Provides an analysis of the forces causing the erratic motion of a knuckleball. Reveals the manner the ball should be thrown to provide maximum deflection. (Author/CP)

Describes construction of a variety of relatively inexpensive cameras for astronomical purposes. (CP)

Photographs show three simple demonstrations of deceptive centers of gravity. (CP)

The circular motion observed when water drains into a smooth opening is analyzed. This action, as well as cycloidal atmospheric motion, is explained as the result of rotation of the coordinate system. (CP)

Describes an elementary school science project focusing on hatching chickens. (PEB)

Provides suggestions for an archaeology activity for elementary school children. (PEB)

Describes five experiments that are done with eggs, including one on osmosis, and an experiment on gyroscopics. (BR)

A simple photometer constructed from an LED and an op amp can be used to measure light in a number of physical situations. A variety of LEDs exist to investigate different wavelength ranges. Combined with an inexpensive transit, the LED photometer can be used to carry out skylight studies and atmospheric optical depth measurements. The activities…

Describes an experiment that allows the students to verify the assumption that light travels in straight lines. (GS)

Describes a science activity, using a bacterium and a fungus, to illustrate the effects of competition and barriers on geographical distribution. (Author/PEB)

Describes an experimental "accident" that resulted in much student learning, seeks help in the identification of nematodes, and suggests biology teachers introduce similar accidents into their teaching to stimulate student interest. (PEB)

Discussed is a science project in which secondary school physics students constructed a radio telescope to use in the study of radio astronomy. (PEB)