These balls will swing. Just drag any ball to one side and leave.
Grab right most One ball, drag it to right and drop, swing starts. Grab from second right ball, drag to right, swing with two starts...
Make various combinations and directions. It is not monotonous at all.
Finally, try and stop it. Hold the middle one at the centre for some time, All would hault.

Enjoy.
A perfect scientific Play.

Source: Thanks to http://abowman.com/ sincerely..