Describes the following: use and construction of a lens-pinhole spatial filter assembly to produce expanded beams; how to modify a unilab V. L. F. oscillator to give variable frequencies between .1 Hz and 10 Hz; to use Crookes radiometer quantitatively; and an externally located, movable probe for plasma physics experiments, using conventional…

Describes a simple method to measure the size of the Earth to an accuracy of order of magnitude 10 percent. The procedure involves finding the time interval between two sunsets, a sunset observed at sea level while lying down, and a sunset viewed at eye height after standing up. (GA)

Discusses several aspects of Fraunhofer diffraction patterns from apertures illuminated by diverging light. Develops a generalization to apertures of arbitrary shape which shows that the sizes of the pattern are related by a simple scale factor. Uses the Abbe theory of image formation by diffraction to discuss the intensity of illumination of the…

Derives an explicit representation of the permutation operator in terms of coordinate and momentum operators. (Author/GA)

Explains the mechanisms through which the complex mixtures of reagents are believed to be effective in the new processes of oxidation of organic compounds. (GA)

An inexpensive DNA preparation is presented which starts with commercially available frozen packed bacterial cells. Methods for analyzing the DNA are also presented, along with physical chemical experiments which can be done using the purified DNA. (BB)

Describes an experiment for the intermediate undergraduate optics laboratory designed to illustrate simultaneously some aspects of the phenomena of diffraction; interference, coherence, apodization, the Fresnel-Arago law; as well as of the interrelations between these concepts. (HM)

Presents an examination of graphical displays of solutions to time-dependent Schrodinger equation modeling a laser-excited three-level atom. It suggests that an energy level may be regarded as virtual when it is detuned from resonance by more than two Rabi frequencies. (Author/HM)

This paper reports an experiment in the teaching of the kinetic molecular theory to nonscience majors by the inquiry method. It allows the student to develop an essentially correct view of gases, liquids, and solids on the atomic or molecular level, and illustrates how one can draw conclusions about the molecular level by simple visual…

Describes the science education improvement project at Hostos Community College (New York). The curriculum consists of a melding of technology and pure science, based on the premise that "science-poor" societies should give priority to applied science education. (JDS)

Describes how a sample of iodine-131-labelled tin (IV) iodide can be used to estimate the mass of tin (IV) iodide present in a mixture with sodium chloride, by isotope dilution analysis. (MLH)

Describes the use of images on an overhead projector to explain concepts like centrifugal force and Cariolis force in such a way that students can realize that they are pseudo-forces, i.e., observations arising only from referring phenomena to an accelerating reference system. (MLH)

Describes how to construct a device that will show interference fringes formed by multiple reflections in an air gap between two partially silvered glass surfaces. (MLH)

Mathematically treats chemical, osmotic, and electrochemical equilibria using the virtual work principle. (MLH)

Explains several laboratory exercises using the skin, including the mapping of receptors, counting of sweat glands, computation of total skin area, comparison of various animal skins, measurement of the palm triradius angle, and study of epidermal ridges (dermatoglyphics) in males and females. (CS)