Butterfly Effect (Encyclopedia of Science and Religion)
Butterfly Effect is a term coined by the American metereologist Edward Lorenz (b. 1917) to describe a special effect in chaos theory. Because of the iterative character of chaos theory, the slightest change in the initial conditions of a chaotic system can accumulate in the long run into an enormous effect. Because of this sensitivity to initial conditions, the state of a chaotic system is practically unpredictable in the long run, even though such systems are deterministic. Lorenz came up with a fanciful image to illustrate this effect: The flapping of a butterfly's wing in the Amazon can result in a tornado in China. Thus, the sensitivity of chaotic systems to initial conditions came to be called the Butterfly Effect.
See also CHAOS THEORY; UNPREDICTABILITY