Second Law of Thermodynamics

by

Gravity and Levity is one of those blogs where the posts are few and far between, but each post is a treasure. I am compelled to mention the latest post on the Second Law of Thermodynamics.

Those of you who follow this blog remember the big discussion we had when it was realized that the Greenhouse Effect cannot exist because it would violate the Second Law of Thermodynamics. Indeed, the 33 degree rise in temperature isn’t at all due to CO2 or any other gas in our atmosphere, but due to gravity and the resulting pressure.

Anyway, to those of you who cling to the notion that somehow one type of gas can magically “trap” heat, or that heat rays exist and can be reflected, I only offer one word of advice: Please go read about the Second Law of Thermodynamics, and realize that no gambler gambled his way to riches, and you have no more control over random processes than anyone else.

The Global Warming movement itself is petering out, due to a lack of funds and interest. But mostly because more and more scientists realize what a giant dupe it was, and what a terrible fraud and scam was pulled off in the name of science. It will be many, many years for climate science ever to be taken seriously again, and even then, I doubt humanity will ever forget about “Global Warming”.

In the end, the smart ones were the skeptics, who said that solutions to problems that involve the government are, except for rare exceptions, not the best solutions. You cannot overcome the laws of physics, nor can you establish scientific fact, with acts of congress or tax hikes and vast budgets.

By the way, you can’t focus the sun’s rays to make something hotter than the sun.

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18 Responses to “Second Law of Thermodynamics”

  1. tensor Says:

    Please rewrite your post, to resolve the following ambiguities:

    Gravity and Levity is one of those blogs where the posts are few and far between, but each post is a treasure. I am compelled to mention the latest post on the Second Law of Thermodynamics.

    The author of Gravity and Levity clearly states that a greenhouse effect exists, and he provides scientific and mathematical justification for his belief. Your citation of his blog, in a post wherein you deny the greenhouse effect, may mislead the reader to believe that the author of Gravity and Levity shares your disbelief. He clearly does not.

    Those of you who follow this blog remember the big discussion we had when it was realized that the Greenhouse Effect cannot exist because it would violate the Second Law of Thermodynamics. Indeed, the 33 degree rise in temperature isn’t at all due to CO2 or any other gas in our atmosphere, but due to gravity and the resulting pressure.

    Your passive construction allows the reader to believe that your interlocutors (demo kid and myself) agreed with you on something in that discussion. In fact, we strenuously disagreed with everything you asserted. Nothing was “realized”; you simply repeated the same errors at the end of the discussion that you had originally made at the outset, without convincing anyone else of anything — except your own self-imposed inability to learn.

    In particular, demo kid asked you a question you answered incorrectly. He asked if the rays of the sun could be reflected to create a volume hotter than the sun itself. You said it could not, and you are clearly still upset that your self-claimed expertise on this point was shown to be illusory. Hence your linking to a fallacious post which agrees with you.

    In reality, the situation is very simple. If one takes the amount of energy expressed by a body, and compresses it into a smaller volume, that smaller body will, by definition, have a greater energy density. If the energy in that body exists primarily as heat, then the temperature will increase. Anyone who has ever played with a magnifying glass in the sunlight can feel this. Your denial does not merely exist in the laws of physics; it extends to denying the evidence of your own senses.

    Again, please correct your post, to eliminate the possibility a reader could infer your agreement with persons who clearly and unambiguously disagree with you.

    • Jonathan Gardner Says:

      The author of G&L did not explain anything to refute my arguments. Physicists are allowed to make mistakes from time to time, especially when they are quoting other physicists who have made mistakes. It doesn’t make them any less wrong, however.

      I understand that you don’t agree with the basic laws of physics, and continue to believe that heat is something that can be trapped or stored, rather than a process.

      “Energy density” is a concept only useful for batteries and capacitors, which hardly applies to thermodynamics. Sure, you can calculate it, but to what end?

