Talk:First law of thermodynamics

edit about the work of Robert von Mayer lacks reliable sourcing
Editor Flugscham has posted a new edit here, drawing attention to the work of Julius von Mayer.

The new edit has no citation of a reliable source. There is a link to the Wikipedia article on Julius von Mayer. Such a link does not make the grade as a reliable source, but it is useful here to check what it says. It has two references to sources. I have not been able to fully peruse the first one, in a book by Albert L. Lehninger, which has a snip on the internet that says "The First Law, enunciated by Robert Mayer in 1841, is the principle of the conservation of energy: energy can be neither created nor destroyed." This one mentions neither heat nor work. The second reference is poorly formatted but I could track it down. It is just a repetition of the first one, worded as follows: "energy can be neither created nor destroyed."

The 1841 statement by Mayer was published in 1842. According to Truesdell, it was a philosophical musing, without specific reference to experiment and without a mathematical expression.

According to Truesdell, Mayer wrote another paper that was rejected by a journal editor, but that he published himself as a monograph in 1845. It does talk of work and heat, but not as a readily comprehensible general statement of the first law. It is specifically about expansion of a gas.

The Wikipedia article on Mayer has a section on Mayer's place in the history of physics, but regrettably it is not supplied with the proper citations of reliable sources. It asserts that Mayer did an experiment with vibration of water. I have read neither the 1842 nor the 1845 paper.

Truesdell (1980) analyses the work of Mayer rather carefully and concludes that Mayer did not state the first law of thermodynamics in full generality till after Clausius had done so in 1850. If one relies on Truesdell, one may say that Mayer made some valuable prophesies of the first law, but that he was not the first to make a full statement of it. I did not find Truesdell mentioning the asserted experiment with the vibration of water.

I have good respect for Truesdell, though he is perhaps not the only source that may be considered reliable on this topic. In the absence of another, better, source, I suppose he is to be relied upon, so that the new edit is not acceptable.

If no better research into reliable sources is quickly forthcoming, I will undo the edit on the grounds of lack of reliable sourcing.Chjoaygame (talk) 05:21, 17 December 2019 (UTC)

Another reliable source that considers the writings of Mayer is Bailyn (1994). Bailyn writes that the interconvertibility of heat and work is generally said to have been first proposed by Mayer. Bailyn does not mention an experiment with vibration of water. In the 1840s, Joule did experiments to quantitate the interconvertibility of heat and work. Bailyn points out that the First Law expresses not only the interconvertibility of heat and work, which are transfer quantities, but also their relation to internal energy, a function of state that was defined by Clausius, but was not considered by Mayer. I will edit accordingly.Chjoaygame (talk) 16:12, 17 December 2019 (UTC)


 * I agree that we should cite the best source we can find on Mayer, which appears to be Truesdell according to your comment. We do need to include something on Mayer since he is mentioned in some textbooks. For example, Peter A. Rock's Chemical Thermodynamics (Macmillan 1969) says in a footnote (p.20) that "The extension of the energy conservation principle to systems involving heat transfer was first made by J.R.Mayer in 1842 and was first experimentally confirmed by J.P.Joule over the period 1840-1849." Truesdell's version would seem to be more accurate.


 * We could perhaps simplify the very awkward phrase "Mayer in 1841 made a statement that meant that" to "Mayer stated that". I realize that the following words are not an exact quote, so we can just remove the quote marks.


 * As for "vibration of water", in the 1840's this would presumably mean vibrating a macroscopic container of water to heat the water. Today chemists might understand the phrase to mean molecular stretching and bending vibrations, but these were unknown at the time. Dirac66 (talk) 20:46, 17 December 2019 (UTC)


 * As I read it, the Wikipedia article on Julius von Mayer says that he actually did vibrate a macroscopic container of water to heat the water. If this is true, it is important and remarkable. It isn't supported by any stated source in the Wikipedia article. It is mentioned neither by Truesdell nor by Bailyn; I guess they would have made much of it if they knew of it. It seems that Peter A. Rock's text excludes it. If a source turns up, I think it should go into the present article on the First Law.Chjoaygame (talk) 22:13, 17 December 2019 (UTC)


 * I have recently learned that Mayer measured a temperature rise caused by friction in a body of paper pulp. It seems to me that this is important.


 * Chjoaygame (talk) 12:33, 8 July 2023 (UTC)

EDIT REQUEST - Energy can be transformed/transferred in an isolated system, but not created or destroyed
Energy can be transformed/transferred in an isolated system, but not created or destroyed. There's a HUGE difference between transformed and transferred and they both apply. There's alot of sources that use both terms. 2601:589:4800:9090:9854:AF5D:3F5D:427E (talk) 12:50, 19 November 2020 (UTC)


 * Not clear about your concern. Please clarify.


