Thermodynamics and The Universe

I fear we may have lost EODoc, I haven't seen him since AdminPD closed that other thread.My knowledge of chemistry is pretty bad, too, but we are both cognizant of how little we know of chemistry. How does someone, anyone, reach the PhD level without passing association with so much knowledge as to force the realization of how little one knows. One thing you can say for EODoc, though - he sure wasn't afraid to make a mistake!--Percy

But QM also obfuscates the subjective so that mysterious interpretations relate to the paintings. Comparing science to decreased entropy applies QM to the earth's quantity and explains the solar system. Analogous beasts irrelevantly beautify thermodynamics and give QM judgmental looks.--Percy

But QM precisely solves the problems you describe. Wherever a planet or atmosphere appears to be, wherever they appear to have been, whatever the indications for entropy, QM and especially retro-causality tell us with precision that patterned reconciliations account for methods and problematic intricacies. Ilogical babies and their bathwater QM-ify proverbial science.--Percy

Entropy as a measure of disorder is a clear concept, but mapping it onto actual physical processes can often be counterintuitive. One way to think about entropy that more often, though not always, yields more accurate conclusions is to think of all the possible states for something to be in, and then judge how likely the current state is. If it isn't that likely compared to the rest, the entropy is low.One of the counterintuitive things about entropy is that though we know it is primarily the energy from the sun that drives biological activity on earth and counters the general tendency toward disorder, this is only because biological organisms store energy in chemical bonds, e.g., though the photosynthetic process. But if you merely heat something, say a non-reactive gas in an enclosed container, then the entropy (of only the gas, not necessarily the system that includes whatever is heating the gas) will increase as the more and more energetic molecules become less and less ordered. In this case we're adding energy to a system in the form of heat and causing it to become more disordered, have higher entropy.An example of cooling (radiating heat to the environment) causing decreased entropy is water turning to ice. The crystalline ice is far more organized and orderly than liquid water.This complex and counterintuitive behavior of entropy is why it is so risky to make explicit statements about the changing entropy of complex objects, such as a pile of manure. There is likely little photosynthesis going on in manure, I think that most of the biological activity in manure would be non-photosynthetic microorganisms, so the heat they give off is radiated into the environment and quite possibly is sufficient to increase the entropy of the manure. But we can't be certain of that without knowing how much of that heat is captured in chemical bonds within the manure, perhaps as trapped methane (I'm speculating, of course). The amount of energy stored in chemical bonds in manure cannot be insignificant, because if memory serves me correctly cow manure can be burned as fuel.Thus I think that any claims about knowing the relative change in entropy of a pile of manure relative to a pile of rocks are specious, at least given the information that has been presented here so far. To answer the question we'd have to know a heck of a lot more about manure, and even then we might not be able to generate a definite answer.--Percy

It's sufficiently complicated that most people wouldn't be able to say for sure. My guess is that most people with a detailed understanding of thermodynamics would just throw up their hands in resignation at the impossibility of solving such a problem, but on the other hand their may be dominating factors at work. But I think that to give an informed answer you would have to learn a heck of a lot about manure. And if a simple cowpat is that difficult, you can imagine the difficulty for entire planets.--Percy

No doubt? There is every doubt. Calculating entropy changes for complex non-homogeneous materials is incredibly complicated. A simple counterexample to "expressions of genes...produce much more entropy than...rocks" is a seed growing into a tree. While such growth is extremely complicated, we know that the tiny seed system with only a little stored chemical energy and information has changed to become a large tree system with a huge amount of stored chemical energy, and more information, too, though not genetic.--Percy

