Re: Gauss' Law

["Glenn A. Carlson" <gcarlson@MAIL.WIN.ORG>]

I like the flow analogy, e.g., water flowing through a square.  I
explain that, though the math works out the same, electric fields
don't "flow" the same way as does water.

Isn't analogizing light rays to E fields similar to using water?
Don't the students imagine photons "flowing" through the glass?

Glenn

>  I use a small bulb halogen flashlight and a beaker.  I ask for acceptance
> of the idea of light rays passing through the glass for cases of bulb
> outside the glass, inside the beaker and then the black end in the beaker.
> I would argue that light rays are only a little more real than field lines
> and a whole lot more "visible"
>
> I also use the overhead rays and a loop to tlak about flux and angle
> between surface and lines.
>
> I believe the transition to field lines is easy and when I have used this
> in the past, my students act like they understand.
>
> Is this a bad analogy? I try to avound the flow word and have rays
> penetrate.....
>
> Ken Fox
> AP/IB Physics Teacher
> Smoky Hill High School
> Aurora, CO
------------
Glenn A. Carlson, P.E.
PO Box 612, St. Peters, MO 63376
gcarlson@mail.win.org
636-922-0488 Voice/Fax
============