Chaos theory began at the end of the last century with some great initial
ideas, concepts and results of the monumental French mathematician Henri
Poincaré. Also the more recent path of the theory has many fascinating success
stories. Probably the most beautiful and important one is the theme of this
chapter. It is known as the route from order into chaos, or Feigenbaum’s
universality.
Chaos and order have long been viewed as antagonistic in the sciences.
Special methods of investigation and theory have been designed for both.
Natural laws like Newton’s law or Kepler’s law represent the domain of order.
Chaos was understood to belong to a different face of nature where simple
— or even complicated — laws would not be valid. In other words, chaos
was seen not just as a higher degree of complexity or as a more complex form
of order, but as a condition in which nature fails to obey laws. Even more
challenging was the observation that natural systems seem to have no difficulty
switching from one state into the other, from laminar flow into turbulent flow,
from a regular heart beat into a fibrillating heart beat, from predictability into
unpredictability.