https://en.wikipedia.org/wiki/H%C3%A9non%E2%80%93Heiles_system Henon?Heiles system (抜粋) While at Princeton in 1962, Michel Henon and Carl Heiles worked on the non-linear motion of a star around a galactic center with the motion restricted to a plane. In 1964 they published an article titled "The applicability of the third integral of motion: Some numerical experiments".[1] Their original idea was to find a third integral of motion in a galactic dynamics. For that purpose they took a simplified two-dimensional nonlinear axi-symmetric potential and found that the third integral existed only for a limited number of initial conditions. In the modern perspective the initial conditions that do not have the third integral of motion are called chaotic orbits.
