Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 116 (8795 total)
Current session began: 
Page Loaded: 10-17-2017 11:11 AM
350 online now:
Coragyps, DrJones*, GDR, Guido Arbia, jar, Meddle, PaulK, Phat (AdminPhat), Stile (9 members, 341 visitors)
Chatting now:  Chat room empty
Newest Member: jaufre
Upcoming Birthdays: Astrophile
Post Volume:
Total: 820,745 Year: 25,351/21,208 Month: 978/2,338 Week: 99/450 Day: 23/34 Hour: 0/8

Announcements: Reporting debate problems OR discussing moderation actions/inactions


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
1
23456
...
9Next
Author Topic:   Thermodynamics, Abiogenesis and Evolution
berberry 
Suspended Member (Idle past 4 days)
Posts: 1853
From: vicksburg, mississippi
Joined: 11-29-2003


Message 1 of 128 (99455)
04-12-2004 3:21 PM


rineholdr's title, not mine. This is a spinoff of 'The Big Bang - Questions from a Teen' in the 'Big Bang and Cosmology' forum.

rineholr wrote:

quote:
Issac Asimove concluded:
Another way of stating the Second Law then is: "the universe is constantly getting more disorderly!" Viewed that way, we can see the second law all about us. We have to work hard to straighten aroom, but left to itself it becomes a mess again very quickly and very easily.

and I responded:

quote:
Where did Isaac Asimov (who didn't take kindly to mispellings of his name, btw) say that? I have his Guide to Earth and Space and I don't see that quote; it doesn't sound like the way he'd put it.
But to be fair, the quote isn't off the mark. The entropy of the universe is increasing. But if you try to use this fact to disprove evolution you'll lose. It is not necessary that the entropy of the earth increase in order for the 2nd law to hold, because earth is not a closed system.

The earlier topic is straying from the original intent of the thread, therefore I'm proposing we move the discussion here.


Replies to this message:
 Message 2 by DNAunion, posted 04-12-2004 3:34 PM berberry has responded
 Message 81 by Brad McFall, posted 04-22-2004 7:34 PM berberry has not yet responded

    
DNAunion
Inactive Member


Message 2 of 128 (99456)
04-12-2004 3:34 PM
Reply to: Message 1 by berberry
04-12-2004 3:21 PM


The second law of thermodynamics poses no problem at all for evolution: abiogenesis is a different story. Why?

Because for existing life - and therefore evolution - we can give a full account of how energy enters organisms and how it is then used to maintain the high degree of order of the organism, and to even increase the organism's complexity (same goes for higher levels, such as populations, communities, etc.).

But we can't yet give such an explanation for the origin of life (we don't even know what the very first life could have actually been). Until some prebiotically plausible mechanism for capturing and channeling the available prebiotic energy into performing useful "biological" work is found, vague appeals to "open systems" just aren't sufficient ("open system thermodynamics" are necessary, but not sufficient).

[This message has been edited by DNAunion, 04-12-2004]


This message is a reply to:
 Message 1 by berberry, posted 04-12-2004 3:21 PM berberry has responded

Replies to this message:
 Message 3 by berberry, posted 04-12-2004 4:07 PM DNAunion has not yet responded
 Message 5 by JonF, posted 04-12-2004 4:44 PM DNAunion has responded
 Message 82 by Brad McFall, posted 04-22-2004 8:01 PM DNAunion has not yet responded

  
berberry 
Suspended Member (Idle past 4 days)
Posts: 1853
From: vicksburg, mississippi
Joined: 11-29-2003


Message 3 of 128 (99464)
04-12-2004 4:07 PM
Reply to: Message 2 by DNAunion
04-12-2004 3:34 PM


DNAunion writes:

quote:
The second law of thermodynamics poses no problem at all for evolution: abiogenesis is a different story.

I didn't realize we had moved so quickly from evolution to abiogenesis. I'm making no claims regarding abiogenesis. Until your 'prebiotically plausible mechanism' is discovered it seems pointless to argue whether abiogenesis conflicts with the 2nd law.

I'm not sure I understand why you brought this point up. I thought the discussion was about evolution and the 2nd law. If I missed something somewhere I'm sorry.


