A science question

I thought your description/overview was faithful to the "heat flow" model of "heat". That appears to be the one that Sylas was using. Percy (and me) would be using a slightly different model of "heat", which is perhaps an older but he (and I to some extent) would argue is more convenient and intuitive.The two are in conflict based on a semantic division between internal energy and heat.Where they coincide is perhaps the most useful for the purposes of this thread anyway. At the very least light is not always heat, and heat is certainly not always light. Whether light may be considered heat in some circumstances is not so important.We can see from this that there is conductive loss of kinetic energy, and EM loss of energy (transfer from kinetics of the system) from any system.I don't think you will be in bad company if you stick with the definition you are now holding, but I think Percy is correct that for purposes of discussion (especially with laymen) the purely chemical kinetic model's def is easier. It certainly would help one visualize "heat loss" better.I think this whole discussion has shown just how arbitrary the concept of "heat" really is.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

But the above is why Percy's (I'll call it that as it's shorter than kinetic) def is more useful and accurate for discussion of this topic.Think of what the above says... "spontaneous" by virtue of some thermal contact between them. This is not a description of light "heating" and more a description of conductive "heating". What's more (and this closes the circle) the potential energy for transfer is a part of system A before it contacts system B and so A can be considered to have "heat".Maybe this is all getting mixed up because definining heat as only transient energy, and internal energy as the potential transient energy, is somewhat overly arbitrary. Why not heat as the potential and change in heat as the transient?At least that's what it seems is going on here.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

Just so we don't get anything confused, I have been admitting that I was wrong and that I stand corrected to what the hardcore scientific def is regarding heat (it is related to flow and not purely a static condition and the flow can include light in some instances). The wiki quotes made those points pretty clear, while supporting much of the rest of what I was saying.While there is at this point in time a difference between heat and internal energy (I even tried to explain to Percy how I conceptualize IE), I am saying it appears more or less semantic rather than conceptual in nature.This is because (if you conceptualize what we are talking about) internal energy is kinetic, and the transfer is generally loss of kinetic from one to impart kinetic to another. A gain in internal energy is a gain in kinetic energy. Thus conceptually gains in internal energy (which it labels as heat), is not really different from the latent heat a system may have to give. It is about moving particles becoming more motive.I can accept the definition you have used (and have already suggested the Literalist would be fine with it), but am pointing out it may lead to some confusion in layman's use.Let me give an example of where this happens in real life. In physics and chemistry we all understand that it is the flow of electrons, negative particles, which creates "electrical current". Yet to the layman electrician (at least up into the 90's US) it is the positive charge which is considered to flow. This is wholly opposite from our chosen arbitrary scientific model, and indeed is incorrect as protons are not moving, yet it still works in practice and so is kept in use.I don't see it as bad if people continue to view an object's internal energy (latent transfer energy) as "heat". It may be colloquial, but is it wrong? We do talk about hot objects and we want to continue using that term right? And hot is having "heat". When talking publically, why not refer to it as heat instead of saying internal energy?Do you see what I am getting at?I think it would confuse things to say to a person who is not in the know, when in the middle of a discussion on global cooling, that heat is not lost but rather heat is the process or quantity of loss. Why not just accept the layman definition and work with it for that discussion.I don't think Percy was arguing for more than that, how we can use the term in discussion with laymen regarding things like global warming/cooling.As it stands I started by trying to make the point that we are talking about energy (leaving out heat) and it didn't seem to help matters. I think it may be a practical one, even if absurd on its face (like talking to electricians about positive charges moving). But if I have not convinced you, then I would rather switch than fight. I do have problems with this notion as it seems bizarre to me to view a mass absorbing radiation that took minutes or days to reach its surface, as being engaged in a spontaneous transfer of energy from another mass. It is contingent not only on chance of contact, but on chance of absorption properties.I can accept it, it is only semantics after all, but I do not have to like it.Just curious, what is your general background? You seem pretty solid in science.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