      How do you intend to compress the “energy expressed by a body”? (How does a body express energy anyway?) I assume you mean, compress the matter that has the energy, correct? After all, energy has no density, only matter does.

      In order to compress matter, you have to DO WORK. This is very clear because a FORCE is applied OVER A DISTANCE which is the very definition of WORK. (W = F*d) As you apply this work to the body, ITS ENERGY INCREASES. (E = total work applied to a system) Where does this energy go? THIS IS THE FUNDAMENTAL OF THERMODYNAMICS. Some of the energy may be spent through HEAT TRANSFER; Some in a change in pressure or temperature. Some may be spent in chemical changes in state or composition. However, no matter how the energy is applied, in no case can the Second Law of Thermodynamics be broken.

      So, OF COURSE, you can take something warmed by the sun and make it hotter than the sun—IF YOU APPLY WORK.

      Please, this is very, very basic physics. You are so wrong I worry that you cannot understand how wrong you are.

      However, in the so-called Greenhouse Effect, there is no external work on the CO2 in the atmosphere, nor is it doing any work on any other system, hence, you cannot change the fact that heat will not flow from cold to hot.

  2. demo kid Says:

    I’m beginning to wonder if you have a consistent problem with the concepts of “evidence” and “proof”… science doesn’t simply confirm all your beliefs at all times, which is apparently how you apply it.

    Yes, let’s look at Gravity and Levity, and at the comments there by CS which have not, as yet, been disproven in that thread and have paralleled previous comments I’ve made. In fact, he provides an interesting and genius example that I didn’t think of: take a gigantic field of solar collectors, and use that to power an arc welder to melt something at 8000 C. There is no other energy input, and no fuel burned. This is actually a demonstrable experiment, but by your bleating of “second law of thermodynamics”, it would not possible. Why?

    Simply put: solar radiation is delivered to the surface of the earth at a rate of about 1,000 W/m^2. Provide me with the temperature included in that value that would control the temperature of anything receiving that radiation.

    Similarly, your skepticism about greenhouse gasses is amusing, since experiments that have proven that gasses absorb IR have been around since the mid-19th century. The adiabatic lapse rate does create the profile of temperatures across different elevations, but it refers to a temperature gradient, and not transport of heat itself. (Note that adiabatic means “without heat transfer”.) The balance of radiation controls temperature, and GHGs in the atmosphere such as CO2 and water vapor directly influence IR radiation from the surface and atmosphere.

    I have no problems with scientific debate, but I do have a problem with your corruption of the scientific method. Apparently, in your version, you can merely cherry-pick data and facts to support the conclusion you came in with. Testing hypotheses must be easy!

    • Jonathan Gardner Says:

      I wish I knew to what comments you were referring to at Gravity and Levity. There is only one article which mentions Greenhouse Gasses, and it doesn’t even bring in the Second Law of Thermodynamics.

      Your examples are terrible. Really, they are. I don’t even know where to begin. Did you even refer to the article which I linked to? Do you understand what an ellipse does and what it means to have two focal points? Even if we concentrated all the energy output of the sun into a single point, that point cannot have a higher temperature than the surface of the sun for the very fact that that point would radiate energy. This is what happens, as the two bodies approach thermal equilibrium, the colder body begins transferring energy to the hotter body and that accounts for why the heat transfer slows down and eventually stops when the two bodies achieve equilibrium. That’s the very definition of temperature—that value of the property of which two bodies having the same quantity do not transfer heat to each other, but remain with the same value, and which a third body will also maintain a thermal equilibrium.

      In other words, and see if you can understand this, if I were to build a parabolic perfect mirror and place something–anything—at one focal point with the sun at the other, so that heat transferred is solely through radiation and only between those two bodies, then allow the sun and that other object to achieve thermal equilibrium so that the net energy transfer between the two is zero, and if I were to build a thermometer and measure the temperature of the sun, and then use the same to measure the temperature of the other body, simply by the definition of temperature and thermal equilibrium, I would find that they would be the same temperature. It would make no sense to have one hotter or colder than the other, since that would imply that they would not be in equilibrium with each other.

