"Like the denizens of some brilliant ocean, humans are awash in light. Surrounded by illuminations both natural and artificial, we remain blissfully unaware of how light determines most of life's rhythms and rituals or how it dominates every field of modern science. Michael I. Sobel, a professor of physics at Brooklyn College, has attempted no less a task than to enlighten us (see how it pervades our language) about the many facets of this ubiquitous...