Second Law of Thermodynamics, and Evolution *GASP!!*

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Cerpin Taxt

Lifer
Feb 23, 2005
11,940
542
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Originally posted by: Gibsons
Here's a restatement of the second law: Entropy within a closed system cannot decrease.

A key point here is a "closed system." You can decrease entropy in a system if you do work on it/add energy to it. The system is not "closed" if this can happen. A molecule is not a closed system, nor is a cell, an animal, a plant or the Earth.

Ask your friend to give you an example of a closed system. Unless she says "the universe" she's probably wrong...

If that's not good enough I can give you examples of well known chemical reactions that would violate her version of the second law.

Just a nitpick... You should replace "closed" with "isolated" in your above explanation. Closed systems can receive energy input, just not matter.

Also, it is not clear that the universe can be treated as any type of thermodynamic system.
 

Descartes

Lifer
Oct 10, 1999
13,968
2
0
Originally posted by: mercanucaribe
OP, if you don't think evolution is fact, how do you think life developed and advanced on this planet? I'd like to hear what you think the other possibilities are.

OP just needs to educate himself a little more on what evolution actually is.

I'm no evolutionary biologist, but I can say with confident that in any conversation on evolution, probably 90%+ don't even have a basic understanding.
 

3NF

Golden Member
Feb 5, 2005
1,345
0
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Originally posted by: Descartes
Originally posted by: mercanucaribe
OP, if you don't think evolution is fact, how do you think life developed and advanced on this planet? I'd like to hear what you think the other possibilities are.

OP just needs to educate himself a little more on what evolution actually is.

I'm no evolutionary biologist, but I can say with confident that in any conversation on evolution, probably 90%+ don't even have a basic understanding.

This link says it was last updated in 1993, about the same time I took thermodynamics as a physics student. Has anything changed since then?
 

BrownTown

Diamond Member
Dec 1, 2005
5,314
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what is missing in the argumnent is the fact that while living being represent highly ordered systems, as a whole they tend to disorder the world around them. For example think of a human being, you have say 150 pounds of chemicals ordered very highly, but to achieve that you are probably producing tens of thousands of pounds of carbon dioxide, water, and several other very stable chemicals. The human body provides a very effecient way to catalyze these reactions in order to convert complex chemicals into simple ones. In fact life does even better than jsut catalyze it is in fact desinged so that the catalyst produces even more of itself! Thats right, living thigs will expand their domain until every available source of easily broken down chemicals is being broken down at as fast a rate as is possible by the living things. And if a certain living organism figures out an even more efficient way of catalyzing these reactions it spreads across the globe displacing the less effecient one. This is essenitally the point of life and the reason evolution is favorable by the laws of thermodynamics.

NOTE: the above is a HUGE oversimplification of everything involved (obviously).
 

Gibsons

Lifer
Aug 14, 2001
12,530
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Originally posted by: BrownTown
what is missing in the argumnent is the fact that while living being represent highly ordered systems, as a whole they tend to disorder the world around them. For example think of a human being, you have say 150 pounds of chemicals ordered very highly, but to achieve that you are probably producing tens of thousands of pounds of carbon dioxide, water, and several other very stable chemicals. The human body provides a very effecient way to catalyze these reactions in order to convert complex chemicals into simple ones. In fact life does even better than jsut catalyze it is in fact desinged so that the catalyst produces even more of itself! Thats right, living thigs will expand their domain until every available source of easily broken down chemicals is being broken down at as fast a rate as is possible by the living things. And if a certain living organism figures out an even more efficient way of catalyzing these reactions it spreads across the globe displacing the less effecient one. This is essenitally the point of life and the reason evolution is favorable by the laws of thermodynamics.

NOTE: the above is a HUGE oversimplification of everything involved (obviously).

But still accurate! :thumbsup:
 

Descartes

Lifer
Oct 10, 1999
13,968
2
0
Originally posted by: 3NF
Originally posted by: Descartes
Originally posted by: mercanucaribe
OP, if you don't think evolution is fact, how do you think life developed and advanced on this planet? I'd like to hear what you think the other possibilities are.

