Re: The 2nd Law of Thermodynamics - Irrelevant to Origins
- From: "wade" <wade.hines@xxxxxxx>
- Date: 16 Apr 2006 08:31:08 -0700
zeteo.eurisko@xxxxxxxxx wrote:
There has been a lot of talk recently on whether the 2nd Law of
Thermodynamics has any bearing on the subject of origins. I have tried
to make the case that it is irrelevant to the ID/evolution discussion.
I the post below is a copy/paste from my blog. Please see the blog
post for all the relevant links - there are lots of them!
Link:
http://tinyurl.com/mqqb7
http://gnosos.blogspot.com/2006/04/2nd-law-of-thermodynamics-irrelevant.html
---
This second law discussion is popping up all over the web at the same
time as it is being discussed here. This debate now has that exciting
real-time quality to it! (If you need a layman's refresher on basic
2nd Law principles, check this one out (PDF).)
For the history of the discussion on this site, this post talked about
an American Spectator article by UTEP mathematics professor Granville
Sewell that reformulated the argument that the process of evolution
violates the 2nd Law of Thermodynamics. On the Panda's Thumb, retired
Cal Fullerton physics professor Mark Perakh wrote an extensive critique
of Sewell's idea. My conclusion on my first post was that Sewell's
argument, stripped of its complexities, breaks down to this paraphrased
statement:
"There is no process that can decrease the entropy of an undeveloped
earth in such a way that would result in the biological complexity
around us without violating the second law of thermodynamics."
The mistake many make is to make the response to this too complex.
There's nothing in the 2nd law that prohibits ice from forming in some
places when there is warm liquid water in other places. If these too
situations occur, one simply notes that the two places are not in
thermal equilibrium. The sun shining on the earth induces complex
weather patterns that leads to this very phenominon.
And the 2nd law doesn't say you can only have so much ice. You can
have vast polar ice caps and vast warm oceans. That's OK.
The argument that biological complexity is somehow different, from
a thermodynamic perspective as would allow you to invoke the
2nd law of thermodynamics, is flatly ill conceived.
The 2nd law does require that any local decrease in entropy, such as
that in forming ice or building up macromolecules like DNA in a cell,
be paid for by an equal or effectively always greater amount of work
being done. This is representable in the Clausius inequality
dS <= dQ/T
The Clausius inequality allows things to be equal. Pragmatically,
it's usually a question of dS << dQ/T
For the formation and evolution of life, the equality and the 2nd
law are readily satisfied.
..
Thus, I perceive that we are back in the realm of biology, discussing
whether evolution is a reasonable mechanism to produce biological
complexity. This does not really seem to augment the ID/evolution
discussion; it just gets us to the starting point of the debate in a
novel way.
But much more has recently been said! Let me lay out the most
interesting points of discussion here, and let the reader wrestle with
them along with me. (Come up with your own opinions and read the
articles yourself. Frankly, my opinion on these matters means little,
for my formal training in physics has reached its expiration date.)
First up, Arthenor, a former home schooler and current community
college student (both experiences I have shared), posts a detailed
response to Perakh's argument. However, Arthenor gets mostly tied up in
parsing both Perakh's and Sewell's spurious and confusing
analogies. His conclusion does not progress the discussion:
"[I]t is EXTREMELY IMPROBABLE that such an outcome [the order found in
nature] should occur or be expected and the fact that the system is
open does not change that any more than the system being open allows me
to fly by flapping my arms. The point, again, is that while entropy may
decrease in an open system, that does not suddenly cause miracles.
Once again, the question left unanswered is whether evolution is a
plausible mechanism to account for this local decrease in entropy
without violating the 2nd Law. And once again, we must look to biology
for the answers, and we're back at the starting point of the
ID/evolution debate - not a conclusion.
Evolution doesn't produce a decrease in entropy. Living systems do.
Much to the chagrin of people who argue about evolution increasing
entropy, there isn't a compelling difference in the entropy of
formation
of a 100 kilogram human, 100 kilograms of fish or 100 kilograms of
algae or 100 kilograms of bacteria, though I would estimate that
there's a smaller entropy of formation in the one with less bone.
The proportion of fat to protein to carbohydrate matter
thermodynamically,
not ill conceived notions of what is more evolved or "complex".
