Describes the physics of an experiment in which an air wedge is formed between two glass plates inclined at a small angle by means of a thin spacer. Implications for instruction are noted. (JN)

Describes simple speckle photography experiments which are easy to set up and require only low cost standard laboratory equipment. Included are procedures for taking single, double, and multiple exposures. (JN)

Describes an apparatus for an experiment on winding motion in three dimensions. Discusses theory and provides a calculation example. (JM)

Suggests experiments to help develop understanding of photoconductivity, photometry, and the inverse square law in optics. The design of a simple absorption colorimeter is also described. (DH)

Describes a physics experiment which demonstrates the pitfalls of assuming that a model which represents an ideal system is applicable to a real experiment. Explains how the failure may give greater understanding of the problem and may lead to improvements in the model. (ML)

Presents an experiment which focuses on the inertial properties of a rigid body as expressed in terms of principal axes and moments of inertia. Background information, a description of the apparatus needed, and a discussion of results obtained are included. (JN)

Background information, procedures, and results obtained are provided for two experiments. One measures the field strength at a particular moment to an accuracy with a level of error less than two percent. The other gives continuous readings or potentials in the field. (JN)

Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

Stefan's law is demonstrated by measuring the temperature of the tungsten filament of an electric light bulb and plotting a log-log graph of temperature against power dissipation. (MLH)

Using the simple optical system and photodiode described in this article it is possible to give clear, quantitative demonstrations of all the Fraunhofer diffraction phenomena at single and multiple apertures. These measurements can be related to the theoretical predictions given in standard textbooks. Circuit diagram and optical layout are…

Discusses issues related to examination questions which begin by asking students to "Describe an experiment to..." Indicates that this strategy is useful when focusing on important quantities/phenomena or "celebrated" experiments and that examining boards should not request students to describe experiments which verify or…

Presents demonstrations, using microprocessors, to show the slow change in relative phase of two sine waves feeding the inputs of an oscilloscope and Fourier synthesis. (SK)

Discusses when alternating and magnetic fields are independent. Provides examples of experiments involving mains hum and the detection of induced signals. Describes electric circuits and oscilloscope displays. (Author/YP)

Describes some experiments for investigating the speed of atomic gas beams and displaying their atomic character. Discusses the experimental apparatus and the time-of-flight method. (YP)

Discusses: how thought experiments (TES) are presented and used in physics textbooks; how and why teachers include TES in their explanations; and what understandings students draw from TES. Indicates that TES are only one of a broad class of "acts of imagination" which are essential in physics education. (JN)