Re: textbook touchstones

["Van E. Neie" <ven@PHYSICS.PURDUE.EDU>]

"Richard W. Tarara" wrote:

> {It seems to me that much of the nit-picking done on this list IS of
> moderate importance in the teaching of future physicists, but very little is
> all that critical in other courses, the courses that comprise the bulk of
> our teaching loads.  We need to digest and discuss these points, but each of
> us, as educators, need to make decisions on the pedagogical value of any
> suggested change in method or content in the context of our classes and our
> students.}

Amen.  Probably nothing we do is ever exact (even if we knew what "exact"
means).  I try always to "do no harm."  By that I mean if the explanation I
give contains the essential ideas and does not lead the student off in a
direction orthogonal to where I think they ought to be, I proceed with the
caveat that it is a workable model that contains the essential ideas, even if
it isn't exact.   I still pretty much like to operate under the essentials of
Thumb's Second Postulate:  "An easily understood workable falsehood is more
useful than a complex, incomprehensible truth."

I know Leigh has some major objection to entropy and disorder being spoken in
the same breath, and I guess I'm guilty of perpetuating that idea, but I
naively assume that if a drop of food coloring is placed in a large container
of water, the food coloring pretty much equally distributes itself throughout
the fluid because the number of states that result in roughly equal
distribution is infinitely larger than those for which the food coloring clumps
in one place.  Thus it is a probability thing.  The molecules are "more
disordered."  Higher entropy.  Is this terribly misleading to the average
student?

I suppose we also need to decide how what is "right" is decided.  I've seen
several postings on this list that essentially take the stand "everybody always
gets this wrong", meaning, I suppose,  "I know what's right and all the other
people don't."  I think it's entirely appropriate to voice objections to
something that you don't agree with, but it has to be done in a way that
doesn't put other people down because they think differently.  I learn a lot
from these discussions, but I suspect several "lurkers" on the list remain just
that for fear of being made to look foolish.


--
Van E. Neie                       Ph:  765-494-5511
Purdue University              FAX: 765-494-0706
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"When we try to pick out anything by itself, we find that it is tied to
everything else in the universe."
               ---John Muir