Conversations On-Line

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From: Alwyn Scott                  Subject: Re: Maxwell's Demon                 Date: 02/27/97

' critiquing Maxwell's Demon'

Hi Jamie,

I don't know who gives the best critique. It is generally agreed that Maxwell's Demon, if it were to exist, would be able to
violate the second law of thermodynamics. Thus one must give up believing in one or the other.

An example of Maxwell's Demon is the "ideal diode" rectifier of electronic circuit theory. This device has zero voltage drop in the forward current direction and zero current flow in the reverse voltage direction. Such a device would allow one to rectify thermal noise. Real diodes rectifiers, it turns out, always have a curvature in the voltage--current characteristic of the order of kT. Thus they don't rectify at the level of thermal noise,

Best, Al
=================================================================
> Hi Al,
>
> A short question... In your opinion, who have given the best critiques of
> Maxwell's Demon, especially in regard to "information theory", or re the
> fact that the demon can be considered an external source of energy to a
> supposedly "closed" system?
>
> Jamie
>