🎡 Triple Pendulum Simulator: Lagrangian Chaos, Lyapunov Exponent and Trajectory Divergence

Planar triple pendulum from the full Lagrangian (RK4 with energy-drift readout) on a Blender-built brass and steel rig: up to 64 ghost copies 1e-9 rad apart show trajectory divergence, the maximal Lyapunov exponent is measured two independent ways (Benettin renormalisation and two-trajectory slope), plus Poincare section, phase portrait, a fractal flip-time map and a lambda-versus-energy scan. Unlike the existing triple-pendulum pages it is a quantitative chaos lab with built-in accuracy checks (normal modes within 1 percent, energy drift below 1e-8).