A crack of lightning. The blue glow of a phone screen. A blinking firefly. The blazing sun. A camera's rapid flash. No matter the source, light travels in waves, and it does so at a speed faster than anything else in the universe. But what is light, anyway, and how do we study it? In this book, readers in grades 4-9 will learn about light waves and light's properties and how people-and animals-manipulate light for their own purposes. This series features...