Re: Light slows down in glass?

["Bob Sciamanda" <trebor@velocity.net>]

-----Original Message-----
From: LUDWIK KOWALSKI <KOWALSKIL@alpha.montclair.edu>
To: phys-L@atlantis.uwf.edu <phys-L@atlantis.uwf.edu>
Date: Sunday, February 08, 1998 2:24 PM
Subject: Light slows down in glass?


> Prompted by Sciamanda's messages I did look into the "EM optics" and many
> things started to make sense to me. (I do not teach this kind of physics
> and forgot what I used to know long time ago.) For example, I see that all
> purely dielectical materials are transparent outside regions of their
> "characteristic" frequencies. The QM apart, these frequencies are
determined
> by the masses of oscillating particles (electrons) and by the restoring
> forces acting on them within moleciles. The mechanical model of a driven
> oscillator (where there is a phase shift PI between the driving force and
the
> displacement, IN THE STEADY STATE for the frequencies above the resonance)
is
> at the heart of all derivations, including those which lead to complex n.
>
> Yes, mathematics is very flexible, it has tools for everything that can,
> and can not, happen. But I am still puzzled. If the phase shift (a small
> delay at each molecule) is an explanation of v<c then how can we use this
> concept when there is not enough time for a steady state to be reached?
>                                          Ludwik Kowalski


This "delay at each molecule" is bogus.  That is NOT the origin of the new
phase velocity in the scattering model.

-Bob

Bob Sciamanda   sciamanda@edinboro.edu
Dept of Physics   trebor@velocity.net
Edinboro Univ of PA  http://www.edinboro.edu/~sciamanda/home.html
Edinboro, PA   (814)838-7185