Double Pendulum

Oscillations

Two connected pendulums exhibiting chaotic motion under gravity — tiny differences in starting angles produce wildly different paths.

How this simulation works

Use the Arm 1 and Arm 2 sliders to set the length of each pendulum rod in metres. Use the Angle 1 and Angle 2 sliders to set each arm's starting position in degrees from the downward vertical. Press Start to release the double pendulum from rest and watch the second bob trace a chaotic path. Press Pause to freeze the motion mid-swing, and Reset to return both arms to their initial positions. Try changing an angle by just one degree and restarting — you will get a completely different trajectory.