces measurement and presents a simple example of how to use error analysis with an obvious illustration of its value. The experiment measures the diameters of pinhole images of the sun and uses them to calculate the heights of the leafy canopy that created the images. (JRH)

Presents a polymerase chain reaction (PCR) laboratory exercise that can be performed by introductory biology students in 1 45- to 55-minute class period. Includes a general description of the polymerase chain reaction, materials needed, procedure, and details of interest to teachers. (JRH)

Describes the construction of a vernier scale made of chart paper that can be used to improve the readability of scales on burettes or graduated cylinders. (JRH)

Describes a lab designed to analyze the organic compounds found in an ordinary fast-food lunch. (ZWH)

Teachers often use demonstrations to prepare students for a science experiment. This article describes a demonstration method to ensure that students are not supplied with all the answers before the actual experiment and to help them to remain an active part of the science lesson. (ZWH)

Examines the experimental program initiated by Albert Michelson at the end of the nineteenth century through a literary analysis of its reception. Provides various interpretations of the failed experiments by science commentators over a period of decades. (HB)

Examines recent developments in Nancy Cartwright's philosophy of science against the background of her earlier ideas. Argues that Cartwright's views fall within the broad empiricist tradition. Contains 19 references. (Author/WRM)

Describes the inexpensive and safe method of using roundworms in the classroom or laboratories. Because parasitic infections are so common, students should learn about worms. Provides statistics on just how many people have a worm infection in the world. Explains how to study living nematodes, and obtain and use earthworms. (Contains 13…

Details a laboratory experiment focusing on the relationship between the structure and function of the tracheary elements of the xylem. (MKR)

Presents a simple experiment to compare the performance of the PASCO Introductory Dynamics System with that of an Ealing student air track. Discusses the relative advantages of both. Concludes that for a wide assortment of motion activities in a low friction environment, or studies of frictional forces, the PASCO Introductory Dynamics System is a…

Discusses enzymes, catalysts, and factors that affect the rate of a chemical reaction. Presents activities based on enzyme action on hydrogen peroxide and lactose intolerance. (Author/JRH)

Explains how to apply India ink to observe phagocytosis and vacuole formation in Tetrahymena. Recommends this experiment for introducing students to microscope use. (YDS)

Aims to determine the pollution content of the water at two locations on Buffalo Creek, Evington, Virginia, by examining the benthic macro-invertebrates that inhabit the test sites. (Author/YDS)

Describes a simple exercise in percolation theory that can be performed easily and quickly in a laboratory using paper and a hole punch. (Author/MM)