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Author Topic:   Entropy in Layman's Terms
Son
Member (Idle past 1909 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009


Message 31 of 51 (557321)
04-24-2010 3:44 PM
Reply to: Message 29 by Buzsaw
04-24-2010 3:14 PM


Re: Comprehending The OP
What I'm saying is that 2lot (as expressed in the op) has nothing to do with order or disorder. The passage you quoted even said it explicitely. So why are you talking about it? Are you actually disagreeing with what 2Lot says?
This message is a reply to:
 Message 29 by Buzsaw, posted 04-24-2010 3:14 PM Buzsaw has responded

Replies to this message:
 Message 32 by Buzsaw, posted 04-24-2010 4:29 PM Son has responded

    
Buzsaw
Inactive Member


Message 32 of 51 (557325)
04-24-2010 4:29 PM
Reply to: Message 31 by Son
04-24-2010 3:44 PM


Re: Comprehending The OP
Son writes:

What I'm saying is that 2lot (as expressed in the op) has nothing to do with order or disorder. The passage you quoted even said it explicitely. So why are you talking about it? Are you actually disagreeing with what 2Lot says?

Rrhain's segment (below) does imply disorder and he goes on to explain what amounts to equalibrium/uniformity and disorder void of management and work (ID). No?

Rrhain's OP writes:

When we reduce the concept of the Second Law and entropy to the phrase, "The universe tends towards disorder," what we mean is that the energy distribution of the universe is tending toward a uniformity. You see, energy transfer depends upon variations in energy states. If everything is the same, then there can be no reaction.

No, I'm not disavowing 2LoT. 2LoT does not rule out the possibility of work relative to the propensity towards enropy. When gas is compressed into a tank, that reversal of entropy is effected by work. When gas is released form the tank, equalibrium is effected via entropy without work relative to the energy inside and outside of the tank after the valve is opened.


BUZSAW B 4 U 2 C Y BUZ SAW.
The immeasurable present eternally extends the infinite past and infinitely consumes the eternal future.
This message is a reply to:
 Message 31 by Son, posted 04-24-2010 3:44 PM Son has responded

Replies to this message:
 Message 33 by Son, posted 04-24-2010 5:32 PM Buzsaw has not yet responded

  
Son
Member (Idle past 1909 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009


Message 33 of 51 (557334)
04-24-2010 5:32 PM
Reply to: Message 32 by Buzsaw
04-24-2010 4:29 PM


Re: Comprehending The OP
Rrhain's OP writes:

This is why concepts of "information" or "disorder" make no sense in their regular senses: It isn't a question of "ordering" the energy. It's that it is no longer physically available to do any work. When we reduce the concept of the Second Law and entropy to the phrase, "The universe tends towards disorder," what we mean is that the energy distribution of the universe is tending toward a uniformity. You see, energy transfer depends upon variations in energy states. If everything is the same, then there can be no reaction.

Rrhain's OP writes:

we have to start with making the point that entropy is a statement about energy. It isn't about "information" or "order" or "disorder."disorder

Obviously, Rhain is describing the 2lot separating it from the common use of order and disorder. Meaning using disorder like you used it if you actually agree with Rhain's description of the 2lot makes no sense. You are talking about disorderly and orderly energy, but what does it mean and what does it have to do with the 2lot?

Buzsaw writes:

What we observe relative to your laymen's definition is that aside from management, things do tend towards disorder. If we don't keep up the barn roof via work, it begins to leak and sooner or later the barn collapses into disorder. Whatever is not ID maintained and managed via work tends towards disorder whereas managed energy effects order.

For example, this does have no relations at all with 2lot. 2lot only states that available energy for work decreases overtime in a closed system.


This message is a reply to:
 Message 32 by Buzsaw, posted 04-24-2010 4:29 PM Buzsaw has not yet responded

    
Admin
Director
Posts: 12579
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.9


Message 34 of 51 (557403)
04-25-2010 6:33 AM


Moderator Request
If there's interest in another 2LOT discussion then could someone please propose a thread for that purpose? This thread is for working out how best to communicate the concept of entropy to laypeople. Thanks.


--Percy
EvC Forum Director

    
Rrhain
Member
Posts: 6349
From: San Diego, CA, USA
Joined: 05-03-2003


Message 35 of 51 (557407)
04-25-2010 8:15 AM
Reply to: Message 11 by purpledawn
04-23-2010 7:32 AM


purpledawn responds to me:

quote:
quote:
There are no perfect refrigerators.

