Right before the Holidays, I had a chance to go to Philcon. It’s the Philadelphia science fiction conventions (despite the fact that it’s held in Cherry Hill, New Jersey), and it’s one of my favorites. It’s not only a great con, but in exchange for speaking on a handful of panels, they let me in for free, win, win. As a science writer, I usually get put on one of the panels about life on other planets, a great topic, with lots of room for interesting questions. This year, there was a Creationist in the audience, so we ended up getting questions about evolution.
After my fellow panelists and I patiently explained that survival of the fittest did not mean that only the strong survive, he fell back on one of the Creationists’ favorite arguments, thermodynamics. It’s a fun argument and it sounds all nice and sciencey, like you’re really trying to be logical and everything. It goes something like this, “The 2nd Law of Thermodynamics says that entropy always increases, so obviously, well organized, living things can’t simply arise from disorganized matter.”
Unfortunately for him, this argument fails on two grounds. First, despite Creationist insistence that Darwin’s theory of evolution is invalid because it doesn’t explain how life started, the theory of evolution doesn’t explain that for the simple reason that the theory of gravity or the germ theory of disease don’t explain it. They aren’t intended or designed to. None of them have anything to do with the origin of life. Darwin’s theory simply explains how populations of living things change and adapt once life is already established.
Second, his argument fails because he doesn’t understand thermodynamics. What the 2nd law of thermodynamics actually says is, “In a closed system, entropy always increases.” Notice the difference? He completely ignored the part about a closed system. Earth, or any other planet, for that matter, isn’t a closed system. It gets hit by meteorites and cosmic rays and all kinds of other things from space. Bits of its atmosphere slowly float away and the occasional bit gets knocked loose, and all of that keeps it from being a closed system. It is a very open system.
The biggest thing that keeps Earth from being a closed system is the sun. It’s the source of our energy. It’s busily burning up hydrogen in nuclear fusion reactions (increasing its own entropy) and pouring out billions of kilojoules of energy each second that we, humble living things, are the beneficiaries of. When those disorganized organic chemicals started coming together to form highly organized living things, they used the sun’s energy to do it. Even though that decreased entropy on our local ball of rock, entropy in the sun and other parts of the universe were increasing, thus maintaining the 2nd law of thermodynamics.
If you want to properly understand entropy, the best way is to look at teenagers. If you have one, you know what I mean. Imagine that your own teenager comes to you and says, “You know, I’d really love to clean my room, but that would cause entropy to decrease. It would violate the 2nd law of thermodynamics. You wouldn’t want me to break the law, would you?”
At this point, you lovingly look at your son or daughter and say, “Are you out of your damn mind? Get up there and CLEAN YOUR ROOM.”
To this, you receive the inevitable, “Fiiiiiiiiiiiiiiinnnne,” and the kid goes back to said room. Two or three hours later, after what should have been a twenty minute job, he/she tromps back and says, “There, I cleaned my room. Are you SATISFIED?”
Going to the room to check, you see, to your amazement, that your kid has actually cleaned up the room. Entropy has been decreased. The 2nd law of thermodynamics is in ruin. Of course, you and I know that what the kid has really done is pick up all the crap on the floor and the bed and shoved it all in the closet. That room is no more a closed system than the planet Earth is. While entropy locally in the room has been decreased, entropy in the closet has increased exponentially.
It gets worse. In the course of picking up all that crap, the teen has performed work. Muscles have been used, and heat generated, thus explaining the smell. All of the energy required to do this originated in your refrigerator, which has been left a hollow, entropy filled husk.
What does this have to do with evolution? Simple, both operate under the same physical laws, the same laws of thermodynamics. As long as there’s an external energy supply available, it’s entirely possible for simple organic molecules to organize themselves. It’s rare, but once it get going, it’s tough to stop. Even if the chances of such an organization are infinitesimally small, all you have to do is play the odds. There are over 300 billion stars in the Milky Way galaxy alone. Current research suggests that many, if not most, of those stars have planets in orbit around them, which they’re churning out energy for. With that much energy and that many planets, the odds of life spontaneously arising are pretty good, probably better than the odds of your teenager spontaneously cleaning his/her room.
Of course, none of this really has anything to do with Darwin’s theory. As I mentioned earlier, it wasn’t intended to explain the origin of life. This does, however, take away one of the main arguments that Creationists try to use against it. Perhaps if we can whittle down enough of their arguments this way, they will eventually have to give up, shaking their heads and tromping back to their rooms with a final parting, “Fiiiiiiiiiiiiiiinnnne.”
Mad4science 