[zwieback]

Of course you don't need to really understand entropy for it to be useful. It's definitely an interesting concept but when I was crunching equations for Thermodynamics, one of the weeder classes for ME, it becomes clear you need it for things to balance out. Once you've cranked threw a dozen or so problems you get a feel for what it is even if the physics and the spiritual side of it remains murky.

Now, 35 years later, when I marvel at my new engine or what have you, I still vaguely remember my entropy-problems days and appreciate that someone worked this stuff out.