Energy can not truly ever be destroyed. Energy just simply changes it's form or dissipates on it's own. Think of it as an electrical current. Now, that electrical current is always going, always flowing. If we put in a switch to stop that flow of energy, it only stops it at the point that the switch is located. The current of energy is still flowing, we've just learned how to manipulate the energy for our uses.

No, energy cannot be created or destroyed. This is the main idea in the Law of Conservation of Energy. Energy cannot be destroyed, but it can change forms. You can find more information here: http://library.thinkquest.org/2745/data/...