Talk:Heat/Archive 21

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Struggle around formal vs informal

The article struggles around formal vs informal as if it was a central issue, but it's not. My bet, I could be wrong, is that the goal is to justify the terminological approach that would be used later in the article. Worst than that, perhaps the goal is to do some propaganda for a terminological approach in the voice of Wikipedia, which is against WP:neutrality. If the goal is to explain what terminological approach will be used in the article, there is a neutral way to do that : the article has simply to identify the different approaches using references in a neutral manner, without claiming in the voice of Wikipedia that one is formal and the other is not, and then it just has to say which approach it uses. The two approaches are not compatible, because one approach insists to disallow the flexibility that is allowed by the other. Therefore, an editorial decision must necessarily be taken. It's not appropriate to take this decision silently or to hide it under a non neutral discussion of formal vs informal. Instead, the readers must be informed about that editorial decision. (Romer 2001) is a reference that claims that the strict approach (strict vs non strict is more neutral and descriptive than formal vs informal) is clearer. If it is used, the point of view must be attributed to Romer. Personally, I disagree and think the approach used by Weinberg, Feynman, etc. is perfectly clear. Yes, in this less strict approach, the term heat has different meanings in different contexts. Some times it means internal energy used in a transfer. Other times, it means the energy in transfer, but it's clear in the context. Being strict is not useful and only creates a struggle. But, I don't mind that the article uses the strict approach as long as it is introduced smoothly, not as if it was (in the view of Wikipedia) the only correct or formal way of doing clear science.

References concerning the struggle

Romer, Robert H. (2001). "Heat is not a noun" (PDF). American journal of physics. 69 (2).

Dominic Mayers (talk) 09:31, 9 October 2022 (UTC)

The clearest explanation I have been able to find is this from an engineering thermodynamics textbook in a section titled "4.12 Heat Modes of Energy Transport" as an introduction to the three heat transfer modes, conduction, convection, and radiation.

In the late 18th century, heat was thought to be a colorless, odorless, and weightless fluid, then called caloric. By the middle of the 19th century, it had been determined that heat was in fact not a fluid but rather it represented energy in transit. Unfortunately, many of the early heat-fluid technical terms survived and are still in use today. This is why we speak of heat transfer and heat flow, as though heat were something physical, but it is not. Because these conventions are so deeply ingrained in our technical culture, we use the phases heat transfer, heat transport, and the heat transport of energy interchangeably.

The section goes on to say that in the late 19th century heat transfer was defined as energy transport limited to that driven by temperature differences. Today it is defined as any transport that is neither work or mass flow.

More precisely, modern non-equilibrium thermodynamics defines heat transfer as just the transport of internal energy into or out of a system. With this definition, all other energy transport modes are automatically either work or mass flow modes.

This article should provide the correct technical definition along with an explanation of how this seeming inconsistency in language developed. We still speak as if caloric is real, flows from the sun, and flows between objects from hotter to colder, and that needs explaining why. But the lead is not the place to do this, since the lead should summarize everything in the article. It needs to be in an article section and mentioned briefly in the lead. StarryGrandma (talk) 18:52, 9 October 2022 (UTC)

References

Thank you for expressing this view, which I suspect is shared by a few, but is not universal enough to be stated in Wikipedia voice. The issue here is not that there are those who understand the need to wean ourselves off the old language and those who don't understand it. More neutrally, the issue is that there are those who feel a need to have a strict language and those who understand the history of heat and the fundamental concepts of thermodynamics as much as the others and yet do not feel this need. Any point of view regarding the superiority of one of these two terminological approaches over the other must be attributed if provided in the article, because there is no universal point of view here and Wikipedia cannot take side in his own voice for one view or the other. Moreover, because the strict approach is not compatible with the more flexible approach, an editorial decision must be taken and it has to be done in a transparent manner, because, otherwise, the readers will be left with the question which one of the two equally possible approaches is going to be used. Dominic Mayers (talk) 20:18, 9 October 2022 (UTC)

I am not quite sure what you mean by two equally possible approaches. The above is not one person's view, but gives both the technical definition and an explanation of why physicists and engineers still talk about heat as if it were a thing that flows from object to object. Both forms are often used at the same time by many authors, and the article can reflect this.

We also have to be very careful to be correct. The lead currently says "For example, Richard Feynman introduced heat with a physical description, the jiggling motion of atoms and molecules, with faster motion corresponding to increased temperature." He did not say it in this way, which might make a reader think, as an earlier revision to the lead said, that heat is only the jiggling motion of atoms and molecules. What he said, in the very first lecture of an introductory course in physics, was "Now the jiggling motion is what we represent as heat". In the same way we represent radiation from the sun as heat when we think about heat as something like caloric, flowing from body to body. This was not a lecture on thermodynamics, and he was introducing the atomic theory of matter, not heat, in this section. StarryGrandma (talk) 22:29, 9 October 2022 (UTC)

If your idea is that the history of the term heat should be discussed in the article, then I don't have anything against it, but it should be done in a history section and might not even need to be mentioned in the lead section. It is not much related to the current debate regarding how we should use the term heat in the article, because in that debate every editor and every source knows that heat is not a kind of substance. For example, it would be misleading to suggest that the expression "heat reservoir", used by Feynman, reflects that false understanding of the past. Instead, the issue that I see is that some editors insist that heat should only be used to refer to energy in transfer, never used as internal energy contained in a reservoir or a body, that is, they insist that it should never be used interchangeably with internal energy as if often done by many authors. This is one possible approach, but it is very strict. Yet, as long as some sources appear to apply this strict attitude, it can be used in the Wikipedia article. The other approach is simply to be more flexible and let the context determines how the term heat is used each time. This other approach has nothing to do with the false beliefs of the past. These are the two possible approaches that I am talking about. They are not compatible, because the strict approach excludes the other approach. Therefore, an editorial decision must be taken. This decision must be made explicit, simply because the readers need to be told in the most simple manner possible the approach used in the article. Dominic Mayers (talk) 00:32, 10 October 2022 (UTC)

The notion of this struggle only exists with people who probably do not appreciate the expansive history of the subject matter and only look at a few sources that on the surface seem to disagree with the definitions, out of context. Then they think they can write encyclopedia articles about it, or want to be judges about the neutrality of existing articles. No matter which point one takes, one can probably find bits and pieces in all kinds of source that contradict something. Citing these apparent contradictions and presenting them on equal footing is not neutrality. There is today no controversy about the understanding of the physics of thermodynamics. The language and history are the problem. Old historic references are nice, but only document the history, not the state of physics. It takes a great deal of experience of be fair to the truth. You cannot be neutral about statements, because that means you are setting aside the truth, if only for a moment. It is plain ridiculous to set aside today's understanding of science in the name of neutrality. For that you have to demonstrate that you have a better framework that explains it all. This will only be accepted by the community if you also demonstrate that you completely understand the current state and argue successfully against. kbrose (talk) 23:36, 12 October 2022 (UTC)

Of course, the discussion here does not reflect at all a controversy regarding the status of thermodynamics. I keep repeating this too. It's only a superficial terminological issue. The point is that good usage of the mathematical language allows different interpretations of a same term in different contexts. This is done all the times in mathematics. The human brain seems very comfortable with that. For some reason, some academic circle insists that "heat" should have the same meaning in all contexts. This has nothing to do with being rigorous. It's only being picky. Dominic Mayers (talk) 00:04, 13 October 2022 (UTC)

