About the Series: Our eyes help us look at the world, but there is still much that we cannot see. Some things are practically invisible because they are so small, but bigger things can be nearly invisible, too. The Invisible Worlds series explores the unseen "worlds" that exist around us. Ancient artifacts and buried bones are hidden underground, while invisible forces-such as earthquakes and winds-shape life on Earth. Some of these worlds are microscopic details inside atoms and molecules, plants, animals, and the human body. Each book in the series is vividly illustrated with photographs and micrographs. Difficult science concepts are explained using easy-to-understand text and helpful illustrations. The series offers plenty of information for reports, while giving readers a different view of the fascinating world around them.