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)

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 thermodynamics of heating and boiling water, including the mechanics of bubble formation. Indicates that when salt was added to boiling water (when cooking pasta) the water temperature rose less than a degree, concluding that salt serves only as a seasoning. (Author/JN)

Examines hydraulic jumps and suggests several simple experiments which can be carried out with limited equipment. (DS)

Provides information regarding the extra bands of color, termed supernumerary arcs, that sometimes accompany a natural rainbow. Several experiments are described that elucidate the phenomenon of supernumerary arcs, involving the illumination of a hanging water droplet with white light from a projector or monochromatic light from a helium-neon…

Describes a method to detect the presence of microgram quantities of nearly any metal in samples of alloys, minerals, water, and air. This chemical-spot testing technique requires no elaborate equipment and can be done by an amateur. (SK)

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 changes in the crystal structure of iron and steel when these materials are heated. Focuses on observations related to an experiment in which a 60-inch length of piano wire (No. 29 steel wire) is heated and then cooled. (JN)

Provides background information on and experiments for determining the spectra of streetlights. Procedures for taking photographs of the spectra produced are included as well as discussions of sodium and mercury spectra. (JN)

Spatial filtering, based on diffraction/interference of light waves, is a technique by which unwanted information in a picture ("noise") can be separated from wanted information. A series of experiments is described in which students can create a system that functions as an optical computer to create clearer pictures. (Author/JN)

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)

Three physics experiments are described, minimizing difficulties for amateur experimenters. One experiment demonstrates the Doppler shift of light, converting the phenomenon into sound. The second measures Planck's constant. The third measures the universal gravitational constant, which does the same in Newton's theory of gravitation. (Author/JN)

Describes experiments in which a ball bearing is used as a tool for the study of light and as a kind of photographic lens. Also shows how results from these experiments contribute to an understanding of the nature of light. (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)