ethan@utastro.UUCP (Ethan Vishniac) (09/04/84)
Warning - This article suffers from quote-in-mouth syndrome >>>What kind of evidence should one expect to find from such a model? The >>>Laws of Thermodynamics are an obvious conclusion, and fit well within >>>the model. >>I'm just a country boy... what aspects of the law of Thermodynamics >>does creationism fit that is not adequately covered by more traditional >>explanations? >The transition from order to disorder. Life requires/is characterized by >order. Sigh... This is not a response. Thermodynamics does *not* forbid a local decrease in entropy (or an increase in order - yes I know the two are not precisely equivalent). It does set conditions on when this is to be expected. The surface of the Earth provides an environment in which this is possible. Most life survives by taking sunlight (color temperature ~6000 K) and degrading to photons with a typical energy corresponding to a temperature of ~300 K). This waste is disposed of into interstellar space (which has a *very* low energy content). Were the sun to cease to exist, or were the interstellar medium to be in thermodynamic equilibrium with the surface of the Earth, life as we know it would be impossible. From a thermodynamic point of view, the maintenance of life is not very different from its origin. Both involve lowering the entropy in certain places. Neither violates any laws of thermodynamics. "Cute signoffs are for Ethan Vishniac perverts" {charm,ut-sally,ut-ngp,noao}!utastro!ethan Department of Astronomy University of Texas Austin, Texas 78712
sharp@aquila.UUCP (09/10/84)
My favourite version of the famous three laws goes rather like:
1: You can never win, you can only break even.
2: You can only break even at absolute zero.
3: You can't get to absolute zero.
However, the major point which has not yet been made is that these
are laws of equilibrium thermodynamics, whilst life is part of a very
definitely non-equilibrium process. (Famous remark: in the likeliest
state, we'd all be dead)
The theory of non-equilibrium thermodynamics, which is what we really
need to start discussing any conflict with evolution, is slowly being
developed by such as Ilya Prigogine, who won a Nobel prize for his
efforts. (Why has no-one from UT Austin, home of the Ilya Prigogine
Center [see, I can spell American when I have to {:-)}], mentioned
this ?) Anyway, since the theory is not applicable, arguing about its
predictions seems rather irrelevant.
--
Nigel Sharp [noao!sharp National Optical Astronomy Observatories]mrh@cybvax0.UUCP (Mike Huybensz) (09/14/84)
Prigogene wrote "The idea of spontaneous generation of life in its present form is therefore highly improbable." Pasteur's experiments have also supported this idea; however it is not in the least incompatible with evolutionary ideas of abiogenesis (the fancy term). No credible evolutionary biologist claims that *poof!* a bacterium appeared by chance in the primeval soup. Current theory concerning the origins of life deals with self-replicative systems composed of a few hypothetical polypeptides. Assuming a single origin of life, all living organisms today are the result of roughly three billion years of evolutionary competition and selection. It would be extremely surprising if the first self-replicating chemical system (life) was robust enough that an unchanged line of descent could have survived until today, through major environmental changes and in the face of the competition of other, evolving lines of descent. For a more thorough explanation, see "The Selfish Gene" by Richard Dawkins.
