Throughout its history, movable elements in books, commonly called pop-ups, have been used to educate, entertain, and inspire both children and adults<i style="mso-bidi-font-style: normal">. "Wow, open this!" </i>looks at the art and science of moveable elements incorporated into books. Books that delight children with that ‘wow’ moment, as a scene comes to life in their hands, were first used in scholarly works to help illustrate a vast array of topics such as geometry, architecture, medical and natural science, cryptography, astronomy, calendars, time telling, navigation, and cosmography. Primarily used as entertainment today, movable elements and variations of the pop-up book are also used by artists who want to challenge our assumptions about what a book really is by reinterpreting the form and how it functions.