Chaos, KAY os, is a field of science that deals with complex and irregular processes. Physical processes that are chaotic include the changing of weather patterns, the collision of billiard balls, and the orbital movement of particles in Saturn's rings. Scientists study chaotic systems, sets of objects that, as a whole, display chaotic behavior. In the case of a collision of billiard balls, the main objects in the system would be the balls, the playing surface of the table, and the cushions at the sides of the playing surface.