gjphw@iham1.UUCP (09/18/84)
In a recent submission, N. Sharp posted a comment concerning an application of nonequilibrium thermodynamics. In reply, P. DuBois provided a quotation from a two part article that appeared in *Physics Today* (vol 25, Nov. and Dec. 1972) entitled *Thermodynamics of evolution* which was written by I. Prigogine et al. Also included was a second quotation (from *Impact of Science on Society*) that I have not checked. > ..."The point is that in a non-isolated system there exists a > possibility for formation of ordered, low-entropy structures > at sufficiently low temperatures. This ordering principle is > responsible for the appearance of ordered structures such as > crystals as well as for the phenomena of phase transitions. > > Unfortunately this principle cannot explain the formation of > biological structures. The probability that at ordinary > temperatures a macroscopic number of molecules is assembled > to give rise to the highly-ordered structures and to the > coordinated functions characterizing living organisms is > vanishingly small. The idea of spontaneous genesis of life > in its present form is therefore highly improbable, even on > the scale of the billions of years during which prebiotic > evolution occurred." > > Prigogine, Nicolis and Babloyantz, "Thermodynamics of Evolution." > Physics Today, 1972, v. 25. > > Speaking of dissipative structures and order through fluctuations, > Prigogine writes, > > "...let us have no illusions - our research would still leave us > quite unable to grasp the extreme complexity of the simplest > of organisms." > > Prigogine, "Can Thermodynamics Explain Biological Order?" Impact > of Science on Society, 1973, v. 23(3). > > (i) WRT the second quote: this is not to say that no progress > can be made in the direction of understanding such complexity. > I say this explicitly in the attempt to ward off the spate of > non-arguments such as were seen in the variable 'c' affair, in > which I was alleged to be arguing for a variable value of 'c'. > I didn't say 'c' varies there, and I don't say here that thermo > will never explain or describe biological complexity. > But perhaps one might reasonably express skepticism about the > place of evolution in producing that complexity? > > (ii) creationists are said to be "notorious" for quoting out > of context. If you think I'm doing so here, explain why, > please. With respect to the first of Mr. DuBois' comments (i), the recognition that the second quotation of Prigogine makes a cautionary statement concerning his research is indeed important. However, with respect to the first, and longer quotation, of Prigogine (ii), I intend to show that it has been taken out of context. Allow me to continue the text from the *Physics Today* article with the paragraph that follows the above quotation and which is used to finish the section dealing with equilibrium thermodynamics: The conclusion to be drawn from this analysis is that the apparent contradiction between biological order and the laws of physics - in particular the second law of thermodynamics - cannot be resolved as long as we try to understand living systems by the methods of the familiar equilibrium statistical mechanics and equally familiar thermodynamics. There is no dispute that the empirically discovered and idealized rules for equilibrium systems (i.e., the four laws of thermodynamics) are unable to explain any increase in order. Indeed, equilibrium thermodynamics (classical thermodynamics) does not permit any increase in order, or even the maintenance of locally ordered systems. What does cause a furor is the inappropriate and naive application of equilibrium thermodynamics (typified by uniform tempera- ture, pressure, mole fractions) to nonequilibrium conditions (systems with gradients or spatial and time variations in temperature, pressure, and chemi- cal concentrations). The out-of-context charge arises because we are led to believe from the ori- ginal quotation that Prigogine was referring to nonequilibrium thermodynamics. In fact, the quotation comes from the leading section of the article showing that while equilibrium thermodynamics does allow ordered systems at very low temperatures (interesting to me, though reasonable), it does not support the spontaneous formation of order at ordinary (e.g., room) temperatures. Systems are given one of three classifications in thermodynamics. The first is called isolated where no energy or matter can be exchanged. A second is called closed because while energy can be exchanged between the system and the outside environment, matter cannot be exchanged. The third category is called open, with both matter and energy being exchanged. Prigogine's reference to *nonisolated* was with respect to the closed system that he used to control the equilibrium temperature of the example system under discussion. It is due to the incorrect impression that the section quoted from the *Physics Today* article was in reference to nonequilibrium thermodynamics, rather than merely a closed system at equilibrium, that merits the out-of-context label. (Note also that the designation of the whole universe as closed is not the same as classifying a thermodynamic system as closed.) Allow me to continue on my soapbox. The studies of thermodynamics and sta- tistical mechanics cover three distinct regimes. The first is the familiar equilibrium thermodynamics, with its four laws (numbered 0 - 3). This occurs for systems having uniform temperatures, pressures, and chemical concentra- tions. The second is thermodynamics in the linear regime, also known as the thermodynamics of irreversible processes. Applied a posteriori, this occurs in systems of shallow or weak gradients. These gradients can only be linear, and spontaneous increases in order are not possible. (It was for his work on the thermodynamics of irreversible processes that Prigogine received his Nobel prize in physics.) A third regime is called nonequilibrium thermodynamics. Systems to which this applies, again a posteriori, have strong gradients which are not neces- sarily linear. Prigogine has already shown that in certain chemical systems, spontaneous increases in local order are possible in strongly nonequilibrium conditions (open systems). It is these nonequilibrium conditions which seem to apply to virtually all observed situations on Earth (at least within the biosphere) and appear to be most promising for further work. Prigogine et al are busily trying to discover the mathematical formulations that describe these systems that are far from equilibrium. Even in his technical writings and monographs, Prigogine has been making claims that his work in nonequilibrium thermodynamics can be used to explain all kinds of phenomena, especially living systems. These claims have all too often been difficult to substantiate or understand at this time. The *Physics Today* quotation struck me as out of character for Prigogine, so I explored it further. The *Impact* quotation is refreshingly cautious. -- Patrick Wyant AT&T Bell Laboratories (Naperville, IL) *!iham1!gjphw