      I have yet to see anyone talk about how the CO2 molecules in the atmosphere transfers heat through any method other than radiative. See, these models do not look at the big, thermodynamic picture, neither do they consider other heat transfer methods outside of radiation, when other heat transfer methods are far, far more conductive. The very fact that the CO2 gas is intermixed with the other gasses in the atmosphere is completely ignored, as they have to imagine that CO2 molecules have no other method of heat transfer than radiative, as if there is a vacuum between it and other parts of the atmosphere.

      We know, for a fact, simply by measuring the thermal properties of gasses with more or less CO2, that the insulation of the gas barely changes at all, and that’s all that really matters. In fact, we know, for a fact, that the 33 degrees warming is caused only by gravity. A high-schooler can calculate what the warming should be due to gravity, and will find the number to correspond exactly with what is measured in reality. This COMPLETELY ELIMINATES any Greenhouse Effect, making such an effect, ultimately, 0.

      I know these points are lost on someone who doesn’t understand basic thermodynamics. When you can’t even think about what heat or temperature is, or when you talk about heat as if it is stored or some property of matter, rather than a process, or when you try to treat one form of heat transfer as if it is the only form of heat transfer, all of these things are completely absurd and typical of the mistakes that lay people make. I don’t think you’re stupid, which I know for a fact Global Warming believers think of the so-called “deniers”. I do think you are simply a little ignorant on the science of the matter. I also find that you are unwilling to simply go look up some basic things in physics, or to trust my interpretation of it.

      Yes, it is possible to concentrate energy THROUGH WORK and thus increase temperatures beyond what they would be WITHOUT WORK. The Second Law of Thermodynamics accounts for this, and exploiting this fact is why you can have refrigerators and heat pumps and arc welders, all powered by the heat of the sun. Yes, energy can be stored in the chemical state and makeup of the substances, which is also accounted for in thermodynamics. Why are you even bringing these things up? Do Greenhouse Gases perform work on the earth? If so, by what mechanism, and from whence is it drawing its power.

  3. tensor Says:

    “Energy density” is a concept only useful for batteries and capacitors, which hardly applies to thermodynamics. Sure, you can calculate it, but to what end?

    Because of demo kid’s example:

    … take a gigantic field of solar collectors, and use that to power an arc welder to melt something at 8000 C. There is no other energy input, and no fuel burned. This is actually a demonstrable experiment, but by your bleating of “second law of thermodynamics”, it would not possible. Why?

    With a large enough field of collectors, we can create and focus electricity into the small volume of the arc, and by increasing the energy density, create a (very small) volume which is hotter than the sun. That’s how we can use the energy of the sun alone to create something hotter than the sun.

    (And, my apologies for using “compress” as a synonym for “concentrate.” You wasted a lot of words on that.)

    • Jonathan Gardner Says:

      Have you considered that the energy so condensed or collected will also radiate? Or have you invented a one-way mirror, a Maxwell’s Daemon, a perpetual motion machine that transfers heat from cold to hot? (You do know that one-way mirrors work only because you can’t see the dark side due to the brightness of the bright side, right?)

  4. tensor Says:

    Have you considered that the energy so condensed or collected will also radiate?

    Of course it will. This is why the energy density is important. By delivering a lot of electrical energy into the small volume of the arc, and converting (almost) all of it to heat, we can raise the temperature of that small volume to beyond even that of the sun. The rate of radiative heat transfer away from the arc depends, in part, on the effective surface area of the arc; a compact arc will emit less heat than a larger arc at the same temperature. Therefore, a small, very hot arc can be created, and maintained, at whatever temperature our equipment will allow. This is all possible because the Laws of Thermodynamics do not limit the amount of electricity that can be turned into heat, nor the rate at which this conversion can occur.

    Or have you invented a one-way mirror, a Maxwell’s Daemon, a perpetual motion machine that transfers heat from cold to hot?

