Re: Electric Force and Shells

[Joe Heafner <heafnerj@VNET.NET>]

> From: Tina Fanetti <FanettT@QUEST.WITCC.CC.IA.US>
>
> silly you....
> You sound like me when I teach.  I expected you to know this and that.
>
> Okay I just wanted to make sure I was crystal clear.
> I think I get it.
>
> It's amazing that some of the problems I had has an intro physics student are back to haunt me.  I remember my second and third EM class. THat i got because it was just div, grad, curl and boundry conditions.
>
> Oh well I am trying
As a ten year veteran of the North Carolina community college system teaching introductory astronomy, vocational physics, technical physics, alg/trig physics, and calc physics I can honestly admit with a clear and unashamed conscience that my undergraduate "education" in physics taught me A-B-S-O-L-U-T-E-L-Y N-O-T-H-I-N-G other than how to work a small subset of problems. Only when I got to grad school did any of it BEGIN to make sense (thank's Drs. Muir, Clark, and Danford!!!). If I had been required to pass an exit exam as an undergrad, I never would have graduated. I'm no dummy either. The problem is how physics is taught, or in most cases NOT taught, in the introductory courses. Of course as a clueless undergrad I didn't know just how much I was being cheated. I wasn't taught HOW TO THINK. I was "taught" how to mechanically crunch equations.

I can cite many examples. Take Newton's third law for example. F = ma. Yeah, yeah...F = ma. Good. It wasn't till grad school that I finally understood what it REALLY MEANS. Gauss' law is another excellent example. Yeah, integral of E dot dA = q_net over eps_0. Fine. Only after teaching this for about five years did it FINALLY hit me! I still discover some subtle point every time I teach Gauss' law. I took a standard undergrad thermo course, and I got NOTHING from it!!!! It was a disgrace to the reputation of that university!!!! Only after reading Chabay and Sherwood's approach to thermo (which was borrowed from Moore's seminal paper on an innovative introduction to stat mech) did ANY of it make any sense to me at all!!!! Arnold Arons (whom I had the great pleasure to meet in person and have a one hour one-on-one conversation with about a year before he died) said it best (I'm paraphrasing): Something just isn't right here, and it isn't me!

I say keep the fundamental questions coming!!!!! I'll bet money that there are plenty of subscribers who are struggling with the same questions despite a formal "education" in physics but are too shy to ask for fear of insolence or demeaning comments. In fact, I'm willing to bet that there are more here who DON'T know all the answers than who do.

Please excuse the sermon, but after all, my father was a Methodist minister. ;-)


Cheers,
Joe

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