Describes the construction and use of an inexpensive, homemade polarimeter which can analyze optically active compounds. Ideas for activities using the apparatus are suggested. (JN)

A thermal oscillator is a self-sustained, nonlinear oscillating system. One part of the system vibrates continuously because of the transfer of heat. Four such devices, two new and two demonstrated in the 19th century are described. Although each depends on the periodic redistribution of heat, they are all quite different. (Author/JN)

A homemade device for testing particle scattering is described. Also described are experiments in zero gravity conducted in free fall in the cargo space of an airplane belonging to the National Aeronautics and Space Administration. (JN)

Discusses the physics behind making ice cream in a hand-cranked ice cream maker. Ingredients in the maker are cooled and hardened by a bath of ice, water, and rock salt. Several experiments to investigate the variables involved in preparing the ice cream (and related desserts) are included. (JN)

Discusses the acoustics of bells by examining what determines the quality of a bell, the frequency it emits, and the note perceived by the listener. The analysis concentrates on a ship's bell but also considers several handbells. Laboratory bench set up for studying bells and nodal lines of bells are illustrated. (BC)

Discusses four types of breaking waves (spilling, plunging, collapsing, and surging) and effect of these waves on beaches. Also discusses various patterns left by waves in sand (for example, ripples) and cusps (thin sheets of water forming horizontal curves as they wash up the slope of a beach). (Author/JN)

A retroreflector is a mirror that removes distortion from a light beam. Describes experiments using the retroreflector as well as related phenomena. (JN)

The tendency of a poured liquid to cling to the outside of a container is known as the "teapot effect." The nature of the teapot effect and experiments investigating this phenomenon are described. (JN)

Describes experiments using fluidyne engines. These engines (which have liquid pistons), started by external heat sources, are used primarily for pumping water. Examples of various engines built from U-shaped tubes or from coiled tubes in fruit jars are provided. (DH)

Explains and illustrates strange events which occur when two pendulums interact through a variety of interconnections. Phenomena addressed include: pendulums coupled by a spring, rod, or string; vertical and rotational oscillations, and synchronous and mirror-image swinging. A resonant-spring pendulum and a Wilberforce pendulum are also discussed.…

Presents a field formula for calculating speed and flight efficiency of soaring birds. By estimating the size of the bank angle and timing the complete circle, the observer can determine the speed and circling radius on a chart provided. Lift coefficients and flight characteristics of several birds are also discussed. (DH)

Discusses how to stop a spinning object (such as rotating fan blades) by humming and the perception of curious blue arcs around a light. Background information, relevant research, and activities related to these two topics are provided. (JN)

Discusses various physics concepts/principles that can be illustrated by amusement park rides. Examples of rotational dynamics, energy conservation, acceleration, and others can be demonstrated by such rides as roller coasters, Ferris wheels, and a variety of rotating rides. (JN)

Water striders are insects that walk and run on the surface of water. Discusses the morphology, physiology, and behavior of these insects. Includes diagrams of stages in the movement of a typical strider. (JN)

Discusses forces that shape the behavior of water as a drop meanders down a windowpane. A homemade apparatus for studying meanders is described along with several experiments. Contact angles, molecule attraction, surface area, air tension, and gravity drag forces are some of the topics addressed. (DH)