DIY_EFI Digest V4 #520

[William T Wilson]

On Sun, 12 Sep 1999, DIY_EFI Digest wrote:

> > I don't know why they can't.  I can; it violates the Second Law of
> > Thermodynamics.  Entropy has to increase.  That engine decreases entropy
> > by converting heat energy into rotational energy.  The engine has to
> > output entropy somewhere.
> 
> You can convert heat energy into rotational energy easily enough...
> it's what you car engine does.  There is a lot of heat energy to
> convert though.

Yeah, but the car engine does this by starting with comparatively well
ordered heat energy.  The air inside the combustion chamber is hot, the
air outside is not.  After one complete power stroke (all 4 cycles from
intake to exhaust) suddenly the air outside the combustion chamber is a
little hotter and the air inside has all been pumped out.  Some of that
energy is converted to rotation, but some of it just contributed to global
warming.  Entropy has increased and the second law is happy.

This engine does the reverse.  It takes regular air, magically extracts
the heat from it, then turns it into rotational energy and blows out the
cold air.  Entropy has decreased because you've taken unordered heat
energy and converted it not only into rotation but into ordered heat, too.
That's against the rules.

> I suspect that there isn't enough heat energy in ambient air
> to drive it through their system and have any energy left over.

There's tons of heat energy in ambient air.  You just can't use it for
anything other than heating stuff. :}