OP just needs to educate himself a little more on what evolution actually is.

I'm no evolutionary biologist, but I can say with confident that in any conversation on evolution, probably 90%+ don't even have a basic understanding.

This link says it was last updated in 1993, about the same time I took thermodynamics as a physics student. Has anything changed since then?

Perhaps not the best resource then, but it's not really a question of whether or not it does occur. The only questions are why and how; the how obviously has many divergent ideas, the most known being natural selection; the why is metaphysics and thus one is free to dream up whatever they wish.
 

sao123

Lifer
May 27, 2002
12,653
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Originally posted by: DanTMWTMP
Originally posted by: RapidSnail
What? There seems to be something wrong with your assessment. Increased entropy does lead to increased disorder of which greater uncertainty is a product. Ice, for example, has a low entropy, and has a highly ordered crystallic structure; however, as the ice begins to melt and then boil steam, the entropy, or disorder of the system, increases which results in a lower probability of accurately describing the position of any given molecule.

i was taught by my professors that "disorder" is a misnomer, and it should be understood as something that, as you say it, going away from the knowledge of describing the position of any given molecule. That's not disorder. That's just having less chance of knowing where the position of the molecule is. She used this "disorder" argument to say that evolution is going into "ORDERLY" complicated organisms. tell me what i didn't understand in my statment.

in a sense, she's mis-using the law of 2nd thermodynamics to further her cause and belief that evolution cannot possibly have happened.



Order & disorder are euphimisms, yes... but
the 2nd law is really talking about energy states & stability...
to gain stability, everything naturally progresses to the lowest potential energy state possible...

Hydrocarbon fuels (which were formed in long energy intensive processes) will readily burn with oxygen to go from a state of high strain molecules, to low potential energy waste products carbon dioxide and water.

Gasesous molecultes will evenly distribute when released to go from a high concentration, to a low concentration, to relieve pressure.

An atom with an unstable nucleas will naturally undergo fission to split into smaller less strained nuclei.

Low energy state (high degree of entropy) is the preferred state for all matter.



Quite simply, complex molecules by rule of thumb would have more strain, higher energy state, than simple ones. The problem quite simply is how isolated the environment was... what point was the boundary of the closed system where complex life evolved?


The problem I have is however the sheer number of mutations necessary to go from a single protein to the diverse number of individual species we have today, the time that it could be accomplished in, and what about the number of failed fatal mutations?

I read somewhere that the number of mutations + the number of failed mutations, mutations would have to be occuring every day, to have enough time for the full course of evolution even if it took the full 4 billion years the earth has existed...

What changed, why isnt that extreme number of mutations happening now?
They want you to believe it happened slowly over time, but the relative quanties of number says it had to happen rapidly.


 

dullard

Elite Member
May 21, 2001
25,913
4,498
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Originally posted by: sao123
I read somewhere that the number of mutations + the number of failed mutations, mutations would have to be occuring every day, to have enough time for the full course of evolution even if it took the full 4 billion years the earth has existed...

What changed, why isnt that extreme number of mutations happening now?
They want you to believe it happened slowly over time, but the relative quanties of number says it had to happen rapidly.
You have to realize how frequently DNA mutates. I am definately talking outside my field here (someone jump in and correct me), but DNA mutates very easilly and very frequently. Heck, to make it more clear RNA mutates ~100 times faster than DNA.

DNA is damaged by heat, by time, by oxidation, by light and other higher frequency waves, etc. DNA is damaged all the time. The rate is on the order of 1000 to 1,000,000 damaged spots on your DNA per cell per day. By the time you are 20 years old, your sperm's (or egg's) DNA has been damaged 7 million to 7 billion times at that rate. Your baby could have 7 billion mutations from your DNA (and 7 billion more from your partner's DNA). Of course, much of that damage is repaired, and much of the damage is lethal. So 14 billion mutations per baby is a massive exaggeration. But it does go to show that 1 mutation per day is an obtainable number.