This message is a reply to:
 Message 2 by DNAunion, posted 04-12-2004 3:34 PM DNAunion has not yet responded

Replies to this message:
 Message 4 by RAZD, posted 04-12-2004 4:43 PM berberry has responded

    
RAZD
Member
Posts: 19074
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 2.7


Message 4 of 128 (99473)
04-12-2004 4:43 PM
Reply to: Message 3 by berberry
04-12-2004 4:07 PM


Your title is the reason - "and the origin of life"

on a molecular level reactions occur that either give off energy or need energy to complete.

in a balanced system one reaction could give off energy that is used by another reaction to fuel it's completion.

the earth is not a balanced system however, as it receives energy from the sun and from impacts of meteors and similar bodies (one theory is that the moon is a remnant of a major collision).

with energy available there is no inherent problem for abiogenesis from the second law of thermodynamics.


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 3 by berberry, posted 04-12-2004 4:07 PM berberry has responded

Replies to this message:
 Message 6 by berberry, posted 04-12-2004 7:05 PM RAZD has not yet responded
 Message 94 by traste, posted 04-21-2009 11:53 PM RAZD has not yet responded
 Message 103 by Creation Guy, posted 08-15-2009 8:48 PM RAZD has acknowledged this reply

  
JonF
Member
Posts: 3969
Joined: 06-23-2003
Member Rating: 2.3


Message 5 of 128 (99474)
04-12-2004 4:44 PM
Reply to: Message 2 by DNAunion
04-12-2004 3:34 PM


Until some prebiotically plausible mechanism for capturing and channeling the available prebiotic energy into performing useful "biological" work is found, vague appeals to "open systems" just aren't sufficient ("open system thermodynamics" are necessary, but not sufficient).

Er, you appear to have a serious misunderstanding of thermodynamics.

The second law deals with entropy, and entropy is a property; that's a technical term that means its value depends only on the current state of the system and not in any way how the system got to that state. (This is often very useful, because it means that we can calculate entropy changes between two states along any possible and equivalent path). Therefore the idea of needing to know a mechanism (for the transition between states) in order to evaluate the thermodynamic possibilities is a red herring.

What counts thermodynamically is the difference in entropy between the initial and final states, not how it got from one state to the other. I think that some people have done such calculations for some proposed scenarios, but I'm not sure. However, what I am sure of is that you can't claim that the second law of thermodynamics poses any problem for any hypothesized event until you have calculated the change in entropy and demonstrated a spontaneous decrease.

Nor can you claim that particular characteristics of a system are or are not necessary, or are or are not sufficient, until you have presented the appropriate calculations.

Of course, we are trying to figure out mechanisms for all sorts fo reasons; but we do not need to know a mechanism to evaluate what thermodynamics allows.


This message is a reply to:
 Message 2 by DNAunion, posted 04-12-2004 3:34 PM DNAunion has responded

Replies to this message:
 Message 11 by DNAunion, posted 04-13-2004 12:27 AM JonF has responded
 Message 83 by Brad McFall, posted 04-22-2004 8:12 PM JonF has not yet responded

  
berberry 
Suspended Member (Idle past 4 days)
Posts: 1853
From: vicksburg, mississippi
Joined: 11-29-2003


Message 6 of 128 (99502)
04-12-2004 7:05 PM
Reply to: Message 4 by RAZD
04-12-2004 4:43 PM


AbbyLeever writes:

quote:
Your title is the reason - "and the origin of life"

Oh, yeah, I should've noticed that. Actually that title was copied from a subtitle in the earlier thread, it isn't mine. It is misleading, though; I wish I'd changed it.


This message is a reply to:
 Message 4 by RAZD, posted 04-12-2004 4:43 PM RAZD has not yet responded

Replies to this message:
 Message 7 by AdminAsgara, posted 04-12-2004 8:31 PM berberry has responded

    
AdminAsgara
Administrator
Posts: 2073
From: The Universe
Joined: 10-11-2003


Message 7 of 128 (99512)
04-12-2004 8:31 PM
Reply to: Message 6 by berberry
04-12-2004 7:05 PM


What would you like it to be called berberry?

