Talk:Entropy/Archive 5

message: To resolve this issue, I am going to type up the correct presentation of entropy by Nobelist Gilbert Lewis and Merle Randall from their famous 1923 textbook Thermodynamics and the Free Energy of Chemical Substances.  According to both chemistry historian Henry Leicester, from his The Historical Background of Chemistry (1956), and Nobelist Ilya Prigogine, from his 1998 textbook Modern Thermodynamics, before 1923 chemists did not make use of “entropy” but instead used the concept of chemical affinity to calculate the driving force of chemical reactions.  According to these sources, Lewis and Randall’s influential textbook led to the replacement of the term “affinity” by the term “free energy” in the English-speaking world.
Hence, all modern-day chemistry textbooks are based on Lewis and Randall’s description of entropy, which they define as, based on the work of Rudolf Clausius and Willard Gibbs, a “scale of irreversibility” that quantitatively measures the irreversible "work energy" or the "degree of degradation" of the system in the irreversible process.  This is the correct perspective.  I will type up the full presentation, from their textbook, over the next few days (Sorry, I ran out of time today). --Sadi Carnot 18:01, 8 October 2006 (UTC)
thread_title: Physical chemistry

message: see  :
:Ah, so you misused Admin tools, eh? (Yes, the protect tag is only for admins).  This shall prove to be interesting, I think.  
:From WP:PPOL
::Administrators have the ability to protect pages so that they cannot be edited, or images so that they cannot be overwritten, except by other administrators. Administrators can also protect pages from moves only. Administrators have the additional ability to protect pages from being edited by unregistered or very new users. 
::These abilities are only to be used in limited circumstances as protected pages are considered harmful.
::Admins must not protect pages they are actively engaged in editing, except in the case of simple vandalism.
:Clearly an RfC is in order here, if not an RfA.  I've contacted several Admins to get their opinion on how best to deal with your behaviour.  BTW: KillerChihuahua, the person you reverted, is an admin.  As I said, this shall prove interesting, I think. •Jim62sch• 18:11, 8 October 2006 (UTC)
replies: text: However, my good man, you have no right to lock, protect, etc., the page, only an Admin (which you are not see here, all) can lock it.  I can just as easily unlock it (as vandalism), but I'll let an admin do it.  Also, the transparency of your archiving is rather clear, and we'll deal with that in due time. Finally, your edit summary is rather misleading -- there is no clear-cut consensus -- there are 5 people who want your version which has the merit of being agreed to in the same way that may believed in geocentrism, and 4 who want the other version, or want that version to remain until the issue is resolved (not, of course that this is a vote).  You see, Sadi, even if there were consensus, it would not override WP:V, WP:RS, WP:NPOV nor WP:NOR (which, as pointed out by KillerChihuahua (see WP:LA, Frank is in no danger of violating).  Thus, you see, your points are, how can I put this, irrelevant.  •Jim62sch• 19:15, 8 October 2006 (UTC)
replies: text: NOTICE: Adding the tag does not make it protected - it is tag vandalism, adding an inaccurate tag. Don't do it again, Sadi. Even if you were an Admin and could protect the page, it would be misuse of the tool to protect a page you were editing; or your preferred version of any page. KillerChihuahua?!? 19:33, 8 October 2006 (UTC)
replies: text: I assumed that since I the tag saved on the edit that I had the rights to use it.  Whatever the case, being that this page been reverted close to a dozen times, by multiple seasoned editors, someone should have put a lock on the page long ago so that we could discuss issue properly on the talk page.  There are so many issues that are awry here, e.g. self-promotion, intelligent-design issues, divine intervention comments and edits, using multiple reference links to the same website over using standard article or textbook references, using months and 100s of kilobytes of talk page space to debate someone’s pet theory, using talk page space to argue that laws of science are false, etc., that this whole situation is making a mockery the Wikipedia science section.  --Sadi Carnot 11:50, 9 October 2006 (UTC)
thread_title: Of interest to all here