I agree.My main argument was just that a person coming on here and talking about the earth losing heat, would be using a colloquial term of heat which is related to kinetics (internal energy), and so it would make sense to stick with that for argument. It certainly is not wholly off the wall or unconnected to an understanding of what is going on in the system.But yes, if we are addressing the scientific understanding of the phenomenon called heat, then it would be useful to be accurate and explain that it is a quantitative measurement of change (or transfer) in internal energy.I guess this thread's topic straddles both realms. Oh that happened to me too, but from a chem/geochem angle (though I reached grad level chem). I have regretted it and have spent years reversing it. I am now almost functionally illiterate in computers (as I showed recently). I am now making some moves toward a full return to science.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

I hope this wasn't serious. If you felt like I was jumping on you then I apologize. I was really trying to back you up regarding the specific scientific property called heat (admitting that some of my own terminology uses had to change), while backing up the practical argument Percy was making.I saw benefits of both sides, and wholly recognized that while much of my conceptual commentary/description regarding heat was valid, your semantic definitions were in line with official scientific use.As far as theLit goes, I supported him when he seemed to take on the definition you used. It was not as early as message 61. I believe I had already (if not shortly afterward) seperated kinetics from heat when discussing what science really conceived of it (Lit noted this as well). I certainly said it is related to kinetic energy, which means Lit's assessment and mine agreed on that account.However, although one could congratulate him for that one correct assessment the rest (the majority) of what he wrote was so filled with errors it seems odd to say he was on the right track. I focused on the errors he still needed to correct.Maybe that makes me too negative? I dunno.In any case, I apologize if it seemed I was trying to beat down anyone or be critical just to be critical. I really thought I was just being helpful. I do agree that theLit is correct in running with the current def which is the one you presented. That is even if I back up Percy's practical argument for those not totally in the know who might appear in the future.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

I addressed this before and got no answer. Let me try again. I do not understand how the above is true.The earth is not a solid block or trapped within walls. It is a mobile system with a rather open/flexible outer boundary.Just because it is hotter on the inside than the outside, does not necessarily mean that it is cooling, only that the greatest amount of energy is coming from internal rather than external sources, or (well I'll get to the other in a sec)...There are internal sources of energy (gravity and radioactivity) which raise the temperature of the internal parts of the planet. This energy is moved through various mechanisms towards the surface, but it does not always reach the surface and definitely not evenly. A hard crust acts much like the crust on the top of a pot of cooking soup, trapping the heat below.At the surface energy is being reflected from external sources, as well as being absorbed and emitted. I don't think we have a budget figured out yet but that we are not totally hot, or hotter than the inner core, at the surface does not seem to me to prove we are losing heat either. We did lose much of our atmosphere earlier, and now that we have heavier atmospheric particles they do not escape as much but still can and certainly do act to redistribute energy through currents.It seems to me the only thing we can know is that there is some reason for the surface being cooler, whether it is that the planet's atmosphere is losing energy to space, or that mechanisms of trapping and distributing energy have kept the hottest parts toward the center does not seem so certain.But I am certainly open to correction on this one.It might be interesting to look at other planets or planetary bodies to make comparisons. Venus for example certainly is an energy trap, yet it still has a solid surface, and perhaps a much hotter interior core.This message has been edited by holmes, 03-10-2005 11:54 AM

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

I want to thank you and percy for both sticking with me on this topic, as if I am wrong it is definitely a deficiency which I need to overcome.That said, I am still not convinced. But maybe we are slightly talking past each other. The problem I had was with Percy's comment that the fact that the atmosphere has a lower temperature than internal lithospheric regions proves that the earth is cooling.I do not understand how that fact necessarily proves the theory, given that what we are discussing is temperature of large scale masses of vastly different chemical constitution and physical environment. I apologize as what I wrote was not exactly what I meant. When I said "only that the greatest amount of energy is coming from internal rather than external sources", I really meant "only that there is greater production of thermal energy at the core due to internal physical processes, than there is production of thermal energy in the atmosphere due to external (off earth) sources."Hopefully the difference is obvious with this clarification.I have tried to emphasize what I was getting at by pointing out that we have a physical boundary between the two systems (mantle/core and hydro-atmosphere). Thus energy and temperatures located in one system do not have any inherent effect on the other (at least not large scale).An analogy I used was a cooking pot of soup or baked beans with a skin that has developed and a heat lamp on it, another analogy could be a pizza with a nice layer of cheese with a heat lamp above it and a grill below. In both cases one can use the heat lamp to remove cooling, yet the internal areas may be much hotter than the externals. Anyone having bit through a warm layer of cheese to find the unbelievably scalding layer of sauce below has an idea what I am getting at. A heat lamp would not necessarily produce an effect where the cheese must be at a hotter temperature.I do get that external heat is not percolating down to the center. This I can understand but it does not derive from the fact that the core is hotter than the atmosphere. That is where I was having problems. The core seems irrelevant to this question.I would add though that rise in temperature change is not necessarily the only result. Atmospheres can store energy and transport it via different mechanisms which do not necessarily require absolute temperature change.I thought your link did a good job of explaining mechanisms atmospheres have for handling energy, beyond purely temperature rises.To conclude let me repeat again, I am not trying to argue we don't have a system which is cooling or stable, I am only having problems regarding what comparisons of core and atmospheric temps have to do with proving theories about the earth as a whole cooling.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

