way will change the whole pattern of my day, the people I meet and the level of stress I experience. I’m sure you can think of similar experiences. Henri Poincaré, a French mathematician, first studied the effect back in 1880. Poincaré was trying to solve an old mathematical problem called the Three Body Proble

hand of evil and the right hand of grace. Oscillations that appear spontaneously in nonlinear systems without external periodic input were known to Henri Poincaré in 1882, and were systematically studied and made accessible to non-mathematicians by early 20" Century Russian mathematicians and physicists, well r