I didn't quite understand where the wasted energy is in this one unless it is still the heat wasted in the moving process.


A refrigerator, at its most basic level, is simply an engine that runs in reverse.

Now, an engine is something that takes energy and converts it into work. Thermodynamically, this means we have a thing that we call a "high-temperature reservoir," that is, the thing that has all the heat, and it delivers it to a mechanism that extracts some of that energy to turn it into work. The rest of it gets dumped to the "low-temperature reservoir." What is being dumped there is the lost energy, the entropy. It hasn't been converted into work and it cannot be used: The engine is hooked up to the high-temperature reservoir, not the low.

Now, the engine works specifically because the heat wants to flow from the high to the low. If the high and low reservoirs were at the same temperature, there would be no heat flow and thus no work could be extracted. What the engine does is extract some of that energy out of that natural flow and use it to do some work, whatever it cannot use being lost.

We can abstract all this to have a box that is the high-temperature reservoir, an arrow coming out of it to another box that is the engine, and two arrows coming out of the engine: One goes to that thing we call "work" and the other goes to a box that is the low-temperature reservoir. If we let the size of the arrows dictate how much energy is being transferred at each step, then the Second Law states that while we can reduce the size of the arrow going from the engine to the low-temperature reservoir (and in compensation, increase the size of the arrow going to the work bubble), we can never reduce it to nothing.

A refrigerator reverses all the arrows. In a refrigerator, we input work into the "engine" and in the process, it pulls some heat out of the low-temperature reservoir and transfers it to the high-temperature reservoir.

Now, suppose there were a perfect engine. That is, suppose there were an engine that could take all of the energy it takes from the high-temperature reservoir and convert it into work: The size of the arrow going out of the engine to the work bubble is the same size as that of the arrow coming in and the arrow going to the low-temperature box doesn't exist. Well, if that were the case, we could hook this engine up to a refrigerator. The work that this engine produces can be used to drive the refrigerator and the net result of this is that energy is flowing from the low-temperature reservoir to the high-temperature reservoir without any external work being required to run the thing...it's being run by the high-temperature reservoir which actually gets hotter and thus has more energy that it can give to the engine.

This is perpetual motion and impossible.

Thus, no perfect engines.

Now the flip side of this is the perfect refrigerator. There are two arrows going into the refrigerator: The energy arrow from the low-temperature reservoir and the work arrow. Those get combined and the result is to dump all that energy upon the high-temperature reservoir. We can increase the efficiency of this by requiring less work to drive the refrigerator. A perfect refrigerator would be to reduce that incoming arrow from the work to zero. We could then hook this up to the engine: The refrigerator takes energy from the low-temperature reservoir and dumps it to the high-temperature reservoir which then is used by the engine to extract work and thus, we get work for nothing.

Once again, this is perpetual motion and impossible.

Thus, no perfect refrigerators.

Does that help?


Rrhain

Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

Minds are like parachutes. Just because you've lost yours doesn't mean you can use mine.
This message is a reply to:
 Message 11 by purpledawn, posted 04-23-2010 7:32 AM purpledawn has responded

Replies to this message:
 Message 42 by purpledawn, posted 04-25-2010 3:58 PM Rrhain has responded

    
Rrhain
Member
Posts: 6349
From: San Diego, CA, USA
Joined: 05-03-2003


Message 36 of 51 (557409)
04-25-2010 9:00 AM
Reply to: Message 18 by Buzsaw
04-24-2010 8:32 AM


Buzsaw responds to me:

quote:
With ID, there is no energy in the system which cannot be managed so as to be used for work.

Which is a direct violation of the Second Law. All physical processes lose energy to entropy. While the processes may be extremely efficient such that this loss is very slow, it can never be eliminated and always takes a finite amount of time which is why your eternal universe is a violation of physics.

I'm still waiting for you to answer the question I asked of you the last time you tried to claim that everything we know about physics is wrong (Message 127):

What would happen if we hooked up your engine to a refrigerator? I wrote about this very specific example when discussing how one can derive the second law from scratch. It is a common example and is used in all three of my physics textbooks, which is why I also used it. You say that god expends work. That's fine. You say that god takes up energy back. That is fine, too.

You seem to think that this cycle can continue indefinitely, especially since you claim that universe is eternal. But this is a direct violation of the second law. Heat to work, work to heat, what does the second law tells about this?