    None of the above. This is an arc-welder, powered by solar cells, via standard electrical transmission lines; all of it would be off-the-shelf industrial equipment. I don’t understand why you insist upon imagining it as something exotic. This is an engineering problem, and not really a difficult one, either.

    • Jonathan Gardner Says:

      Here’s how I know you don’t understand. You think that with an arc welder, there is no work being done but it’s all just simple thermodynamics.

      Do you understand how an arc welder works? Electrical forces are applied over a very small distance. These forces are so powerful that it heats the tip of the arc welder to a very high temperature. This is because work (= force * distance) is being done on the space between the tip of the arc welder and the object being welded.

      Thus, since energy is being added to the system through work, we can have a situation where heat flows from cold to hot, as the Second Law clearly demonstrates. Of course, the arc welder isn’t a system that extracts heat from hot to cold. It simply heats up the tip with a very powerful force. Whenever you have a powerful force doing powerful work, you’re spending a lot in energy and losing a lot to heat. If heat is the goal, then you can make your system as inefficient as you want, just like the arc welder that simply bulldozes its way through the resistance of the material being welded, depositing the vast amount of energy at that tiny point in the form of heat.

      Look, you’re fighting a losing battle. The Second Law is not an easy law to understand and apply, as Gravity and Levity explains. Even good scientists get caught in the trap from time to time. I admit that I have imagined machines and processes that also violate the Second Law. Any good physicist should have. But that doesn’t change the fact that you can’t violate that law, not in the micro and not in the macro.

  5. tensor Says:

    This is because work (= force * distance) is being done on the space between the tip of the arc welder and the object being welded.

    No, heat is being generated by the arc, and applied to the welded materials. The electrical energy (electrons in organized motion) is being transformed into heat energy (random motions of atoms). The Second Law allows all of the electrical energy to be transformed into heat energy. And if enough heat gets concentrated into a small volume, the temperature of that volume can exceed that of the sun, even though the energy originally came from the sun. The heat, combined with a gravity field (or other method of combining the welded materials) causes the welded materials to flow together, but that is an effect of the heat of the arc. The arc is doing no work on the welded materials.

    • Jonathan Gardner Says:

      Let’s be awfully, painfully clear with each other.

      Let me verify: Are you saying that the arc welder does no work on the metal being welded? If so, then either the force is zero or the distance is zero, or both. Which is it?

      Assuming you answer that there is no work being done on the metal by the arc welder, then I want you to think of the microscopic actions. There is a current flowing through the arc welder, to the tip, down to the metal, and then through the grounding wire, back to the arc welder. Since the circuit is not a superconductor, that means that there are voltage drops across any portion of the loop, except the part where the voltage is raised, likely through a transformer of some sort. This voltage drop represents work being done on that section of material, or if you prefer (thought not always correct), the electrons which move through that section. The electric field is applying a force to the electric particles in that section, but only the electrons actually move, which is your force and distance. If you disagree with any part of what I just wrote, please explicitly call it out. I can school you in electrodynamics until you die of boredom if you so desire. It was my favorite subject in Physics.

      If you have come to agree that work is being done on the metal, then we need to consider the energy transfer from the arc welder to the metal. Is the metal accelerating or decelerating? (No, the metal doesn’t move at all–no change in KE.) Is the metal being put at a higher potential energy, or does it remain in the same potential? (The same, so no change in potential energy.) Is the metal being transformed at all, in volume or pressure? (No, it remains the same.) Is the metal changing its plastic properties? (Yes, but not very much.) Is there a chemical change taking place? (Yes, but not very much.) Is there a change in temperature? (Yes, a lot, of which a lot of heat is being transferred to the environment as it cools.)

      The work being done on the metal isn’t considered, technically, “heat”. That is because it really isn’t the same process as when a hot thing transfers energy to a cold thing, or when a refrigerator transfers heat from a cold thing to a hot thing through the refrigeration cycle. It’s electrical work, the net result of which is an increase in temperature. You could, theoretically, create an arc welder that works at absolute zero, which can “heat” (using your definition) the object being welded to many, many times the heat of the sun, and yet remain at absolute zero. Is the arc welder “heating” the metal? Is this an example of cold heating hot, or something else entirely?

