Chaos and order, as used in chaos theory, are terms used to describe conditions of complex systems in which, out of seemingly random, disordered (e.g. aperiodic) processes there arise processes that are deterministic and predictable. Accordingly, despite its name, chaos theory attempts to identify and quantify order in apparently unpredictable systems.

Along with quantum and relativity theories, chaos theory—with its inclusive concepts of chaos and order--is widely regarded as one of the great intellectual leaps of the twentieth century. The modern physical concepts of chaos and order, however, actually trace their roots to classical mechanical concepts introduced in English physicist Sir Isaac Newton's 1686 work, Philosophy Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy). It was Newton, one of the inventors of the calculus, who revolutionized astronomy and physics by showing that the behavior of all bodies, celestial and terrestrial, was governed...