First sentence

The first sentence is currently: In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. Would it be correct to say this: In thermodynamics, heat is the transfer of temperature. It is a form of energy. If so, I would propose this as an order of magnitude easier to understand. It doesn't matter how technical the topic is: the first sentence should be much more accessible linguistically than it currently is. — Bilorv (talk) 21:04, 25 October 2022 (UTC)

I offered to help in RfCs on Science and Maths and was chosen at random to help here about a month ago and I usually try to be as thorough as possible when I help. If we look at textbooks on thermodynamics, the most common context is a heat engine. A heat engine gains energy in the form of heat, does work and loses energy also in the form of heat. Because energy is conserved, the difference $\Delta Q=Q_{in}-Q_{out}$ is also the sum $W+\Delta U$ of the work $W$ done and the added internal energy $\Delta U$ in the engine. In that context, the convention is that heat refers to energy received and emitted (excluding work) and the internal energy is not called heat. There is nothing very fundamental in that convention. The law itself is very fundamental, but what is called heat and what is called internal energy, etc. are just a superficial terminological convention. Sadly, this terminological convention conflicts with the normal usage of the term, because in the normal usage, we have no difficulty in thinking of heat as something in a hot body. Even Feynman, refers to heat informally as the energy in the jiggling molecules within the medium. Nevertheless, many academic textbooks seems to take that superficial terminological convention seriously. Therefore, if the first sentence must start with "In thermodynamics, heat is defined ...", it's hard to justify putting there a definition that is not the one typically used in thermodynamics textbooks. Yet, I agree with all those, the large majority, who say the first sentence of the lead should not conflict with the natural language. I conclude that the lead should not start with "In thermodynamics, heat is defined as ...". Instead, the text must simply explain in very simple terms the concepts using the language that is understood by a large audience. There is no need to insist in defining formally the term heat in the lead. Dominic Mayers (talk) 22:28, 25 October 2022 (UTC)

”Heat is the transfer of temperature”? No, definitely not. Consider boiling water - the water is at its boiling temperature and heat is being added to cause the water to boil away. A lot of heat is added but the temperature does not rise above the boiling temperature. Latent heat etc. Dolphin (t) 15:01, 26 October 2022 (UTC)

Still, it remains that the sentence is problematic because it conflicts with the natural language. There is a misunderstanding of what rigour means here. Rigours does not mean that we should introduce a definition out of context, which is exactly what the lead currently does. If the context of a thermodynamic system with heat reservoirs that take heat in and out of the system was given, one could simply describe the process using the term heat in respect of that "rigorous" definition without having to state that definition explicitly. Given the context, it would be a natural use of the term heat that does not conflict with the natural language. Out of context, it's completely different. It looks weird. Dominic Mayers (talk) 16:42, 26 October 2022 (UTC)

No, it does not conflict with "natural language" either. In the majority of usages, people don't describe that something actually contains heat, but that it is warming something, that one heats something. The common verb usage to heat makes it very clear and nobody has any conflict with that. People say heat it up, and extremely rarely add some heat to it., that something has heat. To emphasize, everyone understands that for heating something, you must have something that is hotter than the destination, a flame, an oven, whatever. People understand perfectly and intuitively that heat flows from hot to cold. So the statement is rather understandable to everyone in principle. Only the talk about thermodynamic systems is unfamiliar. The terms that imply that heat is contained somewhere often have some technical context that is far less common in "natural language". You also seem to indicate that this definition of heat is somehow not common or even wrong, when it is in fact one of the best, and most intuitive, and can be found in more textbooks than any other formulation of definition. I am not necessarily in support of the practice of many wikipedians to stuff a concise all-encompassing definition into the first sentence of the lede, as this has been the attempt here over time. This is probably the reason for recent formulations. Some people can't seem to think beyond the first paragraph of an article. Whatever is to be documented should first be written in the body. kbrose (talk) 22:14, 26 October 2022 (UTC)

@Kbrose: Let us try to agree. I wrote many times that heat as energy in transfer is natural. So, it was unnecessary to argue as you did. There is a big difference between using the term "heat" naturally with one of its natural meaning and insisting explicitly on a particular meaning with a sentence such as "In thermodynamics, heat is defined as <something that seems complicated>". The former would not be problematic at all. The latter is currently problematic. You are taking my sentence "it conflicts with the natural language" out of context: I did write many times that the issue is the big deal that we make about the terminology. This is where I see the conflict. If it is natural and part of the common language, as you seem to agree, then this special definition is weird. Note that the Merriam-Webster definitions of heat as a noun in physics includes physics : the energy associated with the random motions of the molecules, atoms, or smaller structural units of which matter is composed. as a second meaning. So, the definition given in the first sentence does conflict with that second meaning, but, again, that is not what I meant. I meant that there is undue weight given to terminological considerations in a tone that seems conflictual. There is even a complete paragraph about the formal vs. informal usage, as if this superficial terminological consideration was a fundamental concept. It is a shame that the readers will spent some effort to understand these two usages of the term heat and then have the impression that they understood a key concept. It's not. It's only a superficial terminological consideration. Dominic Mayers (talk) 00:15, 27 October 2022 (UTC)

The Merriam-Webster statement is not a definition, merely gives an idea or picture to relate to. The same could be relating to temperature. It is the mechanism of heat, thermal energy. Not a mode of storage. There is no exact definition of heat outside the physics context, other than that it is associated with something hot. That is not a definition. The statement in the article has indeed stood the test of time and is the only real definition that can be supported rigorously and that can be the foundation of an article. Try writing an article about your vague ideas of heat. kbrose (talk) 01:04, 27 October 2022 (UTC)

There are two potentially as much rigorous concepts here. The concept of the kinetic energy of the small components of a body and the concept of the energy transferred in or out of a thermodynamic system by other means than work. Depending on the context, heat can refer to one or the other. There is nothing in that except a superficial terminological convention. It's true that textbooks seems to favour the latter, but it is still a superficial convention that is not always respected, because it's very natural to pass from one to the other. The context makes it clear. And, on the contrary of what you say, it's not that one concept is more rigorous than the other. Also, again, please stop commenting on my person with things like Try writing an article about your vague ideas of heat. It's not nice to do that. Also, this sentence suggests that I am asking that the article does not adopt one convention. That is not the case. My concern, which is shared by many, is how we introduce that natural convention in the lead. I agree that it is a good and natural convention. The problem is how it is introduced. There is undue weight given to that terminological issue. This convention is, on the contrary, so natural, that we could avoid all that emphasis. As you say, we can use that convention and it will be natural for the readers. I don't know why, but somehow, it's important for you that there is a big deal about this choice of convention, but this emphasis on terminology is misleading. Dominic Mayers (talk) 01:24, 27 October 2022 (UTC)

