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Show HN: Free textbook on engineering thermodynamics

(thermodynamicsbook.com)

This is awesome. Also, this quote feels relevant: "Ludwig Boltzmann, who spent much of his life studying statistical mechanics, died in 1906, by his own hand. Paul Ehrenfest, carrying on the work, died similarly in 1933. Now it is our turn to study statistical mechanics." - David Goodstein's States of Matter, Introduction
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ha yes :-) Carnot died of cholera aged 36, and Rudolf Diesel committed suicide too. Maybe I should add an appendix about mental health at the end!
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Love the price transparency, the obvious followup question is where the other ~85% of the pie goes when I buy a ~50€ paper book, if the author only earns a little under 15%?

I imagine printing will be about 2 to 5€, if it's not ultra cheap print on demand refuse. Is the rest all for publishers and Amazon dot com?

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Following up with actual numbers for the project, from Lulu, in Euros: List Price 43 Print cost 11 Distribution fees (read: Amazon, 50% of selling price): 21.5 Lulu share of profit : 2 Rest to author: 8,5

Because of the different prices on different locales in different currencies the actual share I receive averages 7€ (gross revenue before income tax, although in my case the yearly income is too small to trigger it where I live).

For books sold directly on Lulu List price 43 Print cost 11 Lulu share of profit: 6.5 Rest to author: 25.5

The mindset should not be "this is all that’s left for me", however: a book is many things at once and for better or for worse, Amazon creates a big part of it. Kevin kelly has some excellent advice at https://kk.org/thetechnium/everything-i-know-about-self-publ...

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Amazon takes the lion’s share, and then the rest of the pie looks very different depending on which route you go. Big publishers print in batches and have very low print/distribution costs. I ended up on the other end of the spectrum, self-publishing with Lulu (print-on-demand, so much higher costs). I wrote an article in French on exploring the economics of textbooks, from the open-source point of view, a few years back: https://framablog.org/2022/01/20/mais-ou-sont-les-livres-uni...
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Thanks, I enjoyed the article. I've bought a couple creative commons books (PDF and printed), both to have the physical artifact and to send gratitude to the author, in a form that unambiguously means something. I rarely see a pay-what-you-want option, but that would make sense to me. Buying a free PDF isn't really like buying an apple or a manufactured good, it feels more like buying music on Bandcamp. It costs nothing to copy a file, but I still want to send what I can.

Sadly I haven't been very satisfied with print on demand books. It can be serviceable for textbooks, it does make prints a lot more accessible, but the quality has been pretty disappointing for me. When I buy a POD I often end up reading the PDF instead, which seems a bit wasteful.

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> I wrote an article in French on exploring the economics of textbooks, from the open-source point of view, a few years back

Thanks for that, it’s very informative. I contemplated publishing a book that way and never actually got that far into the planning phase. Do you think things have changed much since then?

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I have not kept a very close look on what’s going on. I would say that three things have changed since:

- tablets are everywhere in the classrooms now, so the number of places where a good PDF can do good is much bigger

- there are better workflows to get a high-quality PDF than LaTeX, so much frustration can be saved, and all that can be learned easily with AI tools

- in a sea of AI slop, all the humans are desperate for a One Good Resource they can trust

Go for it!!!!

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When selling a product through a reseller, the markup is around 80-100%. I was horrified by this in the 80s, but soon learned that the resellers would be out of business otherwise.

The reason resellers exist is they do the marketing, warehousing, shipping, customer service, etc.

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What system are you using to get the money? The service is taking 25% of your earnings! Also, I believe you could do some optimization with the heavy images. Anyway, thanks for sharing this. It's gonna help my cousin.
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Glad the book can help! Regarding image size, it’s on my todo list now (see thread further down the page).

I am using Payhip for the transaction, and then Paypal. Fees end up averaging 0,5€. Calculating in terms of percentage is not really helpful here at such low prices: there is an incompressible flat rate pretty much anywhere you go. See it differently: these intermediary fees go towards making the UX smooth, the payment secure, reducing fraud etc. I want to spend my energy on the content, not making a credit card form :-)

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Is this aimed at undergrads or practicing engineers? What's the math background needed?
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It’s accessible with end-of-high school math: you need to be okay-ish with integration and derivation. Practicing engineers might find it a bit slow, but that’s for each to decide :-)
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great job, thank you for this teacher!
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Thank you for the compliment! I am touched by the generosity of the HN people today.
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Tangentially related: It appears that TD ideas pop up in diffusion models, VAEs and neural net training dynamics. Any author/reading advice on links between thermodynamics, information, and neural nets?
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Since you mention VAEs: you might be interested in Active Inference, which is built on minimizing variational free energy. Same E−TS form as the thermodynamic kind (Helmholtz free energy), so it does fit your thermo/info/NN question. And the negative free energy is equivalent to the evidence lower bound used in generative models like VAEs. Lots of really fascinating connections between all of these topics :)

There's a free 2022 textbook: https://direct.mit.edu/books/oa-monograph/5299/Active-Infere...