      You don’t call pounding on a rock with a sledgehammer “heat”, and you don’t call stirring a bowl of liquid “heat”, yet these two processes also cause the temperature to rise, slightly. In fact, every action, every tiny motion in the universe tends to increase the temperature of the object, and so everything could be considered “heat”. Now we have a word that means nothing because it means everything.

      You’re using layman’s terms, where heat is defined as “to increase the temperature”. This definition doesn’t work very well in describing what really happens. So “heat” has been redefined as “a process of energy transfer from a warm body to a cool body”. The net effect is usually the same—the temperature rises. But the process is more subtle than our childish, layman’s understanding of what happens. We certainly don’t say an arc welder “heats” the metal, at least not in strict terms.

      In fact, I can show you systems where heat transfer results in no change in temperature at all. Now the layman’s term “heat” makes no sense at all. Here we have the same action that normally causes objects to increase in temperature, working by the same mechanism and yet we see no rise in temperature at all! (Think: something else must change so that internal energy can increase—volume, pressure, chemical properties.)

      Unfortunately, you can’t count “heat” as energy, the same way you count KE and PE and other energies. It doesn’t work that way. You can find the component of the internal energy that is related to the temperature, and perhaps you might call that “heat”, but then a whole lot of things don’t make sense anymore, because objects with less “heat” (according to this definition) may be found to transfer heat to objects with more “heat”. So we can’t talk about heat like energy, because the model breaks down.

      So we’re left with this narrow definition, almost useless, for heat, to describe a very specific process whereby warm bodies cause cool bodies to increase in temperature or volume or pressure or whatever.

  6. tensor Says:

    Let me verify: Are you saying that the arc welder does no work on the metal being welded?

    Yes. The arc applies heat to the welded materials, not work. The materials flow together (“weld”) because of gravity, or external pressure, not applied by the arc.

    This voltage drop represents work being done on that section of material…

    No. The voltage drop (electrical potential) is being transformed into heat, in full accordance with the Laws of Thermodynamics.

    … or if you prefer (thought not always correct), the electrons which move through that section.

    The electrons do no work. Their energy becomes heat, in accordance with the Laws of Thermodynamics. Once the atoms in the welded materials gain random energy (heat) from the electrons, those atoms may move, and flow together, if there is a gravity field, or compression from a clamp, to drive them together. The heat generated by the arc does no work on the welded materials.

    The electric field is applying a force to the electric particles in that section, but only the electrons actually move, which is your force and distance.

    No, the organized energy of the electrons is transformed, in accordance with the Laws of Thermodynamics, into the heat energy of the molten atoms. The atoms then can move.

    No, the metal doesn’t move at all–no change in KE.

    The atoms in the metal, formerly held in place in their matrices, are liberated by the heat of the arc. Now, those atoms can move, and diffuse through each other’s matrices. This is the definition of hot welding.

    Is the metal being put at a higher potential energy, or does it remain in the same potential?

    The metal receives energy from the arc, and thus the metal atoms can now move. The atoms in the metal receive higher potential energy from the electrons, and now that potential energy can become kinetic energy of motion.

    You don’t call pounding on a rock with a sledgehammer “heat”, and you don’t call stirring a bowl of liquid “heat”, yet these two processes also cause the temperature to rise, slightly.

    Because the organized mechanical energy of the hammer, or stirrer, becomes the heat energy of the rock, or the liquid, in accordance with the Laws of Thermodynamics.

    In fact, I can show you systems where heat transfer results in no change in temperature at all.

    Please do.

    Consider three arc-welding machines, “S”, “T”, and “H”. One receives all of its’ electrical energy from a solar array, one receives all of its’ electrical energy from a coal-burning power plant, and one receives all of its’ electrical energy from a hydroelectric plant. Are you saying the temperature of arc “S” is limited by the temperature of the surface of the sun? Do the electrons which generate each arc somehow know their origin?

