This glass sphere is filled with fluid. Spin it slowly to see smooth streamlines; spin it quickly to make turbulent ripples and swirls.
If you could follow one tiny blob of fluid as it moved through these swirls, you would see it perform a random dance-moving slowly, then quickly, first in one direction, then in another.
Patterns created by flowing liquids can show up in many places and on many scales, from the swirls of cream stirred into a cup of tea to the clouds that move with the earth's atmosphere.
(c) The Exploratorium, 1996