Here's my explanation why perpetual motion doesn't work. 1. Whatever underlying mechanism it uses, the device eventually moves to lower it's potential energy (

Here's my explanation why perpetual motion doesn't work. 1. Whatever underlying mechanism it uses, the device eventually moves to lower it's potential energy (ball falls down, magnet moves away, pendulum swings, spring releases, etc). You can calculate potential energy anywhere in the lifecycle of the device. 2. In order to be perpetual, it has to form some kind of circle, eventually it must reach its starting point. 3. If potential energy in the starting point is X, when the device returns back to it's starting point (to close the circle) it will have the same potential energy X. 4. If you have two points in time that both have same potential energy X, the device will not move there because it would not lower it's potential energy. It will either don't move at all, or start moving to reach some intermediate step with lower potential energy and then stays there because it would need to increase potential energy to go back to level X. But device only moves to decrease it's energy, not increase.