Two paragraphs, including the longest one, more than half the lead, are about terminology, more specifically, about the convention that heat is energy in transfer. The lead should simply summarize what is said in the article using a natural language, without having to be formal regarding the definition that is used by convention. The problem is that some editors consider that the terminological convention that heat is energy in transfer is a concept in itself, but it's not. It's just a terminological convention. They even argue that it is a part of the first law of thermodynamics. It's not. We can state the law using that convention, but we could also state it using a different convention. It's a superficial convention. It's not a concept that deserves to be brought out explicitly. For example, if the article needs to state the law of conservation of energy in the context of thermodynamics, then it can use that convention. Just say that the heat, a form of energy, that goes into the system less the heat that comes out of it must equal the sum of the increase in internal energy and the work done by the system. There is no confusion possible between the internal energy and the heat transferred in that kind of statements. There is no need to be formal about this. The context makes it clear. We can also go into more details about what kind of microscopic process is behind the transfer of heat. That's a concept independent of a terminological convention. The lead and the article would be more useful and easier to read if it focused on the key concepts instead of superficial terminological conventions. As long as stating a terminological convention as if it was a key concept remains the goal of some editors, the article will remain problematic. Dominic Mayers (talk) 04:06, 27 October 2022 (UTC)

Lead

I would like to preface this stating that I am not at all knowledgeable in this area.

I participated in the RfC a while back and I think we failed to provide a clearer lead. This was part of the lead at the time of the RfC:

In thermodynamics, heat is energy in transfer to or from a thermodynamic system, by mechanisms other than thermodynamic work or transfer of matter (e.g. conduction, radiation, and friction). Like thermodynamic work, heat transfer involves the surroundings of a system, as well as the system itself, and so is not a property of the system alone, though it contributes to change in the system's internal energy, which is a property of the system alone. This is distinct from the ordinary language usage of the word 'heat' as a property of a system in itself.

Currently, the first two paragraphs of the lead look like this:

In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy. An example of formal vs. informal usage may be obtained from the right-hand photo, in which the metal bar is "conducting heat" from its hot end to its cold end, but if the metal bar is considered a thermodynamic system, then the energy flowing within the metal bar is called internal energy, not heat. The hot metal bar is also transferring heat to its surroundings, a correct statement for both the strict and loose meanings of heat. Another example of informal usage is the term heat content, used despite the fact that physics defines heat as energy transfer. More accurately, it is thermal energy that is contained in the system or body, as it is stored in the microscopic degrees of freedom of the modes of vibration.

I feel that we have created more confusion for the reader, because

• it kind of relies on an image being the way for a reader to understand the difference between the informal usage of heat and the formal one, which ignores MOS:ACCESSIBILITY issues among others,
• we are trying to fully explain the difference in the lead at all when the brunt of it should be explained in the body,
• "nevertheless" is very weird and confusing, because we require the reader to read more to understand how said nevertheless makes sense,
• usages of 'if' and other similar words that seek to define the process with arbitrary (and IMO unnecessary) constraints,

and more smaller style issues. I feel like we did not reach the RfC's stated goal of 'starting from ordinary language', and we did not keep it overtly technical, but it doesn't even seem like we mixed the two meaningfully. It feels like we mashed together suggestions until people got bored of the topic and moved on. I would propose rewriting the entire lead. I would not know where to begin. If there is anyone knowledgeable in this area at all, help is appreciated. I will start an RfC in a week's time if no one responds to this. Cessaune (talk) 03:59, 19 January 2023 (UTC)

RfC

I would like to preface this stating that I am not at all knowledgeable in this area.

I participated in the RfC on this page a while back and I think we failed to provide a clearer lead. This was part of the lead at the time of the RfC:

In thermodynamics, heat is energy in transfer to or from a thermodynamic system, by mechanisms other than thermodynamic work or transfer of matter (e.g. conduction, radiation, and friction). Like thermodynamic work, heat transfer involves the surroundings of a system, as well as the system itself, and so is not a property of the system alone, though it contributes to change in the system's internal energy, which is a property of the system alone. This is distinct from the ordinary language usage of the word 'heat' as a property of a system in itself.

Currently, the first two paragraphs of the lead look like this:

In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy. An example of formal vs. informal usage may be obtained from the right-hand photo, in which the metal bar is "conducting heat" from its hot end to its cold end, but if the metal bar is considered a thermodynamic system, then the energy flowing within the metal bar is called internal energy, not heat. The hot metal bar is also transferring heat to its surroundings, a correct statement for both the strict and loose meanings of heat. Another example of informal usage is the term heat content, used despite the fact that physics defines heat as energy transfer. More accurately, it is thermal energy that is contained in the system or body, as it is stored in the microscopic degrees of freedom of the modes of vibration.

After reading these, should the lead be rewritten, should we revert back to the old lead, or keep it as is? Cessaune [talk] 02:42, 26 January 2023 (UTC)

Voting

• Support as nom because I feel that we have created more confusion for the reader:

1. It kind of relies on an image being the way for a reader to understand the difference between the informal usage of heat and the formal one, which ignores MOS:ACCESSIBILITY issues among others,
2. we are trying to fully explain the difference in the lead at all when the brunt of it should be explained in the body,
3. "nevertheless" is very weird and confusing, because we require the reader to read more to understand how said nevertheless makes sense,
4. usages of 'if' and other similar words seem to seek to define the process with arbitrary (and IMO unnecessary) constraints,

and more smaller style issues. I feel like we did not reach the RfC's stated goal of 'starting from ordinary language', and we did not keep it overtly technical, but it doesn't even seem like we mixed the two meaningfully. . Cessaune [talk] 07:48, 26 January 2023 (UTC)

• Bad RfC Not enough context to immediately discern the essential details of the proposal. –LaundryPizza03 (dc̄) 09:33, 26 January 2023 (UTC)

  @LaundryPizza03, I rewrote the proposal. I have no idea how to write it any better. Cessaune [talk] 12:53, 26 January 2023 (UTC)

  @Cessaune: Please drop all of your opinions about the current state of the lead, as RfC's are required to be brief and neutral. Just ask if Paragraph X should be rewritten as Paragraph Y. –LaundryPizza03 (dc̄) 12:56, 26 January 2023 (UTC)

  I think it is a neutral statement now, but I'm not sure. Thanks for your help. Cessaune [talk] 13:07, 26 January 2023 (UTC)

• Bad RfC. There is no clear neutral statement of the desired change, and I've not found any prior discussion - see WP:RFCBEFORE. Thryduulf (talk) 12:08, 26 January 2023 (UTC)

  @Thryduulf, I'm very aware of RFCBEFORE. I didn't know how to go about it. No editors replied to my original attempt. Cessaune [talk] 12:51, 26 January 2023 (UTC)

• The first is a good, concise, precise lede. The second seems to have an axe to grind about informal definitions of heat. It's useful to go into that detail somewhere in the article, but it is undue weight as the lede. It would work fine as an additonal paragraph somewhere in the article. Sennalen (talk) 01:03, 14 February 2023 (UTC)

Discussion

This [1] is the lead way back in September 2022, the one I would like to revert to. Cessaune [talk] 13:14, 26 January 2023 (UTC)

Heat as energy in transfer presented as the universally accepted definition.

The current version of the lead starts with

In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy, and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy.

