Aahz

Or just how laws of thermodynamics there are.

They should know, after all Dembksi has proposed a 5th law, the Law of Consevation of Information.

I gotta tell you, Dembksi's ego must be the size of Nevada and growing.

Hey does that violate any of the laws of thermodynamics?

hezekiah jones

I think Dembski, in No Free Lunch, refers to the 'existing three laws of thermodynamics,' apparently unaware of the so-called zeroth law. The uncharitable might say this goes to his credibility.

Starboy

Why are they so hung up on thermodynamics? It doesn't begin to describe macroscopic behavior due to microscopic phenomena.

Starboy

DMB

I've always liked the song(!), First and Second Laws written over forty years ago by Michael Flanders & Donald Swann
[ August 03, 2002: Message edited by: DMB ]

[ August 03, 2002: Message edited by: DMB ]</p>

DNAunion

DNAunion: No, not a single process itself (a living cell, which is composed of many "bio-organic chemical processes", obviously is alive).

My point was that the biochemistry of a living cell IS ordered chemistry; highly ordered chemistry (as opposed to the disordered - or at least more disordered - chemistry of nonliving systems).

Therefore, entropy increases when a cell or organism dies (implicit in this statement is that your typical natural processes, like decay, follow the instant of actual death).


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By the way, taking this in the opposite direction is interesting. That is, going from disordered nonliving matter to a highly ordered living cell represents a large decrease in entropy, and thus, will not occur by itself spontaneously.

Increased order associated with the evolution and development of life does not pose a problem because BOTH sufficient energy AND sufficient information are and have been available; the information being housed and passed on from generation to generation in the nucleic acids (DNA in particular).

But the origin of life by purely natural means is a different matter. I believe a decent "thermodynamic" argument can be put forward in relation to it (not to disprove it, but to show that it is unlikely). For sure energy was plentiful on the prebiotic Earth (or whereve else life may have originated before then arriving here on Earth), but was sufficient information there to properly capture, harness, and direct the energy towards increasing order?

Well, the information used by many or most extant organisms to do so was not available prior to the origin of life. The information coding for the photosynthetic method of energy capture/harnessing, for example, is not considered to have been present at the point of origin because photosynthesis is considered too complex, and to be an evolved process.

We also know that polymers are more ordered than individual monomers (due to a decrease in freedom of movement after being polymerized), and therefore polymers would have an entropic tendency to decompose: not to increase in size. This is why special conditions (such as mineral catalysts and preactivated monomers) are needed to get oligonucleotides to form in "prebiotic" experiments.

Also, two nucleotides can join in many different orientations, and only the one (with 5'-3' phosphodiester bonds) are biologically relevant. So there are many more ways for two nucleotides to bond 'incorrectly' than to bond 'correctly' (so correct bonding is statistically far less likely, "lower entropy").

And what percentage of, say, 200-mers (i.e., RNA molecules comprised of 200 individual ribonucleotides linked together linearly by 5'-3' phosphodiester bonds) can function as a true RNA replicase? None have been found so far, even though several experiments, each involving 10^15 "random" sequences of about that size, have been performed (the word random is a poor choice here, but was used instead of going into detail at this point). Take the number of ways 200 ribonucleotides can be arranged linearly (4^200) and consider that the sequence space. Then consider how few of those can function as an RNA replicase (if even 1 can!). That gives a statistical idea of how unlikely finding an RNA replicase by truly random polymerization is (statistically "low entropy"?).

[ August 05, 2002: Message edited by: DNAunion ]</p>

Starboy

All of this does lead one to conclude that life is not a thermostatic system. In some sense it is a self-organizing force. I suspect that if all life on the earth were to die this instant, there would be a huge jump in entropy. If there is a miracle of life it is not that it occurs naturally, but that it is a fundamentally different state of matter. Self-organizing matter.

Starboy

Randy

This is my first post here but I think some of you may know me from other boards. It happens that I occasionally teach classes about the basic thermodynamics of surfaces, oil/water interfaces and emulsions and I would like to start by saying that what Lentic Catachresis said about oil and water separating can be interpreted somewhat differently than it was by supramolecular and I think that it is not really incorrect. It is true that the hydrophobic effect is entropic in nature and that oil is not soluble in water because of loss of entropy due to clatharate structures formed in the water due to the presence of oil. It should really be called the oilophobic effect of water because there is appreciable solubility of water in many oils, but there is more to the story than that.

When you mix oil and water together you form an emulsion, however briefly it lasts. Emulsions (with the exception of microemulsions) are not thermodynamically stable. The situation when an emulsion separates is as follows: The free energy of emulsion breaking(deltaGbreak) is given by the oil/water interfacial tension(Gamma) multiplied by the change in surface area (deltaA) minus temperature multiplied by the change in the configurational entropy of the oil droplets(deltaSconfig).

deltaGbreak = gamma*deltaA – T*(deltaSconfig).

Both the change in surface area and the change in the configurational entropy of the oil droplets are negative. Thus there is a loss of configuration entropy of the droplets when an emulsion separates that is compensated when the work that went into forming the emulsion in the first place is released as heat. The interfacial tension can be measured and the configurational entropy can be calculated to a good approximation from the phase volume of the oil and the number of oil droplets but I am not going to try to write out the formula here. For a reference see Tadros and Vincent, “Emulsion Stability” in Encyclopedia of Emulsion Technology. Volume 1 Basic Theory, Paul Becher ed. Marcel Dekker 1983.pp 129-285.

So the separation of oil droplets from water after mixing does indeed involve loss of the configurational entropy of the droplets. Of course the laws of thermodynamics are not violated because the free energy change is negative as it must be for a spontaneous process since gamma*deltaA is larger than TdeltaSconfig under conditions of temperature and pressure where separation is spontaneous. (near the critical point gamma drops to 0 and separation is not spontaneous)

Now to go back to the topic of the thread, one of the times that the subject of thermo and evolution came up on OCW Tim Thompson raised the following question (I am not sure I have his wording exact but I think I have the spirit of his post)

"Exactly which step required for evolution is prevented by the second law each and every time that it might occur?"

In my opinion, if creationists can’t answer this question they should give up the argument and I have yet to see any coherent answer.

Randy

scigirl

Randy,

Welcome to infidels! If you are planning on sticking around, you can introduce yourself <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=forum&f=43" target="_blank">here</a> if you so desire.

Thanks for that post - I took thermodynamics a while ago so I'll have to read it a couple times to grasp it I think!

scigirl

Supramolecular

Welcome Randy.

Can you really juggle guitars?

Randy

Actually, I suppose that I could with a little practice but since my guitars are Martins and Gibsons and thus quite expensive I don't want to risk it. Do you have three cheap ones I could try it with?

Randy