Re: teaching electric circuits

[Leigh Palmer <palmer@SFU.CA>]

> Thank you for saying something that I strongly believe but was
> afraid of saying on this list.
>
> ==>use of these physically "naive" assumptions gives the students
> ==>an opportunity to practice physical concepts. After relationships
> ==>between electric field, potential and current are understood I
> ==>complete the physical aspects that are initially neglected.
> Actually after presenting the naive concepts, I often decide its
> more productive to move on to the next topic, so that at least
> they will have seen the next topic.
>
> Flame shields on full power! Warp 9! The Death Star (AKA Leigh)
> just materialized out of hyperspace. Scotty, Get me out of here! Now!

I don't expect any student will absorb everything at first exposure.
Every physics course I teach starts with a healthy dose of previously
covered material. I never expect 100% performance on exams; does
anyone? Perhaps Bill Larson is right, that exposure to entropy (with
absolutely no understanding and no motivation for understanding) is
enough; the student may learn more next time because of the earlier
exposure, but I doubt it in the case of entropy. When I present
entropy I expect the student to come away with something physical, or
at least I will from now on, if they let me teach again.

That said, I agree there is value to superficial exposure (I hesitate
to call it "conceptual" exposure). The student will benefit later,
when he remembers wondering about what he saw happening at an earlier
time. However if there is no wonder, there is no value to the exposure.
Entropy is like that. No naive student ever asks eagerly "What was the
entropy change associated with that phenomenon you just demonstrated
to us?"

Leigh