    Now, tie all three machines together, via a common electrical bus, which combines the electricity from the three sources, and distributes all three sources equally to each machine. Are all three arcs now limited by the temperature on the surface of the sun?

    • Jonathan Gardner Says:

      Yes. The arc applies heat to the welded materials, not work.

      OK, just to be clear, you are saying the electric force caused by the electric field and the resulting drop in electrical potential energy over the gap means there is no work being done?

      The voltage drop (electrical potential) is being transformed into heat, in full accordance with the Laws of Thermodynamics.

      Which laws?

      The atoms in the metal, formerly held in place in their matrices, are liberated by the heat of the arc. Now, those atoms can move, and diffuse through each other’s matrices. This is the definition of hot welding.

      What I was saying is the atoms themselves may move a little bit during the process, but the metal isn’t accelerating and flying out of the gap like a bullet. At the end of the process there is no change in kinetic energy, at least of the system as a whole. This is one of the tricky things about thermodynamics—being able to know when to stop thinking of particles and to start thinking of systems.

      Because the organized mechanical energy of the hammer, or stirrer, becomes the heat energy of the rock, or the liquid, in accordance with the Laws of Thermodynamics.

      Which laws?

      In fact, I can show you systems where heat transfer results in no change in temperature at all.

      Please do.

      Any process where the temperature doesn’t change. The energy from the heat transfer ends up as entropy, pressure, volume, or even chemical or state changes. A simple example would be a pot of boiling water. No matter how much heat you transfer to the pot, it will never rise above 212 F (until you run out of water.)

      I see we have a clear problem, a misunderstanding. You will do well to go back to physics 101, and review the definition of work and energy. These are not simple concepts, but it is critical that you have a clear understanding before you can start talking about what you can do with energy from the sun. Note that in all cases where energy from the sun was accumulated and then condensed so that it can create temperatures in excess of the sun, there was work being done by an external force. Thus, the Second Law wasn’t violated.

      Do you really feel comfortable arguing against the Second Law? It hasn’t earned a reputation for being a law by being based on questionable physics or theories.

  7. demo kid Says:

    I think you’re getting painfully confused — and I’m being painfully unclear — with the examples provided. I also think that your statement that “By the way, you can’t focus the sun’s rays to make something hotter than the sun” is still amusingly incorrect.

    First, I will happily state that the example of the arc welder requires work to function. However, so does ANY other attempt to “focus the sun’s rays”! Using a gigantic solar mirror, for example, will cause light pressure on the mirror itself. You need force to move the mirror in place, and you need force to keep it in place to focus the sun’s rays. Anything else, from the arc welder to the magnifying glass to a solar tower, will also require work. Therefore, your statement about how you cannot “focus the sun’s rays” is woefully incorrect.

    But this completely evades the point of your failure to understand science. And yes, it is a tricky concept, and I’ll admit that I cannot fully grasp all of the complexities without further study… but unlike you, my thinking about physics is not guided by my politics.

    The point of all of this argument is that radiation transfers heat. The Earth is not warmed by convection, despite all your claims to the contrary, and it does not “know” the temperature of the Sun. If we had a star that was much more radiant and much further away, or dimmer and closer, solar insolation would be the same. We would have a longer or shorter year, of course, but as long as it would stay around 1400 W/m2, there would be no difference.

    Also, gross heat transfer is not simply a matter of looking at the temperature of two bodies — it’s a matter of looking at their irradiance. When IR radiation is emitted from anything, the measure is of energy intensity, not of temperature, and that energy intensity has NO temperature attached. The heat of a candle does “warm” the Sun, but this is NOT part of the NET heat flow in the system, once all accounting of heat flows is finished. Still, “net” heat flow is not ALL heat flow. Until you explain the mechanism by which one object can “tell” what the temperature of something else might be at a distance, you’re continuously going in circles.

