Chaotic Attractors

AN IMPORTANT aspect of explaining dynamical phenomena is the description of attractors. Newton knew of two types of attracting motion that systems settle into: the apple sitting on the ground is in equilibrium, and the planets in the solar system are undergoing periodic, or more properly quasiperiodic motion, at least to good approximation. For the next 300 years, these were the only kinds of motion known for simple dynamical systems. Maxwell and Poincaré were among a small number of scientists who were not content with this view. The small number grew, but it was not until the widespread availability of desktop computers in the last quarter of the 20th century that the third type of motion, chaos, became generally recognized.