Other Types of Entropy
|September 6, 2012||Posted by Granville Sewell under Intelligent Design|
If you look at university physics texts which discuss the second law, you will find examples of “entropy” increases cited such as books burning, wine glasses breaking, bombs exploding, rabbits dying, automobiles crashing, buildings being demolished, and tornadoes tearing through a town (I have actually seen each of these cited). According to Sal, all of these “creationist” text writers are confused, because in most or all of these cases, “entropy” is actually decreasing. When an albatross dies, or a tornado destroys a 747, entropy is actually decreasing, he says. Of course, Sal is talking about “thermal” entropy, since the only formulation of the second law he recognizes as valid is the early Clausius formulation, which deals with thermal entropy alone.
Well, no one is arguing that these examples result in thermal entropy increases, they are examples of “entropy” (disorder) increases of a more general nature. The reason tornadoes can turn a 747 into rubble and not vice versa is, of all the configurations atoms could take, only a very small percentage could fly passengers safely across the country, and a very large percentage could not. Thus we can argue that the original 747 has lower “entropy” (more order) than the demolished machine. Another very confused creationist, Isaac Asimov, even wrote, in the Smithsonian Magazine,
We have to work hard to straighten a room, but left to itself, it becomes a mess again very quickly and very easily…How difficult to maintain houses, and machinery, and our own bodies in perfect working order; how easy to let them deteriorate. In fact, all we have to do is nothing, and everything deteriorates, collapses, breaks down, wears out—all by itself—and that is what the second law is all about.
There are many formulations of the second law, the later ones recognize a more general principle, for example, Kenneth Ford in Classical and Modern Physics writes
There are a variety of ways in which the second law of thermodynamics can be stated, and we have encountered two of them so far: (1) For an isolated system, the direction of spontaneous change is from an arrangement of lesser probability to an arrangement of greater probability, (2) For an isolated system, the direction of spontaneous change is from order to disorder.
Sal says the second law has nothing to do with order or disorder; that is certainly not true of these more general, later, formulations.
OK, so Sal doesn’t like these examples, since they are difficult to quantify; he is not alone. Thermodynamics texts, as opposed to general physics texts, tend to shy away from them for that reason. Goodness knows, if we watch a video of a tornado tearing through a town, it is so difficult to quantify what we are seeing that we can never be sure if the video is running forward or backward, or if entropy is increasing or decreasing. But there are other types of “entropy” which are as quantifiable as thermal entropy, for example, the “X-entropy” which measures disorder in the distribution of any diffusing component X is defined by essentially the same equations as are used to define thermal entropy, which measures disorder in the distribution of heat as it diffuses, and X-entropy is certainly equally quantifiable. And X-entropy has little or nothing to do with thermal entropy (doesn’t even have the same units), one can increase while the other decreases in a given system. So why do people like Styer and Bunn and Sal, insist on treating all types of entropy as thermal entropy, and attempt to express the entropy associated with evolution, or the entropy of a 747, in units of Joules/degree Kelvin?
If you insist on limiting the second law to applications involving thermal entropy, and that the only entropy is thermal entropy, than Sal is right that the second law has little to say about the emergence of life on Earth. But it is not just the “creationists” who apply it much more generally, many violent opponents of ID (including Asimov, Dawkins, Styer and Bunn) agree that this emergence does represent a decrease in “entropy” in the more general sense, they just argue that this decrease is compensated by increases outside our open system, an argument that is so widely used that I created the video below, Evolution is a Natural Process Running Backward to address it a few months ago.