I understand the point you're trying to make, but you're going to have to consider much more simple and homogeneous objects than manure and rocks in order to be certain of your answer. How much information is contained in 97 billion nearly identical copies of a microorganism? Is your rock homogeneous or does it consist of many different elements and crystalline structures, or does it contain significant amounts of radioactive elements?Though I was originally replying to Buzsaw and his manure example, I also have in mind what you said back in Message 94, that "Earth has a great deal more entropy production than Mars or Venus, because dissipative structures (e.g., bacteria) produce considerably more entropy than non-dissipative structures (e.g., rocks)..." But what you're doing is drawing conclusions about apples from an example about oranges. In the short term, whether the entropy in a recent cowpat is increasing or decreasing is an extremely complicated and probably unanswerable question. In the long term I'd have to concede it very likely that considered as isolated systems a pound of cowpat began with lower entropy than a pound of, say, granite, but planets that orbit active suns are not isolated systems. If a cowpat has lower entropy than a rock, it still tells you nothing about whether earth is currently gaining or losing entropy. The sun is pouring energy onto the earth, and whether it results in net entropy gains or losses at this point in time I don't think anyone knows. Certainly in the long term, billions of years, earth will experience huge entropy gains, but right now, who knows?The reason I'm quibbling over this is because Buzsaw seems to believe that we can know whether entropy is increasing or decreasing for something the size of a planet. My point is that entropy change is very difficult to determine even with something as simple as a cowpat (especially while the microorganisms are still active), let alone a planet.--Percy

You're still using an example orthogonal to your point, so let me try again, this time explaining in a slightly different way. If you separately isolate a cowpat and a rock so that each is an isolated system, then I concede it very likely that as time goes by the cowpat will experience a larger increase in entropy than the rock, assuming the rock isn't of some interesting material.But you're using this example to make a point about the earth, and the earth is not an isolated system. So to make your example relevant we have to consider a cowpat and a rock in situations where they, too, are not isolated. So we have to consider something more like the situation the earth is in, such as a cowpat and a rock sitting in a field. The sun is beating down on them during the day. Are they gaining or losing entropy? Beats me, and probably everyone else, too. Do undigested seeds embedded in the cowpat that begin to grow count? Do microbes that fall onto it from the air count? Fly larvae? Do microbes that somehow make a living off rock count?A planet is far more complex. Is the earth gaining or losing entropy right now? Who knows! This reads like you've got the definition of entropy backwards. Let me get this straight. You feel that some significance can be attached to whether the earth is changing entropy at rates different from other planets, but you don't know whether it is changing at a faster or slower pace, or even whether the change is in a positive or negative direction. Whatever the actual situation turns out to be, since we don't know what the situation is at this point it neither supports nor negates your point.Referring back again to your Message 94, now I'm beginning to wonder if you *are* misunderstanding the nature of entropy. I'm looking at this: I originally assumed you misspoke and meant to say that any life-supporting planet should have measurably higher rates of increasing entropy, but in this last message you've repeated this. The raw materials of life mixed up and compressed into a rock have much *higher* levels of entropy than the same materials realized as a large colony of bacteria. Life is highly ordered and hence has *lower* entropy.--Percy

You're talking about something else now. In this response you're making statements about entropy change, but my response wasn't to a comment from you about entropy change. I responded to your comments about the amount of entropy in life versus a rock. Here's the most relevant portion again from your Message 129: Entropy is a measure of disorder. Highly ordered life would have low entropy. As I said before, the raw materials of life mixed up and compressed into a rock have much *higher* levels of entropy than the same materials realized as a large colony of bacteria. Life is highly ordered and hence has *lower* entropy. Entropy is not like radioactivity, clicking off with relentless precision for half-life after half-life. Just because something is highly ordered and has low entropy does not mean that it is increasing in entropy today. In the very long term, systems with low entropy will experience greater increases in entropy than systems that already have high entropy. But that doesn't allow you to reach any conclusions about what is happening today. Today the sun is still shining on the cowpat, the rock and the earth, and whether the net result is an increase or decrease in entropy, God only knows. Is there really anyone advocating taking both approaches at the same time? You can approach the analysis from a traditional thermodynamic perspective, or from an information entropy perspective, but to analyze from both perspectives would require separating physical entropy from information entropy. I haven't heard of anyone doing this before.--Percy

