Re: what is understanding?

[trappe@PHYSICS.UTEXAS.EDU (Karl Trappe)]

I agree with Leigh and Hugh.  I even tell my students that physics is a
series of LIES.  The question then becomes one of deciding how much of a
lie we are willing to accept.  To clarify, the most accurate description of
nature is nature itself. I point out that in this one extreme of
accuracately identifying physics you can just "look" at the phenomena and
marvel--kind of an "Oh, Wow!"
When you start "taking it apart", you begin to see different aspects very
accurately, but have to tell yourself "lies" in order to understand each
single aspect.

What I recall from freshman physics was being *told* to neglect friction in
a certain problem.  At the same time, I was learning that to accept a false
premise would lead you to a false conclusion.  So, neglecting friction was
a LIE, and I fought that instructor like a kid learning to swim fights
water.  Eventually I came to understand that you have to accept the "lies"
in order to get some deeper understanding of the "parts".  You can then
correct the "lies" (often exchanging them for other ones) as you gain
comprehension.

My most rewarding confirmation of this came when my step-father loaned me a
1800's encyclopedia that his parents had passed to him.  In it I read about
the luminiferous either.  It was not presented as a theory.  These
"scientist" were dead serious, and their (now rediculous) description
taught me that a little humility in what we call "the truth"
("understanding") might serve us more kindly in *our* old age, when others
read our descriptions of nature, and want to laugh their heads off at our
stupidity.  Karl

> > I think understanding of physics is never attained. One can always
> > see deeper into a subject even after one feels one understands it
> > satisfactorily. Understanding admits of various degrees. Even the
> > simplest of concepts can be deeper than an expert on the concept
> > realizes. I have seen the understanding of the entire physics
> > community deepen beyond the previous understanding of even the
> > acknowledged world expert too many times to accept the
> > pronouncements of authority as final.
> >
> > Leigh
>
> It seems to me that Leigh has put his finger on an important aspect of
> understanding that has not come up in this thread (at least I haven't
> noticed it). We keep thinking of understanding as a binary quantity-either
> you have it or you don't. This is clearly not true. Understanding is a
> continuum ranging from little or none to truly profound. Most physics
> teachers are somewhere in the middle and the question we need to address is
> what level of understanding is appropriate for students at various levels,
> and should it be evenly spread across the spectrum of topics we deal with
> or is is acceptable if the depth varies from topic to topic, and if so,
> which topics are the most important to put our effort into to make sure
> that the understanding has passed beyond the little or none stage?
>
> I've seen a dozen different definitions of understanding in this thread,
> some better than others, but none that satisfy me. Unfortunately, I haven't
> got any improvements to offer. It begins to seem to me that understanding
> may be one of those words like art-we may not be able to define it but we
> usually know it when we see it.
>
>
> ***************************************************************************
> *****
> Hugh Haskell
>
> <mailto://hhaskell@mindspring.com>
>
> The box said "Requires Windows 95 or better." So I bought a Macintosh.
> ***************************************************************************
> *****

Dr. Karl I. Trappe                              Desk Phone:  (512) 471-4152
Physics Dept, Mail Stop C-1600                  Demo Office: (512) 471-5411
The University of Texas at Austin               Home Phone:  (512) 264-1616
Austin, Texas 78712-1081