Feigenbaum Constant

The universal rate at which period-doubling cascades approach chaos, the same in every such system.

Specifications & Metrics

symbol

δ

approx

4.66920160910299…

Core Principles & Analysis

• Mitchell Feigenbaum found it in 1975 with a pocket calculator and logistic maps.
• The same ratio governs dripping taps, flickering lasers and population models alike.
• It is experimentally measurable and theoretically unexplained: no closed form is known.