The Second Law Argument and Specified Complexity
In my 2010 Discovery Institute Press book In the Beginning..., I pointed out that the second law argument for intelligent design, discussed extensively in Chapter 5, was essentially equivalent to Bill Dembski's "specified complexity" argument:
The underlying principle behind the second law is that natural forces do not do macroscopically describable things that are extremely improbable from the microscopic point of view... The reader familiar with William Dembski's "specified complexity" concept, from The Design Inference, will recognize similarities to the argument here: natural forces do not do things which are "specified" (macroscopically or simply describable) and "complex" (extremely improbable). Both are just attempts to state in more "scientific" terms what is already obvious to the layman, that unintelligent forces cannot do intelligent things.But what is the advantage of the second law argument if it is almost equivalent to another argument already used to defend ID? The advantage is, it is based on a widely recognized, fundamental law of Nature; a law recognized even by people who have no sympathy for ID.
Although the first statements of the second law dealt exclusively with conduction (diffusion) of heat, it was soon realized that the reason thermal entropy cannot decrease in an isolated system is that would be macroscopically describable and extremely improbable, and this more general principle was then applied to other applications, including the diffusion of other substances.
Over time, the second law was applied more and more generally, to less quantifiable applications, and today most scientists will agree that, in an isolated system, the second law dictates that natural (unintelligent) causes can turn computers and jet airplanes into rubble but not vice versa because, of all the arrangements atoms could take, only a very small percentage would be capable of mathematical computation or long distance air travel. If you say, how then did natural forces alone create computers and jet airplanes out of rocky rubble on Earth, most will of course respond that the Earth is not an isolated system, because it receives energy from the Sun.
At this point all you have to do is point out that if decreases in entropy on an isolated planet such as atoms spontaneously rearranging themselves into machines capable of mathematical computation or long distance air travel are forbidden by the second law, because these are macroscopically describable things which are extremely improbable from the microscopic point of view, then they are still forbidden by the same law in an open system, if the only thing entering the system is solar energy, for the same reason: they are still extremely improbable.
Here your debate opponent could argue that, thanks to the influx of solar energy (and, of course, thanks to natural selection), the spontaneous rearrangement of atoms into computers and jets is not really astronomically improbable, but it is very hard to find anyone willing to go that route. Instead, he will point to the early applications of the second law, and argue that thermal entropy can decrease in an open system, thus entropy can in general decrease (order can increase) in open systems.
Now you only need to point out that when thermal entropy decreases in an open system, it is not because anything macroscopically describable is happening which is extremely improbable from the microscopic point of view, something is simply entering the open system which makes the decrease not extremely improbable. In fact, in "A Second Look at the Second Law," I showed that, in an open system (assuming nothing is going on but diffusion), the "X-entropy" associated with any diffusing component X (if X=heat, X-entropy is just thermal entropy) cannot decrease faster than it is exported through the boundary, or, stated another way, the X-order in an open system cannot increase faster than it is imported. Thus the fact that thermal entropy can decrease in an open system does not suggest that computers can appear on a barren planet as long as the planet receives solar energy. The appearance of computers on a barren planet is consistent with the second law only if something enters that makes this not extremely improbable: for example, if an alien imports them from his planet!
Thus, the advantage of the second law argument for ID is that physics texts already almost make the argument for you. All you have to do is point out that the fact that the Earth is an open system does not mean that extremely improbable things can happen here without violating the second law, it just means you have to take into account what is entering our open system before deciding whether the spontaneous rearrangement of atoms into computers, jet airplanes, spaceships and nuclear power plants is extremely improbable or not. (See footnote 4 in the above referenced article for more on what is meant by "extremely improbable.")
If we watch a video of a tornado running backward, turning rubble into houses and cars, would we argue that tornados derive their energy from the Sun, and the increase in entropy on the Sun is far greater than the decrease in entropy seen on this video, so there is no conflict with the second law? No, because what we see on the video is still extremely improbable, even if tornados do derive their energy from the Sun!
Once the debate gets to this point, I have found that the next line of defense is always to say, oh heck, the second law of thermodynamics should have never been generalized beyond thermodynamics, it should only be applied to quantifiable applications. If we see a video of a tornado running backward, we cannot tell if there is a problem because it is just too difficult to quantify what we are seeing in the video. But ID opponents raise the same objection to the specified complexity argument: we can't tell if the faces on Mt. Rushmore are the products of natural or intelligent causes, that is just too hard to quantify. And some things are obvious even if they are difficult to quantify!
In fact, as I pointed out in an earlier ENV article, all of the arguments used to deny that what has happened on Earth violated the second law can equally be used to argue that tornados that turn rubble into houses and cars would not violate it either. Well, would tornados turning rubble into houses and cars violate the second law?
According to many general physics textbooks the answer is yes, but it depends on your formulation of the second law. It would certainly not violate the early formulations, which were all about heat, and it can even be argued that it would not technically violate the more general statements, which also begin with "in an isolated system...." So you can of course state or interpret the second law so that neither tornados running backward, nor computers arising out of a rocky planet, would violate it.
But it is obvious to all of us that a tornado running backward would violate some fundamental law of Nature, whether it is one of the man-made formulations of the second law, or just the basic natural principle behind all applications of that law. And it should be equally obvious that any attempt to explain what has happened on Earth in terms of entirely unintelligent causes runs afoul of the same Natural principle, whatever it is.
That, by the way, is the point made by my video, "Evolution Is a Natural Process Running Backward." Please note that there is now a Spanish version of this video also; see below.