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Re: A cool fractal



On Sun, 3 Aug 1997, Karl Trappe wrote:

Bill: I haven't seen that one, but I used to marvel at the standing wave
patterns in my cup as I drove to work in the mornings. These patterns are
like Chladni plate patterns or vibrations of a drum head. Just allow the
cup of coffee to rest on some part of the console, like, rest the bottom of
it on the gear shift knob and enjoy, enjoy, enjoy...Try to look at the road
every now and then. I commute 27 miles so I have a lot of daydreaming
time. Karl

I'll have to try that one. THERE'S an interesting topic: boredom-
inspired driving (or car-ride) physics.

While riding in the back seat with inlaws, the faceted glass "jewel"
hanging from their rear-view mirror swayed gently so it struck my eye with
a sweep of spectrum colors. I discovered that if I squinted at it, I
could see all kinds of Fresnel diffraction fringes surrounding the shadows
of eyelash hairs and eyelid rims. (Any bright point source such as distant
streetlights at night will do this.) But the changing frequency from the
rocking prism caused the entire pattern to expand and contract! When the
prism became still, I could move my head through the color pattern and
"manually" cause the entire pattern of fringes to shrink or swell in size.
A diffraction demo with no equipment (if we ignore the naturally occurring
prism.)

Now if Newton had squinted into his prisms, rather than projecting their
patterns on walls, the wave theory of light could have taken off many
decades earlier than it did.

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William Beaty voice:206-781-3320 bbs:206-789-0775 cserv:71241,3623
EE/Programmer/Science exhibit designer http://www.eskimo.com/~billb/
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