 * The law of conservation of energy is not restricted to thermodynamic systems. It is a much more general law, referring to a great diversity of physical objects.


 * 'Transfer' is a special or technical term or term of art of thermodynamics. It refers to the intrinsic energy, or other extensive state variable, of a thermodynamic system. It doesn't have a specially defined meaning as a term of art for general physical objects.


 * It does perhaps make sense to say, for example for the Joule experiment, when the movement of the paddles induces friction, that work can be transformed into heat. The  work is done by forces in the surroundings, while the energy enters the thermodynamic system as heat.


 * 'Transform' is not a special or technical term or term of art of thermodynamics. It may have a more or less well defined meaning for general physical objects.


 * 'Transfer' would not fit in the sentence "Energy can be transformed from one form to another, but can be neither created nor destroyed." But I think 'transform' is ok for that.Chjoaygame (talk) 14:36, 19 November 2020 (UTC)
 * This /64 IP range has been blocked as a sockpuppet of . Feel free to revert all edits by this range. –LaundryPizza03 ( d c̄ ) 04:58, 18 January 2021 (UTC)

reasons for undo of good faith edit
I have undone this edit for the following reasons.

The mighty work of Émilie du Chatelet is notable, but this article is not primarily about the law of conservation of energy. This article is about the first law of thermodynamics, the essence of which is in the distinction between thermodynamic work and heat, and their relations to specifically thermodynamic concepts such as internal energy, enthalpy, and Gibbs free energy. This distinction is far from elementary and far from obvious, and is not deducible from the law of conservation of energy by itself. This should be kept clear throughout the article.

The edit did not provide a reliable source. The work of Émilie du Chatelet is important and deserves proper reliable sourcing from the start.

When the new material is added again, these points should be attended to.Chjoaygame (talk) 15:03, 5 March 2021 (UTC)


 * The edit mentioned above said in the History section that Conservation of Energy was the (historical) precursor to the First Law, so I think it clearly did not claim that Conservation of Energy is identical to the First Law. And I have found two sources for the contribution of Émilie du Chatelet which were cited in the History section of Conservation of Energy, and which I copied to the Intro of that article. I will now restore the deleted edit and insert the same sources for this article also. Dirac66 (talk) 17:54, 25 March 2021 (UTC)


 * I had been hoping that Editor Katejeffery would do this.


 * Editor Dirac66 rightly observes that the words "The precursor" indicate that the Conservation of Energy is not identical to the first law of thermodynamics. I feel that this leaves gaps. The first law is about heat and work. The words "The precursor", I feel, are too vague here.


 * At this moment I cannot check the following that I vaguely seem to remember, and am much doubtful about; I am sure that it needs checking. A difference between Newton and Leibniz might be thought of in terms of 'heat', or 'intrinsic energy'. Leibniz was interested in vis viva, $$mv^2$$, which he held to be conserved. Newton was interested in momentum, $$mv$$, also a conserved quantity. For a collision in which the final velocities were zero, Leibniz thought that, in a collision, vis viva, created by God at the beginning of the universe, was conserved, while Newton that that momentum vanished. Leibniz thought that further motion was determined by the conserved 'intrinsic energy', while Newton thought that further motion was initiated by God. Newton thought that 'heat' was a matter of motion of intestine parts of bodies; how he connected that with momentum I do not know. Exactly what du Chatelet thought about all this I do not know; I think this should be clarified in this section of this article.


 * If it is to be said that the Law of Conservation of Energy is a "precursor" to the first law of thermodynamics, then I think Helmholtz deserves a mention in this section of the article.


 * Perhaps someone will do something about this.Chjoaygame (talk) 07:27, 26 March 2021 (UTC)

Hagengruber
Reading the first essay, by Hagengruber, in the cited source, I was expecting to find a statement that du Chatelet discovered the law of conservation of energy, but so far I have not discerned such a statement. Du Chatelet was a respected scholar, debating with Leibniz, Newton, Maupertuis, and Bernouilli, on topics such as vis viva and momentum.

The debate is learned and subtle. I shall try to pursue it further.Chjoaygame (talk) 10:04, 30 March 2021 (UTC)

Reading the second essay, by Hartmut Hecht in the cited source, I was expecting to find a statement that du Chatelet discovered the law of conservation of energy, but so far I have not discerned such a statement.

More reading needed.Chjoaygame (talk) 07:09, 3 April 2021 (UTC)

Reading the third essay, by Sarah Hutton in the cited source, I find this comment about Émilie du Chatelet: "...her crowning achievement was her translation of Newton’s Principia mathematica into French, which was completed just before she died."

