Creationists repeatedly claim that the Second Law of Thermodynamics prohibits evolution. Buzz. Wrong. False. Incorrect. This claim has been around at least back to when I was in college, back when disco was popular. It was wrong then and it’s still wrong.
On the website ChristianAnswers.net, in the article “Second Law of Thermodynamics – Does this basic law of nature prevent Evolution?” the author states:
Naturalistic Evolutionism requires that physical laws and atoms organize themselves into increasingly complex and beneficial, ordered arrangements. Thus, over eons of time, billions of things are supposed to have developed upward, becoming more orderly and complex.
However, this basic law of science (2nd Law of Thermodynamics) reveals the exact opposite. In the long run, complex, ordered arrangements actually tend to become simpler and more disorderly with time. There is an irreversible downward trend ultimately at work throughout the universe. Evolution, with its ever increasing order and complexity, appears impossible in the natural world.
Christian Answers says this after crudely stating the Second Law:
It is well known that, left to themselves, chemical compounds ultimately break apart into simpler materials; they do not ultimately become more complex. Outside forces can increase order for a time (through the expenditure of relatively large amounts of energy, and through the input of design). However, such reversal cannot last forever. Once the force is released, processes return to their natural direction – greater disorder. Their energy is transformed into lower levels of availability for further work. The natural tendency of complex, ordered arrangements and systems is to become simpler and more disorderly with time.
I say “crudely” because
- Chemical compounds do not “ultimately break apart”–it depends on whether there is energy to break them apart. If there isn’t enough energy to break them apart, the compounds will just remain inert until there is enough energy somehow or protons decay away, or the Universe ends. Never mind how the Universe ends for right now. That’s for another time.
- It’s energy, not outside forces that reverse entropy. Force is not energy. A lot of people confuse them. I’m not going to explain the difference now, because for this it’s irrelevant.
- For the record, I want to object to the word “simpler.” Increased entropy does not mean things become “simpler,” it means they become more disorganized, and that definition of “disorganization” is mathematically complex. I really don’t want to go into the math here, so let’s just assume that by “simpler,” the creationists meant “more disorganized.”
If I were to describe the Second Law of Thermodynamics in simple words, I would say “Systems will remain at the same level of organization or become more disorganized over time. Any organization in one part of the system must be offset by disorganization elsewhere in the system, such that the total disorganization remains the same or increases.” I’d actually rather throw an equation at my readers, but explaining that equation would get even messier.
Note: There’s a special case. Theoretically, if you perform certain actions in a certain way (1), then you can wind up not changing the overall entropy at all. In practice, there will be friction or some sort of energy loss so the entropy of the Universe will increase, but if you could eliminate friction and other losses, the change in entropy would be zero.
Anyway, the ability to trade entropy around using energy is what makes pretty much everything possible–to quote Douglas Adams, “Life, the Universe and Everything.”
When you eat food, you decrease your entropy, at the expense of whatever you just ate. The stuff you give off as a result of your digestive processes (CO2, water vapor, methane, and those “excretory products”) are at a higher entropy than when you ate them. Your entropy decreases, but the overall entropy increases in the process of digestion and metabolism.
If entropy prevented evolution, it would also prohibit:
- The formation of crystals (salt in solution is more disorganized than salt in crystal form).
Embryos becoming babies becoming adults (an embryo is far more disorganized than the bundle of joy that arrives about nine months later.
- Children growing up to adults (same as an embryo growing into a baby).
- All of those things are possible because energy can be used to decrease entropy in a localized area.
Another trick to “disprove” evolution is to improperly draw your boundaries. The Second Law of Thermodynamics assumes that what you’re looking at is in an area where nothing comes in or leaves. If the “box” is big enough (the Universe), there’s no problem. But if you draw the “box” around an organism with the food outside and say “evolution can’t happen because of thermodynamics,” then you’ve drawn your box improperly. If you draw the “box” around the Earth and leave out the sun that produces the energy life needs, then you’ve left out the place the energy for the food comes from–and you’ve drawn your “box” incorrectly. One of the big tricks in thermodynamics is figuring out how to draw those “boxes.”
Here is a chart I put together to help explain this. Now, I did the chart humorously and only had vector graphics for what I hope is a Tyrannosaurus Rex and an Apatosaurus. No, they didn’t live at the same time. I got the Apatosaurus the same place I got the T. Rex and the Earth and the sun for this gedanken experiment.
In the end, the point is, life gets the energy necessary to locally reverse entropy from food. Food gets the energy from other food, which gets it from the light that comes from the sun. The sun gets the energy from fusion. Every step along the way, entropy increases. It’s energy from the sun that ultimately powers evolution.
The Second Law of Thermodynamics in no way prevents evolution. Anyone telling you differently doesn’t know what they are talking about.
Saying that they don’t know what they’re talking about is the most optimistic interpretation I can think of. The late Duane Gish of the Institute for Creation Research was a biochemist and claimed the Second Law prevented evolution. I don’t know why. Maybe he was bad at thermodynamics. It’s a difficult class. Maybe he never had thermodynamics. Maybe he forgot his thermodynamics.
In (I believe–I can’t find a copy of it) the first issue of the defunct Science 80 magazine, there was a debate between Gish and Dr. Isaac Asimov. Yeah, the science fiction writer Isaac Asimov–he was a good scientist, too. Asimov clearly pointed out to Gish that the Second Law did not prohibit evolution. Years later, Gish was still claiming the Second Law prohibited evolution.
Maybe Gish didn’t understand Asimov. Maybe Gish rejected what Asimov said because he didn’t like the conclusion. Maybe…maybe Gish preferred something that “disproved” evolution to the truth. I don’t know, and Gish is no longer here to defend himself. As a Christian, I hope that Gish was doing his best and that was all the better it got.
But in the end, anyone who tells you the Second Law of Thermodynamics prohibits evolution is telling you something false.
Finally, I just noticed that nowhere did I capitalize “sun” in the graphic or text. Redoing the graphic is something I don’t want to do, so I’m leaving “sun” uncapitalized. As an editor, I’m horrified, but I’ve got about 5 more minutes to get this up and go do other stuff. Actually, I hope that’s the worst spelling or grammar error I’ve made here. I don’t have time to proofread today.
- It’s called “adiabatically and no way will I describe what “adiabatically” means here. Go take a thermodynamics class like I did if you really want to know. [↩]