Branley's clear and simple text explains two basic yet important physics concepts: very hot objects produce light, and we see because light from these objects travels to our eyes or reflects off everything else. Multiple examples from children's experiences reinforce these ideas. The illustrations work well with the text, although more emphasis on how light reaches our eyes would help readers' understanding.

In this work from the Let's-Read-and-Find-Out Science series, Branley discusses darkness, heat, light sources, reflection, vision, and the speed of light, keeping the examples and vocabulary within a child's experience. A simple activity, observing a white plate in a dark room, gives young children a chance to understand firsthand the idea that some light is always present in our world, despite the appearance of darkness. Handsome acrylic paintings appealingly interpret the text, though the presence of fireflies in some illustrations raises a point not discussed, cold light sources. Overall, the book succeeds admirably in leading readers to look at familiar phenomena from different perspectives. (Reviewed December 1, 1997)

For this Let's-Read-and-Find-Out Science entry, originally published in 1975, Schuett brings an artistic spirit to Branley's facts about the origins of light: A child perched in a treehouse discovers light from a luminous jar of fireflies; candles on a birthday cake illustrate the concept of light coming from sources that are hot. Within a text that is somewhat repetitive, Branley offers elementary explanation of properties of light: reflective light, speed of light, and what happens inside an electric light bulb. Sunlight, candlelight, flashlight, campfire, lanterns, and stars are discussed. The mention of simple experiments, e.g., placing a white plate in a dark room, provides hands-on opportunities for very young learners. A snug atmosphere and palette are reminiscent of some scenes in Schuett's own Somewhere in the World Right Now (1996, not reviewed). (Picture book/nonfiction. 5-8)"