Hutton writes about du Chatelet in a footnote on page 78: "[3] Ira O. Wade deemed her Institutions de Physique, ‘essentially derivative’, believing that she was unlikely to have inﬂuenced Voltaire who, he claimed, had ‘a deeper understanding of Newton’, Wade. 1947. Studies on Voltaire . 221." I do not have access to Wade's Studies on Voltaire, but I have accessed another thoroughly scholarly book by Wade on Voltaire, The Intellectual Development of Voltaire. The latter book by Wade gives very much information about the relationship between Voltaire and du Chatelet, and presents information about du Chatelet's thinking.Chjoaygame (talk) 17:06, 3 April 2021 (UTC)

I did not discern a statement in Hutton's essay that du Chatelet discovered the law of conservation of energy. More reading needed.Chjoaygame (talk) 07:41, 3 April 2021 (UTC)

The fourth essay, by Fritz Nagel, in the cited source, is about du Chatelet's interest in optics.

I did not discern a statement that du Chatelet discovered the law of conservation of energy. More reading needed.Chjoaygame (talk) 08:01, 3 April 2021 (UTC)

The fifth essay is by Dieter Suisky in the cited source. A quote from its summary may help indicate some of what it says:


 * In 1740, Du Châtelet published her treatise Institutions de physique as a methodological and historical analysis of the controversial debates on the foundation of mechanics that completes advantageously Euler’s systematic presentation of the principles of mechanics in the Mechanica in 1736. Euler translated Newton’s Principia in the language of the Leibnizian calculus. In the 1740s, Du Châtelet translated Newton’s Principia into French and Euler composed the Anleitung zur Naturlehre that corresponds in goal and spirit to Du Châtelet’s Institutions.
 * In view of the educational attitude, both treatises fulﬁlled the same purpose to made [sic] science available to the common reader.

I did not discern a statement that du Chatelet discovered the law of conservation of energy. More reading needed.Chjoaygame (talk) 15:40, 3 April 2021 (UTC)

The sixth essay, by Andrea Reichenberger, in the cited source is easier to examine.

Quoting page 159:


 * For example, Wilhelm Jacob ‘s Gravesande, a famous Newtonian scholarship [sic] in Holland, did experiments in which he found out that if dents in clay were used to measure the force [vis] of a body in motion, the height from which a ball falls is as the square of the velocity acquired in falling and with which the body strikes the clay. Thus, force [vis] would have to be understood as vis viva. The Italian physicist Giovanni Poleni conducted similar experiments. He dropped balls onto tallow to compare impacts. He demonstrated as well that the force [vis] of motion is proportional to the square of the velocity.

Quoting page 166:


 * But at Du Châtelet’s time a clear distinction between the concepts of force, energy and momentum was not available. An ‘objective’ evaluation leading to the legitimacy of both interpretations $$mv$$ and $$mv^2$$ was not open to her because there were deep disagreements about the nature of matter and force.

In conclusion, on page 169, Reichenberger writes:


 * Du Châtelet made an important contribution to bring the problem of quantity of motion and force to the attention of a wide variety of philosophers and physicists.

I did not discern a statement that du Chatelet discovered the law of conservation of energy. More reading needed.Chjoaygame (talk) 09:46, 4 April 2021 (UTC)

The seventh and last essay in the cited source is by Ursula Winter

I did not discern there a statement that du Chatelet discovered the law of conservation of energy.

It seems that Hagengruber is not an adequate source for the added material. More reading needed.Chjoaygame (talk) 11:00, 4 April 2021 (UTC)

Arianrhod
Reading Robyn Arianrhod's cited book.

I will try to report progress.Chjoaygame (talk) 12:54, 4 April 2021 (UTC)

I have long been a little thrown by Newton's "hypotheses non fingo". Arianrhod makes it clear for me. Leibniz rejected Newton's work on gravity because it didn't provide a 'causal' mechanism, which would have been hypothetical. On page 108, Arianrhod writes:
 * ...[Newton] was more interested in certainties than possibilities, which is why he built his theory not on hypotheses about possible causal mechanisms, but on observable physical effects.

