Wikipedia
Tilt-A-Whirl, also known as Waltzer in Europe, is one of the best-known flat rides, designed for commercial use at amusement parks, fairs and carnivals in which it is commonly found. The rides are manufactured by Larson International of Plainview, Texas.
The Tilt-A-Whirl is a platform-type ride, consisting of seven freely-spinning cars that hold three (sometimes four) riders each, which are attached at fixed pivot points on a rotating platform. As the platform revolves, parts of the platform are raised and lowered, and the resulting centrifugal and gravitational forces on the cars cause them to spin in different directions and at variable speeds. The weight of passengers in these cars (as well as the weight distribution) may intensify or dampen the spinning motion of the cars, adding to the unpredictable nature of the motion. Mathematicians call this unpredictable nature chaotic motion.
Physicists Bret M. Huggard and Richard L. Kautz came up with a mathematical equation that approximates the motion of the Tilt-A-Whirl. Although it was without knowledge of chaos theory that Herbert Sellner invented the ride, in his patent text he clearly demonstrates an appreciation of chaos – "A further object is to provide amusement apparatus wherein the riders will be moved in general through an orbit and will unexpectedly swing, snap from side to side or rotate without in any way being able to figure what movement may next take place in the car."