This is not neutral. It makes Wikipedia presents one terminological approach as being the correct one. Then it continues with "Nevertheless, ..." suggesting that there are some that do not use the correct definition. The correct approach would be to be neutral and simply attribute the approaches. Also, to help the readers, the most natural terminological approach should be presented first. The article can adhere to the stricter approach, but the readers should be informed in a transparent and simple manner. Dominic Mayers (talk) 21:35, 12 October 2022 (UTC) Dominic Mayers (talk) 21:35, 12 October 2022 (UTC)

References

This is indeed the correct one. The one most often cited as a definition. If you don't agree, than you should not way in, frankly. Encyclopedia Brittanica is also on this side. kbrose (talk) 22:07, 12 October 2022 (UTC)

The article should discuss both usages of heat, the formal and the informal, to appeal to a general audience. But it is an article of thermodynamics, or physics, and cannot start with the casual view that heat is stored somewhere. This directly contracts the first law of thermodynamics, which defines heat and work as process properties. Neither can be stored, both are converted into internal energy, which is the form that can be stored. Unfortunately the word heat is just as difficult to translate between languages and many text books suffer from this. It is such a descriptive word for something that deals with hotness. in any meaning. This indeed must be explained in the article. Dominic Meyers seems to dispute the clear thermodynamic requirement, by insisting on tagging only the version he disagrees with. The lede is not the place to argue this. Write a meaningful section in the body instead. I have tried to keep both usages alive in contrasting the controversy, but more is needed and it takes time to formulate sensible prose. This is not easy and frankly, I am not sure that I have ever seen a good attempt at that anywhere. Feynman's explanation are notable for scientists, sure, but he had a colorful style of relating physics principles to students, and in this he introduced methods that were impressionable, but not necessarily rigorous. Mentioning him in the lede is not helpful, WP has a different audience than Feynman. In any case, I can't see starting the article with anything than some form of the most accepted formal definition, that heat is like the verb form, to heat, meaning to introduce energy in to a system, like like work. The best method is to use the term thermal energy, and there are plenty of authors who do this, but by and large the term is also poorly recognized in physics, largely because physics already has the property temperature, and thermal energy is just a multiple of kT. Temperature is hotness as an intensive property, while thermal energy is hotness expressed extensively. It is is just a matter of systems of measure, note that temperature is expressed in some branches of physics in pure energy units. The article should keep things fairly simple. It has been grown into something completely unreadable, with details that are poorly constructed, in arcane language, and are just out of scope. This cannot be a comprehensive treatise, but a historical and technical overview. kbrose (talk) 22:02, 12 October 2022 (UTC)

And as for the bullying threads of 3RR, as you practiced, it is you who started this by tagging the article unduly for only your ideas about heat, without respecting even the references cited. I could tag you just the same. The statements had a reference, so tagging it with "according to whom"", is completely inappropriate. WP relies on references. kbrose (talk) 22:15, 12 October 2022 (UTC)

(edit conflict) @Kbrose: I am not bullying you. I am just informing you about a well known principle in Wikipedia, the 3RR rule, which is there for the benefit of every one. It applies here. I understand the situation more than you think. I suspect that there seems to have an agreement among many scholars, perhaps the majority of them in some academic circle, that the term heat should be used to mean energy in transfer, not energy within a body. It may even be that students failing to follow that definitions would lose points in an exam. In this perspective, which you have adopted, the use of "heat" to mean internal energy is considered "informal", but this is part of this particular view point. As part of this view point, you say that Feynman is impressionable, but not necessarily rigorous. This is clearly not neutral. Wikipedia cannot be guided by this non neutral view. You even say things like this "casual approach", directly contracts the first law of thermodynamics, but a terminological convention, which does not obviously change the underlying laws, cannot do that. You seem to miss the point that it is just a terminological issue and that every reliable source here, certainly Feynman, understands the same laws of thermodynamics as any other reliable source. Dominic Mayers (talk) 22:55, 12 October 2022 (UTC)

You blame my statement about Feynman for not being neutral, yet you insert your unqualified tagging, when even a reference is cited. That is even less neutral. Furthermore, my statement was not in an article, only my explanation. One cannot be neutral about Feynman's style, as he surely had a lot of fans and success, but to be neutral one would have to take a poll of many scientists to make a judgement, which is ridiculous and cannot be the goal of anything. Teaching makes a lot of compromises to get students one step further to better understanding, especially when such common language is involved. You want to be completely logical and neutral, perhaps a noble undertaking, but hardly the reality of life, science, religion, the human experience. The key is references that a reader can use to get a better picture. kbrose (talk) 23:11, 12 October 2022 (UTC)

I was not using "neutral" with its common meaning, but with its meaning in WP:NPOV, including the sections WP:IMPARTIAL and WP:SUBSTANTIATE. In particular, the idea that Feynman was not rigorous cannot be even suggested in Wikipedia's voice. Dominic Mayers (talk) 23:53, 12 October 2022 (UTC)

So now you have to redefine neutral too. This comment is rather unnecessary, as this notion never appeared in the article. It was my explanation of his style in my commentary. And I can do that as much as I want to make a point. OTOH, including his picturesque explanation in the lead was improper, partial, unsubstantial, or non-neutral, because it was taken out of context and misinterpreted, not reflecting the true intent of his explanations. Without checking the passage and context in the book, I suspect that he used the example to show that heat causes 'changes' in the vibrations, a change in temperature, and not just plain storage. kbrose (talk) 00:15, 13 October 2022 (UTC)

It's not me that "redefine" the term neutral. It's Wikipedia. Even the founder of WP acknowledged that. So, yes, neutral has a different meaning when we refer to WP policies and guidelines. It means that WP should not take position and only report what sources say, attributing the point of view to the source when needed, not that it should take a neutral position or that it should hide a point of view of a source because it is not neutral. It should not hide a non neutral view, if it is notable, but it should not state it in its own voice, as if it supported it. You are right that this is a rule for what is written in the article. I consider that the use of "Nervertheless, ..." in the lead is not neutral, because it suggests that the convention used by some should apply to others. The "nevertheless" had no place in the article. In fact, the idea that the convention stated in the first sentence "In thermodynamics, heat is defined as ..." is universal is also not neutral. There is a hierarchy of communities involved. There is the large community that is the audience of Wikipedia. Inside it, there is the scientific community that includes Weinberg, Feynmann, etc. who know very well thermodynamic. Inside it, there is a smaller community that specializes in thermodynamics and has its own convention concerning the term "heat". I am not sure what is this community exactly, but it has written books that explains this convention. Within that community, it's OK to say that it's not rigorous not to respect the convention, because there is a purpose to that convention. However, there is a large consensus that the article must not start by adopting the specialized convention of this smaller community. The first sentence does not respect that large consensus, because it states the convention of the smaller community as if it was the correct one. I do understand that within that community it's perfectly natural to consider that it is the correct one, but the article cannot start with that view point and then say "Nevertheless, others do not follow that view point, ..." That's not neutral. Keep in mind that there is nothing rigorous per se in that convention. It's just a terminological convention. Once it is adopted, it's not rigorous not to follow it, but outside that smaller community its perfectly fine not to respect that convention and thus give different meanings to heat in different contexts. Dominic Mayers (talk) 01:29, 13 October 2022 (UTC)

