Measured by the lab
4.6692012
How does a simple map's long-term behaviour depend on its growth rate — and how chaotic does it get?
▶ Run the simulationSee the measured result
Units: dimensionless (Feigenbaum δ, quadratic-maximum class; Briggs 1991 high-precision value)
Plot the attractor at every growth rate r (the bifurcation diagram) and measure the Lyapunov exponent λ(r) beneath it.
the universal Feigenbaum constant 4.669, λ(4) = ln 2, and chaos onset at r∞ ≈ 3.5699