Energy from gravity? Impossible? Why?

[Cole Powers]

Hi,
I understand that perpetual motion machines don't truly work because gravity is not putting any energy into them. Gravity is a force and is just turning the potential energy into mechanical energy. You need something to give it the potential energy. But would there be a way to prolong this potential energy, for example, getting electricity from pressure. The logistics of such a machine aside, liquids boil under high pressures, right? I am pretty sure that this isn't possible, but if anyone could help me understand why not I would greatly appreciate it. Thanks!
Cole

[Rob Beckers]

Cole, the easier way to view perpetual motion machines is by following the flow of energy. They all claim that more energy is coming out than is put in, often through ingenious schemes that make it near impossible to figure out what's happening. At the end of the day the laws of thermodynamics state you can't make energy out of thin air, moreover, you constantly loose energy in forms that aren't readily reversed into something more useful (such as heat through friction).

Some want to claim that just because someone made up "laws" doesn't mean they are real or apply. Look, even at the gut level it makes sense that energy doesn't come from nowhere. On top of that nobody has yet been able to show that those laws are flawed, and they've been around a while now.

Perpetual motion machines are also referred to as "over-unity machines", for the reasons above: They all claim more energy output than went into them, hence the 'over-unity' part. The one thing they all have in common is that they don't work...

-RoB-

[Ralph Day]

Very nicely explained Rob. You sound like the great high school science teacher we all wish we'd had.

Ralph

[Rob Beckers]

Thanks Ralph!
I once had a gig as an English teacher in Spain, maybe that helped... :nuts:

-RoB-

[Cole Powers]

Thank you for this response! I understand it better now.
Cole

[Abe Gonzales]

lmao "the one thing they have in common is they don't work"

Maybe one day =P