Describes 5 solar energy experiments that can be used in secondary school: flat-plate collector, solar thermoelectric generator, simple concentrators, solar cell, and natural storage of solar energy. (MLH)

Describes an experiment that used a four-element radio interferometer to illustrate gravitational deflection as predicted by the theory of general relativity. (MLH)

Described is a physics experiment in which small bits of metal on a water surface will move towards, and away from an electrostatically charged rod. The explanation for the motion of the metal bits deals with their shape and the electrical force on the water surface. (SL)

Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

Describes the experimental procedures used for detecting DNA and RNA synthesis in xenopus cells by autoradiography. The method described is suitable for senior high school laboratory classes or biology projects, if supervised by a teacher qualified to handle radioisotopes. (JR)

Describes an experiment designed to provide the opportunity for studying some of the parameters affecting the stability of Vitamin C in various environments, and to acquaint the student with an experimental procedure for studying simple reaction kinetics and the calculations of specific rate constants. (Author/JR)

Reviews the Hafele-Keating experiment on relativistic changes in eastward and westward moving cesium atomic clocks. Recommends the use of the Sagnac effect to remove the east-west time asymmetry and of the general-relativistic effect to elucidate the clock-rate changes. (CC)

Discusses research activities conducted by scientists from the United State of America, Canada, and the United Kingdom to determine the long-term effects on natural marine ecosystems, especially plankton communities, of such pollutants as heavy metals, synthetic hydrocarbons, and petroleum hydrocarbons. (CC)

Describes a microbiological experiment designed to study the competition between two species of bacteria. Experimental procedures and data obtained in conducting this experiment are provided, together with a discussion of the results. (JR)

Describes the commercial applications of hydroponics, and then outlines ways in which this soilless plant culture method can be used in the science classroom and laboratory. Gives directions for making a suitable growth solution, and suggests appropriate student experiments involving hydroponics. (JR)

Provides description of an activity in which students synthesized sulfanilamide or sulfathiazole, II. The drug was then used as a chemotherapeutic agent. (RH)

A practical magnetotropism experiment with seeds is presented. The procedures, needed controls, and observations of results are described. (DF)