A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

The model for color vision put forward by Edwin Land is explained. The aspects of the theory that can be demonstrated within the classroom are described. A random arrangement of straight-edged colored areas mounted on a screen, called a Mondrian, projectors, and a computer are used to calculate reflectance. (KR)

The nature and place of biology in Chinese schools, the teaching methods employed, and the training of biology teachers are described. Acknowledging that foreign influences have impinged on it during the past 90 years, the author suggests that Chinese biology teachers are seeking to improve the teaching of biology to suit current Chinese needs.…

Presents low-cost learning activities to help teach elementary students about the earth's magnetic field. One project has students make a model of the earth's magnetic field. Another has them experiment with magnetism. (SM)

Describes some of the activities developed by Project SEED (Science Education through Experiments and Demonstrations) to teach middle-level students basic concepts and principles of physical science in a logical sequence using inexpensive demonstrations, activities, and experiments. (ZWH)

Describes an activity that helps motivate students to learn motion equations by allowing them to observe and analyze their own sports performances. (ZWH)

Dichotomous key for 18 woods in common domestic and architectural use in Britain is provided. It is based upon structures visible with the naked eye and a hand-lens. Descriptions of the necessary anatomy and terminology are given. Timbers include yew, pine, spruce, oak, sweet chestnut, elm, ash, teak, cherry, walnut, mahogany, box, beech,…

An assessment of the water quality of the Colorado River in the Grand Canyon was made, using the following parameters: dissolved oxygen, water temperature, hydrogen ion concentration, total dissolved solids, turbidity, and ammonium/nitrogen levels. These parameters were used to provide some clue as to the "wellness" and stability of the…

A computer program that simulates the random evolution of a metabolic pathway is given. The program shows that natural selection preserves favorable traits if they occur in a specific sequence. (KR)

Described is an activity in which students determine the percent composition of zinc and copper in pennies minted before and after 1982. Students also use pennies to show the natural relative abundance of isotopes and to explain how the weighted atomic mass of the elements is determined. (KR)

Presented is an activity in which students make models of viruses, which allows them to visualize the shape of these microorganisms. Included are some background on viruses, the biology and geometry of viruses, directions for building viruses, a comparison of cells and viruses, and questions for students. (KR)

The planning and organization of problem-solving workshops for teachers are discussed. Suggestions for activities and anecdotes of teacher participation at workshops are provided. (CW)

Described is how the construction of a breathalyzer was used by high school students to focus on a variety of concepts and principles of science and mathematics. The procedure for constructing the breathalyzer, related material, and summary are included. (KR)

Three activities in which students identify and demonstrate similarities and differences in plants and in plant growth are presented. The activities include background information, objectives for the tree ring activities, a list of needed materials, procedures, evaluation procedures, and a glossary. (KR)

A play written for young audiences about recycling and environmental quality is provided. The characters are a young forest dragon, a man, a wizard, and a narrator and are played by puppets. Directions for making the costumes, the wizard's castle, and the dragon's cave are included. (KR)