Re: Diffraction

[Bob Sciamanda <trebor@VELOCITY.NET>]

Sure!
That's just what Brian is saying in the part of his post that you snipped:

"In an elementary treatment of one slit, it is necessary or at least
possible to think of two beams, one from each half of the slit,
interfering at the appropriate angle.
The distance seperating the centers of each beam are
a half slit apart, and this is the distance used for the treatment"

Bob

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor


----- Original Message -----
From: Cliff Parker <cparker@EMPOWERING.COM>
To: <PHYS-L@lists.nau.edu>
Sent: Friday, September 24, 1999 10:31 PM
Subject: Re: Diffraction


> brian whatcott wrote:
>
> > At 21:35 9/24/99 -0400, you wrote:
> > > Good approach, Brian.  But the quantitative calculation shows that
the
> > > first minimum (zero) occurs at an angle such that the wavelets from
the
> > > two slit ends are IN PHASE.  The wavelets cancel in pairs, with the
first
> > > pair being one end and the center (these are 180 deg out of phase).
> > >
> > > Bob
> >
> > Good catch, Bob!
> > The elementary approach I sketched works better for two slits.
>
> Can't the single slit be considered in the same way as two slits if one
> considers each half of the slit separately?
>
> Cliff Parker