Zero point energy

No, it's not just the dastardly energy ray of the fiendish Syndrome in The Incredibles, it's a real thing! And there are plenty of cranks out there who think that it is an inexhaustible source of free energy - but damn those governments and oil companies who are suppressing the truth!

In fact, zero point energy can never be harnessed. It exists, yes, but only as a concept of quantum mechanics, in which it is the lowest possible energy state of a given system.

By implication, getting this zero point energy to do work for humans would mean it would have to drop from its current energy state to an even lower energy state, just like a battery slowly runs out as it powers your PC or car or whatever.

But this is impossible, as it is already at the lowest state possible. So I'm afraid there won't be any perpetual motion machines any time soon...