Re: [Fis]: Re: Distribution of Energy is (not) the same as disorder?

Below Michel asks about Jerry's phrase, the "distribution of energy". As I
was reading Jerry's posting, I spontaneously translated his "distribution"
into 'dispersion'. I found that this way I could clearly visualize what he
was saying. So, I guess I should ask Jerry if one could substitute
'dispersion' for 'distribution', thereby obviating some of Michel's
worries. My reasoning is straightforward: 'distribution' could refer to
any pattern whatever, while 'dispersion' signifies spread-outness, thus
capturing the essence of the traditional use of 'disorder' in
thermodynamics talk. To me, as well, dispersion suggests a lowest free
energy pattern, as a gradient would be better symbolized by a mound or lump
of stuff -- a nice dollop of ice cream instead of melted pool of liquid
spread out on a plate. So, I advocate 'dispersion of energy' as being the
same as -- or indeed, a definition of -- 'disorder'.

STAN

>To: "fis-listas.unizar.es" <fis@listas.unizar.es>
>Subj: [Fis]: Re: "Distribution of Energy is (not) the same as "disorder"?
>
>Dear Jerry, dear FISers,
>
>Thanks, Jerry, for this very interesting question.
>In fact there are several questions here:
>(a) Is "Distribution of Energy" the same as "disorder" ?
>(b) Is entropy the same as "Distribution of Energy" ?
>(c) Is entropy the same as "disorder" ?
>
>Let us look first to "disorder". There was a thread initiated on the
>FIS forum the 28 April 2004: <<[Fis] definition(s) of order/disorder ?>>.
>It seems from the messages posted about this topic, that the "disorder"
>concept is still undefined, and thus it is an intuitive concept, despite
>it is useful for those who teach thermodynamics. As noted by Jerry in this
>forum the 24 May 2004, the situation is different for "order", since the
>mathematicians have a definition for this term: see partial ordering,
>total ordering,... But in thermodynamics, this definition is not
>suitable.
>It follows that we cannot answer "yes" to questions (a) and (c),
>or, rather, (a) and (c) cannot be answered until somebody exhibits
>a rigorous definition of "disorder".
>
>Let us look now to (b): "Distribution of Energy" is defined from
>two known terms: "Energy", in the sense of Newtonian mechanics
>(we could take a more advanced definition, but I prefer restrict
>here to simple thermodynamic systems), and "distribution", in the
>sense of probability theory, or at least in the Newtonian mechanics
>sense (e.g., for a mass distribution, the total mass has to be unity
>to be modelized by a probability distribution).
>It follows that answering "yes" to (b) assumes that the thermodynamic
>system is modelized such that the energy has indeed a <<distrbution>>,
>varying along the time (then come problems related to equilibrium,...)
>I observed that many people (scientists or not) used probabilistic
>terms in a non adequate manner: e.g. probability that it rains today,
>etc.. (I do it myself sometimes). Alas, it happens sometimes also
>in a more scientific context. Thus, many care should be carried
>to ensure that the "distribution of Energy" makes indeed sense.
>Anyway, if the probabilistic tools are adequately used in the
>model, relating entropy to distribution of energy may be
>successful.
>
>Jerry asks also:
>> How would this change of semantics influence the philosophy of science a=
>> ssociated with the concept of entropy?
>
>Here it is much more difficult to reply. I just would remark that
>even mathematicians use non adequate vocabulary since a long:
>e.g., the Dirac delta function is not a function, the random variables
>are not variables, etc... So I thank the thermodynamicians for
>their efforts done to clarify the teaching of their science, which
>I found to be the more difficult that I have learned when I was
>student.
>
>Michel Petitjean Email: petitjean@itodys.jussieu.fr
>Editor-in-Chief of Entropy entropy@mdpi.org
>ITODYS (CNRS, UMR 7086) ptitjean@ccr.jussieu.fr
>1 rue Guy de la Brosse Phone: +33 (0)1 44 27 48 57
>75005 Paris, France. FAX : +33 (0)1 44 27 68 14
>http://www.mdpi.net/entropy http://www.mdpi.org/entropy
>http://petitjeanmichel.free.fr/itoweb.petitjean.html
>....................................................................
>> From fis-bounces@listas.unizar.es Thu Sep 9 20:36:40 2004
>> Date: Thu, 09 Sep 2004 11:35:18 -0700
>> From: Jerry_Lr_ Chandler <jerry_lr_chandler@mac.com>
>> To: fis@listas.unizar.es
>> Subject: [Fis] "Distribution of Energy is (not) the same as "disorder"?
>>
>> Dear Colleagues:
>>
>> I would like to open an academic aspect of the entropy issues.
>>
>> I recently rec'd the email copied below. It is being circulated among l=
>> eaders of the chemical community.
>>
>> The objective of the dialogue is to substitute the words "distribution o=
>> f energy" in the place of "disorder" in developing a semantic terminolog=
>> y for entropy. The arguments for this substitution are given in publicat=
>> ions that are referenced. Many of these are available on line.
>>
>> I ask the following questions:
>>
>> What are the views of experts on entropy on this semantic substitution?
>>
>> (No syntactical change is proposed. The general problem of relating synta=
>> x to semantics extends across the sciences and includes mathematics and m=
>> odels.)
>>
>> How would this change of semantics influence the philosophy of science a=
>> ssociated with the concept of entropy?
>>
>> Cheers
>>
>> Jerry LR Chandler
>>
>>
>>
>>
>> -----Original Message-----=20
>> From: CHEMICAL INFORMATION SOURCES DISCUSSION LIST=20
>> [mailto:CHMINF-L@LISTSERV.INDIANA.EDU]On Behalf Of=20
>> dzrlib@LIBRARY.CALTECH.EDU=20
>> Sent: Tuesday, August 17, 2004 1:10 PM=20
>> To: CHMINF-L@LISTSERV.INDIANA.EDU=20
>> Subject: Entropy is NOT disorder ...=20
>> . . . snipped . . .
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Received on Fri Sep 10 22:31:27 2004