Re: I guess I get to "put up or shut-up".

["Eugene P. Mosca" <mosca@nadn.navy.mil>]

Hi Paul, you wrote,

> I've been teaching both physics and calculus for quite some time. There
> is a lot of calculus reform material out there, much more, it seems to
> me, than physics reform material. Take a serious look at the text
> Calculus by Hughes-Hallett, Gleason, et.al.  . . .  I've taught the
> first two semesters using these materials, and am about to teach
> multivariable calculus using them.

This text is used to teach calculus in my school.  Last year, after
attempting to guide my students through Gauss' law, I looked up the
treatment of flux in the multivariable calculus book.  It seemed to me the
presentation of flux lacked any intuitive feel for what flux is used
for.  Instead, it was presented as an exercise in doing integrations over
projection surfaces.  In addition, the artwork was inadequate.  The
figures, which appear to come directly from the output of Mathematica
program, fail to convey their intended meaning.

What I would like my students to learn about doing flux integrals is that,
like with any surface integral, you start by mentally dividing the surface
up into small (infinitesimal) elements of area.  Next, on each of these
area elements you dot the area vector with the vector field vector, and
then you sum up the resulting values.  From my read of the presentation in
Hughes-Hallett, Gleason, et.al., the book doesn't even attempt to do the
job.

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Eugene (Gene) P. Mosca           Phone 410-293-6659 (FAX 3729)
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