That said, there is a building array of evidence that evolution didn't occur entirely on Earth. (1) There probably aren't enough generations in some cases for the evolution to have occured (unless the DNA damage rate was higher in the past than it is now). (2) Material from outer space shows crude forms of biological chemicals. (3) The most ancient known forms of DNA on Earth are viruses. Viruses can't duplicate on their own. What did the viruses infect? Thus, many biological scientists are beginning to think the earth started with an array of biological chemicals from space. That is, we got a head start and have more diversity than if life started on Earth. That doesn't mean that aliens built UFOs and landed here. Did the viruses (with billions of years of evolution already built in) come attached to a metorite to the fledgeling Earth?
 

Jeff7

Lifer
Jan 4, 2001
41,596
19
81
Originally posted by: Amused
Two words:

The sun.
Exactly.
Thermodynamics assumes a CLOSED SYSTEM. Earth is not a closed system - it receives many many many TERAWATTS of power from the sun. Not a closed system. Not even close.


Maybe the Universe itself is a closed system. Over time, it will degrade as it spreads out. In the short term, there may be small "bursts" of order, such as star systems and life, but eventually they too will all come undone as their energy disperses throughout the expanding Universe. Thermodynamics - still works.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Quick lesson on entropy:

Entropy is a logarithmic counting of microstates of a system. A microstate is a way of arranging all of the elements of the system, such that the system is determined. Count up the microstates, take the natural log, multiply by Boltzmann's constant and you have entropy.

Let's imagine our system is 4 coins. They each have 2 states, heads or tails. There are 16 microstates:

HHHH

HHHT
HHTH
HTHH
THHH

HHTT
HTHT
HTTH
TTHH
THTH
THHT

TTTH
TTHT
THTT
HTTT

TTTT

Notice how they are grouped. 1, 4, 6, 4, 1. Now, each state is equally probable. That is you are just as likely to get HTTH as you are to get TTTT. However, we tend to view MACROstates. That is, we just look at how many heads and tails there are and disregard order. This means we have a 3/8 chance of getting a 50/50 H/T split. Thus, it is most likely that we find the system in the 50/50 macrostate, even though any of its microstates are just as probable (or improbable) as any other. In fact, in a dynamic system, you would find the system evolving from one microstate to the next, spending a proportion of time in a macrostate equal to its relative probability.

Now let's look at some entropies.

S = k ln(Omega)

S = entropy
k = some number
Omega = # of microstates in a given macrostate

We can see that ln(6) > ln(4) > ln(1), so one would expect that if we started the system in the HHHH state, it would, through random dynamical processes evolve into one of the 50/50 split microstates.

So this is sort of true. In fact, if we just let it go randomly, it would eventually re-order itself back into the HHHH state according to some time constant. Of course it would then move out of that state again. If we let this happen for 15 minutes say, we could expect that the system would be in the HHHH state for about 1 minute of that time. Same with the TTTT state.

So why don't we ever see a box of air molecules randomly and spontaneously condense to form a perfect crystal, with the GUT etched into its surface? After all, it is just as probable for the air molecules in the box to arrange themselves in this way as it is for them to be in any other microstate. Well, if you calculate how many microstates there are in such a box, it is insanely high. Each particle has 6 pieces of information assigned to it if you ignore rotations (so I guess we're dealing with Argon here). Take 10^23 particles and that's a lot of microstates. The fraction of time the air particles would spend in any one microstate is miniscule. I'm not 100% sure of the numbers right now due to not going through the calculations again, but I seem to recall that you would have to wait something like a billion times the age of the universe to observe a macrostate with a single microstate.

Thermodynamics and statistical mechanics works so well because of the huge numbers involved.


edit: I'll add a summary here.

So why do we say systems tend to larger entropies? Well, look at the coins. The macrostate we would find the system in is associated with the largest entropy. Here we are relating ln(6) to ln(1) and it doesn't seem so convincing. But in the real world we're relating ln (10^10^20) to ln(1) (ie, 10^20 to well, 0).
 

