Q. re. statistical mechanics

[chilehed]

For quite a while I’ve been trying to explain the Second Law to laymen (young-earth creationists in particular), and although I have a decent background in classical thermo I don’t know much at all about statistical mechanics. YECs often say things like “evolution involves an increase in information, which violates the Second Law”. I know that this is wrong, but so far I haven’t formulated (or stumbled upon) a simple, coherent explanation that I was able to understand. A few years ago I asked some questions about information theory, and needed some time to think about the answers I got. So now I’m back.

 

I think I understand the statistical entropy definition S = k_B lnΩ, where Ω is the number of microstates corresponding to the macrostate.

 

And I see that thermodynamic entropy S = -k_B ∑(ρ_i lnρ_i ), from which I see that the information function -∑(ρ_i lnρ_i ) is equal to lnΩ.

 

And since for any real process dS >/= 0, every real process results in a change in the information function greater than or equal to zero.

 

So that the proper response to the YEC argument is to point out that, by demanding a reduction in information, it is they who are demanding a violation of the Second Law.

 

Part of the problem is that they seem to be defining "information" as nothing more than the fact that certain molecules react in certain ways, that it is the nature of particular atoms to behave in a certain manner under certain conditions, whereas in statistical mechanics "information" is defined as lnΩ.

 

Did I get this right?

 

Buffy, Qfwfq and sanctus, thanks for your help previously.