Thank you, Arianrhod.Chjoaygame (talk) 13:07, 4 April 2021 (UTC)

The book gives a lot of information about du Chatelet's thorough and well respected studies of the works of Newton and of Leibniz, as well as much other information about her. I haven't read every bit of Arianrhod's book, but I have searched it with some care for a claim that du Chatelet discovered the law of conservation of energy. I found none.Chjoaygame (talk) 15:09, 4 April 2021 (UTC)

More explicit statement from APS News
An interesting document is the December 2008 This Month in Physics History in APS (American Physical Society) News here, which says "One of her most important contributions to science was her elucidation of the concepts of energy and energy conservation." I think this may be as explicit a statement as we are likely to find. Dirac66 (talk) 16:32, 3 April 2021 (UTC)


 * Quoting a bit more from that source:


 * One of her most important contributions to science was her elucidation of the concepts of energy and energy conservation. Following experiments done earlier by Willem ‘s Gravesande, she dropped heavy lead balls into a bed of clay. She showed that the balls that hit the clay with twice the velocity penetrated four times as deep into the clay; those with three times the velocity reached a depth nine times greater. This suggested that energy is proportional to mv2, not mv, as Newton had suggested.


 * Leibniz proposed $$mv^2$$, which he called vis viva, as a 'quantity of motion'. Evidently du Chatelet was developing the ideas of Leibniz and 's Gravesande, as well as integrating the ideas of Leibniz and Newton. The word 'elucidation' here perhaps itself needs elucidation. More reading needed. Perhaps further sourcing?Chjoaygame (talk) 17:26, 3 April 2021 (UTC)


 * According to Jennifer Coopersmith, Leibniz wrote:
 * [I maintain] that active forces* [vires vivae] are preserved in the world. The objection is that two soft or non-elastic bodies meeting together lose some of their force [vis]. I answer that this is not so. It is true that the wholes lose it in relation to their total movement, but the parts receive it, being internally† agitated by the force of the meeting or shock . . . There is here no loss of forces [vires], but the same thing happens as takes place when big money is turned into small change.[Leibniz, Gottfried Wilhelm, Philosophical Writings, edited by G.H.R. Parkinson, Dent, London, 1973.]


 * Coopersmith continues:
 * The equivalence of this ‘active force’ to our concept of energy is striking, especially when we realize that Leibniz’s concept of force [vis] is not Newton’s, but is given by the quantity $$mv^2$$. Leibniz called it ‘vis viva’, or ‘living force’ (emphatically not the same thing as a ‘life force’). Apart from the factor of ½, this is identical to our modern expression for kinetic energy.


 * Besides Newton, Leibniz was one of du Chatelet's sources.Chjoaygame (talk) 22:03, 3 April 2021 (UTC)

summary
I don't find the remarks of the article in the above-quoted APS News to be a reliable source for the new material in the history section of the article. I didn't find in the cited sources, Hagengruber and Arianrhod, reliable sourcing for that new material. I think the new material is misleading and lacking in reliable sourcing. I think it should be deleted.Chjoaygame (talk) 15:18, 4 April 2021 (UTC)


 * Perhaps the description of du Châtelet's role can be improved. We could first mention the contributions of Leibniz and 's Gravesande, and then note how du Châtelet's improved both the theoretical understanding and the experiments. If we do not say that she proposed the law of conservation of energy, we can indicate that it was she who clarified the concepts of kinetic (or mechanical) energy and work sufficiently so that they could be related to heat in the first law. In that sense her work can be described as a precursor.


 * As you seem to have read the sources already cited in some detail, I would invite you to try your hand at editing a more accurate version of her role. But please don't delete her from the article entirely, as there seem to be significant voices saying that her contribution was important. Dirac66 (talk) 18:42, 4 April 2021 (UTC)

further information
The following will help clarify du Chatelet's contribution.


 * These were the issues Emilie wanted to explore further. No one had synthesized the thinking of Leibniz and Newton before. Why couldn't she, showing how the best ideas of both their systems could be combined? It would be a step beyond her uncredited co-authorship of that recap of Newton's basic work that she and Voltaire had written at Cirey. Other researchers wouldn't consider undertaking the new syntheses she had in mind, for they were all, very distinctly, either in the Newton camp or in the Leibniz camp. But once again there were advantages in being excluded from the main science academies. Emilie was far enough outside that she could view them both objectively.

Further reading needed.Chjoaygame (talk) 21:24, 7 April 2021 (UTC)

mass–energy
This edit diff moves a comment within the lead.

The comment proves that its author knows about mass and energy, but it isn't a summary of anything in the article.Chjoaygame (talk) 07:15, 4 July 2023 (UTC)


 * I agree. Not only is this comment not supported by anything in the body of the article, it is unsourced so not supported by an inline citation. Our article Mass-energy equivalence contains nothing about the First Law of Thermodynamics. Let’s remove the offending comment. Dolphin ( t ) 08:13, 4 July 2023 (UTC)


 * Yes.Chjoaygame (talk) 09:32, 4 July 2023 (UTC)
 * I erased the paragraph. Dolphin ( t ) 07:19, 8 July 2023 (UTC)
 * Well done.Chjoaygame (talk) 12:35, 8 July 2023 (UTC)