Almost. I am not saying that there cannot be heat flow, but the nature of the flow (as well as other physical realties) could be such that higher temperatures are found within the planet rather than in the surrounding atmosphere, and thus where the hottest temps are does not suggest if the entire system is cooling. Hey now, you should know I already understand this concept. Interestingly enough styrofoam cups are often used in chemistry experiments on thermodynamics because of their insular properties. They do not have to be perfect in order to trap the greatest heat (or temperatures) within, even over a very long period of time. While this is correct, it still does not add up to all portions of the earth necessarily having the exact same temperature at this time. Further, it does not indicate at all that the atmosphere should be hotter than the core.One aspect where the earth differs from a piece of sytrofoam is that it has distinct layers of material, sublayers within those layers (based on further physical differences), and some form of movement within the layers which means energy is removed in some other fashion than simple temperature increase.Let us say at the core was a simple cigarette lighter. Even if it stayed lit for 4.5 billion years and there was no energy loss from the earth system, would we have to see the atmosphere be the same temperature as the core... or hotter? I think you will agree it would probably not.The important factors are not just temperature and time, but amount of internal energy (which we see is different than temperature), the total amount of matter, its various phases and mechanisms for heat distribution within those phases.Just because the amount of energy (as well as temperature of core material) is substantially more than a lighter, I am not sure I can say that it must all have been distributed evenly by now. Much could be trapped within the molten cycles of the core and mantle, expansion of material causing the loss of much of the energy it has to impart before it hits the crust.And even when it reaches the crust, how much will be tranferred and trapped within the next layer for a portion of time?As far as whether the atmosphere is relatively insulated from core temps I note the following from Sylas's citation: Now I realize that the trivial reference could be because solar energy could be so much more than the energy being produced at the core, but I am not sure if that is so. That there is more reaching the atmosphere from solar than core is true, but that does not mean it is greater in toto for the earth system as a whole.I might also mention that we can see thermal layering within the hydrosphere and atmosphere. Despite billions of years the oceans of water and air contain different thermal layers and are not of one temperature... they have not evened out, and it does not appear to simply be a product of the earth cooling.For example the atmosphere is made up of several layers which go back and forth in temperature. While the troposphere does decrease in temperature, the next does not, the following one does, and the one after that increases. Here is a link to Wikipedia's page on the atmosphere. It has a pretty good breakdown of layer and temperature properties. The outside (or top) is not necessarily the coldest layer.It is also interesting to note the history section regarding the formation of earth's atmosphere and that this is considered our third one so far. Is this our final one? How much of the crust formation and so formation of the 2nd and 3rd atmospheres were a result of internal cooling rather than cooling to the outside? With the crust formed, why can temps not be regulated and trapped much as in the atmosphere?I hope this is not annoying to you or Sylas. I am sincere in not seeing the connection between simple temperature variance between core and atmosphere as indicative of anything. I can see saying there is evidence of cooling to the outside based on the fact that our atmosphere is not totally gone, or that it should be higher than it is in general... just not because it would be as hot as or hotter than the core.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

