Put the mouse cursor inside the box below to activate the movement.Double click the figure to stop and start the animation. You can hold the RIGHT mouse button down and drag it HORIZONTALLY across the figure to sequence through the frames of the animation.
Look at Greg Frederickson's website for more swinging stuff, plus a few twists.
See Ivars Peterson's MathTrek column, "Chemical Dissections", at MAA Online, for a link to the real world.
This image was produced using Mathematica and converted to the animation with LiveGraphics3D.