A major technological breakthrough--the isolation and then combination of narrow bands of blue-violet, pure green, and orange-red energy--has resulted in a highly efficient white fluorescent lamp. (Author/MLF)

The arrangement of colors in Newton's color circle suggests that it was derived from paint mixtures, not light mixtures. If this is true it may be concluded that what Newton called indigo represents violet in modern terminology, and what he called violet represents purple. (Author/TS)

The fundamental concepts of holography are explained using elementary wave ideas. Discusses wavefront reconstruction and contrast in hemigraphic images. The consequence of recording only the intensity at a given surface and using an oblique reference wave is shown to be an incomplete reconstruction resulting in image of low contrast. (LC)

Attempts to quantify the subjective sensation of brightness of the spot projected by a helium-neon laser and compares this with conventional sources of light. Provides an exercise in using the blackbody radiation formulas. (JRH)

Here is a quick way to measure the index of refraction of water using the phenomenon of total internal reflection.

Education administrators do not have to be deeply committed to the ecology movement to see the value of conserving energy and providing more environmentally friendly facilities. Reducing energy costs frees up funds for learning programs. Providing more healthful facilities can help students and teachers ward off illness and disease and perform…

A teacher narrates from activities and discussions that arose among undergraduates and herself while doing critical explorations of mirrors. Surprised by light's behaviors, the students responded with curiosity, losing their dependence on answers as the format of school knowledge. Inadequacies in how participants supposed light works emerged in…

In one of the classic free-fall experiments, a small mass is attached to a strip of paper tape and both are allowed to fall through a spark timer, where sparks are generated at regular time intervals. Students analyze marks (dots) left on the tape by the timer, thereby generating distance-versus-time data, which they analyze to extract the…

In this article we investigated 4th, 6th, and 8th grade students' misconceptions about light, sight, vision, source of light and examined students' conceptual development of these concepts at different grade levels. Data collection was done using five two-tiered test questions with one open-ended question, an interview about concepts and a drawing…