A mechanism for describing the transition to chaos in certain dynamical systems. If the force on a body produces a regular orbit with a specific period a sudden increase in the force can suddenly double the period of the orbit and the motion becomes more complex. The original simple motion is called a one-cycle, while the more complicated motion after the period doubling is called a two-cycle. The process of period doubling can continue until a motion called an n-cycle is produced. As n increases to infinity the motion becomes non-periodic. The period-doubling route to chaos occurs in many systems involving nonlinearity, including lasers and certain chaotic chemical reactions. The period-doubling route to chaos was postulated and investigated by the US physicist Mitchell Feigenbaum (1944– ) in the early 1980s. Routes to chaos other than period doubling also exist.