Feedback archive Feedback 2011

Thermodynamics and evolution

How useful is the Second Law of Thermodynamics as an argument against evolution?

Image Wikipedia
As water freezes, it becomes more ordered.

In this week’s exchange, Dr Jonathan Sarfati discusses how useful the the Second Law of Thermodynamics is as an argument against evolution. David H. from the United States writes:

I heard an example used by an atheist to show proof self-organizing systems or increased complexity by way of a naturalistic manner. This is done to support molecules-to-man evolution. The example is: As two hydrogen molecules come together with an oxygen to form water they say it is proof that the complex can come from the simple without help from God in some kind of autopoietic(?) fashion perhaps. Of course, the first question of where the two elements came from in the first place is another discussion for another time. I want to submit an article to you on this particular idea but I need to bounce it off you guys first and make sure I am heading in the correct direction before I do too much work on it.

My first reaction when I heard this was to bring up the Second Law of Thermodynamics. Indeed, complexity seems to increase but at the expense of heat loss as an exothermic reaction where some (or most? don’t remember right now) of the heat is never to be recovered again. This shows entropy of the system/universe as a whole, an enemy of their attempt to see this as an autopoietic system. Added energy later could be introduced to ‘de-organize’ the molecule, perhaps through photodissociation or whatever adds enough but I don’t know that this needs to be part of the discussion. Would the entropy of the heat/work available in the system support a refutation on the biblical creationist’s part regarding the impossibility of any system to ‘self-organize’ due to the Second Law. Am I leaping too far at this point?

I may be heading in two directions at once on this since a discussion of Thermodynamics may be all that’s needed without dragging in a secondary one regarding Information Theory or something. Although I’m not sure how to apply Information Theory to the water molecule formation yet, I would like to if it fits somehow or helps the creationist refutation.

Next, I was stumped for a while on trying to decide what to do with ‘endothermic’ reactions. If an endothermic reaction borrows heat from its surroundings then it only temporarily stores heat until released by another type reaction later perhaps. Maybe like a tree? Would not a tree be something like an endothermic reaction that increases in apparent complexity from a seed to a full grown specimen drawing in energy from its surroundings, IE. the sun?

With Information Theory and molecular genetics telling us that the seed has all it needs to be a tree, it indeed then ‘borrows’ energy from the sun for a time building in ‘apparent’ complexity through a type of endothermic system. However, in the end the tree would finally give up this ‘borrowed’ energy in the form of heat exothermically by way of being burned, eaten, or chemically rotted away perhaps. This would then be an end process like the exothermic formation of a water molecule in a ‘Second Law supporting’ event, again upholding the previous idea of increased entropy in the system.

So, do I drag in Thermodynamics, Information Theory, Autopoiesis, or what to draw up a good article on this idea of the humble water molecule?

Thank you!

David H.

Dr Jonathan Sarfati responds:

Dear Mr H.

Thanks for writing to CMI. That is quite an ambitious project you have in mind.

This atheist is totally clueless. The reaction 2H2 + O2 → 2H2O occurs because it is exothermic, which pumps heat (Q) into the surroundings, thus by definition increases their entropy by Q/T. This outweighs any loss because of the higher ordering of the water molecules.

Also, the order in the water molecules is based on the chemical properties of the component atoms. This is very different in kind from the organization of proteins and DNA. My response to an evolutionary science writer explains this in more detail as does my book By Design.

Endothermic reactions I’ve touched on in this article I co-authored for the homeschooling magazine The Old Schoolhouse: Scientific experiments for homeschoolers.

I tend not to use entropy arguments at all for biological systems.

I must admit that I hardly ever refer to the second law, although as a Ph.D. physical chemist I am well qualified to do so. Without meaning to brag, if I don’t use it, then few people should; instead, concentrate on the information argument. I’ve seen both creationists and evolutionists make mistakes in their discussions; see for example The Second Law of Thermodynamics: Answers to critics. But for a sound discussion on second law arguments, which are strongest when dealing with chemical evolution (origin of life from non-living chemicals), see the chapters from The Mystery of Life’s Origin.

I tend not to use entropy arguments at all for biological systems. I have yet to see the calculations involving either heat transfer or Boltzmann microstates involved for natural selection. Until creationists can do that, they should refrain from claiming that organic evolution contradicts the Second Law; a trite appeal to “things become more disordered according to the Second Law” is inadequate.

Origin of first life is different, since natural selection can’t occur without two or more self-reproducing entities.

I hope these comments are helpful.


Jonathan Sarfati

David H. replied:

It looks like we’re on the same page! It appears that your first paragraph supports what I was trying to say in the thermodynamic sense. However, please clarify the “loss” you spoke of in the last sentence of that paragraph where you say “This outweighs any loss…” Do you mean loss of heat or entropy?

My first need on this subject is to produce an easy response that the layman can use, which is why I thought thermodynamics would be a good start. The next level of response would be something greater and it looks like bringing in Information Theory is the place to go for that support. I have studied this to a small degree but I will refresh and add to that before proceeding it appears.

I bought big pile of stuff at CMI a couple weeks ago and didn’t get your book “By Design” for some reason, time for yet another book order! I do have “In the Beginning Was Information” by Gitt and “Thermodynamics and the Development of Order” by Williams in my library to go over as well. Thermodynamics was covered in my engineering degree but it’s been a while.

I certainly agree that dragging complex biologic systems into a discussion of entropy would be too untenable. I was hoping to keep that part at the basic molecular level, indeed just focus on the water molecule formation for simplicity since that was what the original discussion was all about.

Dr Sarfati responds:

It is rather daunting to laymen in general to read about thermodynamics. It might not actually help them as much as you might think; it’s different for someone like you with an engineering degree.

The second law says that the entropy of the universe as a whole must increase, but for any considered reaction, the universe = system surroundings. So when I said “loss”, I was talking about the entropy decrease in the system as it becomes more ordered. But this reaction will be spontaneous if the surrounding entropy is increased by a greater amount when heat is released into the surroundings. Since this latter is inversely proportional to temperature, this outweighing effect will diminish. Or in layman’s term, heating something tends to make things more disordered. The above-mentioned page http://www.ldolphin.org/mystery/chapt7.html illustrates this with a simple example of water freezing (becoming more ordered). Even in your example, at a sufficiently high temperature, the reaction 2H2O → 2H2 + O2 becomes spontaneous (dissociation).

Since you like Dr Gitt, you might be interested in his brand new book on information theory, Without Excuse.

Published: 18 October 2011