Hi!
Concerning this topic and the comments by Leigh, Rick & Bea, David and
Joel, I lean towards the opinion of Rick & Bea, but this comment is
really independent of the idea of entropy. It affects all the teacing
of physics.
A basic problem of teaching physics (and mathematics) is that the
common everyday language is much to imprecise for our needs. We all
know what a "house" is, but: is it still a house if it has no windows?
If it doesn't have doors? Or no roof? What if it is only a roof and
nothing else? So, what is the DEFINITION of a house?
We face the problem of building up a precise (scientific) language,
but we must do this using the imprecise everyday language. It is
similar to have to construct a machine having a precision of, say
10^(-3) cm, using only tools of a precision of the order of 1 cm.
Seems impossible, but humanity did it over the centuries.
So, it is not unreasonable to use the everyday word of DISORDER
to explain the meaning of the scientific word ENTROPY. The difficulty
lies in the fact that the word DISORDER is not very well defined.
Indeed, DISORDER refers really to the INFORMATION we have about
the system. Example: If you take a deck of cards, and have no idea of
its previous history, and you should guess which is the third card
from the top, then you have no idea of the correct answer and any
guess is as good as any other. AND THIS REMAINS TRUE even if the
deck of cards is perfectly ordered as it came from the factory.
This because you DON'T KNOW IT. So, don't tell me that everybody has
a CLEAR IDEA of what ORDER and DISORDER means in common language.
It is such a discussion which we should have with students when
trying to make them understand the concept of entropy.
Regards Emilio