Re: Waddington: theory of NS invokes "a Maxwell demon"

Robert Parson <[EMAIL PROTECTED]> wrote:

> On Tue, 25 Nov 2003 13:41:26 +0000 (UTC), [EMAIL PROTECTED]
> (H,R.Gruemm) wrote:
> 
> >[EMAIL PROTECTED] (Steven Carr) wrote:
> >> On Tue, 25 Nov 2003 05:05:16 +0000 (UTC), david ford
> 
> >> In http://www.leaderu.com/offices/dembski/docs/bd-idesign2.html
> >> William Dembski tells us how Maxwell's Demon works
> >> 
> >> 'It is CSI that enables Maxwell's demon to outsmart a thermodynamic
> >> system tending towards thermal equilibrium'
> >> 
> >> 
> >> I'm not sure of David's point. The burgeoning science of CSI can
> >> explain Maxwell's Demon perfectly adequately, so what does he have
> >> against it?
> >
> >It should be noted that even an intelligent demon does not "outsmart"
> >a thermodynamic system. He uses up free energy in *determining*
> >whether an incoming particle is slow or fast.
> 
> Not quite, as shown by Landauer and Bennett. Contrary to what Szilard,
> Brillouin, and a library shelf's worth of textbooks say, the demon need
> not consume free energy in the process of measuring the particle's
> velocity. The ineluctable entropy-producing step comes later, when the
> demon resets his memory prior to performing the next measurement.
> This step compresses the demon's phase space (two states are mapped into
> one), and is therefore inherently dissipative. 

But if the Demon interacts with the particles of light or any other
radiation in order to determine the position of the gas molecules, the
entire thermodynamics change, don't they? And isn't there a problem of
Heisenbergian proportions? How could the Demon know when the molecule
was approaching the gate in order to open it?
> 
> Of course your larger point is correct: the resolution of the paradox of
> Maxwell's demon lies in realizing that the demon is itself a
> thermodynamic system. Any entropy decrease that the demon produces in
> the gas is offset either  by an entropy increase within the demon, or by
> an expulsion of heat into the surroundings. 
> 
> Dembski's discussion is hopelessly confused - he seems to believe that a
> "4th Law of Thermodynamics" is needed to resolve the paradox, when the
> First and Second work perfectly well so long as they are consistently
> applied.

What do you expect from someone who thinks information is preserved
locally?
-- 
John Wilkins
DARK IN HERE, ISN'T IT?
wilkins.id.au