Why the 2nd Law of Thermodynamics should be taught as a criticism of evolution
Sleazy PZ Myers   (identical posts) and Jason Rosenhouse   are only proving my point that studies of criticisms of evolution theory -- even pseudoscientific criticisms -- are worthwhile educational experiences for students. Indeed, their discussion of the relation of the Second Law of Thermodynamics to evolution shows that even many professional scientists and engineers are unaware of or ignore some of the best reasons why the SLoT is not a valid criticism of evolution (the engineers who get the most training in thermodynamics are mechanical and chemical engineers -- aeronautical engineering is really a branch of mechanical engineering and an "aerospace engineer" is any engineer who works for an aerospace company).
Here are two reasons why the SloT is not a valid criticism of evolution:
(1) There are many different ways of defining or describing the SLoT, but many of these ways have nothing to do with biology. Probably the most popular statement of the SLoT is as follows: "It is impossible to construct an engine which, operating in a cycle, does nothing but absorb heat from a single reservoir and perform an equivalent amount of work." This principle is illustrated by the Carnot cycle. The work performed by a Carnot engine operating in a Carnot cycle (see the above diagram) is represented by the enclosed area inside the pressure-volume diagram of the cycle. It is evident that to have both (1) a positive enclosed area and (2) a return of the cycle to its starting point, there must be a stage where the engine rejects heat to a reservoir -- the Carnot engine cannot return to the starting point by a purely adiabatic process. The rejected heat represents the inefficiency of the Carnot engine. However, this statement of the SLoT does not introduce the concept of entropy, and SLoT arguments against evolution theory are often based on the concept of entropy.
(2) The SLoT's entropy property is quantified only for homogeneous substances and mixtures of homogeneous substances (e.g., water and steam) -- for example, entropy values are given in steam tables and Mollier charts. However, living things are generally not homogeneous, even at the microscopic, submicroscopic, and even molecular levels -- for example, a DNA molecule is not homogeneous. Yet both PZ Myers and Jason Rosenhouse present arguments that attempt to quantify the entropy of living things.
Also, Jason Rosenhouse insists that SLoT criticisms of evolution be quantified, but SLoT arguments cannot always be quantified -- for example, my above SLoT arguments are not quantified. Jason says,
Knowledgeable people will not show any respect for Sewell's argument, because he has produced virtually no argument at all. He describes it as his opinion that evolution violates the second law. This is not the sort of thing about which scientists are supposed to have opinions. We have ample evidence that evolution happened and that natural selection was the driving force of it. Biologists find evolutionary thinking to be very helpful in their research. If Sewell believes that it runs afoul of the second law nevertheless, then he needs to carry out the calculations that show that to be case. Otherwise he has only an opinion based on nothing.
Anyway, as the Darwinists point out, even if the entropy of the biosphere could be calculated, the biosphere is not a closed system and hence a decrease in the entropy of the biosphere could be compensated by an increase in entropy elsewhere, and hence the SLoT would not be violated.
I previously discussed the SLoT here and here.
Labels: Non-ID criticisms of evolution