Gibsons

Lifer
Aug 14, 2001
12,530
35
91
Originally posted by: dullard
Originally posted by: sao123
I read somewhere that the number of mutations + the number of failed mutations, mutations would have to be occuring every day, to have enough time for the full course of evolution even if it took the full 4 billion years the earth has existed...

What changed, why isnt that extreme number of mutations happening now?
They want you to believe it happened slowly over time, but the relative quanties of number says it had to happen rapidly.
You have to realize how frequently DNA mutates. I am definately talking outside my field here (someone jump in and correct me), but DNA mutates very easilly and very frequently. Heck, to make it more clear RNA mutates ~100 times faster than DNA.
--snip--
Well, this is my field, to some degree... of course the question "What changed, why isnt that extreme number of mutations happening now?" includes an assumption about mutations: that they were "extreme" and are somehow less frequent now. I don't see any reason to think that's the case/don't agree with the assumption (except in a few very limited cases). More info available upon request.
 

newmachineoverlord

Senior member
Jan 22, 2006
484
0
0
Originally posted by: dullard
1) Give up on the entropy != disorder part. They are basically the exact same concept. You are wrong.

2) She was wrong that things cannot go from disorder to order. If I throw a deck of cards all around the room (disorder), can you pick them up, sort them, and put them back in the box (order)? Yes? Then things can go from disorder to order. Bingo, her 2nd law evolution argument is already disproven.

3) But the 2nd law says they can't go from disorder to order? Well that is only half of the 2nd law. The 2nd law ACTUALLY says they can't go from disorder to order UNLESS something else does goes from order to disorder. She got the 2nd law only half correct. That is pretty bad for a chem major.

4) Doing work is a form of going from order to disorder. For example, in your card picking up exercise, you do work. If you do work, you require fuel. You burn a nice orderly chemical (lets say you ate a sugar cube) and create heat, lots of water, carbon dioxide, etc and spread those all over the place.

This basically sums up what I would have said had I been logged on when you posted this topic.

She is making several faulty assumptions, one of which is the assumption that the species evolving is a closed system. This means that the evolving species, according to her evaluation, does not eat, excrete, metabolize, or otherwise exchange energy or materials with the outside world. The direct analogy is that by her logic, the second law of thermodynamics means that it is impossible to clean your room, or build anything, as this would involve making something more orderly. This is a common misinterpretation of the second law amongst anti-evolutionists.

Furthermore, the second law of thermodynamics turns out to be more like what you call guidelines anyways. Violations of the 2nd law have been found on a very small scale. Really the whole source of the 2nd law comes from the fact that when dealing with large numbers of molecules, improbable events are extremely unlikely to happen in a net manner. Water can in fact flow uphill, it's just that the probability of it doing so is so small that it will never happen in an observable amount. Individual molecules are more likely to move downhill than uphill, so the net observed movement is always downhill. Thus the second law of thermodynamics is really just an application of the law of large numbers combined with the fact that it is more likely for a molecule to randomly change from a high energy state to a low energy state than the other way around. Anyways evolution is so well documented that if there was an apparent conflict with the 2nd law of thermodynamics the logical result would be a rewrite of the 2nd law of thermodynamics, not a change in evolutionary theory.
 

Parasitic

Diamond Member
Aug 17, 2002
4,000
2
0
The creation of molecules and structures from "disordered" (horrible term by the way) to "ordered" structures requires energy, and which increases entropy in the overall system.
Entropy is a function that monotonically increases with energy. From chemical to biological evolution energy is taken into different entities via light energy (from the energy) or chemical energy (from food) over time. Along with this uptake of energy we have increased the entropy of the system.

By the way this entropy as a monotonically increasing function of energy is straight out from "Introduction to Modern Statistical Mechanics", a graduate-level textbook by David Chandler, an authority figure in statistical mechanics at UC Berkeley.