Pendulum will appear to be in balance if we hold it off-centered, but it will stay that way for as long as we hold it. And if we let it go, it will swing. 

 

The key to the pendulum effect is that it will not just swing to come to the center again. It will swing to the other side, way past the middle point. As I call it, pendulum will over-correct. And it will swing back and forth for a while until it finally returns to the balance.