This is a simulation of a double pendulum system implemented in HTML5. You can drag the pendulum bobs around to set the starting positions. The orange circles are draggable handles that represent each bob’s angular velocity. You can also directly set the values using the controls on the left. Set the pendulum colors with the color inputs.

The “Run” button starts the simulation, the “Clear” button will erase the traces, and the “Save” button will let you save the traces as a PNG image.

The angles and angular velocity are in degrees.

Want to embed this on your own site? I’ve put an embeddable double pendulum simulation at Clockwork Magpie Studios.