{Note from Adminnemooseus - It was also started in the "Origins of Life" forum. Personally, I kind of like the concept of a thermodynamics/abiogenesis topic. Anyhow, to me, message 1 is pretty vague about what you intended the topic to be. That said, I'll let AdminAsgara handle any title changes and moves}

[This message has been edited by Adminnemooseus, 04-12-2004]


AdminAsgara
Queen of the Universe

This message is a reply to:
 Message 6 by berberry, posted 04-12-2004 7:05 PM berberry has responded

Replies to this message:
 Message 8 by berberry, posted 04-12-2004 10:01 PM AdminAsgara has responded

    
berberry 
Suspended Member (Idle past 4 days)
Posts: 1853
From: vicksburg, mississippi
Joined: 11-29-2003


Message 8 of 128 (99531)
04-12-2004 10:01 PM
Reply to: Message 7 by AdminAsgara
04-12-2004 8:31 PM


How about 'Thermodynamics, Abiogenesis and Evolution', since that seems to cover all the bases?
This message is a reply to:
 Message 7 by AdminAsgara, posted 04-12-2004 8:31 PM AdminAsgara has responded

Replies to this message:
 Message 9 by AdminAsgara, posted 04-12-2004 10:02 PM berberry has not yet responded

    
AdminAsgara
Administrator
Posts: 2073
From: The Universe
Joined: 10-11-2003


Message 9 of 128 (99534)
04-12-2004 10:02 PM
Reply to: Message 8 by berberry
04-12-2004 10:01 PM


Your wish is my command oh squirrelly one


AdminAsgara
Queen of the Universe

This message is a reply to:
 Message 8 by berberry, posted 04-12-2004 10:01 PM berberry has not yet responded

Replies to this message:
 Message 10 by mike the wiz, posted 04-12-2004 10:14 PM AdminAsgara has not yet responded

    
mike the wiz
Member (Idle past 9 days)
Posts: 4600
From: u.k
Joined: 05-24-2003


Message 10 of 128 (99541)
04-12-2004 10:14 PM
Reply to: Message 9 by AdminAsgara
04-12-2004 10:02 PM


I see you have answered one request. But it will be hard to answer everyones, now you know the diffculty with the unbeliever.

[This message has been edited by mike the wiz, 04-12-2004]


This message is a reply to:
 Message 9 by AdminAsgara, posted 04-12-2004 10:02 PM AdminAsgara has not yet responded

  
DNAunion
Inactive Member


Message 11 of 128 (99579)
04-13-2004 12:27 AM
Reply to: Message 5 by JonF
04-12-2004 4:44 PM


quote:
DNAunion: Until some prebiotically plausible mechanism for capturing and channeling the available prebiotic energy into performing useful "biological" work is found, vague appeals to "open systems" just aren't sufficient ("open system thermodynamics" are necessary, but not sufficient).

quote:
JohnF: Er, you appear to have a serious misunderstanding of thermodynamics.

No, you appear to have a serious misunderstanding of bioenergetics.

quote:
JohnF: The second law deals with entropy, and entropy is a property; that's a technical term that means its value depends only on the current state of the system and not in any way how the system got to that state.

Yeah, so what? Youre confused. You see, I am not talking about only thermodynamics: I am talking about thermodynamics as it applies to the origin of life more than one field of science is involved here.

Explaining how life could arise from nonlife requires explaining the mechanism by which a decrease in entropy - associated with the formation of biological polymers and systems of such polymers - could have plausibly occurred in a prebiotic context. Simply saying sufficient energy was available because the Earth is an open system is insufficient.

quote:
JohnF: Therefore the idea of needing to know a mechanism (for the transition between states) in order to evaluate the thermodynamic possibilities is a red herring.

No red herring...you're just confused.

quote:
JohnF: What counts thermodynamically is the difference in entropy between the initial and final states, not how it got from one state to the other.

And what counts in explaining the origin of life is explaining how things got from one state to another! This particular discussion does involve the origin of life...remember: its not about some simple thermodynamic process like a cup of hot tea cooling off.

quote:
JohnF: However, what I am sure of is that you can't claim that the second law of thermodynamics poses any problem for any hypothesized event until you have calculated the change in entropy and demonstrated a spontaneous decrease.

