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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).
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