From: Anonymous <nobody@REPLAY.COM>
Date: Sat, 31 Jan 1998 08:28:27 +0800
To: cypherpunks@cyberpass.net
Subject: Re: Interesting Chemical Reaction
Message-ID: <199801310015.BAA00313@basement.replay.com>
MIME-Version: 1.0
Content-Type: text/plain



> Date: Wed, 28 Jan 1998 17:36:28 -0500
> From: ghio@temp0200.myriad.ml.org (Matthew Ghio)
> Subject: Re: Interesting Chemical Reaction

> Here's something to ponder:
> 
> Consider two objects initially at the same temperature.  One is at the
> focus of a hemispherical mirror.  An elliptical mirror with both objects
> at its foci encloses the remaining space.
> 
> Because of the spherical mirror, the first object reabsorbs most of its
> heat lost by radiation, but most of the second object's radiated heat is
> reflected upon the first.  Hence the first object becomes warmer relative
> to the second.
> 
> The entropy here appears to decrease, but according to thermodynamics that
> is impossible.  Can anyone explain how it is that the total entropy would
> not decrease?

Perpetual motion machines built on violations of thermodynamics involving
hemispherical and ellipsoidal mirrors have been around for years.  They
don't work.

The objects do not change temperature.

Trace a ray from each object.  In every direction, it hits an object which
is at exactly the same temperature as it is.  It may be itself, or it may
be the other object.  But in each case, the temperature is the same in all
directions.  The "sky" is the same temperature as the object, so it does
not change temperature.