To: atm{at}shore.net
From: Jim Burrows 
Reply-To: Jim Burrows 


At 19:09 2003-06-18 -0700, Mel Bartels wrote:

>For those who would put foward the hypothesis that diffraction is caused by
>the spider's edges, please explain these two observations
>
>1. ...

The easiest way to get an intuitive feel for spider diffraction is to put
on your wave optics hat as follows:  at each point of the obstruction,
rather than the incoming light being absorbed, think of it continuing on,
but interfering with a Huygens' wavelet of "new" light of the
same intensity, but opposite phase.  The interference between
"old" and "new" light explains observed diffraction
effects.  This is known as Babinet's Principle in Diffraction 101.

         -- Jim Burrows
         -- mailto://burrjaw{at}earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84)

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