ATD sighting

[kelber at mindspring.com]

Dug out a long-forgotten microscopy textbook to read up on refraction and bi-refringence.  Basically, objects are visible to us because they have a different refractive index than the surrounding medium (air, water, etc.).  Bi-refrigent crystals and fibers can be identified under polarized light microscopes by measuring their interference patterns in different orientations (polarizations) of light waves.  

The book contained this interesting description of the phenomenon of "white-out":

"[white-out] has been a problem for fliers in the polar regions where all surface features are covered with snow.  On an overcast day diffuse light from the sky and reflected light from the snow can result in the illumination becoming quite symmetrical.  Under such conditions entire snow covered mountains can be invisible even though the air is perfectly clear."

Not a bilocation, but a dislocation.

Laura




-----Original Message-----
>From: David Morris <fqmorris at gmail.com>
>Sent: Oct 24, 2006 9:10 AM
>To: Tore Rye Andersen <torerye at hotmail.com>
>Cc: pynchon-l at waste.org
>Subject: Re: ATD sighting
>
>On 10/24/06, Tore Rye Andersen <torerye at hotmail.com> wrote:
>>
>> Some thoughts: Iceland Spar is a form of calcite used for optical purposes, and one of its interesting features is that it causes double refraction. See the image on this link, and then compare it with the cover of the novel:
>>
>> http://geology.about.com/library/bl/images/blcalcite.htm
>
>bi·re·frin·gence (br-frnjns)  Pronunciation Key
>n.
>The resolution or splitting of a light wave into two unequally
>reflected or transmitted waves by an optically anisotropic medium such
>as calcite or quartz. Also called double refraction.
>
>http://micro.magnet.fsu.edu/primer/java/scienceopticsu/birefringence/index.html
>
>Light bends when it moves at an angle from one transparent substance
>through another. This bending of light is called refraction. Some
>transparent substances cause light to bend or refract in two different
>directions, causing light to divide into two rays. This is called
>double refraction or birefringence. When you look at something through
>a birefringent substance, you can see a double image. Iceland spar, a
>type of calcite crystal, is birefringent. Below, you can see a double
>image as you look through a piece of Iceland spar.
>