Newton's cradle Newton's cradle Newton’s cradle is a device that demonstrates conservation of momentum and energy using a series of swinging spheres. When one sphere at the end is lifted and released, it strikes the stationary spheres, transmitting a force through the stationary spheres that pushes the last sphere upward. The last sphere swings back and strikes the still nearly stationary spheres, repeating the effect in the opposite direction. The device is named after 17th-century English scientist Sir Isaac Newton. It is also known as Newton's balls or Executive Ball Clicker. A typical Newton's cradle consists of a series of identically sized
Stone spheres of Costa Rica with bulldozers and heavy equipment, damaging some spheres. Additionally, inspired by stories of hidden gold, workmen began to drill holes into the spheres and blow them open with sticks of dynamite. Several of the spheres were destroyed before authorities intervened. Some of the dynamited spheres have been reassembled and are currently on display at the National Museum of Costa Rica in San José. The first scientific investigation of the spheres was undertaken shortly after their discovery by Doris Stone, a daughter of a United Fruit executive. These were published in 1943 in "American Antiquity", attracting the attention of Samuel Kirkland