Kugel fountain

A kugel fountain (also called a floating sphere fountain or by the pleonasmic name kugel ball) is a water feature or sculpture where a sphere sits in a fitted hollow in a pedestal, and is supported by aquaplaning on a thin film of water. Pressurized water flows between the sphere and socket, creating a mechanical hydrostatic bearing that is nearly frictionless. The sphere can weigh thousands of kilograms, but the efficient bearing allows it to be spun by the force of a hand. The sphere does not float, being denser than water; it is often made from granite.^[1] The hydraulics of the fountain can be controlled so that the axis of rotation of the sphere changes continually.^[2] Ring sculptures that rotate on an axis are also built.^[2][3]

Kugel fountains can be found all over the world. Many are at popular tourist destinations, such as science museums,^[4] shopping centers, lobbies, and gardens.

Kugel is the German word for ball or sphere.^[5]