Unless and until you can answer this question, I'm going to respectfully ask you that stay out of this thread because I don't want it derailed.


Rrhain

Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

Minds are like parachutes. Just because you've lost yours doesn't mean you can use mine.
This message is a reply to:
 Message 18 by Buzsaw, posted 04-24-2010 8:32 AM Buzsaw has responded

Replies to this message:
 Message 37 by Buzsaw, posted 04-25-2010 10:55 AM Rrhain has not yet responded

    
Buzsaw
Inactive Member


Message 37 of 51 (557414)
04-25-2010 10:55 AM
Reply to: Message 36 by Rrhain
04-25-2010 9:00 AM


Rrhain writes:

Which is a direct violation of the Second Law. All physical processes lose energy to entropy. While the processes may be extremely efficient such that this loss is very slow, it can never be eliminated and always takes a finite amount of time which is why your eternal universe is a violation of physics.

Interestingly, you choose to ignore problems with the 1LoT relative to the BB alleged singularity event; problems like no before relative to energy, no outside of in which to expand and no time in which to have happened etc but disallow ID relative to 2LoT. No ID is allowed by your definition but 2LoT does allow for work effected decrease in entropy. The ID PoV calls for enough work to effect the perfect perpetual system, This all has to do with physics. It just that you mine out of physics what suits your PoV.

You assume the right to waive off problems with things like the alleged singularity, all the while disallowing any unknowns relative to the possibility of eternal energy, which in fact, happens to be more compatible to 1LoT than temporal energy. You can't have it both ways. The universe is either eternal or temporal.

There are waived off problems as well with the notion of alleged multiverses; problems with the properties of space. If there was no outside of the alleged singularity expansion of space, you can't have multiverses without space between them, etc.

What I'm saying is that there are unknowns relative to all PoVs. You choose to ingnore your own and harp incessently on ours.

OFF TOPIC - Please Do Not Respond to this message by continuing in this vein.
AdminPD

Edited by AdminPD, : Warning


BUZSAW B 4 U 2 C Y BUZ SAW.
The immeasurable present eternally extends the infinite past and infinitely consumes the eternal future.
This message is a reply to:
 Message 36 by Rrhain, posted 04-25-2010 9:00 AM Rrhain has not yet responded

Replies to this message:
 Message 38 by Taq, posted 04-25-2010 12:33 PM Buzsaw has not yet responded
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 Message 41 by AdminPD, posted 04-25-2010 3:20 PM Buzsaw has not yet responded

  
Taq
Member
Posts: 7673
Joined: 03-06-2009
Member Rating: 2.6


Message 38 of 51 (557417)
04-25-2010 12:33 PM
Reply to: Message 37 by Buzsaw
04-25-2010 10:55 AM


No ID is allowed by your definition but 2LoT does allow for work effected decrease in entropy.

Can you name one instance where a human has been able to violate the 2LoT? Humans, like all other natural processes, are subject to the 2LoT. All processes that humans are involved in result in less work availabe at the end than at the beginning. All processes that humans are involved we observe that heat disperses through the system towards equilibrium. The only way we can make this go into reverse is to pump energy into the system in accordance with the laws of thermodynamics.

So what are you on about?

OFF TOPIC - Please Do Not Respond to this message by continuing in this vein.
AdminPD

Edited by AdminPD, : Warning


This message is a reply to:
 Message 37 by Buzsaw, posted 04-25-2010 10:55 AM Buzsaw has not yet responded

Replies to this message:
 Message 39 by Iblis, posted 04-25-2010 1:29 PM Taq has not yet responded

  
Iblis
Member (Idle past 1975 days)
Posts: 663
Joined: 11-17-2005


Message 39 of 51 (557423)
04-25-2010 1:29 PM
Reply to: Message 38 by Taq
04-25-2010 12:33 PM


Buzsaw's Demon
So what are you on about?

His god is functioning as Maxwell's Demon, going around using his omnipotence to move water back up to the top of wheels and drag hot air back to its source and so on. Scientifically it isn't a violation of the Second Law because the god is doing work, but that energy "doesn't count" because he has an infinite supply of it in his ineffable pancreas or somewhere.

The reason there isn't any evidence for this happening is, we have the wrong world-view. If we would all just agree together to believe what he says, it would be a well-known fact.

