Science and Exploration

[dreadgeek]

Originally Posted by Midnight

Great article. It seems that with this superfluid you could make a perpetual engine for power (once all the leaks are resolved!) Mind you that means the world economies would crash!

Midnight:

Actually, whatever else you might be able to do with superfluid helium one thing you *can't* do is make a perpetual engine. The Second Law of Thermodynamics utterly precludes any type of perpetual motion machine. The reason is that perpetual motion machines violate either of the aforementioned laws.

Perpetual motion machines of the First Kind violate the First law of Thermodynamics because they do work without an input of energy. Energy is conserved in a closed system (the Universe is a closed system, the Earth is not) which means you cannot create new energy and you can't destroy existing energy you can only transform it from state to state.

Perpetual motion machines of the Second Kind (which is the kind under discussion here) violate the Second Law because in any system where work is done there is some loss due to inefficiencies. That can't be eliminated no matter how hard you try. This means that even if you could harness the superfluid helium to drive a turbine, say, you would *still* lose some energy due to friction which would, eventually, run down the power source.

You might be able to build an exceedingly long-lived power source from superfluid helium but it wouldn't be a perpetual energy source.

Cheers
Aj