Re: Polarization

[Bernard Cleyet <anngeorg@PACBELL.NET>]

No, the only error, already discussed, was the electrostatic shielding,
by an UNGROUNDED conductor, of an internal charge.  Sorry, the
conclusion jump is understandable.

My shock is because it's not a minor error.  Especially since he
diagrammatically illustrates how the electric wave is generated.  [My
copy is the 6th. (1989).  How about the most recent ed.?]

I don't know what JD means by function.  The ball and stick model does
shown the kink produced by a double bond in, for example, oleic acid
[olive oil].  Some models include different sticks for diff. kinds of bonds.

bc, who wonders if the mag. field could be absorbed by a resistive
"picket fence".  What does skin effect have to do with this.  [bc too
lazy to check with Harnwell or RF.]

p.s. Where would "we" be if RF, et al. had written an elementary text?

p.p.s. "... recall him [his] saying ..."

John Denker wrote:

> Quoting Bernard Cleyet <anngeorg@PACBELL.NET>:
>
>
>
> > Aliquando bonus dormitat Hewitus
>
> OK.
>
>
>
> > (et Feynman)
>
> Huh?  That's true as a general proposition, but why tar
> RPF with this particular brush?  I don't recall him
> saying anything about pickets or fences.
> -- I-34 (plus the last bit of I-33)
> -- III-11
>
>
>
> > Easy correction:  the jump rope represents the magnetic com 'pon ent.
>
> That seems like a trick, verging on a dirty trick, since
> the interaction is basically electrical not magnetic.
>
> A better correction would be to follow the example of
> Feynman and introduce the concept in terms of _birefringence_.
> Then you can't go wrong:  either the ordinary ray *or* the
> extraordinary ray is aligned with the axis of your microscopic
> 'pickets' or whatever you want to call them.
>
> ==================
>
> As a philosophical remark:  I don't see why people should ever
> be "shocked" when this-or-that ball-and-stick model fails
> to entirely capture the physics.  For example, chemists make
> ball-and-stick models of molecules all the time ... these are
> useful for some purposes, even though they are far from 100%
> realistic.  They model the structure but not the function;
> obviously they fail to _react_ with one another the way real
> molecules do.
>
> -- Is it important for students to appreciate the range of
> validity versus invalidity of a model?  Sure.
> -- Do students often overestimate or underestimate the
> range?  Yes.
> -- Is it possible for teachers or textbook authors to
> completely specify the range of validity for every model
> that gets mentioned?  No.
>
> ===========
>
> Some people may be thinking that the desired outcome is to
> get to the point where polarization is described in terms
> of vectors and polaroid sheets are described in terms of
> projection matrices.  But remember:  equations are themselves
> just a *model* of reality.  And in this case the equations
> have problems, profound problems, widely-underappreciated
> problems.  See next note.