OFF TOPIC - Please Do Not Respond to this message by continuing in this vein.
AdminPD

Edited by AdminPD, : Warning


This message is a reply to:
 Message 38 by Taq, posted 04-25-2010 12:33 PM Taq has not yet responded

  
Son
Member (Idle past 1909 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009


Message 40 of 51 (557429)
04-25-2010 2:18 PM
Reply to: Message 37 by Buzsaw
04-25-2010 10:55 AM


But if you believe what you says, it means you actually DISAGREE with 2lot (maybe because it doesn't invoke God or something?). This thread is to discuss how to explain what 2lot says, if you disagree with it, start another thread and show where it's wrong. By the way, if you manage to make a perpetual system, better make, proves us wrong and get the nobel prize. (In case you still didn't understand what 2lot says, it disallows the possibility of a perpetual system)

OFF TOPIC - Please Do Not Respond to this message by continuing in this vein.
AdminPD

Edited by AdminPD, : Warning


This message is a reply to:
 Message 37 by Buzsaw, posted 04-25-2010 10:55 AM Buzsaw has not yet responded

    
AdminPD
Inactive Administrator


Message 41 of 51 (557433)
04-25-2010 3:20 PM
Reply to: Message 37 by Buzsaw
04-25-2010 10:55 AM


Off Topic
Buzz,

You know the routine and you know you're off topic. Please respect the request of the originator and Admin.

Please direct any comments concerning this Administrative msg to the Report discussion problems here: No.2 thread.

Any response in this thread will receive a 24 hour suspension.

Thank you Purple
AdminPD


This message is a reply to:
 Message 37 by Buzsaw, posted 04-25-2010 10:55 AM Buzsaw has not yet responded

  
purpledawn
Member (Idle past 1537 days)
Posts: 4453
From: Indiana
Joined: 04-25-2004


Message 42 of 51 (557437)
04-25-2010 3:58 PM
Reply to: Message 35 by Rrhain
04-25-2010 8:15 AM


Work or Waste
quote:
Does that help?
I understand why there can't be a literally perpetual motion machine. I wouldn't have considered that a possibility even before I read this thread just by looking at the world around me.

So as heat moves it either does work or it is wasted (can't be used for work or no opportunity to do work). Heat that is not used for work is entropy?

So from a very very simplistic view, entropy is wasted heat. I understand the waste in machines. How does the waste manifest itself in things that are not manmade or influenced by man?


This message is a reply to:
 Message 35 by Rrhain, posted 04-25-2010 8:15 AM Rrhain has responded

Replies to this message:
 Message 43 by Rrhain, posted 04-26-2010 2:34 AM purpledawn has responded

  
Rrhain
Member
Posts: 6349
From: San Diego, CA, USA
Joined: 05-03-2003


Message 43 of 51 (557468)
04-26-2010 2:34 AM
Reply to: Message 42 by purpledawn
04-25-2010 3:58 PM


purpledawn writes:

quote:
Heat that is not used for work is entropy?

In the sense of there being a process by which energy is flowing, yes. But, we must be careful to recognize that the products of a reaction can themselves be used in another reaction. That is, the heat from the hot water can be used to melt the ice, but depending on just how much heat was used in the process, the leftover warm water might be capable of being used in another reaction.

When we say it is "lost," we are referring to that one particular reaction. If you take a hot object and you put it in contact with a cold object, heat naturally flows between them until the two reach equilibrium. The engine allows us to extract some work from that flow. But once the system reaches equilibrium, no more work can be extracted because there is no more flow.

If, however, you introduce a third object into this system that is at a different temperature, then we can hook the engine up again and extract some work while the two reach equilibrium.

On a cosmological scale, eventually all energy gets bled away. Eventually, everything in the universe will be of the same uniform temperature. This is what we mean by the "heat death" of the universe. But we're a long way from that and while we're still in the middle of things, plenty of reactions can take place, chained together. And with a star shining down on us, continually dumping energy onto the planet, we don't really have any problem with entropy.

quote:
I understand the waste in machines. How does the waste manifest itself in things that are not manmade or influenced by man?

That's the glory of the Second Law: It doesn't matter what the engine is. Human-created engines are fairly obvious because they're big and we can directly see how energy comes in, stuff comes out, and the engine heats up. But there are other kinds of engines, too.

