Discusses how the celebration of the centennial of the electric lamp raises the claim of the supporters of Sir Joseph Swan in England that Swan not Edison was the first inventor of the light bulb. (HM)

Describes the total internal reflection process that occurs when the internal angle of incidence is equal to or greater than the critical angle. Presents a demonstration of the effect of frustrated total internal reflection (FTIR). (YDS)

Presents resources from Alhazens' investigations on curved mirrors that investigate diffuse reflection from the moon's surface, composite mirrors, and the problem of possible points of reflection. (Author/YDS)

Proposes a ray tracing approach to thin lens analysis based on a vector form of Snell's law for paraxial rays as an alternative to the usual approach in introductory physics courses. The ray tracing approach accommodates skew rays and thus provides a complete analysis. (Author/KHR)

Health educators are in an ideal position to teach individuals about dangers from the sun's ultraviolet light and how to prevent damage to eyes. Ultraviolet light is described, eye pathology which can be caused by it is outlined, and protective eyewear is discussed. (IAH)

Explores some of the principles behind the working of fluorescent bulbs using a specially prepared fluorescent bulb with the white inner fluorescent coating applied along only half its length. Discusses the spectrum, the bulb plasma, and light production. (JRH)

Describes a modification of the traditional demonstration of Newton's rings that magnifies the scale of the interference pattern so that the demonstration can be used for the whole class or for semiquantitative measurements in any high school laboratory. (JRH)

Discusses Fermat's Principle: Light always travels the path that requires the least amount of time. Includes discussion of refraction, angle of incidence, and angle of reflection. (MKR)

Presents an explanation on subtractive and additive color processing using the colors yellow and pink as examples. (MVL)

Discusses descriptions of the way in which an optical system controls the quantity of light that reaches a point on the image plane, a basic feature of optical imaging systems such as cameras, telescopes, and microscopes. (JRH)