A better way to think about this is to consider how likely a state is. If it is relatively unlikely then it has low entropy. The ordered state of ice is less likely than the random motion of water molecules which is in turn less likely than the even more random motion of steam molecules, representing a progression from less to more entropy.In the same way, life has lower entropy than the same chemical constituents just randomly mixed together, because the organization of chemicals in life is much less likely than a random mix. Unlike water, where raising the temperature from ice to water to steam merely causes state changes and increasing entropy, adding heat to life drives chemical reactions that both store and release energy, and whether the net change in entropy is positive or negative is anyone's guess in many situations.As near as I can make out, you seem to be equating higher metabolic activity with higher entropy. What leads you to believe Prigogine is saying anything like this?--Percy

It looks to me like you're still confusing two different concepts. These are two different things:

1. The amount of entropy contained within a system.
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2. The rate and direction of entropy change within a system.

What you've done above is respond to arguments about #1 with arguments about #2. That a system is rapidly producing entropy tells you nothing about the amount of entropy it contains.Your Prigogine quote doesn't directly bear on what we're discussing, but I think you've misunderstood what Prigogine means by far-from-equilibrium processes and dissipative structures. A dissipative structure is one which is far from thermodynamic equilibrium. An example of a system in thermodynamic equilibrium would be a gas which has been left undisturbed for some time, and so all the gas molecules have had a chance to exchange and even-out energy and momentum, making the gaseous mixture homogeneous. The lack of energy differences in the gas would mean that no energy is available to do work, and so this system would have very high entropy. By definition, a system in thermodynamic equilibrium is in its highest possible state of entropy.Since a system in thermodynamic equilibrium has high entropy, and since a dissipative structure is far from thermodynamic equilibrium, it must therefore have low entropy. It cannot be any other way.--Percy

Yes, of course. The lower the entropy the greater the potential of the system to perform work. Knowing that gasoline is low in entropy compared to smog, which would you choose to power your car? I can see now that that's what you were interested in, it's just that you sometimes phased things that seemed like statements about amount of entropy rather than about entropy change. Both entropy and entropy change can be of interest depending upon what you're looking at. Given that this discussion developed out of comments from Buzsaw, who was confusing QM with thermodynamics on a planetary scale, I'm uncertain what we're focusing on. But I'm pretty sure that we don't know if entropy on earth as an open system is increasing or decreasing. Arguments like Buz's that are based upon claims that this is something we can know are specious.--Percy

When Prigogine says equilibrium he means thermodynamic equilibrium. Processes that take place far from thermodynamic equilibrium are merely those which take place in a system with low entropy. The mistake you're making is in thinking that dS=0 is only possible for thermodynamic equilibrium. This isn't true. dS=0 can equal 0 for any system. On average from day to day dS=0 for most human adults, since they roughly take in as much matter and energy as they give off. The entropy S of me today is likely very close to the entropy of me yesterday, meaning that my dS is very close to 0. During a period of a few weeks where my activities are the same and I neither gain nor lose weight and my entropy is measured on a daily basis (not something we can really do, but we're speaking hypothetically), likely my entropy is a little more some days and a little less other days, but on average the difference will be 0.So now let's examine precisely what you go on to say about entropy and life: This is insufficiently precise for a definitive reply, but I can at least note that of course dS=0 has meaning for life. Any living organism is an open system, and during periods when it is simply maintaining itself, neither growing nor dying, dS=0 will be approximately true. This is an example of the misunderstanding I addressed before. This, too, is imprecise, so critiquing it isn't something I'm going to attempt, but there is no reasonable interpretation of what you said that is correct. Thermodynamic equilibrium is not defined as dS=0, but rather is defined as a system in a state where dS cannot be anything but 0. But clearly an open system where as much work is being imported as exported has dS=0. I don't think you have a clear understanding of what Prigogine means by a dissipative structure, and the ambiguity in your understanding is causing you to draw false conclusions. This is as untrue today as it was all the other times you said this. Manure is an open system. In an open field with the sun beating down on it, a recent cowpat that is full of microorganisms will likely have a negative dS, while a rock would have a positive dS. In other words, the rock would have greater dS.--Percy

