Without the sun, nothing could live on Earth. Its light helps plants make energy, and it provides warmth. People have found lots of ways to make their own light, too, from prehistoric fires to today's lasers. But what exactly is light? Readers will learn this and lots more! Including cool topics such as bioluminescence and X-rays, the main content illuminates an important curriculum concept with relatable examples and cool photographs to accompany each section. Fun facts add even more interesting information about light waves, color, refraction, and reflection.