2006年12月01日

生命とは何か―物理的にみた生細胞 (新書)E.シュレーディンガー (著), 岡 小天, 鎮目 恭夫

生命とは何か@amazon―物理的にみた生細胞 (新書)
E.シュレーディンガー (著), 岡 小天, 鎮目 恭夫


http://home.att.net/~p.caimi/schrodinger.html
Erwin Schrodinger

http://whatislife.stanford.edu/LoCo_files/What-is-Life.pdf
- What is Life? - 1944 - pdf -
THE STATISTICAL MEANING OF ENTROPY
I have mentioned this technical definition simply in order to remove entropy from the atmosphere of hazy mystery that frequently veils it. Much more important for us here is the bearing on the statistical concept of order and disorder, a connection that was revealed by the investigations of Boltzmann and Gibbs in statistical physics. This too is an exact quantitative connection, and is expressed by
entropy = k log D,
where k is the so-called Boltzmann constant ( = 3.2983 . 10-24 cal./C), and D a quantitative measure of the atomistic disorder of the body in question. To give an exact explanation of this quantity D in brief non-technical terms is
well-nigh impossible. The disorder it indicates is partly that of heat motion, partly that which consists in different kinds of atoms or molecules being mixed at random, instead of being neatly separated, e.g. the sugar and water molecules in the example quoted above. Boltzmann's equation is well illustrated by that example. The gradual 'spreading out' of the sugar over all the water available increases the disorder D, and hence (since the logarithm of D increases with D) the entropy. It is also pretty clear that any supply of heat increases the turmoil of heat motion, that is to say, increases D and thus increases the entropy; it is particularly clear that this should be so when you melt a crystal, since you thereby destroy the neat and permanent arrangement of the atoms or molecules and turn the crystal lattice into a continually changing random distribution. An isolated system or a system in a uniform environment (which for the present consideration we do best to include as the part of the system we contemplate) increases its entropy and more or less rapidly approaches the inert state of maximum entropy. We now recognize this fundamental law of physics to be just the natural tendency of things to approach the chaotic state (the same tendency that the books of a library or the piles of papers and manuscripts on a writing desk display) unless we obviate it. (The analogue of irregular heat motion, in this case, is our handling those objects now and again to without troubling to put them back in their proper places.(P.25-26)

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