The book might disappoint some.. >I have largely avoided the second law of thermodynamics ... Thus, the aspects of entropy most beloved by physics popularizers

The book might disappoint some.. >I have largely avoided the second law of thermodynamics ... Thus, the aspects of entropy most beloved by physics popularizers will not be found here. But personally, this bit is the most exciting to me. >I have tried to say as little as possible about quantum mechanics, to keep the physics prerequisites low. However, Planck’s constant shows up in the formulas for the entropy of the three classical systems mentioned above. The reason for this is fascinating: Planck’s constant provides a unit of volume in position-momentum space, which is necessary to define the entropy of these systems. Thus, we need a tiny bit of quantum mechanics to get a good approximate formula for the entropy of hydrogen, even if we are trying our best to treat this gas classically.