Wikipedia:Reference desk/Archives/Science/2019 October 22

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October 22

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Is there any relation between the Honey badger and the Wolverine. Their respective articles don't appear to link them and I found the Wolverine article to be a bit lacking on Latin nomenclature. They appear to be very similar in appearance as well as temperament and resilience. How close is the link between the two, considering we are all linked to some ancient fish or amoeba. Thanks Anton 81.131.40.58 (talk) 15:56, 22 October 2019 (UTC)

Both animals, as noted in both articles, are mustelids, and thus members of the same taxonomic family. Indeed, the Honey Badger article directly mentions the degree of kinship with the Wolverines, and both articles clearly show the taxonomic classification in the infobox on the right. --Jayron32 16:01, 22 October 2019 (UTC)

Enthalpy in introductory college level physics books

I was checking the index of some well-known physics books, and couldn't find an entry for 'entropy' 'enthalpy'. Isn't it a basic concept that should be teaching alongside 'quantify of hear' for example?

How do they choose what belongs in the category 'basic'? C est moi anton (talk) 22:35, 22 October 2019 (UTC)

As you haven't mentioned which books, how could we reply? Bleaney and Bleaney is one of the core textbooks of modern physics for over 60 years, yet it doesn't mention it until page 637. Andy Dingley (talk) 00:23, 23 October 2019 (UTC)

In Physics by Robert Resnick and David Halliday they adequately cover the flow of heat to and from a gas at constant pressure, and they also define the specific heat at constant pressure C_p, but they stop short of introducing the word enthalpy. Dolphin (t) 12:21, 23 October 2019 (UTC)

The question is not about any concrete textbook. It's about what belongs in an college-level introductory physics book. Is 'enthalpy' maybe too chemistry-ish to be included? C est moi anton (talk) 00:28, 23 October 2019 (UTC)

But is it a thermodynamics book? Entropy pops up in B&B (eventually), but enthalpy doesn't. Andy Dingley (talk) 00:40, 23 October 2019 (UTC)

The heading uses the word enthalpy, but the original question uses the word entropy. Since then, responses mention both. Enthalpy and entropy are significantly different. I have read all the answers but what is the question? (Enthalpy or entropy?) Dolphin (t) 01:33, 23 October 2019 (UTC)

It's about enthalpy. Sorry for the confusion. C est moi anton (talk) 02:16, 23 October 2019 (UTC)

A recent-ish editorial, Modernizing the Physics Curriculum by Being Less Modern, was published online at the website of the American Physical Society.

It is not the first that I've heard the argument; thermodynamics and fluid mechanics are often called out because they are featured less prominently in modern undergraduate treatments of physics compared to the curricula of previous generations of physics students. Each university selects its own syllabus. The syllabus is designed to provide education for the average student: specialists can and do pursue further study - and if they specialize in an area that needs a concept or skill, they will surely pick it up in multiple classes, or else they will learn it by indirect exposure to it.

We could quibble about whether enthalpy is helpful or useful for the average physicist; we might make the case that well-rounded physicist has a sufficiently general understanding of energy, and of general equations of state, such that "enthalpy" doesn't need additional special treatment. I am tempted to say that "enthalpy" refers to a particular operational definition for a specific form of internal energy that only helps in certain problem-domains (like the analysis of chemical reactions). Pure physicists prefer to generalize such expressions.

A couple of professors at my undergraduate institution became famous for their proposed introductory physics curriculum: APS cites Matter and Interactions on their list of research-based curricula - that is to say, there is experimental evidence to support the premise that students learn physics better when educated with this style of presentation and this curated list of topics. Notably, the heat engine is a supplementary chapter, rather than a primary topic of emphasis, in that book. In our curriculum, students in the physical and mathematical sciences would opt to proceed to study Physical Chemistry or Thermal Physics in an advanced course (e.g. over an additional semester or full year); or they could proceed down the engineering route (in which case they would study fluid mechanics and thermal engineering in another department); else, they could conclude with a degree in the humanities.

The "basic" classes taught to physicists, which would later be succeeded by multiple advanced courses, were very different from the "basic" classes taught to engineers to prepare them for further study in engineering domains; and those were different still from the "basic" classes taught to the humanities students as general education.

At the micro-level, if individual students needed more learning, they took another class; if the Engineering department didn't like the Physics course coverage, they worked to change it or supplement it; at the macro level, when empirical studies proved statistical success rates for students who followed certain curricula, other professors bought in to the books, and other departments and schools followed suit.

The point is, nobody decides what goes in the curriculum: prominent educators make proposals, and slowly influence the community of other educators by demonstrating some kind of positive educational outcome. And a positive outcome can be subjectively defined quite differently for different categories of students. So all we can really do is point to the presentations show up in popular books or in the classes of famous universities, and so on. Because... a good "basic" book for me might not be a good basic book for everybody else, depending on what we all want to get from reading it. I mean, golly..., what introductory textbook did M. Stanley Whittingham read as an undergraduate, and do you think he learned about enthalpy in it? ... and so what does that even matter, whether he did, or even if he did not? ...and did he include a chapter on enthalpy when he wrote his book on energy conversion and storage?

And finally, if you want to see what a physicist has to say about the difference between enthalpy and energy, here is Bruce Sherwood, an award-winning physics educator, on the difference between work and pseudowork. Chances are, if you see what any of this has to do with enthalpy, and why this demo is really more about atomic physics and thermodynamics than it is about strings and pulleys, then you're probably already a physicist; and if you can't see the connection, you're probably the type who needs somebody else to provide you with domain-specific state equations!

Nimur (talk) 05:08, 23 October 2019 (UTC)

Thermodynamics is a very specialized branch of physics or more fitting Engineering. Maybe similar like the term Thixotropy in Rheology. --Kharon (talk) 11:19, 23 October 2019 (UTC)

• Enthalpy is covered in many chemistry courses as part of chemical thermodynamics. You'll find a discussion of it in any first-year college-level chemistry text book. You'll find more details in any physical chemistry course, where the things you learn in the first year class are expanded on. --Jayron32 12:18, 23 October 2019 (UTC)