Isaac Newton did not invent the device known as Newton’s Balls. According to "The New York Times," it was invented by actor Simon Prebble in 1967. It is named for Newton because it demonstrates conservation of momentum and kinetic energy as described in Newton’s second law of motion.
Newton's Balls, or Newton’s Cradle, consists of an odd number of steel balls. Each ball is attached to two parallel bars by two strings so that the balls hang next to each other in a horizontal line. When the first ball is pulled away from the rest and released, the last ball, on the opposite end, swings away from the rest at the same speed as the first ball. This indicates that the kinetic energy from the first ball has been transferred to the last ball.