Exterminas said:
Oh, this thread will be going well.
There will be the usual pseudo-science-crowd, most of which don't have any scientific qualification beyond a freshman and they'll immediately shout down this idea. They will repeat the phrase "second law of thermodynamics" over and over, without actually being able to name the other laws of thermodynamics.
Aaand there will be the other pseudo-science-crowd who'll tell a bunch of things about sub atomic particles and magnets and thermodynamics who are convinced that this sort of thing can actually be humanity's hope for energy!
I honestly can't tell which side of this argument I want to be on.
You say that like there haven't already been several posts not doing either of those things. Why?
OT: Molecules and atoms do move, but that is due to their thermal energy, not any innate properties. Thermal energy is a) not that easy to harness, especially in small amounts, and b) can still be depleted.
Of course, it is true that you can't completely make an atom or molecule stop (this would be reaching absolute zero), but since everything in the universe is warmer than something near absolute zero, they'd be absorbing energy, not producing or maintaining it, if you slowed them down that much. They reason they can't reach absolute zero is because there is always some slight motion from quantum mechanical effects. These motions are in random directions though, so it's not possible to use them for a task. They are also so small as to almost be nonexistent.
Subatomic particles might also be what you're thinking of when you say that some things must move, but this is entirely due to quantum mechanics, and it's not so much that they move, but that their location can't be constrained when their velocity is constrained, and vice-versa. At this scale it's not accurate to think of these particles as billiard balls. It's better to think of them as a probability cloud, where the density of that cloud at a given location represents the chances of finding that particle at a given instant. The particles don't necessarily move from one place in that cloud to another; if their velocity is constrained (say, to zero, or any other exact velocity) they actually exist in several places in the cloud at once, and the degree to which they exist is governed by the cloud density at each point. At least, that's my understanding. QM is a difficult thing to conceptualize.
Long story short, the innate motion that you mentioned does not exist, except for vanishingly small movements generated by quantum effects that, because of their inherently random nature, cannot be made to act in a particular direction. Other people have already explained how gravity is not energy and wouldn't work out the way you suggest.
The biggest problem with perpetual motion, however, is that the absolute BEST you could do if you could create one would be to make it just idle in a running state forever. If it were a vehicle, or some sort of machine, it would lose energy to you once you got in, or to whatever you gave the machine to process. So even if you could make one, the act of doing anything with it would make it stop eventually. A useful PMM would not only have to not lose energy, which breaks the second law of thermodynamics, but create it, which would also break the first law. The third law doesn't really apply in this case; all it really says is that having a vanishingly small amount of energy doesn't mean you can't keep losing it.