That is just a bunch of gobbledygook, paralysis by analysis. What community do you belong to? You'll never write a good article that way, especially in thermodynamics. kbrose (talk) 22:26, 13 October 2022 (UTC)

I am just giving names to what is acknowledged in the article. It says "In thermodynamics, the definition is that..." "Nevertheless, others (Feynman, etc.) do not respect that definition (I paraphrase here)". So, I am returning the question to you, what is meant by "In thermodynamics, ..." if it does not refer to a convention adopted by people? I am only being concrete : conventions are established by people. They don't arise magically from nowhere, from some absolute. Dominic Mayers (talk) 22:55, 13 October 2022 (UTC)

Frankly, I don't see anymore what this whole talk page chatter is really about. You seemed at one point to want to accommodate the common language use of heat, which is good. But are you a science refusenik now? The article is principally based on the common scientific approach based on the first law of thermodynamics, and its historical context. To cast a different view, you need to rigorously define all your terms in a different framework. There may be books out there that have tried, not sure whether successfully. Eventually you have to make compromises. How do you want to name Q when heat is something that is stored? kbrose (talk) 22:32, 12 October 2022 (UTC)

I see that at one point you wrote, With a little search effort, I found two books that are not picky about heat being never something within a body, but only a measure of an amount of energy transferred between bodies by other means than work or exchange of matters. Well, true. I don't recall ever having seen a work that was picky in every instance. It is very difficult, because too many common terms used in the sciences and technology of heat or hotness are deeply intrenched in understanding and practice. Essentially scientist don't mind, because their goals is not to redefine the world, but to present progress in the physics. High energy physicist have the luxury to create colorful names for new particles that have never been known or named before. Thermodynamicists have to relive history, and deal with it. No one is particularly picky, but everyone understands. As an outsider you have to understand too, and not mince the non-picky writings as disagreement with the basics. That seems to be your case. kbrose (talk) 22:55, 12 October 2022 (UTC)

I rather object to the policy of explication on what many would consider to be incorrect usage of the term “heat” in the expository body of the article. It could lead to confusion and misconception among the casual readers.

I suggest the article would be improved if you start with the commonly accepted modern definition and relegate alternatives to a separate section, including therein historical references when they can add clarity. 70.123.150.35 (talk) 17:15, 26 April 2023 (UTC)

THE UNIVERSAL, RIGOROUS DEFINITION OF HEAT ... that is not adopted by many

In some contexts in some books, heat appears to be internal energy or maybe the part of that energy that corresponds to the kinetic energy of the molecules. In other contexts, it is only energy in transfer. There is no lack of rigour in this, because it's perfectly fine to interpret a term differently in different contexts. In fact, there is a simple way to see this: heat is internal energy, but when it is used in a machine, part of it is doing work and that work cannot be called heat. So, part of that internal heat becomes work and another part is heat in transfer. Yet, many have decided to define heat as energy in transfer that is not work or transfer of matter and to be strict that it is not in anyway the internal energy. Though it is NOT universally adopted, I am not questioning the popularity of this terminological attitude in at the least an academic circle. It's a difficult situation to manage, because it's not a bad definition. Certainly, it's fine that the article adheres to that approach. The problem is that Wikipedia cannot say in its own voice that it is the universally adopted definition. The fact that this definition is not natural for a large audience makes thing worst. However, that's not the most difficult issue, because this could be managed by saying "In the scientific language, in contrast with the common language, heat means..." and nobody would complain, at the least, I would not complain. However, it's not true, because many excellent scientific books, even a recent one by Nobel laureate Steven Weinberg, are not so strict about the use of the term heat. Even if was a good idea to be strict about the term heat, Wikipedia cannot be a platform to claim that it's the UNIVERSAL RIGOROUS DEFINITION OF HEAT as claimed in this recent edit. Dominic Mayers (talk) 04:47, 14 October 2022 (UTC)

Steven Weinberg has no different view or definition of heat as any other physicist. You are completely outside your understanding of this matter. I doubt you understand his writings when only picking out words or phrases. He uses the exact same language that has been common in thermodynamics all along. Terms like heat reservoir, which to the laymen perhaps indicate that heat is contained in such a device, are commonly accepted. They do NOT define heat. A heat reservoir is only a potential SOURCE of heat, because of its large heat capacity (also called specific heat, historically) another one of these historical terms that few care to redefine. Call it a thermal energy bath or reservoir. The geoscientists do prefer the term thermal energy. Show me a passage in Weinberg's text that defines heat as anything else as defined UNIVERSALLY, RIGOROUSLY by the first law of thermodynamics. The connection to the kinetic energy of molecules is only because this is the mechanism by which heat is carried, but not stored. When it is 'stored' it is thermal/kinetic energy and even then it is constantly consumed and converted into potential energy and vice versa. Heat is never internal energy, that contradicts the definitions of the first law of thermodynamics, but it can be converted into internal energy, an important distinction. kbrose (talk) 20:12, 14 October 2022 (UTC)

(Edit conflict: I have not read the next comment). You are confusing terminological conventions with concepts. I agree with all the concepts that you mentioned and, of course, Weinberg, Feynman, etc. express these same concepts. For example, there is a flow between the different forms of internal energy, this is the equipartition theorem, but this can be understood with or without the strict convention that the term heat is never used to mean energy within a body. It has nothing to do with this strict convention. It's indeed easy to translate the language of Weinberg, Feynman, etc in terms of this strict convention. For example, you do that when you insist that "heat reservoir" does not mean that the reservoir contains heat. Indeed, it works. This is why I wrote very early that Weinberg, Feynman, etc. would not consider that this terminological issue is important. What makes no sense is that the lead focuses on that terminological distinction. It has even a paragraph entirely dedicated to that distinction. If the article is to express explicitly a strict convention that the term heat never refers to the energy within the body, as if was a rigorous universal definition, to follow Wikipedia's rules, it must be attributed to sources that have presented the same claim, but it must be done in a very simple and neutral manner, without suggesting that others misunderstand or are less rigorous or less formal, etc. Wikipedia itself must stay out of this. Also, if there are arguments to support this strict convention, they must also be attributed to sources. The lead does not seem the appropriate place to present these arguments, but it can be discussed in the body of the article. The problem is that the lead makes a big deal about what is only a terminological convention. Yes, I make a big deal about the fact that the lead makes a big deal about it, but that is justified. Concretely, I am going to add again the tags {{According to whom}}, because we are in serious need of external opinions about this issue. Do not remove them, because otherwise I will seriously consider reporting your attitude to administrators. Dominic Mayers (talk) 21:49, 14 October 2022 (UTC)

You will be reverted. Do not even attempt such nonsense. The current definition is the universally accepted definition, and you have no sources that contradict this DEFINITION. Your attempts here are ludicrous. You do not understand the equipartition theorem. There is no flow of energy in that; this is not the view of physicists. You must stay out of the correct representation of science, not Wikipedia. kbrose (talk) 23:44, 14 October 2022 (UTC)

