Entries by Chestermiller

Lessons From the Bizzaro Universe

The terms Bizarro and Bizarro World originated in Superman comics, where strangely imperfect versions of Superman, other action characters, and even Earth itself were conceived of, and provided the basis of stories.  And who can ever forget the Seinfeld episode entitled “Bizarro Jerry,” in which there are Bizarro versions of Jerry and all his friends….

Grandpa Chet’s Entropy Recipe

How do you determine the change in entropy for a closed system that is subjected to an irreversible process? Here are some typical questions we get at Physics Forums from confused members: If I have an irreversible adiabatic process, shouldn’t the change in entropy be zero since q/T is zero? Since entropy is a function of…

Reversible Vs Irreversible Gas Compression and Expansion Work

Introduction In learning Thermodynamics, one of the difficult concepts that many students struggle with is the difference between reversible and irreversible work in expansion/compression of a gas.   They wonder, 1.  Why is it that we need to use two different equations to calculate the work done by the system on the surroundings, one for a reversible process…

Understanding Entropy and the 2nd Law of Thermodynamics

Introduction The second law of thermodynamics and the associated concept of entropy have been sources of confusion to thermodynamics students for centuries.  The objective of the present development is to clear up much of this confusion.  We begin by first briefly reviewing the first law of thermodynamics, in order to introduce in a precise way the concepts of…