No. 92: Mar-Apr 1994
Readers of Science Frontiers are well aware that some denizens of our solar system exhibit chaotic motion, as do some pendulums and even dripping faucets. Chaosists seem to be able to find chaos everywhere they look.
If you have ever ridden on that amusement park staple called the Tilt-A-Whirl, you will recall that the ride is fun because you never know exactly what the car you are riding in will do as the platforms move along the hilly circular track. Each car is free to rotate about its center and will also tilt in all possible directions as the cars go up and down the hills. Can one mathematically predict whether the car will spin clockwise, counterclockwise, or not at all? What a neat problem for a physicist!
And two physicists, R.L. Kautz and B.M. Huggard, have developed a mathematical model of the Tilt-A-Whirl. By integrating the equation of motion, they find that the Tilt-A-Whirl is, indeed, a chaotic system. You really cannot tell what the car is going to do -- even if you take your laptop along with you!
(Kautz, R.L., and Huggard, Bret M.; "Chaos at the Amusement Park: Dynamics of the Tilt-A-Whirl," American Journal of Physics, 62:59, 1994.)