Your criticism of the term "flow" is a diversion from the real issue. You are trying to discredit the person instead of addressing the arguments. Stop focusing on the person. It's not the first time that you do that. You also wrote That is just a bunch of gobbledygook, paralysis by analysis. ... You'll never write a good article that way, especially in thermodynamics. Please focus on what is said about the article, the sources or mention the Wikipedia guidelines and policies when needed. I am doing that now: I don't need to find a source that contradicts a content such as "A thermodynamic system does not contain heat..." to exclude it. It's the person who wants to include a content that must provide the source that says it. On top of this, because the content is controversial, as clearly seen in the RfC, it should be attributed. It cannot be stated in Wikipedia's voice. You will perhaps continue to attack me personally instead of discussing in a nice and respectful manner, but this cannot continue for ever. Dominic Mayers (talk) 01:24, 15 October 2022 (UTC)

There have been so many misconceptions expressed on this entire page (for years) that it is hard labor to combat this. But it is really simple, because every introductory course in thermodynamics gets it RIGHT. The whole debate about is heat energy or is it energy in transit is meaningless to a degree. Heat is a form of energy, it just happens that it is DEFINED as energy in transit. and the issue whether it is flowing/in transit or not is complete irrelevant as to the issue of energy. A stationary mass is energy too, and whether the mass is in motion, or flowing as gas or liquid does not change that. They are all forms of energy. The first law of thermodynamics expresses that the total energy of all forms in the universe is constant, including the potential energy as in the mass of matter or the kinetic energy of galaxies colliding, or radiation streaming through the cosmos. For a single smaller thermodynamic system that has a neighboring environment, the law states that its change in internal energy is the sum of heat introduced less the work performed, or express it as a sum of heat and work (with a different sign convention for the work). The two sides of the equation, delta U = Q + W, cannot be different physical phenomena. They must all be energy. You can't add volume or entropy, for example, to a pool of energy. The definition of heat therefore is Q = delta U – W. The internal energy U is an energy, therefore Q must be energy too. Whether it is flowing is irrelevant. Heat is a form of energy. And this is what Weinberg confirmed was the result of recognition when caloric theory was discredited. It was not some kind of invisible fluid permeating space and matter. His statements are nothing more than that. Don't create crazy controversies here. kbrose (talk) 21:18, 14 October 2022 (UTC)

To be honest, I learned something here. To be very honest, what I learned was not important at all. What I learned is that, indeed, when a process involves both internal energy and thermal energy in transfer in and out of the system, it makes sense not to call the internal energy of the system "heat", because we want different terms for the internal energy and the thermal energy in transfer. Now, that I think about this, I see that it is indeed a convenient terminological convention. But, there is no fundamental concepts in this. It's a technical convention that will naturally be adopted when needed. We do not want to bother ourselves with that convention when it's not needed to introduce the notion in the lead. There is undue weight on a technical terminological convention in the lead. Dominic Mayers (talk) 08:04, 15 October 2022 (UTC) Dominic Mayers (talk) 08:04, 15 October 2022 (UTC)

RfC about the title or general approach of this article

Should this article be basically on thermodynamics or basically start from ordinary language?Chjoaygame (talk) 04:46, 26 September 2022 (UTC)

Discussions Rfc 02BF554

It's not clear to say there are two subjects that are the same

The problem when we say or imply there are two subjects that are the same is that we don't know what is the other subject beside heat as a thermodynamic concept? There is no second article to merge here. So, it's not clear what is being proposed by this claim? Is it proposed to cover movies in which heat is an important phenomena, the climate change problem, etc. ? Dominic Mayers (talk) 20:48, 30 September 2022 (UTC)

Survey Rfc 02BF554

• Comment I used to think that every article on Wikipedia should be almost entirely accessible in ordinary language. Then I found out that the Simple English Wikipedia exists. What a wonderful project! Have the participants in this disagreement/discusson considered heading over to Simple:Heat and working on it as a companion article to this one? It needs more simplification. Darkfrog24 (talk) 18:58, 26 September 2022 (UTC)
• Disagree with the premise I see no difference between the options nor do I see that the choices of approach are even separable. The ordinary language of heat is consistent with the thermodynamic explanation of heat. That is 'heat' has the same meaning in rigorous thermodynamics as in vernacular speech (with a few unusual edge cases and quirks of language). The common understanding of something being hot can only be experienced directly through heat (energy transfer). That is what we mean in the vernacular. Without heat we can not and will not directly experience the thermal energy contained therein. If you touch something that is hot it will burn you by the process of transferring energy i.e. heat. We even understand heat to be distinct from thermal energy in our most intuitive human experiences. On a warm summer day wearing shorts, given the choice between a metal bench and a wooden bench, we know which will be hotter even though they are the same temperature. It is heat that we experience not temperature and not thermal energy. Thus, the article should address the subject of heat (full stop). Addition of more accessible or introductory language, or even vernacular usage, or even quirks of the english language, may be helpful; however, the phenomenon should not be addressed from a factually incorrect perspective. The recently reverted language "Heat is a form of energy..." is simply factually incorrect by both our modern scientific understanding and the conceptual understanding of the human experience in the broader philosophical sense. By the way this exact same debate has been had on this very page before (now archived) and I am conveying basically the consensus opinion of these prior debates. Nick Y. (talk) 21:46, 26 September 2022 (UTC)

  Nick Y.'s comment is sound, logical, and reasonable.

  There remains a slight hitch, the cause of the present RfC. Some readers and Wikipedia editors, especially those who have not studied the history and logic of thermodynamics, will not immediately see the soundness, logic, and reasonableness of his comment. They will be inclined to see 'heat' as Laplace and Lavoisier saw it, or in some other way, not clearly distinguishing between heat and internal energy. The present RfC has examples of that. I think that ordinary language, as distinct from rigorously logical language, does allow some latitude for that. In the historical emergence of thermodynamics, it was a struggle to establish the distinction between internal energy and heat. Even now, the terms 'latent heat' and 'sensible heat', as applied to evaporation, are not too clear, because evaporation might be viewed as a form of matter transfer.

  To deal with this, I think, a past suggestion might be reconsidered: to change the title of the article to Heat (thermodynamics). A long-standing half measure to that end, starting the lead of article with the phrase 'In thermodynamics', has just been undone by Editor VQuaker, I suppose because he sees it as clumsy; yes, it is a bit clumsy. Changing the title to 'Heat (thermodynamics)' would deal with that, and perhaps with Nick Y.'s comment "the article should address the subject of heat (full stop)"?Chjoaygame (talk) 02:25, 29 September 2022 (UTC)

  No. VQuakr (talk) 02:43, 29 September 2022 (UTC)

• Yes, according to WP:TECHNICAL. Here's my proposed first sentence (which does nothing to fix the problems I have with it but is a little more concise): Heat is energy in transfer to or from a thermodynamic system, as distinct from thermodynamic work or matter transfer.
  Heat is too generic of a word for this article to start out so technical. I would compare this article in technicality to something like the derivative article, which is not an ordinary topic of conversation in the way that heat is. Heat, as it is one of the most important considerations in day-to-day life, and as such, is going to be searched up by many thousands of different, average people, requires something a bit more approachable, like real-world examples and not only stuff like friction due to isochoric mechanical or electrical or magnetic or gravitational work done by the surroundings on the system of interest. Of course, this article's always going to be technical, but it should start out calmer so us average Joes can claim our info and skedaddle. Cessaune (talk) 05:42, 27 September 2022 (UTC)

