Presents a procedure by which cytokinins are used to induce a population of dividing and differentiating cells on the cut surface of the roots of an intact plant. Includes the method used, results, and suggestions for a variety of variables that may be tested. (RT)

Investigates the nature of catastrophic volcanism and the rifting process. Describes two kinds of evidence: quantitative descriptions of rock melting and a wide range of observations. Discusses examples of continent growth in the North Atlantic, India and the Seychelles islands, and the South Atlantic. (YP)

Described is the construction and use of an osmometer that is low in cost, easy to make, and durable. Materials needed and procedures are outlined. Diagrams show an assembled instrument and individual parts. (RT)

Makes use of distinctions between experiment and demonstrations to resolve a paradox for the sociology of scientific knowledge. Describes two public tests which illustrate these themes. Discusses types of core-set distortion and suggests a partial solution. (YP)

Discusses how laboratory skills or experiences learned in a chemistry course can be used to help students to better understand physics. (ZWH)

Presents a procedure that students can use to determine the center of mass of a thin (two-dimensional), homogenous object experimentally, analytically, and numerically. Requires students to use three distinctly different approaches to a single problem and necessitates a combination of laboratory skills, a knowledge of fundamental calculus, and…

Uses the Science Process Skills Inventory (SPSI) to analyze student efforts at writing experimental designs. Results indicate that explicit, incremental development of the science process skills of formulating hypotheses and identifying variables, together with model examples, may be a means to facilitate student success in designing science…

Discusses concerns regarding the assessment of scientific investigations in the National Curriculum. Presents observations and assessment advice and guidance. (JRH)

Presents experiments that use the Mattel's Hot Wheels Top Speed toy set to show that work is a measure of energy transferred to or from a system. (JRH)

Describes problems that are presented in the form of experiments. The philosophy, method of solution, and several examples of mechanics experiment problems are described. (LZ)

This paper extends discussion of Cushing's contribution to Bohm's deterministic interpretation of quantum mechanics, which raises the question of whether self-understanding is at issue in physical science as it is in social science. Addresses ideas by Bevilacqua and Giannetto about the use of historical texts and the primacy of experiment. (LZ)

Discusses the use of 40 kHz ultrasonic transducers to study wave phenomena. Determines that the resulting wavelength of 9 mm allows acoustic experiments to be performed on a tabletop. Includes transducer characteristics and activities on speed of sound, reflection, double- and single-slit diffraction, standing waves, acoustical zone plate, and…

This photosynthesis exercise is intended for introductory college biology or botany courses. It is based on the principle that a closed suspension of algal cells may be expected to produce more dissolved oxygen with a greater photon fluence rate, but within limits of the photosynthetic capacity of the system. Describes materials and methods. (LZ)

Describes the use of geiger counters for scientific investigations and experiments. Presents information about background radiation, its sources and detection. Describes how geiger counters work and other methods of radiation detection. Provides purchasing information for geiger counters, related computer software and equipment. (MCO)