Describes methods to observe diffraction effects without special equipment. Discusses the theory behind the different methods and associated problems. (JRH)

Presents useful tips for taking pictures of stars and comets without any special equipment. (JRH)

Discusses issues related to perpetual population growth. Argues that if we believe that there are no limits to growth, we will have to abandon the concept of a spherical Earth which puts limits to growth. (JRH)

Discusses the behavior of the current near the end of the paper in the electric-field mapping experiment and approaches to solving problems associated with this behavior. Presents programs that can be used to model the boundary condition computationally. (JRH)

Describes an experiment that involves measuring the intensity of laser light passed by a linear polarizer. Discusses polarization effects, orthogonal polarizations, instrumentation, and further experiments. (JRH)

Describes systems used to introduce students to the concept of torque and discusses the effects that puzzle the beginner in the introductory lab. (JRH)

Describes a stimulating interactive group project on measuring the lengths of solar days that directly supports concepts related to orbits, motion, and time in a physics or astronomy curriculum, and has the flexibility to extend from a few days to several weeks. Provides new measurement experiences for students and teachers and opportunities for…

Presents a course, Physics and Time, that centers on a few topics that students with limited mathematics training and no previous science can explore in depth. Discusses concepts of time, measuring time, arrows of time, and linearity versus nonlinearity. (JRH)

Discusses the working of a dial lock using a scaled-up model. (JRH)

Describes a method to teach introductory astronomy students about the phases of the moon. Uses video techniques to aid students in developing the skill of visualizing the same phenomenon from different frames of reference. (JRH)

Describes an experiment to measure the speed of air in the air jet caused by blowing air through a drinking straw. (JRH)

Describes a physics demonstration show where students conduct demonstrations for the rest of the school. By demonstrating a concept, students are forced to learn that concept in depth. Appendix includes a physics demonstrations resource list. (JRH)

Describes an experiment to measure the acceleration of a bungee jumper. Uses energy considerations to explain this anomalous acceleration and presents experimental results using several different types of ropes and a chain. (JRH)

Presents a method to teach the concept of beats as a generalized phenomenon rather than teaching it only in the context of sound. Involves using a video camera to film a computer terminal, 16-mm projector, or TV monitor. (JRH)

Describes an apparatus that can be used to illustrate the relationships that are necessary between the earth, the moon, and the sun, and the orbital tilts of these bodies to produce eclipses. (JRH)