AbE: Let me quickly add a comment that I actually deleted before posting this. After seeing that Cavediver's message it's probably important to note that Hoot Mon seems to move back and forth freely in questionable ways between an information theoretic approach to entropy and a traditional thermodynamic approach.Good question. You're of course absolutely right that both orderings are arbitrary and equally unlikely. Hoot Mon's example does not state that the information about whether a deck is sorted or not is communicated to the person examining the decks. Without this information, both decks have equal entropy.If you change the example so that before examining a deck the person is told whether or not it is sorted, then he receives no information from actually examining the sorted deck because he already knows the order of the cards. All the necessary information was already communicated when he was told the deck was sorted. Once he was told it was sorted he already knew the order of the cards. Since he learns nothing from examining the order of cards in the sorted deck, in other words, no information is communicated, the entropy in the sorted deck is low. In information theory, low entropy is associated with communicating little information.On the other hand, in examining the shuffled deck the person examining it learns something new about the order of cards with every next card he examines. He is, of course, learning less and less information with each card. For example, the first card has 52 different possibilities, and so by examining the first card he learns a great deal. The last card has only one possibility, since by process of elimination there's only one card that could be left, so once 51 cards have been examined there is no point in actually examining the last card since it is a virtual certainty what it is. But the random deck has very high entropy since something is learned with every card but one.So if we change Hoot Mon's example to assume we're told which deck is sorted, then this is consistent with what Hoot Mon claimed.--PercyEdited by Percy, : Add brief clarification.

Your example is correct, but it's just an example of a different situation, not a counter example, and it isn't equivalent to the manure in your other example. In your car example you're considering the car as a closed system with no energy input (in the form of gasoline fillups). In your manure example, the manure is an open system, not closed, and what I originally said is that it is very difficult to know whether the entropy of the manure is increasing or decreasing. A recent cowpat in the hot sun is likely decreasing in entropy as the microorganisms transform the heat from the sun and the raw materials from the cowpat into methane and other chemicals as well as reproducing more of themselves. An old cowpat, perhaps at the bottom of a pile of old cowpats, with dying or diminishing populations of microorganisms is likely increasing in entropy.But my main point is that the determination of the direction of entropy changes in something as complex as life is often not a realistic possibility. You can draw broad trends in certain situations as I've tried to do, but there are so many factors involved that it is very difficult to be certain. That's why I keep telling you that you can't make definitive statements such as that manure gains entropy faster than rocks. First it depends upon a lot of factors, and second those factors aren't easy to analyze. I think the clarifications I've offered you about your manure versus rock example are far more than mere negation. I've explained the same thing a number of times and a number of different ways. I don't have quotes from any experts, just an understanding of thermodynamics that I learned at university, honed over the years through frequent discussions such as this one. I didn't learn thermodynamics by reading quotes from experts, and I don't think I could really name any experts.Your Prigogine excerpt is just a simple illustration and description of 2LOT, but it is fundamental to this discussion. Anything either of us says must obey 2LOT or it's wrong. But this isn't the tricky part of thermodynamics for this particular discussion. The tricky part is building an understanding of which types of processes tend to increase entropy versus which types decrease entropy. In general, heating that merely causes state changes increases entropy, but once the system heats up it will begin radiating as much heat as it absorbs and entropy will increase no longer. But heating that drives chemical reactions that store energy decrease entropy. In other words, the system has stored the potential to do work in the newly formed chemical bonds.I'd never heard of Prigogine until you mentioned him, and if his ideas about viewing life as dissipative structures are influential within biology then it is a rather quiet influence, as I hadn't heard of them before. I'm a little puzzled why you would focus on the ideas of Prigogine instead of just studying up on thermodynamics. I quick Google reveals that Prigogine is mentioned in some creationist source material, such as Duane Gish's book Creation Scientists Answer Their Critics, but only to dismiss his ideas.--Percy