The arena

Four pendulums, same chaos.

The untouched files each model wrote, running live. Click a panel to start it, then Play/Pause and Reset the simulation — or hit each build's RUN REFEREE button and watch it grade its own physics headless over 60 simulated seconds. The energy-drift and Lyapunov numbers on the scoreboard reproduce right here, in your browser.

▶ Run all four

Every panel is the actual deliverable, not a screenshot — the same identical initial condition (θ₁ = θ₂ = 120°) in each, diverging into four different chaotic paths only because the integrators differ in the last decimal places.