From: Don Stockbauer on 29 Jan 2010 10:11 1. Potential 2. Actualized
From: Don Stockbauer on 29 Jan 2010 10:25 On Jan 29, 9:11 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > 1. Potential > > 2. Actualized Some of SEN's dialogue is taken from speeches by Richard Nixon.
From: Don Stockbauer on 29 Jan 2010 10:28 On Jan 29, 9:25 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > On Jan 29, 9:11 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > > > 1. Potential > > > 2. Actualized > > Some of SEN's dialogue is taken from speeches by Richard Nixon. This statement is false.
From: Don Stockbauer on 29 Jan 2010 10:40 On Jan 29, 9:28 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > On Jan 29, 9:25 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > > > On Jan 29, 9:11 am, Don Stockbauer <don.stockba...(a)gmail.com> wrote: > > > > 1. Potential > > > > 2. Actualized > > > Some of SEN's dialogue is taken from speeches by Richard Nixon. > > This statement is false. One interesting thing is that even in Utopia people will still get irritated at each other. It helps stir the broth.
From: Pentcho Valev on 30 Jan 2010 01:49
More ENTROPY-GATE: For a closed system doing reversible work of expansion the first law of thermodynamics takes the form dU = dQ - PdV /1/ where dU is the internal energy change, dQ is the heat absorbed, P is pressure and V is volume. Since the system is CLOSED and undergoes reversible changes the entropy change is, by definition, dS=dQ/T and / 1/ becomes: dU = TdS - PdV /2/ J. Gibbs managed to convince the world that, if the system is OPEN (substances are added to it), /2/ should be replaced by dU = TdS - PdV + SUM mu_i dn_i /3/ where mu_i is the chemical potential and n_i is the amount of the ith component. However Gibbs failed to explain the meaning of the entropy change, dS, for an OPEN system. Was dS again equal to dQ/T, as it is for a closed system, or was dS equal to something else when substances were added to the system? The fact that dS was not defined for open systems made the equation / 3/ so fashionable (scientists adore equations with undefined terms) that in the end /3/ was called "the fundamental equation of thermodynamics": L. McGlashan, Chemical thermodynamics, Academic Press, London (1979), pp. 72-73: "For an infinitesimal change in the state of a phase alpha we write dU = T dS - p dV + SUM mu_B dn_B (1) We regard equation (1) as an axiom and call it the fundamental equation for a change of the state of a phase alpha. It is one half of the second law of thermodynamics. We do not ask where it comes from. Indeed we do not admit the existence of any more fundamental relations from which it might have been derived. Nor shall we here enquire into the history of its formulation, though that is a subject of great interest to the historian of science. It is a starting point ; it must be learnt by heart." Yet scientists somehow felt that a new explicit definition of dS could bring even more career and money. The quickest among them, Ilya Prigogine, simply combined /1/ and /3/ and obtained dS = dQ/T - (1/T)SUM mu_i dn_i /4/ That was a new incredible definition of the entropy change (the scientific community had never seen anything like this) so the Nobel Committee immediately gave Prigogine the Nobel Prize. Pentcho Valev wrote: http://web.mit.edu/keenansymposium/overview/background/index.html Arthur Eddington: "The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Maxwell's equations. If it is found to be contradicted by observation - well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics, I can give you no hope; there is nothing for it but to collapse in deepest humiliation." http://www.beilstein-institut.de/bozen2004/proceedings/CornishBowden/CornishBowden.htm ATHEL CORNISH-BOWDEN: "The concept of entropy was introduced to thermodynamics by Clausius, who deliberately chose an obscure term for it, wanting a word based on Greek roots that would sound similar to "energy". In this way he hoped to have a word that would mean the same to everyone regardless of their language, and, as Cooper [2] remarked, he succeeded in this way in finding a word that meant the same to everyone: NOTHING. From the beginning it proved a very difficult concept for other thermodynamicists, even including such accomplished mathematicians as Kelvin and Maxwell; Kelvin, indeed, despite his own major contributions to the subject, never appreciated the idea of entropy [3]. The difficulties that Clausius created have continued to the present day, with the result that a fundamental idea that is absolutely necessary for understanding the theory of chemical equilibria continues to give trouble, not only to students but also to scientists who need the concept for their work." http://philsci-archive.pitt.edu/archive/00000313/ Jos Uffink: "This summary leads to the question whether it is fruitful to see irreversibility or time-asymmetry as the essence of the second law. Is it not more straightforward, in view of the unargued statements of Kelvin, the bold claims of Clausius and the strained attempts of Planck, to give up this idea? I believe that Ehrenfest- Afanassjewa was right in her verdict that the discussion about the arrow of time as expressed in the second law of the thermodynamics is actually a RED HERRING." ftp://ftp.esat.kuleuven.ac.be/pub/SISTA/markovsky/reports/06-46.pdf "From the pedagogical point of view, thermodynamics is a disaster. As the authors rightly state in the introduction, many aspects are "riddled with inconsistencies". They quote V.I. Arnold, who concedes that "every mathematician knows it is impossible to understand an elementary course in thermodynamics". Nobody has eulogized this confusion more colorfully than the late Clifford Truesdell. On page 6 of his book "The Tragicomical History of Thermodynamics" 1822-1854 (Springer Verlag, 1980), he calls thermodynamics "a dismal swamp of obscurity". Elsewhere, in despair of trying to make sense of the writings of some local heros as De Groot, Mazur, Casimir, and Prigogine, Truesdell suspects that there is "something rotten in the (thermodynamic) state of the Low Countries" (see page 134 of Rational Thermodynamics, McGraw-Hill, 1969)." Pentcho Valev pvalev(a)yahoo.com |