    And likewise, the concept that the adiabatic lapse rate is completely responsible for the temperature at the surface of the earth is absolutely ludicrous. “Adiabatic” means “without heat transfer”. If this were truly the mechanism for determining surface temperature, it would essentially mean that ALL warming would occur at some higher level in the atmosphere and be transferred downwards through convection alone. Given that most of the atmosphere is transparent to IR, and about half of the energy of the sun reaches the Earth’s surface, that’s pretty off the mark. It also would render albedo or the heat capacity of land cover pointless in calculations of surface temperature, which would be amusing for anyone in a city downtown during a hot day.

    The adiabatic lapse rate does determine the temperature profile of the earth, and the movement of air in adiabatic “packets” up and down through the atmosphere is the basis for atmospheric physics. However, your argument confuses the temperature profile of the earth and cooling of gasses due to decreasing pressure — a real phenomenon — with the mechanisms by which that heat is delivered to the earth in the first place.

    • Jonathan Gardner Says:

      I also think that your statement that “By the way, you can’t focus the sun’s rays to make something hotter than the sun” is still amusingly incorrect./blockquote>

      I can’t think of a way to do it. Can you?

      You’ve mentioned magnifying glasses. Why don’t you measure how much temperature change a magnifying glass can cause, and to what limit the temperature will rise? You will want to be sure the target is properly insulated, although with some work you can calculate how much heat is being transferred to the environment regardless of the source.

      I’ll do one better. Let’s suppose we build an ellipsoid with two focal points. This ellipsoid is perfectly polished so that none of the sun’s rays are absorbed and all of them are reflected. At one focal point we put the sun, and at the other some material—it doesn’t matter what. All the suns rays will focus on the other focal point. Now, if you follow this, and apply state of the art computational models to it, you will come to the same conclusions that physicists have discovered before calculators even existed: You can’t transfer heat from cold to warm.

      Now, if you add in work from an external source, then you can invent processes that have a net heat transfer from cold to hot, and this is why we can have refrigerators. But refrigerators can’t power themselves—they need external work in the form of electrical energy to function.

      I am offended that you think politics colors my physics. There really is no politics here.

      Also, gross heat transfer is not simply a matter of looking at the temperature of two bodies — it’s a matter of looking at their irradiance.

      Stop right there. That is not how you calculate heat transfer, nor is it how you measure it. The method of heat transfer is irrelevant. Considering only one method of heat transfer at the exclusion of others will get you the wrong answer. Besides, when talking about air (CO2) mixed with air (N2, O2, H2O, etc..) you must consider that convection and conduction play a much, much larger role than radiation.

      What I’ve just said has completely obliterated your arguments. You cannot continue your line of thinking unless you can explain why you need to only consider radiation when you admit you don’t understand the physics behind all of this.

      Your arguments about adiabatic lapse rate sound absurd to me, just as mine sound absurd to you. The reason why you have to consider the “adiabatic” (no heat transfer) is because the atmosphere reaches an equilibrium. If you were to apply a local heat source, there would be some heat transfer from the heat source to the atmosphere, but among the atmosphere itself, which conducts heat transfer through convection and conduction and to a tiny degree radiation, it would quickly reach an equilibrium, especially when you consider things on a global scale.

      Now, once you consider that the atmosphere has, more or less, stabilized in that no heat transfer is occurring between parts, then you can start talking about what temperature the atmosphere is at which elevations. (REMEMBER: HEAT != CHANGE IN TEMPERATURE.)

      Your last paragraph seems to contradict everything you just said, but I really don’t quite grasp what you are getting at. Are you agreeing with me? You do realize that heat can transfer by transmission of particles, that you do not need to consider systems as having constant mass?

      Bottom line, the reasons why you continue to believe in the Greenhouse Effect is because you do not understand the implications of the Second Law. That’s fine, but do not think that because you do not understand something it means you are not wrong.