This is definitely the impression I was getting. You had mentioned it at least twice but we can deal with the last comment you made (which renewed my interest)... The only way this reads to me is that if the earth was getting hotter, the outside must be hotter than the inside. Now you're a stickler for language? I have already said I know that the only perfect insulator and so perfect "heat trap" (at least as far as conductivity is concerned) is a vacuum. I even used the styrofoam cup as an example of the kind of "trapping" I am talking about.While a gradient certainly indicates that heat flow will occur, the amount of heat flow can be minimized (not negated) due to material properties, and movement of materials. This means that due to a slower rate of convection than if it was simply a solid block of the same material, we can have a situation where temperatures are higher in certain regions for long periods of times. I am suggesting this kind of "trapping". It does not have to be perfect or permanent, just a slowing such that a gradient is retained for a long time. I do not believe we can say that at all. According to the history of the atmosphere at Wikipedia it suggests that layers have changed in temperature and as a result, composition, which further alters temperatures.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

Maybe I need to find another word than trapped. Let me try and start clean...What we are talking about is a temperature gradient moving from the core toward the atmosphere. So yes, it is understandable that the energy which causes the high temps within the core will be moving outward toward the surface and into the atmosphere.However, the fact that energy is moving toward the surface does not mean that it will always coincide with an equivalent temperature rise as it moves outward.First, by nature of geometry there is succeedingly greater amounts of material above than below. That means the core is a smaller mass, heating a larger mass.Second, the material above does not have to simply use the energy it receives to gain in temperature, it does move (usually expanding) and creates currents and upwellings which reduce the amount of energy it has to impart to the next layer.Third, materials may differ in how much energy they can absorb before ultimately transmitting the energy through to the next layer in the form of raising temperatures. This means that it may take time to get temperatures equalized between layers. As I analogized before, you can put a lighter in the center of the earth and let it run in a closed system, one might not see a rise in any temperature beyond the core even after billions of years.Fourth, equalization is complicated even more based on the fact that some layers can move and use energy to do something other than increase in temperature.So when I say temperatures or heat flow may be "trapped", I am suggesting that the flows may be slowed or unevenly distributed based on the physical makeup of the system such that one can see gradients last for long periods of time. It is like the lighter being trapped at the center of the earth... yes heat is always being radiated out, but its progress may be slowed or hindered compared to what we would see in other systems.I do understand that in any isolated system, eventually temperatures will even out, because eventually energy will even out throughout the system. But the amount of time this will take depends on the system, doesn't it? During the time of "evening out" various pockets of high temps could exist.I guess what i am saying is that I am not seeing how we have the knowledge that just because there is a gradient we have proved that earth is definitely cooling as an entire system. Do we really know that enough time has passed such that everything should have evened out by now, or that such a large gradient could not exist?Especially hard for me is to accept any references to the atmosphere in comparison to the core. The atmosphere is free to move and expand and thus "cool" itself by using the energy in ways other than simply staying in place and gaining in temp. I can accept this way of handling why we can know if it is cooling or not, though now I am confused as it seems you are saying it is not cooling.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)

Okay this makes more sense. Like I said I was having problems that the gradient itself proves that the earth system is cooling.If what is being said is that the gradient shows that heat/energy is moving from the core (a continual source of energy) to the surface and we know that the energy has not been accumulating (fixed temperature at surface being different than just saying there is a temperature difference between core and surface) then clearly it must be cooling.Here are my theoretical issues with saying we do know that the atmosphere is not accumulating energy:1) As was stated in the wikipedia history of our atmosphere, this is essentially our third atmosphere. The first one was theorized to have been blown off in part because of the energy being pumped into it. The second and third show that our atmosphere has been continually changing and perhaps it is due to its "handling" of energy being pumped into it. Stable temps may not necessarily indicate that energy is not being accepted by a system.2) What do we really know about temperatures within our atmosphere? While we may have good data regarding surface temperatures for some time (not sure if it stretches to a billion years though) we cannot say what the total atmospheric temperature was like. It could be that surface temps stay relatively stable as any increases in temp cause a movement upward to higher layers. Other atmospheric layers vary in temperature and I believe the last one gets very hot. The thickness and temperature of that or other layers may have been changing over time.In any case, I at least see where the argument is coming from if we are talking about stability of temps, rather than just that there is still a gradient.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)"...don't believe I'm taken in by stories I have heard, I just read the Daily News and swear by every word.."(Steely Dan)