The folks over at Uncommon Descent have unveiled a new blogger: mathematician Granville Sewell. He’s the latest know-nothing to convert a comically simplistic version of the second law of thermodynamics into an anti-evolution argument.
Of course, this is one of those shark-jumping, litmus-test arguments that tell you immediately you are dealing with a crank. The second law of thermodynamics and modern evolutionary theory are not in conflict. That is a fact, not an opinion. Anyone claiming they are in conflict is confused about at least one of them, and probably both.
I have previously dealt at length with Sewell’s arguments. Let’s have a look at his latest rantings.
After linking to a blogger from Colombia who endorsed Sewell’s view of things, Sewell writes the following:
Every time I write on the topic of the second law of thermodynamics, the comments I see are so discouraging that I fully understand Phil Johnson’s frustration, when he wrote me “I long ago gave up the hope of ever getting scientists to talk rationally about the 2nd law instead of their giving the cliched emotional and knee-jerk responses. I skip the words ’2nd law’ and go straight to ‘information’”. People have found so many ways to corrupt the meaning of this law, to divert attention from the fundamental question of probability-primarily through the arguments that “anything can happen in an open system” (easily demolished, in my article) and “the second law only applies to energy” (though it is applied much more generally in most physics textbooks). But the fact is, the rearrangement of atoms into human brains and computers and the Internet does not violate any recognized law of science except the second law, so how can we discuss evolution without mentioning the one scientific law that applies?
The sheer, breathtaking gall of these folks is simply not to be believed. Phillip Johnson was the Berkeley law professor who got the ID movement rolling with his book Darwin on Trial. This book contained very little that was scientifically accurate. The very idea of Johnson lamenting the lack of rationality in the way scientists discuss the second law, or anything else, is just too rich.
Sewell does not link to any critics actually making either of the points he attributes to them. I’d be surprised if any scientifically knowledgeable person has ever suggested either that anything can happen in an open system, or that the second law only applies to energy. It is probably too much to hope that Sewell will engage seriously with criticisms of his argument (doing so, after all, would force him to admit that he is wrong). Nonetheless, let us explain why he is not correct.
The second law is ultimately a mathematical statement concerning the change in entropy that results from a physical process. It asserts that the change in entropy must be greater than a certain mathematical expression whose value can be determined (sometimes!) from an understanding of the physical paramters of the system. This expression is generally written using the language of calculus (it is the integral of dQ over T), but that level of detail is not necessary here.
If you imagine a system that is isolated from its surroundings, so that neither matter nor energy are crossing the boundary, then the integral has the value zero. That would mean that the change in entropy must be positive in this situation, which indicates an increase in entropy as the result of the physical process under consideration. We can therefore say that a spontaneous natural process taking place in an isolated system can not cause entropy to decrease.
If the system is not isolated; that is, either matter or energy is crossing the boundary); then the entropy can spontaneously decrease. However, it still can not decrease by more than the value given by the mathematical expression mentioned previously. So entropy can decrease, but the second law puts a lower bound on the magnitude of that decrease.
The conclusion is that if you have a system that is receiving energy from the outside, such as the Earth, then it is not even an apparent violation of the second law to see entropy decreasing. Any asserrtion that evolution or any other physical process violates the second law has to be backed up with a calculation. You have to show that the decrease in entropy that resulted from the physical process is smaller than the value of the mathematical expression mentioned previously. Minus that calculation you have only an assertion based on nothing. And recasting the second law in the language of probability or information does nothing to change that conclusion.
There’s plenty more to say of course. If you’re interested I invite you to follow the link above to my earlier essay on this subject. As it stands, Sewell has not even made an argument to show that evolution and the second law are at odds. He has merely asserted that they are, apparently based on nothing more than the fact that organisms have gotten more complex over time. His assertion is incorrect because the second law contains nothing to prevent such growth in complexity. His assertion is asinine and worthy of contempt because he doesn’t seem to have thought seriously about this subject, even as he pompously lectures others about it.