This article reports a design experiment conducted over three successive school years, with the teacher's goal of having his Grade 4 students assume increasing levels of collective responsibility for advancing their knowledge of optics. Classroom practices conducive to sustained knowledge building were co-constructed by the teacher and students,…

Explains the asymmetry between left-right and up-down when your image is viewed in a plane mirror in psychological rather than physical terms. (GS)

Discusses developments in the field of gradient index optical lenses for resolving problems of lens spherical abberration. (SL)

Explains the three characteristics of laser light (monochromatic light, divergence, and coherence), the components of a laser, applications of the laser (alignment, distance measurement, welding/cutting, marking, medical applications), and a complete laser training system appropriate for classroom use. (CT)

Report on characteristics of different kinds of microfilm available indicates proper film for specific needs. Silver halide and nonsilver films, diazo film, vesicular film, reaction of films to light, effect of heat and humidity on films, film susceptibility to scratching, and potential longevity of film types are covered. (35 references) (EJS)

Discusses the optics of fly fishing, considering where to cast the fly once a fish is seen. Also considers what the fisherman looks like to the fish, examining refraction at a water surface, actual and apparent light rays, and how sticks in the water might look to a fish. (JN)

Shows that the perceived shade of gray depends on the luminance relationship between surfaces perceived to be in the same plane and not between surfaces that are merely adjacent in the retinal image. This implies that lateral inhibition cannot explain lightness constancy. (MLH)

This study expands and validates previous research that found a statistical correlation between the amount of daylight in elementary school classrooms and the performance of students on standardized math and reading tests. The researchers reanalyzed the 19971998 school year student performance data from the Capistrano Unified School District…

This study examines the effect of daylighting on human performance, focusing on skylighting as a way to isolate daylight as an illumination source, and separate illumination effects from other qualities associated with daylighting from windows. It establishes a statistical connection between daylighting and student performance and between…

The diffraction bands caused by a thin transparent plate of glass inserted over half the field in a spectrometer are discussed. (TS)

Presents the history of the discovery of pulsars, observations that have been made on pulsar radiation, and theories that have been presented for its presence and origin. Illustrations using pulsar's properties are presented in mechanics, electromagnetic radiation and thermodynamics. (DS)