Photometry and Radiometry: A Tour Guide for Computer Graphics Enthusiasts

What is light? Aristotle (384-322 B.C.) believed that light consists of “corpuscles” that emanated from the eye to illuminate the world. Today we favor the theory of quantum mechanics (e.g., Hecht and Zajac 1987) or perhaps the possibility that light may be vibrations in the fifth dimension of ten-dimensional hyperspace (e.g., Kaku 1994). Even so, the true nature of light remains a mystery. It is perhaps appropriate that the preeminent dictionary of the English language describes light as: