When people perceive the world, what they see is based on the physics of light reflecting off surfaces and entering their eyes. Their brain then processes the raw data so that photoreceptor activity becomes perceptual awareness. Most textbooks and chapters on sensation and perception follow this formula, building student understanding of…

Fluorescence spectra excited by laser pointers have been the subject of several papers in "TPT". These papers all describe a fluorescence phenomenon in which the reflected laser light undergoes a change in color: this color change results from the combination of some partially reflected laser light and additional colors generated by…

Contrarily to color research, white values of paint are the most commonly applied finish selection on classroom walls today. White walls have been used in American schoolhouse settings since the first discovered paint, also white, was invented and made available some two hundred years ago. Originally, white paint was seen as hygienic and…

This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)

It is argued that a reflectance channel that requires priority information is shown to be less plausible for the human visual system than J. L. Dannemiller (1989) argued. In the response, Dannemiller replies that lightness is not an illuminant invariant surface descriptor when daylight illuminant substitutions are considered. (SLD)