Explains why one orientation of an asymmetric spring-and-mass system leads to a higher frequency of 0000000000 than another orientation. (WRM)

Explains the shape distortions that take place in fluid packets (bubbles or drops) with steady flow motion by using the laws of Archimedes, Pascal, and Bernoulli rather than advanced vector calculus. (WRM)

Examines the design and construction of a mini-sextant and its use in demonstrating Fresnel reflection, geometric optics, and several common optical techniques. A sidebar explains the basic use of the mini-sextant as a navigational tool. (WRM)

Explains how students can perform a refutation of the ether theory using information from the Global Positioning System (GPS). Discusses the functioning of the GPS, qualitatively describes how position determination would be affected by an ether wind, and illustrates the pertinent ideas with a simple quantitative model. (WRM)

Explains some of the properties of refrigerator magnets by conceptualizing their makeup as a line of tiny, consecutive horseshoe magnets. (WRM)

Argues for innovation in teaching physics. Contends that the major premise of work in physics education is that educational innovations should be based on research into student learning, and that the effectiveness of an innovation should be evaluated by openly assessing what students have actually learned--a notion that is starling to those in…

Describes a lesson in which students perform simple body movements in order to gain insight into the relationship between time and the astronomical motions of the earth, and how these motions influence what we see in the sky at various times of the day and year. (WRM)

Describes how to observe the pulse structure of the infrared signals from the light-emitting diode in a TV remote control. This exercise in decoding infrared digital signals provides an opportunity to discuss semiconductors, photonics technology, cryptology, and the physics of how things work. (WRM)

Discusses the nature and orientation of the forces that allow an engineless airplane (a glider or sailplane) to fly. A glider flying at constant velocity provides a nice example of an object moving under the action of several forces that add to zero. (WRM)

Discusses possibilities for the application of telepresence to physics and teaching. Telepresence allows a computer user to effectively be present at some other location through the use of remote cameras, sensors, and controls. (WRM)

Describes a contest in which students attempt to build a device that produces a donut-shaped air pulse that will travel the greatest distance with the most accuracy. (WRM)

Explains the origin of supernumerary rainbows--the appearance of three or more rainbows in the sky at a time. (WRM)

Provides a qualitative explanation for why the electric field far from a dipole is inversely proportional to the cube of the distance from the center of the dipole. (WRM)

Describes an experiment undertaken to determine what relative electric charges would result if three or more pieces of transparent tape were placed on top of each other and then separated one at a time. Makes suggestions for using the project in high school and undergraduate classes. (WRM)

Explains the motion that occurs when a particle with an initial velocity to the right is acted upon by a constant downward force. Considers what happens when the speed of the particle approaches the speed of light in particular. (WRM)