This uses real-world examples to guide students to an understanding of the nature of light. They learn that light is a form of energy that travels in waves. Students discover that most everything we can see results from the interaction of light with matter. They find out that nothing travels more quickly than light and that visible light makes up just one part of the electromagnetic spectrum. At the end of each two-page spread, a brief statement called The Bottom Line reinforces students' understanding by summing up the key ideas about light covered in those pages. Lexile Measure 800.