Presents the basic principles of gravity, a history of how the theory was developed, the revisions made by Albert Einstein, and descriptions of how gravity works in space, with examples from America's space program.

Forces move everything around us. That may sound scary and complicated, but this book shows readers that forces like friction and other laws of motion can be fascinating and fun! Innovative flowcharts bring these abstract concepts to life via brilliant photographs matched with fact boxes showing readers how the moon impacts tides on Earth, and how magnetic forces act on matter throughout the universe. From the tectonic plates that move Earths crust...