For example, photosynthesis. It's a chemical engine. Two photons strike a molecule of chlorophyll and excite the electrons in it to a higher energy state. Because those electrons are now at a higher energy state, the chlorophyll can now engage in a reaction that transfers those electrons to another chemical. That chemical then transfers the electrons to another, those to another, etc., until eventually the electrons get passed back to the molecule of chlorophyll and the process can start all over again. This is called "photophosphorylation." Here's how my biology textbook described it:

A person swings a sledgehammer, hitting a lever that throws a heavy ball into the air (like a"ring the bell" game). The ball lands on a ramp, rolling down it and dropping to a second ramp; from there it falls onto a wheel, causing the wheel to turn. When the ball falls from the wheel, it falls into another ramp, rolls down it, and finally falls back onto the lever where it started. If the turning wheel is used to do work (to run a machine), then we can see that the system transforms the original work of the person swinging the hammer into work done by the machine attached to the wheel. The energy of the falling sledgehammer is analogous to the photon in photophosphorylation, the lever to chlorophyll, the ball to an electron, the ramps to the electron carriers, and the turning of the wheel to the formation of ATP.

--Life: The Science of Biology, "Photosynthesis"

Each step of this process is its own reaction and thus has its own options to bleed energy out of the system, but that's fine so long as the energy of the original photons is enough. If the excited chlorophyll is energetic enough, there will be enough energy in the system such that even though we lose some to entropy, heating up the cell, there is enough energy to drive all the reactions and deliver the electrons back to the chlorophyll to be used again. That's why chlorophyll requires sunlight of a certain wavelength. Put your plants under red light, which doesn't have a lot of energy, and they won't survive for long. That's why grow lights tend toward the blue end of the spectrum: There's more energy in blue light which will activate the chlorophyll sufficiently.

Does that help?


Rrhain

Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

Minds are like parachutes. Just because you've lost yours doesn't mean you can use mine.
This message is a reply to:
 Message 42 by purpledawn, posted 04-25-2010 3:58 PM purpledawn has responded

Replies to this message:
 Message 44 by purpledawn, posted 04-26-2010 5:44 AM Rrhain has responded
 Message 48 by Taq, posted 04-27-2010 11:57 AM Rrhain has not yet responded

    
purpledawn
Member (Idle past 1537 days)
Posts: 4453
From: Indiana
Joined: 04-25-2004


Message 44 of 51 (557477)
04-26-2010 5:44 AM
Reply to: Message 43 by Rrhain
04-26-2010 2:34 AM


Entropy and the Layperson
quote:
In the sense of there being a process by which energy is flowing, yes. But, we must be careful to recognize that the products of a reaction can themselves be used in another reaction. That is, the heat from the hot water can be used to melt the ice, but depending on just how much heat was used in the process, the leftover warm water might be capable of being used in another reaction.

When we say it is "lost," we are referring to that one particular reaction.


So energy lost in one reaction is not necessarily unusable in another reaction.

quote:
But once the system reaches equilibrium, no more work can be extracted because there is no more flow.
Now I understand the equilibrium part. Equilibrium means no "work" is possible.

quote:
That's the glory of the Second Law: It doesn't matter what the engine is. Human-created engines are fairly obvious because they're big and we can directly see how energy comes in, stuff comes out, and the engine heats up. But there are other kinds of engines, too.

For example, photosynthesis. It's a chemical engine. Two photons strike a molecule of chlorophyll and excite the electrons in it to a higher energy state.


Understood.

Why would a layperson need to understand entropy?

I understand what you're saying concerning entropy on a very basic level, but what does this knowledge do for me or any layperson?


This message is a reply to:
 Message 43 by Rrhain, posted 04-26-2010 2:34 AM Rrhain has responded

Replies to this message:
 Message 45 by Percy, posted 04-26-2010 8:29 AM purpledawn has acknowledged this reply
 Message 46 by Taq, posted 04-26-2010 9:48 AM purpledawn has acknowledged this reply
 Message 51 by Rrhain, posted 05-01-2010 4:25 AM purpledawn has not yet responded

  
Percy
Member
Posts: 18309
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.7


Message 45 of 51 (557484)
04-26-2010 8:29 AM
Reply to: Message 44 by purpledawn
04-26-2010 5:44 AM


Re: Entropy and the Layperson
purpledawn writes:

Now I understand the equilibrium part. Equilibrium means no "work" is possible.

--Percy


This message is a reply to:
 Message 44 by purpledawn, posted 04-26-2010 5:44 AM purpledawn has acknowledged this reply

    
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