I had to take two semesters of thermodynamics to get my undergraduate degree. The textbook we used in that class was not very good. Even the professor of one of the sections admitted that. Besides the “you have to know it to learn it” problem, there were a few more entertaining errors, as the following picture shows:
You probably immediately noticed them because they were circled in pencil. First off, the line describing density is completely scrambled. I suspect something got pasted into the wrong column during the editing process. How this lead to units of kg/m instead of kg/m3 I don’t have an idea of.
Secondly, a unit of pressure called the “millimeter of energy” is defined below. Wouldn’t it be awesome if there was such a thing, and that you could measure the energy of a substance with a ruler, the way we can measure pressure? No more steam tables or relative reference states! Everything could be absolutely quantified with a ruler! I may have to turn this into a story somehow, I just need a plot.
Two last things: the correct unit is “millimeter of mercury” (760 mm Hg is equal to a standard atmosphere of pressure) and this textbook partially inspired the authoring of another thermo textbook with the goal of being better than this one.