This is the sister animation to the other similar one on the animations page called 'Linear'.  It was originally titled 'bouncy sinusoidal' but I felt that was a bit of a mouthful so I shortened it to 'Wave'.  Its exactly the same as the animation 'Linear' however when the phase of each of the bouncing balls is put out of step by varying degrees the result is this travelling wave type looping animation.  I don't think I'll ever produce a more interesting animation than this one.