Listening for chaos

Struck dynamical systems heard as sound while they decay. Work in progress.

Double pendulum
Strike it, watch and hear the motion turn regular as the energy decays; Lyapunov exponent and Poincaré section.
FPUT chain
A struck chain of N masses with cubic springs; energy spreading up the modes, Lyapunov exponent and Poincaré sections for N = 2 and 3.