A Selection of the Scientific American Book ClubProfiling 50 of the world's most popular playthings-including their history, trivia, and the technology involved-this guide uncovers the hidden science of toys. Discover how an Etch A Sketch writes on its gray screen, why a boomerang returns after it is thrown, and how an RC car responds to a remote control device. Leaving no detail unrevealed, the guide includes original patent-application blueprints and photos of the
