Discusses the history of electron theory from 1897 to 1987. Includes the works of some physicists, such as Thomson, Lorentz, De Broglie, Bohr, Pauli, Dirac, Feynman, Wheeler, Weinberg, and Salam. (YP)

An analogy from the game of baseball can be used to examine the philosophy involved in statistics surrounding quantum mechanical events. The "Strong Baseball Principle" is proposed and discussed. (CW)

Reports on the implementation of a relatively low-cost, versatile, and intuitive system to teach basic mechanics based on the use of a Charge-Coupled Device (CCD) camera and inexpensive image-processing and analysis software. Discusses strengths and limitations of CCD imaging technologies. (JRH)

Describes the planning and conducting of snow sled competitions as a means to teach concepts in classical mechanics. (JRH)

Describes the use of a laboratory-based exam in mechanics that makes students use metersticks, stopwatches, and spring scales to examine physical situations, make some calculations to predict what will happen, and then test their predictions. Includes a description of the lab stations for the actual exam. (JRH)

Describes an experiment to study the motion of a rocket-propelled vehicle over the entire duration of the engine burn using a video system with a frame-by-frame playback and a Sonic Ranger for ultrasonic position movements. Enables students to study the impulse-momentum principle and the effects of a time-varying force. (JRH)

Presents a brief historical review and a discussion of the Bohr theory aimed at helping readers understand more completely the development of atomic quantum physics and comprehend more precisely and profoundly the essence of the correspondence principle. (JRH)

Discusses the effects of blowing bubbles in extremely cold weather. Describes the freezing conditions of the bubbles and some physical properties. Suggests using the activity with all ages of students. (MVL)

Describes the brake sensors and the essential elements of a differential in explaining how antilock braking systems (ABS) function. (MVL)

Discusses five problems concerning Newton's law of universal gravitation. Provides detailed answers to each question. (MVL)

Presents an excerpt from the book entitled "Lonely Hearts of the Cosmos." Provides narration of behind-the-scenes events in the lives, the scientific debates, and the intellectual triumphs of the two physicists responsible for inventing the concept of the black hole. (JJK)

Fifteen true-false statements are provided that are to be used to spur discussion and arguments about the concept of motion. Each statement is carefully worded to sound plausible, but each one attacks some misunderstanding common to students who are encountering Newton's mechanics for the first time. (KR)

A model of the inelastic collision between two spheres rolling along a horizontal track is presented, taking into account the effects of frictional forces at impact. This experiment makes possible direct estimates of the coefficients of restitution and friction. (Author)

The forward force of water on a hose is calculated using only the pressure gradient, the radius and length of the hose. The misconception about recoil on the nozzle is discussed. Dissipation energy and the consequent heat generation in a fluid flow are also described. (KR)

Describes an activity to determine whether the length of the yellow (warning) signal of a traffic light provides adequate time to stop or pass through the intersection. Discusses the necessary equations, mathematics, and subsequent graphs. (MVL)