message: Has nobody noticed that putting a particular theory on a separate page is completely in contradiction to NPOV? 
The only way to do something of the sort within the rules might be to link to an external source.  It is really just the same as  Origin of species (Biology) and origin of species (biblical) DGG 05:03, 13 October 2006 (UTC)
replies: text: As stated at #Intelligent design above by KillerChihuahua at 19:00, 9 October 2006, discussion here and mention in the article of a simplified teaching approach for beginners (NOT a theory) was moved by an opponent of these ideas to a new "attack article and POV split article", which is jargon for the point you're making: see Wikipedia:Neutral point of view#POV forks. However, as Wikipedia:Content forking#Article spinouts - "Summary style" articles points out, it is often good practice to have a brief summary on the main article linked to a spinoff article giving additional detail. By the way, origin of species is a redirect to an article about the book On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, the various theories and religious faiths all have their own articles: Wikipedia is not a paper encyclopedia. ...dave souza, talk 10:24, 13 October 2006 (UTC)
thread_title: NPOV

message: :: I of course have to respond -
::"The entropy of a perfect gas mixture is equal to the sum of the entropies each pure gas would have if it alone occupied the volume of the mixture” (temperature unchanged)"
::Exactamundo - This is Gibbs theorem, and it deserves a place in a Wikipedia article if not its own article. 
::"It is the spreading out of the molecules in space that is crucial, not the intermixing of them."
::By Gibbs theorem, its hard to argue against this. These statements do not support nor deny the "entropy change is energy dispersal" contention, but they are useful tools to bring to the discussion of energy dispersal in the mixing case.
::"When A and B are mixed, their groups of different molecules can move to spread their “A” or “B” internal energy throughout the larger combined volume."
::Here is where the problem lies. The quantity defined as "the internal energy of the A molecules" does disperse under any reasonable definition, but I still object. For technically, quantitative minded people, I have another argument which I hope will be helpful in understanding my objection. To others I apologize. For the technically minded, let me just write down an expression for entropy from the first and second law.
:::dS \ge \frac{1}{T}\,\left(dU + PdV -\sum_i \mu_i dN_i\right)
::Nobody disagrees that "energy dispersal" occurs in the first two terms (heat dissapation and expansion of a gas). Its that third term which applies to the mixing case that I am using to object to the above quote. Suppose I put forward a "mirror image" theory that all entropy change is particle dispersal, not energy dispersal. Then no one would disagree that "particle dispersal" occurs in the second and third cases. But for that first case, there would be an argument (mirror image of the entropy of mixing argument) saying "what if you had a hot iron bar and a cold iron bar connected - there would be entropy increase with no particle dispersal". But I could respond - lets call the system composed of both iron bars the "whole system". Consider the hot particles in the whole system  - those half of the particles that are above the average energy/particle of the whole system. They will be concentrated in the hot bar at the beginning, much less so in the cold part. As time goes on the density of the hot (and cold) particles will even out, they will disperse throughout the whole system. Thus there is hot and cold particle dispersal.
::Now the obvious objection to this scenario is the same that I have for the idea that the separate energies are dispersed in the entropy of mixing case. There is no "tracking of the identity" of the energy in the energy dispersal argument any more than there is any "tracking of the identity" of the particles defined as "hot" in the mirror image argument. PAR 15:31, 17 October 2006 (UTC)
replies: text: In rereading the response of Frank Lambert, I realize now the reason for stating Gibbs theorem in support of the energy dispersal idea. I think it is being used to demonstrate that mixing is essentially equivalent to the free expansion of two different gases. The final entropy of the mixture is the same as the sum of both gases if they freely expanded, yes, but there is a difference, and its crucial. In free expansion, there is no transfer of energy, between the A and B gases. In free expansion, all collisions are of the AA type or  BB type, while in mixing there are AB collisions as well. Energy is moved back and forth between the A and B gases, and has no tight connection to either the A or B gas. PAR 16:35, 17 October 2006 (UTC)
replies: text: So what if who hits who!!. In common language, not a bunch of QM talk, the mass and other characteristics of A only allow its energy to be transferred and accepted on SPECIFIC energy levels; i.e., the initial "group" of A molecules after infinite collisions with B or itself or the walls will -- even spread out in the final larger volume -- will have the same internal energy characteristics of A at T -- i.e., the group of A will have the SAME ENTROPY finally OR the measured change entropy due to mixing would be different than simple expansion of each component. It isn't!!! FrankLambert 17:29, 17 October 2006 (UTC)
replies: text: An issue I see here is a lack of agreement on operational definitions of the term "entropy".  That is, to what extent, beyond the measurable quantification of entropy as S on a cardinal scale, is entropy also properly taken to refer to the process of energy dispersal the results of which are quantified as \Delta S . ... Kenosis 16:52, 17 October 2006 (UTC)
replies: text:  Ok, FrankLambert has responded to my second post, but what about the first? That is the main argument. If there is a telling response to the first, then I concede your point on the second. And To Kenosis, I think entropy is very well defined, it is energy dispersal that is not being adequately defined. S stands for entropy, and ΔS is a measure, a direct measure, of the change in entropy. It cannot be defined as the degree of energy dispersal, it already has a definition. The idea that it is equivalent to energy dispersal is the very point under discussion. Energy dispersal has to be independently defined, as Dr. Leff's article has done, and then shown to be equivalent to entropy increase ΔS. (Not that I agree with his definition). PAR 18:22, 17 October 2006 (UTC)
replies: text: Well, yes PAR.  The question I'm posing is: "To what extent, if any, is the process itself properly termed "entropy", or is the term strictly limited to the quantity S "?  If the term "entropy" is properly extended to include the process quantifiable as \Delta S, then the description of the process as "energy dispersal" is very reasonably applied in explaining the process in the article! And, if not, then the use of a descriptor such as "energy dispersal" must be limited to explaining that particular aspect of the process which results in the quantification of S or \Delta S.  Either way, it appears to me that FrankLambert's basic pedagogical approach is an extremely reasonable one which can be sourced in accordance with WP:VER and WP:RS.  ... Kenosis 20:32, 17 October 2006 (UTC)
replies: text: To cite, "Entropy measures the spontaneous dispersal  of energy... — at a specific temperature." Which is now used by a number of authors as a much more useful description than it being "a measurement of the disorder or randomness of a system", for example. Neither of which deviates from the definition of ΔS ... dave souza, talk 21:22, 17 October 2006 (UTC)
replies: text: Well, I should think it's time to begin including a modified version of FrankLambert's earlier explanation in the article, properly sourced to some of these modern texts, so that readers who are not so technically inclined might have an opportunity to better understand this subject. Any controversy about the use of the words "energy dispersal" can be readily mentioned to the extent that it reflects current controversy between the traditional approach and this particular modern approach, in keeping with WP:VER and WP:NPOV#Undue_weight of course.  ... Kenosis 21:49, 17 October 2006 (UTC)