As a significant corralary, a given mass of human DNA has basically
the same entropy of formation as fish or algae or bacterial DNA with
entirely different sequence (the thing that would change things would
be the GC/AT content).
Much more interesting than Arthenor's discussion were questions
raised in comments on my site by "A Friend," who is a mathematical
physicist nearing the end of his PhD studies. He reformulates
Sewell's conclusions into a set of questions:
"I'd like to follow up for a moment on my first comment where I
mentioned the interaction of different "kinds" of order. If there were
only thermal order, and the thermal distribution follows a diffusion
equation as is commonly accepted, then there would be no escaping the
implications of the 2nd law for the development of life. However, our
universe doesn't work like that. There are different kinds of
particles, different chemicals, and all sorts of intricate interactions
that can occur between them. So, the question that is important in the
evolution debate is not one of equilibrium thermodynamics (dominated by
the diffusion equation, entropy increases, and the second law) but
rather one of non-equilibrium dynamics (where the interactions of the
various types of distributions is taken into account mathematically).
Can the large thermal gradient generated by the sun drive the entropy
(of some non-thermal parameter, like the distribution of carbon atoms)
down? Will it be driven down sufficiently for "rare" reactions to occur
spontaneously? Specifically, can it drive the biochemical reactions
necessary to produce life?"
It drives the reactions of life. Other sources also drive life in
places
where we have black smokers. Other sources of chemical energy
drive chemical synthesis. The energy availability isn't the problem.
The answers to these questions are perhaps not given but at least
framed, by Jason Rosenhouse, a mathematics professor from just up the
road at James Madison University. He has just published another
response to Sewell. This one, like Perakh's, does not honor
Sewell's request for respectful discussion sans personal attacks, but
he much more effectively and concisely frames the problem with
Sewell's argument:
"[F]ormulating the second law mathematically makes it clear that Sewell
cannot merely assert that some process (evolution by natural selection
in this case) violates the second law. There is a very clear test to
pass to show that a given process really has a second law problem.
"You see, any claim that evolution violates the second law must be
backed up with a calculation.
Hallalueh Amen!
Sewell believes that the second law is a
problem for evolution? Very well. Let him evaluate the integral I
mentioned [see the article] and show that the change in entropy has
been smaller than it should be. Anything short of that is no longer an
argument based on thermodynamics. It is just ye olde argument from
personal incredulity, in which Sewell is expressing nothing more than
his own disbelief that biological complexity could have evolved
naturally. Since every formulation of the second law allows for local
increases of order and complexity, the mere observation of such
increases does not constitute an apparent violation of thermodynamic
principles."
His discussion, in a way, supports my assertion that we have once again
reached the starting point of the ID/evolution debate. Sewell's
argument makes no comment - except the argument from incredulity -
on the quality of evolution by natural selection as an explanation for
the observed order in nature.
This begins to provide answers to A Friend's questions. Until Sewell
can accomplish the virtually impossible task of proving that
abiogenesis and evolution definitively violate the 2nd Law, we must
rely on other observations to inform their plausibility. While it is
well beyond the scope of this post to list them, there are enough
observations in favor of evolution that many are convinced that it did
occur and that, being the concrete law that it is, the 2nd Law must not
have been violated.
One can avoid the detail calculation with the following analysis.
One acorn grows into an Oak and produces hundreds of thousands
of new acorns. Nobody reasonably claims this violates the 2nd law.
In synthesizing the genetic material in each of those acorns, there
are copying errors made so that each acorn has added genetic variation
compared to the parent. There isn't a definable entropic difference
between changes that are beneficial and those that are not. In all
cases, biochemically enough energy is burnt in synthesizing the
DNA to more than satisfy the Clausius inequality and thus the 2nd
law.
Repeat for 1 million generations and changes accumulate. Each and
every cycle, each and every life, spends more energy than it converts
into the seeds of the next generation. Each and every seed
consumes and spends more energy than is minimally required for
it to grow.
A sequence of many positive changes in entropy always sums to a
positive change in entropy. Evolution requires no negative changes
in entropy, only life imperfectly replicating its genetic material.
There's no point in trying to calculate the decrease in entropy of
something that is obviously an increase in entropy.
.
- References:
- The 2nd Law of Thermodynamics - Irrelevant to Origins
- From: zeteo.eurisko@xxxxxxxxx
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