  I do not see that your proposed first sentence is substantially more accessible or less technical. It might be a little more clear, mostly due to sentence construction and not starting with a dependent clause. I would encourage concise language that lends a more accessible and intuitive understanding but it must be rigorously accurate. An explanation of the relationship between our modern rigorous understanding and our intuitive experiences may be helpful to both lay and technical students. If in the introduction it should be very concise. However, I see the value of a concise statement such as: "In common language heat refers to the sensation of warmth as generally perceived through the transfer of thermal energy from one body to another." However, from a technical perspective all this is really doing is saying that humans can sense the process described. There already is some of this type of language within the article. Of course there is always opportunity for improvement. Nick Y. (talk) 16:39, 27 September 2022 (UTC)

  Reply to Cessaune:
  Cessaune proposes "Heat is energy in transfer to or from a thermodynamic system, as distinct from thermodynamic work or matter transfer" instead of 'Heat is energy in transfer to or from a thermodynamic system, by mechanisms other than thermodynamic work or transfer of matter (e.g. conduction, radiation, and friction).' The words 'other than' exhaustively cover all other than, and focus on mechanism, while the words 'as distinct from' are vague on those important points.Chjoaygame (talk) 17:26, 29 September 2022 (UTC)

  Not to disagree, but - "it should start out calmer so us average Joes can claim our info and skedaddle" - what sort of info do you expect an "average Joe" would avail of that is 1. not scientifically dense, and 2. not immediately obvious to someone familiar with the general concept of heat? I can't think of any. WPscatter ^t/_c 05:08, 3 October 2022 (UTC)

• They are the same thing. All articles should start one "level down" in complexity in the lead and then get into more detail in the body. BTW the first sentence starting with "In thermodynamics" isn't great and should be reworked. VQuakr (talk) 17:01, 27 September 2022 (UTC)
• Wikipedia often struggles with this issue, often with well deserved criticism that our articles often end up incomprehensible aimed at the highest possible technical level. Heat is such a basic every-day concept that at least part of the article needs to be readable by the general public. The article Simple:Heat is short, and does a better job for the non-technical reader. I would suggest we can steal much of that as at least part of the lead section and perhaps a first section of the article. Just be sure to link to the source-revision in the edit summary, for mandatory copyright attribution. In fact I might even just copy-paste the Simple:Heat article above the current lead, save it, and five seconds later paste and save a prepared first draft attempting merging the two into a coherent article. That way other editors can look at that first revision when considering&discussing how to best implement and improve the merging.
  There was a suggestion above about renaming this article Heat (thermodynamics). That is only appropriate if another Heat article is created first, or at the same time. I am neutral on that idea, but it might be interesting if someone thinks they can reasonably distinguish this as two separate topics. Alsee (talk) 05:55, 29 September 2022 (UTC)
• I agree with PaulT2022 that there is no need to imply a contradiction between heat being energy in transfer and heat being internal energy. Yes, most authors if not all authors when they describe a process that involves both the internal energy of the system and this energy in transfer in and out of the system do not refer to the internal energy as "heat", because its clearer to use different terms for these two distinct quantities of energy. But, it's only a convenient terminological convention useful in a technical context. There is no deep concepts in this. For example, Feynman, as do many authors, does not call the variation in internal energy $\Delta U$ "heat" when he describes the law of conservation of energy $\Delta U=\Delta Q+\Delta W$. Yet, he would not make a big deal about this when he introduces heat. He would say that heat is the energy in the jiggling atoms of the systems. Dominic Mayers (talk) 06:31, 15 October 2022 (UTC)
• I generally object to disambiguating "heat(thermodynamics)" from "heat". No, these are not distinct subjects. Yes, the article can be improved.Nick Y. (talk) 20:35, 30 September 2022 (UTC)

  @Nick Y.: see my discussion point. Dominic Mayers (talk) 20:53, 30 September 2022 (UTC)

• Start from ordinary language and then explain with thermodynamics. Emir of Wikipedia (talk) 13:19, 9 October 2022 (UTC)
• The article should be about use of the term in modern physics; however, lead should describe colloquial use of the term early on, before it gets into technical details, and without unnecessarily implying contradiction (as there's none: heat received by an object and heat stored as internal energy is the same energy). The lead can be improved by removing A thermodynamic system does not contain heat. Nevertheless, so that a link to Thermal energy (or another article describing heat in a dictionary sense of temperature/internal energy) is more prominent, possibly can be added to the disambiguation hatnote as well. The paragraph starting An example of formal vs. informal usage is excessively detailed and can be removed from lead to the History section per MOS:LEADREL. PaulT2022 (talk) 03:37, 15 October 2022 (UTC)

In the record, the wording of 'formal' versus 'informal' was introduced on 8 Oct 2022 by an anonymous IP editor at this edit: https://en.wikipedia.org/w/index.php?title=Heat&diff=next&oldid=1114283454 Chjoaygame (talk) 02:10, 22 June 2023 (UTC)

• I am in favour of extending the name of this article to Heat (thermodynamics) and retaining its scientific & engineering rigour. We don’t say “energy flows”, but heat flows, as does electric current, but heat and electric current are not energy which is why I don’t append the word “energy” as I do with genuine forms of energy such as mechanical energy and internal energy. Similarly, work is not energy even though it is a mechanism for conservation of energy by causing total energy to be reduced in one location and increased in another. We say “heat is generated by combustion and friction” but we also say “energy cannot be generated or created”. If someone wants to start another page about the everyday meaning of heat I won’t object, although be careful because Wikipedia isn’t a dictionary. Dolphin (t) 00:54, 16 October 2022 (UTC)

  Analyzing the differences between the concept of heat (transfer) and internal energy is interesting and I am tempted to discuss it, but that would only create more confusion. The issue here has not much to do with the concepts themselves. No new definition or concept is involved in the current issue. The issue is only what terms should be used to refer to these existing concepts. What you suggest here is that the concept of heat transfer is very different from the concept of internal energy. It's not clear to me how much they are different. Of course, they are different quantities : one is determined by the state of the system whereas the other depends on the transfer process. But, they are both given in unit of energy and one is the source or the target of the other. The point here is that, how much they are different is not that important to explain the issue, because it's a terminological issue that remains essentially the same: what terms do we use to refer to these different concepts. It's very superficial. Only a choice of terminology. Undue weight is definitively given to this terminological consideration. Dominic Mayers (talk) 01:58, 16 October 2022 (UTC)

  It's not that heat as energy in transfer is not natural. It's perfectly natural, but heat as internal energy is also natural. There is no need to make a big deal about this, as if it was fundamental. It's not. It's only a choice of terminology. We can use sentences that suggest that heat is internal energy and never explicitly insist that heat cannot be internal energy, while adopting that strict convention when needed. There is no fight here against this convention, only a fight against making it explicit when it's not needed, thus putting undue weight on it. Dominic Mayers (talk) 09:50, 20 October 2022 (UTC)

Heat as entropy

There is a paragraph in the article that states: "Today's narrow definition of heat in physics contrasts with its use in common language, in some engineering disciplines, and in the historical scientific development of thermodynamics in the caloric theory. The terminology of heat in these instances may be replaced accurately with entropy." This is backed up by a citation to a textbook by Hans U. Fuchs. However, this textbook is associated with the Karlsruhe Physics Course (de:Karlsruher Physikkurs), a somewhat controversial pedagogical program that renames some thermodynamical terms, and emphasizes the flow of entropy. I think this claim that common notion of heat can often be replaced by entropy should be backed up by mainstream sources. In case that is not possible, it should be removed. Jähmefyysikko (talk) 06:27, 21 June 2023 (UTC)

It may perhaps be possible to find 'mainstream sources' that seem to back up the claim that "The terminology of heat in these instances may be replaced accurately with entropy." In thermodynamics, almost anything can be found in 'mainstream sources', there are so many of them with such variety. I think that merely finding a 'mainstream source' for it, or several, is not sufficient reason to put it unqualified in the article as a reliably sourced proposition. On such a venerable topic as heat in thermodynamics, Wikipedia editors need to use experience and judgement in picking the mainstream, based on a wide reading of reliable sources. I think it unwise to try to represent every shade of opinion. I favour going for the best mainstream thinking.

