[Prev][Next][Index][Thread]

Re: Ecological Economics and Entropy



In article <JMC.96Nov3112605@Steam.stanford.edu>,
   jmc@Steam.stanford.edu (John McCarthy) wrote:
>Jay Hanson has finally given us something to chew on rather 
than
>merely references.
>
>     The two essential forms of stored thermodynamic 
potential
>     are "energy" (e.g., a barrel of oil) and "order" 
(e.g.,
>     clean drinking water and deep topsoil). "Entropy" is a
>     measure of the unavailability of energy: the entropy 
of oil
>     increases as it burns, and the entropy of a water 
table
>     increases as it falls because more energy will be 
required
>     to pump it to the surface. Entropy can also be thought 
of as
>     a measure of disorder in a system: polluted water that
>     requires purification has higher entropy than the same 
water
>     unpolluted, and the entropy of topsoil increases when 
it is
>     dispersed or polluted by salt from evaporating 
irrigation
>     water.
>
>Thermodynamics only recognizes one entropy, because all of 
its
>manifestations are transformable into one another.  For 
example, water
>that requires purification can be purified (its entropy 
reduced) by
>using free energy from nuclear or solar power (thereby 
increasing the
>entropy of the rest of the universe). 

You guys are getting way out in left field here.  Let's do a 
quick thought experiment.  If the polluted water was 
polluted by oil, and you happened to be a particular 
bacteria that used oil for food, you would consider this 
water to be loaded with a food source.  To you, maximum 
entropy would correspond to water with no oil in it.  I 
maintain that it is very difficult to formulate a consistent 
picture of entropy in a very diverse ecosystem.  You tend to 
stay on much firmer ground when talking about things like 
the conservation laws (e.g., conservation of energy and 
matter).








===================================================================

For some *very* interesting alternate viewpoints, look at
http://www.hamblin.com/mf.main/welcome.html