Indicates that the concept of definite proportions or constant composition should be introduced with qualification. Presents arguments against the Law of Definite Proportions and cites examples in the areas of solid solutions, compounds of the transition and inner transition elements, and in some compounds of the representative elements. (GS)

In his "The Making of the Atomic Bomb," Richard Rhodes remarks of the July 16, 1945, Trinity atomic bomb test in New Mexico that "had astronomers been watching they could have seen it reflected from the moon, literal moonshine," an allusion to Ernest Rutherford's famous dismissal of the prospect of atomic energy. Investigating…

Several times a week I walk by a metal chair that is fastened to a flat concrete slab at an outdoor bus stop here in Boulder. One day I noticed on the concrete a nice shadow image of the woven metal seat of the chair (Fig. 1). The seat and back of the chair are formed from 3.8-cm wide strips of metal spaced 3.8 cm apart. The seat is about 39 cm…

Reports on the physical origins of spherical aberrations in axially symmetric electrostatic lenses to convey the essentials of electon optics to those who must think critically about the resolution of the electron microscope. (GS)

Family research has been hindered by a reliance on either empirical relationships or abstract theoretical claims. There has been no effective way to bridge the gap between statistical relationships and theoretical propositions. The application of linear structural equation models helps to bridge this gap. Empirical propositions are not developed.…

The strength of intuitive knowledge is illustrated by the difficulty that individuals have in trying to restructure student misconceptions. In order to harness this power, intuition must be developed within the context of each new concept to be taught. An experiment with one possible approach to this instructional problem is described and…

The transfer of technology as an important dimension for technical education in West Africa is discussed, concerning prerequisites, education, training, and socio-cultural considerations. (Author/PG)

Elementary technology, the study of technical objects, will provide a basis for development in Nigeria. Students will develop new capacities for harnessing local resources and for controlling the environment for human benefits. (Author/PG)

There is a need for a new approach to the teaching of English as a foreign language which will shift the focus of attention from the grammatical to the communicative properties of language in order to show how the language system is used to express scientific facts and concepts. (Author/LG)

Presents two arguments concerning the role of the photon. One states that the photon is just another particle distinguished by a particular value of charge, spin, mass, lifetime, and interaction properties. The second states that the photon plays a fundamental role with a deep relation to ultimate formulas of physics. (GS)

Presents a summary and comparison of various views on the concepts of mass and weight. Includes a consideration of gravitational force in an inertial system and apparent gravitational force on a rotating earth. Discusses the units and methods for measuring mass and weight. (GS)

Presents a schema to replace the generally accepted notion of the scientific method being described as an individual scientist's behavior. The schema is described as the summary process by which scientific understanding of the universe is advanced, how knowledge is created and tested, and how workable models emerge. (EB)

Presents a brief discussion of lightning and its causes; makes the point that lightning kills more individuals than do the more-widely publicized tornadoes. (PB)