And Id disagree. For example, we know that the change from free monomers to polymers involves a decrease in entropy (increase in order) and is endergonic (which is why OOL researchers preactivate their monomers). And we know this without having to know exact values. So polymer formation goes in the wrong direction and is thus a nonspontaneous process. Therefore, some sort of process or mechanism must be present in order for such an uphill process to occur (for example, cells couple endergonic reactions with exergonic reactions, usually using ATP as an energy intermediate). What was the prebiotic mechanism? Simply saying that sufficient energy was present is not a sufficient explanation. It's like trying to explain translation in extant cells by simply saying that cells have ATP at their disposal: insufficient explanation. Worse yet, even having sufficient ATP in a cell won't produce proteins if ribosomes - the cellular "machine" that makes proteins - are absent. So relying on just vauge appeals to "open system thermodynamics" for translation is insufficient in more than one way - same goes for OOL.

[This message has been edited by DNAunion, 04-12-2004]


This message is a reply to:
 Message 5 by JonF, posted 04-12-2004 4:44 PM JonF has responded

Replies to this message:
 Message 12 by berberry, posted 04-13-2004 3:17 AM DNAunion has responded
 Message 13 by JonF, posted 04-13-2004 8:48 AM DNAunion has responded
 Message 89 by Brad McFall, posted 12-11-2006 4:26 PM DNAunion has not yet responded

  
berberry 
Suspended Member (Idle past 4 days)
Posts: 1853
From: vicksburg, mississippi
Joined: 11-29-2003


Message 12 of 128 (99592)
04-13-2004 3:17 AM
Reply to: Message 11 by DNAunion
04-13-2004 12:27 AM


DNAunion writes:

quote:
Simply saying sufficient energy was available because the Earth is an open system is insufficient.

Insufficient for what? You keep repeating this, and I would agree that to the purpose of explaining abiogenesis certainly it's insufficient. But is that your whole point? That seems too obvious.

Are you saying that abiogenesis could not have happened because it is made impossible by the 2nd law? If so, how do you suppose life began on earth?

You seem to know a good deal more about this subject than I do, so please don't think I'm challenging you. I'm simply trying to be sure I understand you.


This message is a reply to:
 Message 11 by DNAunion, posted 04-13-2004 12:27 AM DNAunion has responded

Replies to this message:
 Message 14 by DNAunion, posted 04-13-2004 9:54 AM berberry has not yet responded

    
JonF
Member
Posts: 3969
Joined: 06-23-2003
Member Rating: 2.3


Message 13 of 128 (99633)
04-13-2004 8:48 AM
Reply to: Message 11 by DNAunion
04-13-2004 12:27 AM


JohnF: The second law deals with entropy, and entropy is a property; that's a technical term that means its value depends only on the current state of the system and not in any way how the system got to that state.

Yeah, so what? Youre confused. You see, I am not talking about only thermodynamics: I am talking about thermodynamics as it applies to the origin of life more than one field of science is involved here.

It doesn't matter how many fields of science you are talking about, it doesn't matter if you are talking about thermodynamics as it applies to the origin of life or as it applies to steam power plants or as it applies to anything at all. Entropy is a property and its value depends only on the current state of the system and not in any way how the system got to that state. Until you realize and accept that your thermodynamic claims are gobbledygook.

Explaining how life could arise from nonlife requires explaining the mechanism by which a decrease in entropy - associated with the formation of biological polymers and systems of such polymers - could have plausibly occurred in a prebiotic context.

From the point of view of thermodynamics, absolutely not. If you wish to claim (as you have) that there is a thermodynamic problem with abiogenesis, the only way you can support that statement is with calculations that demonstrate an overall decrease in entropy.

Of course, from the point of view of abiogenesis research, explaining the mechanism is key ... but we're not discussing that, we're discussing your claim of a thermodynamic problem.

Simply saying sufficient energy was available because the Earth is an open system is insufficient.

Agreed, but irrelevant to your claim of a thermodynamic problem.

In the absence of calculations we don't know if there is a thermodynamic problem. As I said in my earlier message, I think such caclulations have been made for some scenarios; but the relevant item is your claim that there is a problem. Simply saying that it hasn't been proved that there is no problem is insufficient; you claimed there is a problem, support that claim.