And a brand new one (though it's a bit pricey): https://mitpress.mit.edu/9780262050951/fundamentals-of-activ...

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Hello,

The textbook seems nice and clear. The only nitpick i have is that it should talk more about equations of state. I understand that it may not be the focus of the text, but mentioning the current state of equations of state (SAFTs, cubics, multiparameter) would help guide readers looking on how to generate their own steam tables for their fluid of interest, even if the advice is just "go use CoolProp"

On the other hand, i really like the ilustrations on turbomachinery, helps ground the theoretical content.

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Thank you! To be honest I think there is not much there because when I started 17 years ago my technical skills were much shallower, plotting a diagram to visualize/compare two models would have been quite a lot of work. But if I can be frank, at undergraduate level playing with equations of state is not expected nor a requirement. I’m happy to just say "there are others and they all have some common things". I‘d much rather the students and I spend our energy wrapping our heads around say the concept of entropy and what it allows us to do. Regardless, I appreciate your comment muchly (and shall look up CoolProp tomorrow).
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Cool, putting that to my reading list. And the pricing comparison is fun!
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Thank you! ^^
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I'd love to send you a few euros; but the checkout process requires both an email and a cell number. Are those strictly necessary to authorize a cc payment?
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The payment for the paid-for PDF is processed through Payhip. As far as I can test here in Germany no cell number is required. Maybe you trigger some extra verification that I don’t?

As for the email, I require it so that I can subscribe all of my readers to a weekly newsl… haha just joking. Juuuuust joking :-) If you try it, you will find that a bogus email address works just fine.

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Nice, I’ll definitely check this out. You might want to look at optimising the PDF, it’s sitting at 40MB right now.
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Thanks! I think most of the weight comes from the PNG diagrams, but I don’t actually know: I’ll put it on my to-do list to investigate, maybe there are some easy wins here.
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The ~750 pngs are about 15 megabytes. The 77 photographic images are 22 megabytes.

Somewhat a death of 1000 cuts.

I used https://www.xpdfreader.com/pdfimages-man.html to extract them and take a look.

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Thanks for that. At first glance, it looks like that is a good place to be, regarding images. I will still investigate when I find time.
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Probably the main thing you could look at is what pixel density you want in your images.

For example, there's a 1 megabyte image of a tanker trailer that is displayed at about 1.5 x 3 inches, you could get rid of 3/4 of those pixels (going from ~400 ppi to ~200 ppi) and not really change the quality of the image for a casual reader.

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that’s a really good place to start, thank you!
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Claude was able to optimize the hell out of one of mine, might be worth a try
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Does it matter?
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Nice. Good to see actual hard science books popularized and available for free.

The textbook industry is a criminal cartel shafting both the students/knowledge seekers and authors/professors. Hence i really appreciate the way you have made the pdf available both for free and for a nominal price; so thank you.

We need more hard science (Physics/Chemistry/Biology/etc.) content (books/articles/videos/etc.) on HN. For example, the interdisciplinary field of "Materials Science" (https://en.wikipedia.org/wiki/Materials_science) is one the most practical and important for our modern world and yet there is hardly any discussions/popularization about it.

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I used to think that way about the publishing industry too, but I now think that this description is not deserved. Just observing it from an operational perspective: a laptop to type, software to edit, book printers that will talk to you, payment rails, and even access to world-class distribution: it’s all available to us now. On the other side of the market, students and teachers are not locked in either. Barriers to entry are nonexistent. For context, see the links I posted in my other comments on this page. It’s all in our hands!
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Engineering books are very expensive in my country. I want to give calculus a spin. Spivak is a hundred dollars.
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I would bet that you can find used calculus textbooks quite easily.

I did chemical engineering long ago (how long? Computerized process control was just being introduced into the curriculum, and we learned to program in Fortran). I did several calculus courses, but it was always just a matter of memorizing techniques.

Much later, I came across Calculus Made Easy on Project Gutenberg, a textbook from 1914 that actually helped me to understand why calculus works, instead of just treating it like magic.

https://www.gutenberg.org/files/33283/33283-pdf.pdf

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Calculus hasn't changed a whole lot. There are probably better books for learning than I used in the 1970s, but I have to believe that you can find pretty decent older calculus texts for not a lot.
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Spivak is a different category of calculus text.
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All textbooks are free if you know where to look
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A scan of contents list suggests that it is mostly about heat engines. No mention of chemistry. Chemical reactions are mentioned in passing in the text but with no detail. Also no obvious signs of much interest in conduction, convection, or radiation.

So it's fairly narrow focus, but that is not necessarily a bad thing.

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Indeed! Truth be told, I think the book really is missing a chapter on refrigeration systems. I had to call it done at some point for my own sanity. Maybe someone will jump in and add one someday!
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I suggest clicking on the link and easily discover for yourself.
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