text:  Boo-booing the loose speak of "disorder or randomness" is a red herring. "dispersal of energy" is still less exact (and only questionably more intuitive) then S = k \cdot ln (Unkenntnis) as can be found in Becker's Theorie der Wärme and any number of other classical treatments of the subject. --Pjacobi 21:46, 17 October 2006 (UTC)

text: Kenosis: Entropy is the quantity S.  Entropy change is the difference ΔS.   Processes can be associated with an entropy change.  But entropy is a property of the system at a given moment - a state function. Jheald 21:59, 17 October 2006 (UTC)
replies: text: Sure, and that state function is the result of a process, not just something divorced from the dynamics of the natural world.  It is that process that needs some reasonable explaining in the article. ... Kenosis 22:11, 17 October 2006 (UTC)
thread_title: Discussion of 'entropy of mixing'

message: Sorry, I’ve been away and have to go quickly. Norman Craig (text: Entropy Analysis) says: “Entropy in thermodynamics always means entropy change.” S lacks meaning without its reference to a substance/system at T.  S0  refers to a change from 0 K – the dispersal of thermal energy from the surroundings/T to a substance beginning at 0 K for incremental values of T up to 298.15 K.  Specifically, the process involves calculation from 0-10 K, then summation from 10 K to 298.15 K of incremental/reversible measurement of heat transferred/T  (shown in most phys chem. texts as Cp/T versus T, with the area under the curve to 298.15 K as the summation of  ∫ Cp/T dT).  S0 of course is the most telling example of the importance of viewing energy dispersal as integral to any consideration of entropy change.FrankLambert 23:06, 17 October 2006 (UTC)
thread_title: S, S<sup>0</sup>, &Delta;S