For example, we know that the change from free monomers to polymers involves a decrease in entropy (increase in order) and is endergonic (which is why OOL researchers preactivate their monomers). And we know this without having to know exact values. So polymer formation goes in the wrong direction and is thus a nonspontaneous process. Therefore, some sort of process or mechanism must be present in order for such an uphill process to occur (for example, cells couple endergonic reactions with exergonic reactions, usually using ATP as an energy intermediate).

Agreed. However, in order to determine the thermodynamics of the situation we do not have to have the slightest idea of what that process is or was. All we have to know is the starting state of an appropriate system and the ending state of that same system. It may be convenient to calculate the changes by integrating along a process path from the initial to the final state, but it is not required to do so, and that process path can be any physically possible path; it need not be the actual path and it can be a ludicrously unrealistic path.

So relying on just vauge appeals to "open system thermodynamics" for translation is insufficient in more than one way - same goes for OOL.

True; but appeals to open system thermodynamics do demonstrate that it's plausible that there may not be a problem. However, it's still irrelevant to your claim that the second law of thermodynamics poses a problem for abiogenesis. You need to supply positive support for that claim, not just vague appeals to a supposed lack of support for other's claims.


This message is a reply to:
 Message 11 by DNAunion, posted 04-13-2004 12:27 AM DNAunion has responded

Replies to this message:
 Message 21 by DNAunion, posted 04-13-2004 2:48 PM JonF has responded

  
DNAunion
Inactive Member


Message 14 of 128 (99639)
04-13-2004 9:54 AM
Reply to: Message 12 by berberry
04-13-2004 3:17 AM


quote:
DNAunion: Simply saying sufficient energy was available because the Earth is an open system is insufficient.

quote:
BerBerry: Are you saying that abiogenesis could not have happened because it is made impossible by the 2nd law?

No, that is not my point.

Let me try an analogy. We see an antenna on the top of the Empire State building. Getting it up there is an uphill process and won't occur spontaneously. There's no problem explaining it though because we know how cranes, elevators, motors, etc. were used to get it up there (this is analogous to how cells make their uphill processes work today). But what about the pyramids? There were no cranes, elevators, motors, etc. so we can't use them to explain how the top blocks got up there - gravity poses a problem for the origin of pyramids (analogous to how the second law poses a problem for OOL). It is insufficient to say simply that there was sufficient free energy - volcanoes, wind storms, sunlight, etc.: that fails as an explanation for how the top blocks got up there. What is needed is some plausible, "pretechnology" mechanism that would allow those blocks to get up there and that is what several teams have attempted to explain.

**********************************
PS: Please note that my use of a pyramid analogy does not mean I am saying that intelligence was required for OOL.


This message is a reply to:
 Message 12 by berberry, posted 04-13-2004 3:17 AM berberry has not yet responded

Replies to this message:
 Message 15 by NosyNed, posted 04-13-2004 11:55 AM DNAunion has responded
 Message 16 by Percy, posted 04-13-2004 12:34 PM DNAunion has not yet responded
 Message 17 by JonF, posted 04-13-2004 1:29 PM DNAunion has not yet responded

  
NosyNed
Member
Posts: 8800
From: Canada
Joined: 04-04-2003
Member Rating: 10.0


Message 15 of 128 (99664)
04-13-2004 11:55 AM
Reply to: Message 14 by DNAunion
04-13-2004 9:54 AM


agreeing
I just want to toss my 2 cents (Canadian so really, really small) in here.

DNA has a clear point. The free energy is available but there must be some mechanism for allowing it to perform the work. That is all he is saying and it is the basic issue of abilogenesis.

We don't know the mechanism.

For example, it is perfectly fine to point out the sunlight makes the earth an open system. But without the mechanism of photosynthesis we still don't get life working.

Now DNA, the discussion was thermodynamics and you did confuse the topic by bringing in something else.


This message is a reply to:
 Message 14 by DNAunion, posted 04-13-2004 9:54 AM DNAunion has responded

Replies to this message:
 Message 18 by RAZD, posted 04-13-2004 1:38 PM NosyNed has not yet responded
 Message 19 by DNAunion, posted 04-13-2004 2:22 PM NosyNed has responded

  
1
23456
...
9Next
Newer Topic | Older Topic
Jump to:


Copyright 2001-2015 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2017