      The math behind the Second Law is not simple. Physicists make mistakes when they think about things. It relies of the nature of random motions, which is very counter-intuitive. (Meaning, what you think is obviously correct is not, when it is closely examined.)

  8. tensor Says:

    The point of the arc-welder is to show that energy from the sun, and from the sun alone, can be concentrated to produce an arc with a higher temperature than the sun. Nothing in the laws of thermodynamics prevents this, and none of the comments here contain any attempt to show how said laws would so prevent it.

    Our theoretical arc-welder exists to make a point about the relationship between radiative heat transfer and temperature. Since radiative heat transfer is how (almost all) energy enters and leaves our climate, understanding this relationship is vital to understanding climate change.

    What happens to the heat of the arc, or what it does to the metal, are entirely beside the point. The arc is hotter than the sun, although created entirely from the radiated heat from the sun. Does this mean that “heat is flowing from cold to hot”? Yes. But the Second Law does not absolutely forbid this in all cases, it simply makes it unlikely in most circumstances. This example is not one of those circumstances. (Evaporative cooling is another example of heat flowing from cold to hot, without violating the Second Law.) Inherent to thermodynamics is probability (hence statistical thermodynamics) and the improbable can sometimes exist.

    As far as convective heat transfer in the atmosphere, of course it happens. Once a molecule of greenhouse gas has absorbed energy from the earth, via radiative heat transfer, it may indeed transfer that heat via convection, to another molecule of atmospheric gas. Thus, the heat stays in the atmosphere, so looking at convection becomes immaterial to the question of global warming. Heat can’t leave the atmosphere via convection, because the gravity of the earth prevents the atmospheric gasses from leaving with their heat.

    A simple example would be a pot of boiling water. No matter how much heat you transfer to the pot, it will never rise above 212 F (until you run out of water.)

    Only because the system boundary is open — the water can escape. If the water is in a pressure cooker, the temperature will rise until some of the water can escape, because boiling point depends upon pressure.

    But yes, you are correct. Melting ice has the same property, without the pressure requirement. The heat transferred into the ice goes into liberating the water molecules from their matrices (increasing entropy) without increasing temperature.

    It just goes to show that thermodynamics has some pretty odd special cases. Making absolute declarations is fraught with peril.

    • Jonathan Gardner Says:

      What you fail to understand, and what I must continue to repeat for you, is that WORK allows you to “violate” the Second Law. Or rather, the Second Law says heat flows from hot to cold WHEN NO WORK IS DONE.

      Your arc welder is doing work.

      You fail to understand what heat is because you say “heat stays in the atmosphere”. Heat is not a property, it is not a substance. It is a process of energy transfer from hot to cold bodies. It’s what happens when there is a temperature difference.

      Thermodynamics isn’t full of special cases, once you stop using the layman’s definition for heat and adopt a consistent definition that works for all system boundaries, even system boundaries where mass transfer occurs. Physics can and does make ABSOLUTE declarations about the physical properties and behaviors of matter regarding thermodynamics. As I point out “special cases” that your layman’s understanding cannot comprehend, your mental model of what is happening becomes broken, but the physical model, the one where heat is not a property or a substance but a process, does not.

  9. tensor Says:

    Your arc welder is doing work.

    Irrelevant, even if true. Even if the arc does no welding, it is hotter than the sun. The importance of the arc is that it is hotter than the sun, even thought the sun is the sole source of power for the arc. This demonstrates how we can direct the rays of the sun to create an entity hotter than the sun. Your failure to understand this renders you unable to understand other solar-powered entities, such as the earth’s climate.

    (BTW, did you notice that you’re claiming that heat is doing work, in a post titled The Second Law of Thermodynamics? Do you understand why this is so funny?)

    • Jonathan Gardner Says:

      The Second Law of Thermodynamics is that in the absence of external work entropy increases over time, meaning, temperature flows from cold to hot. Why is it irrelevant that work is being done by the arc welder, if the absence of work is central to the 2nd Law?

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