Some writers distinguish the French terms chaleur and calorique. For example, Stephen Brush, discussing Carnot, writes in a footnote:

Since Carnot did later abandon the caloric theory, it has sometimes been suggested that Carnot's discussion in the Reflexions should be considered as a "correct" modern thermodynamic analysis, by reinterpreting his term "calorique" as "entropy." I think T. S. Kuhn has effectively disposed of this suggestion by showing that whatever pedagogical value it may now have, this reinterpretation has no basis whatsoever in Carnot's own exposition of his theory, and can only confuse our historical understanding of the subject. Am. J. Phys. 23, 91, 387 (1955).

That relates closely to the claim presently under discussion.

I think that Editor Jähmefyysikko is right to remark that Fuchs' textbook is associated with a controversial pedagogical program. I think that if Wikipedia wishes to cite such a program, it should be done with clear indications of its controversiality, as distinct from mainstream orthodoxy.

Orthodox thermodynamics, perhaps mainly following Gibbs, uses two cardinal characteristic representations, the 'energy representation' $U=U(S,V,\{N_{j}\})$ and the 'entropy representation' $S=S(U,V,\{N_{j}\}).$ I think that putting the viewpoint of Fuchs as if it were mainstream tends to confuse. Usually, in contrast to the Fuchs viewpoint, that of Clausius is followed, in which an infinitesimal quantity of heat transferred is often enough shown in some way such as ${\text{đ}}q=T\ {\text{d}}S.$ This distinguishes 'heat' from 'entropy'.Chjoaygame (talk) 08:55, 21 June 2023 (UTC)

The comment in question does not belong in the History section.Chjoaygame (talk) 01:29, 22 June 2023 (UTC)

Removed it. Jähmefyysikko (talk) 04:13, 22 June 2023 (UTC)

Revised lead

I just note my change here because there is a really nasty debate above me.

Old first paragraph:

In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy.

New first paragraph:

In thermodynamics, heat is the thermal energy transferred between systems due to a temperature difference. In colloquial use, heat sometimes refers to thermal energy itself.

I am not an expert in thermodynamics, so any comment on my rewrite is appreciated. Pinging User:Bilorv, User:Dominic Mayers, User:Kbrose, and User:Cessaune per above. CactiStaccingCrane (talk) 16:09, 1 June 2023 (UTC)

It was not a good idea to create an article only for the notion of heat transfer in thermodynamic. Of course, in that context, the term "heat" refers to transfer of energy. This shocks people because the term "heat" is often used differently, even in scientific contexts. The solution is to be less dogmatic. There is no need to make a big deal about the different allowed usages of the terms nor to emphasis a particular usage of the term. It is sufficient to naturally use the term to refer to energy transfer. People will understand perfectly with all the rigour needed and there will be no confrontation with other natural usages of the term. This requires a complete change of attitude where we worry less about defining a term, but convey the concepts instead. For example, we can say, when we give give a formula that $Q$ is the heat transferred, but the focus is on the concept, on the law, not on a general definition of the term "heat" in thermodynamic. Dominic Mayers (talk) 18:43, 1 June 2023 (UTC)

I think it's a good thing as well. CactiStaccingCrane (talk) 01:59, 2 June 2023 (UTC)

So, hopefully someone will find the time to remove all the unnecessary emphasis on definitions and just naturally explain the concept of heat transfer in thermodynamics. It's not easy, because one needs to take a different attitude that focalizes less on definition and more on what are the laws, the concepts, that the readers need to learn. A definition by itself is not interesting, especially if it shocks the readers. Dominic Mayers (talk) 02:59, 2 June 2023 (UTC)

When it comes to these concepts, definitions *are* the crux of correct descriptions in the respective disciplines. For example, even the term heat transfer is not a common term of physicists or in thermodynamics as a pure science, it is mostly a term of thermal engineering. In the scientific context it is just heat, because it already implies transfer. While some notable teaching physicists have used the term heat energy, it also is not commonly accepted language, because experts know that heat is always energy and nothing else. Perhaps some have used it in context of contrasting with other types of energy. Even the novice and casual use of heat is rarely accompanied with energy. So the idea that the laws of thermodynamics can be explained with casual language in a precise manner, is an illusion, and the notion that people will understand perfectly is nothing by subjective POV blubber, and not borne of the experience of teaching thermodynamics. When we cite Q as heat, it needs to be very clear what that means. kbrose (talk) 18:16, 2 June 2023 (UTC)

Just above is an example of someone who claims to be an expert in writing encyclopedic articles only because he teaches the subject and says that what others say is only subjective POV blubber, and not born of the experience of teaching. He forgets that the audience here are not his students. I maintain my common sense point. There is nothing non rigorous in explaining the meaning of a quantity $Q$, called heat, in the context of the laws that are introduced. Also, I am not saying that it's a bad idea to always use the term heat in a way that is consistent with the use of the term in these laws. But, we can do all these things, without making a big deal about terminology in the lead. We can mention at some point in the article that we use the term heat only with a given meaning, if we think it can help. It's not clear to me that it will help that much, but that is not what I discuss here. I say that it's weird to make a big deal about this in the lead. It makes the subject seem superficial. Dominic Mayers (talk) 02:55, 22 June 2023 (UTC)

I would recommend changing "heat is the thermal energy transferred between systems..." to "heat is the transfer of thermal energy between systems...".

This would emphasize that heat is a process (the transfer of energy) rather than implying that heat is a type of energy that resides within a system. Curiousdashpot (talk) 15:49, 28 February 2024 (UTC)

Semi-protected edit request on 20 May 2024

Delete or change ext broken link

http://www.ing.unibs.it/~beretta/www.EliasGyftopoulos.org/EPGyftopoulos-papers/p84-BerettaGyftopoulos-ASME-AES20-33-1990.pdf

to

https://gianpaolo-beretta.unibs.it/Beretta-papers-online/m49-BerettaGyftopoulos-JERT-137-021006-2015.pdf

Thanks Cavallinux (talk) 10:33, 20 May 2024 (UTC)

 Done -Lemonaka‎ 11:30, 20 May 2024 (UTC)

Thanks Cavallinux (talk) 12:20, 21 May 2024 (UTC)