These little steel balls will keep you entertained all day. The back and forth motion is a soothing experience you'll enjoy day after day while also learning about the conservation of momentum and energy. Desktop display version of Newton's cradle performing based on Newton's Law. Made with technology that gives the balls perfect alignment so you will never have to worry about the strings becoming tangled and looking messed up. Newton's Cradles demonstrate Newton's laws of motion, specifically that 'for every action there is an equal opposite reaction.' This helps people better understand the concepts of conservation and momentum. SIZE: L6.2' x W3.5' x H4.5'