Astrojax

Astrojax is a toy consisting of three balls on a string. One ball is fixed at each end of the string, and the center ball is free to slide along the string between the two end balls. Inside each ball is a metal weight. The metal weight lowers the moment of inertia of the center ball so it can rotate rapidly in response to torques applied by the string. This prevents the string from snagging or tangling around the center ball. Roughly, Astrojax play is a cross between juggling, yo-yo, and lasso. A wide variety of tricks and maneuvers can be performed with it. The basic maneuvers are vertical orbits, horizontal orbits and a figure-eight (butterfly) pattern. Astrojax was invented by physicist Larry Shaw in 1987. It first appeared on the market in 1994, when it was sold through The Nature Company. Over the next several years it won a number of toy awards. In 2000 Astrojax was acquired by Active People, a Swiss company specializing in yo-yos, juggling toys and kites.