Well, that has changed in the last few days. And while there are now a couple subjects I wish to post on, today’s article will be on the subject of a few scientific terms that are getting massively and ignorantly abused these days: “Theory of Evolution,” and “Second Law of Thermodynamics.” Both of these terms are thrown out as criticisms of evolution, mostly by someone who understands neither concept claiming that they somehow disprove that evolution occurs.
First, I want to take a look at “Theory of Evolution.” Specifically, I’m addressing the claim that “It’s only a guess; that’s why it’s called the ‘Theory,’ of Evolution!” This is what is called an equivocation fallacy. If you’re not familiar with what an equivocation fallacy is, it’s when you treat two different concepts as if they were the same thing for the purpose of trying to make an argument about one of them by arguing about the other.
What are the two concepts being equivocated here? The colloquial usage of the word “theory,” versus the scientific usage of the word “theory.” It’s kind of unfortunate that they use the same word so differently, because it makes this particular equivocation so very easy for people to make. But hopefully this can clear things up a little bit.
See, in conversational usage, a theory is basically just a guess at an explanation for something, and it pretty much just stops there. This usage is closer to what, in science, would be called a hypothesis, and it is only a starting point. Scientists don’t get to stop there. Once they’ve made that guess (that hypothesis), they then have to test it. Usually, this involves making predictions of things that would have to be true in the real world if their hypothesis is correct, then performing tests to see if those predictions are true. If the real world doesn’t bear out the hypothesis, then it must be discarded or modified. The new hypothesis is then tested. Over and over, until you arrive at a hypothesis that passes all of the tests that you devise.
But even then, it still isn’t a theory. A hypothesis that reaches this stage must then be exposed to other scientists, including a complete explanation of the hypothesis and a detailed description of all the tests performed and data that supports it. Then it is up to these other scientists to try and disprove it. They try to duplicate your test results. They try to devise their own tests. All of this is aimed at demonstrating that you aren’t fooling yourself, or that you didn’t miss some crucial piece of information, or even that you aren’t simply lying.
Once the scientific community has had their way with your hypothesis and come to accept that it is most likely correct, then and only then does it become a theory. In scientific usage, a theory is an explanation that has been so thoroughly documented, tested, retested, updated, and tested again that it has become a virtual certainty. There is no higher level of certainty afforded to a scientific explanation. To call the Theory of Evolution “just a theory” is like calling Usain Bolt “just a sprinter,” or Isaac Newton “just a mathematician.”
To put it another way, do you doubt that you will fall if you jump off a cliff just because the scientific explanation for why is called the “Theory” of Gravity? Do you doubt that viruses and bacteria cause illness just because the explanation for how is called the Germ “Theory” of Disease? Do you reject the idea that the earth orbits the sun because it’s called the “Theory” of Heliocentricity? Because that is the level of certainty that scientists are talking about when they reference the “Theory” of Evolution.
I have to admit that it’s a little aggravating to have to explain this, because it’s basic Middle School science. Virtually every child in the United States should have had this explanation in school. So anyone parroting “it’s just a theory,” as an adult, and pretending that makes it OK to dismiss scientific theories out of hand, has allowed their religion to actively destroy knowledge that was already contained in their heads.
The second term, Second Law of Thermodynamics, is a bit more understandable. After all, it’s kind of an advanced subject that doesn’t really get tackled until Physics class in High School. And even then, it’s done pretty superficially, and the implications may not be soundly explained until college (and then, only if you’re taking technical classes).
The way this is misused by creationists is basically in the following form: “The Second Law of Thermodynamics says that all systems tend to disorder. Since living things are highly complex order, and evolution says they arise out of the disorder of random chemical reactions, the Second Law of Thermodynamics means evolution is impossible.”
Now this one can be a difficult one to explain accurately without trying to teach you thermodynamics; something that normally takes multiple semesters of specialized college courses. That’s actually why this is such an effective line of bullshit – it sounds smart and scientific, and most people simply aren’t going to have the education to understand why it is completely and utterly wrong. And I, unfortunately, am going to have to try and explain to a lay audience who doesn’t have that background why it is wrong.
The Second Law of Thermodynamics is not about order and disorder, but about the direction that energy flows in a system and how much of it is available to do work. It says that energy always flows from regions of high energy density to regions of lower energy density, and never the reverse. Which means that, over time, a closed system will tend toward equalization. This means the energy density will be equal everywhere, and no energy will be available to do any work (such as organizing things). Since, in that state, nothing can be done, this is often characterized as the state of maximum disorder. Hence the claim that the Second Law says that all systems tend inevitably to disorder (which, you’ll probably notice, is not in the sense we generally mean when we say “disorder” in casual conversation).
Now, the words “over time,” and “closed system” are italicized in the above description because they are important. Because in the real world, nothing ever happens instantaneously, and there is no such thing as a closed system (which is one in which there are no interactions whatsoever with anything outside the system). The earth, for example, is constantly bombarded with energy from the sun (which has a vastly higher energy density, so the one-way flow demanded by the Second Law is maintained), and that constant input of energy means that systems on the earth don’t tend toward thermodynamic equilibrium at all. There’s a huge amount of energy available to do work (such as the work of organizing living systems).
You see, the 2nd Law, like all scientific laws, is descriptive. It describes what we observe to be happening in reality. And the fact is that spontaneous organization happens all the time. We observe it when snowflakes crystallize, or when quartz crystals form. And yes, in the complex chemistry of living systems. These are observed realities. If the 2nd Law claimed that these observations were impossible, then the 2nd Law would be demonstrably wrong and would have to be discarded or reformulated in a way that didn't contradict reality. But thermodynamics is a pretty well understood science, so the chances of that happening are vanishingly small.
I hope you can see from these brief discussions how the standard apologetics on these topics are extremely misleading. They are used to throw a scientific gloss over specious arguments, because that makes them sound profound when they are in fact merely uninformed. What makes them seem effective is that they can be dashed off in thirty seconds, but take hours of effort backed by years of education to refute in even so basic and abbreviated a form as I've been able to do here. I hope seeing this will encourage readers to seek clarification on scientific topics from scientists rather than theologians.