Re: Simple explanations. Was: what are the labs for?

["Donald E. Simanek" <dsimanek@eagle.lhup.edu>]

On Sun, 8 Feb 1998, Rick Tarara wrote:

> Let me respond with my very first thoughts on this.  WHO CARES?  OK, such
> phenomenon are interesting to many of us as puzzles in and of themselves,
> but certainly there are far more 'meaningful' (at least to students) things
> to worry about than a falling spring which is being stretched only by it's
> own weight (once released).  Perhaps, if the answer really demonstrates some
> important aspect of forces that is applicable in other situations, then the
> effort is worthwhile.  However, I am skeptical, and worry that if we are
> presenting this kind of thing to all but our most dedicated Physics-major
> students, then we are likely to elicit (not to our faces) the response
> above.
>
> Of course I don't really know Donald's intentions toward this
> question--maybe just for his own edification or to challenge the rest of us
> on this list.
>
> Rick

Rick, and others:

Intentions? Both of the above, and more. What stimulated me to ask was a
passing comment someone made about simple explanations, giving the
impression that good, simple explanations were usually available for
teaching physics, and we ought to use them in teaching. Of course we do
use them, when we are clever enough to think of them! And usually we only
are *able* to think of them because we already understand something of the
problem already, through experience, and through an understanding of the
mathematical theory behind it. Only then do we teachers have the broader
perspective to *know* whether a simplified explanation is valid, or
fraudulent. The student isn't usually able to make that judgment. 

The student hears our *simple* explanations and is intimidated. The
student feels that these would never have occurred to his or her mind
(rightly so, usually) and wonders what special insight the teacher had.
The better students realize that often these simple explanations are quite
limited in scope and applicability.

So I posed two simple demos, easy and inexpensive to do. And if teacher
and student see these and aren't surprised and intrigued by them, then
they aren't seriously in the game. They challenge our understanding. If
our "simple understanding" of force and motion can't deal with these, then
maybe it wasn't very powerful or useful understanding after all. It may
even have been wrong. What's the use of understanding which can't be
successfully applied to *new* experiences, even ones you don't happen to
care about? And what relevance does "caring about" something have to do
with it anyway? 

I had another motive. To challenge those who crow about how they 
teach "conceptual physics" and who emphasize "simple" explanations over
mathematical ones. I wonder, sometimes whether it's all smoke and
mirrors accomplishing nothing but a feel-good *illusion* of understanding.
Perhaps it includes some of the "lies" we've been talking about lately.

Oh, yes. These two examples *do* demonstrate aspects of physics which are
applicable in many other situations.

	-- Donald

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Dr. Donald E. Simanek                            Office: 717-893-2079
Professor of Physics                                FAX: 717-893-2048
Lock Haven University, Lock Haven, PA. 17745
dsimanek@eagle.lhup.edu                 http://www.lhup.edu/~dsimanek
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