What are forces? These are the pushes and pulls on something that come from the world around them. Gravity, friction, lift, and drag are all forces explored in this title presented by Scientific American. Young scientists have a chance to test centripetal force using marbles, make a paper rocket, and examine how a hovercraft hovers, among other questions and ideas, in curriculum-supporting experiments and activities. Each includes a Background section that explains the scientific concept explored in the project as well as clear instructions on how to do it. Science fair ideas are included as well as an explanation of the scientific method.