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Herman Daly seems quite confused here:

The economist's notion of infinite substitutability bears some resemblance to the old alchemists' dream of converting base metals into precious metals. All you have to do is rearrange atoms! But the potential for rearranging atoms is itself scarce, so the mere fact that everything is made up of the same homogeneous building blocks does not abolish scarcity. Only Maxwell's Sorting Demon could turn a pile of atoms into a resource, and the entropy law tells us that Maxwell's Demon does not exist.

Converting base metals into precious metals requires, of course, something far more difficult than rearranging atoms. The process must transmute atomic nuclei, which requires roughly a million times more energy.

Daly then states that the potential for rearranging atoms is scarce, which is true, but only because the required energy (that is, in the technical sense, "free energy") is scarce. It doesn't require Maxwell's Demon to do the job -- the impossible demon would decrease entropy by sorting atoms according to their thermal energies, which is quite different from moving them around and sorting them by their kinds.

Does anyone know whether Daly has been influenced by Rifkin? Referring to "the entropy law" and declaring that it prohibits unmixing atoms is an error that Rifkin first popularized.

Words and ideas I offer here may be used freely and without attribution.

by technopolitical on Mon May 1st, 2006 at 11:59:48 PM EST
All true, but do you have an estimate as to the free energies involved in unmixing two species of atoms?

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Carrie (migeru at eurotrib dot com) on Tue May 2nd, 2006 at 02:50:25 AM EST
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Starting with a mixture containing equal amounts of two species, the theoretical minium energy for separating them is ln(2)kT per molecule, the reduction in entropy. This is, of course, quite small -- the same as the free-energy cost of compressing the volume of a gas by a factor of two.

Words and ideas I offer here may be used freely and without attribution.
by technopolitical on Tue May 2nd, 2006 at 11:24:49 PM EST
[ Parent ]
Mixing entropy and particle (in)distinguishibility is a fascinating topic. Maybe I should write a diary about it...

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Carrie (migeru at eurotrib dot com) on Wed May 3rd, 2006 at 05:05:03 AM EST
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