Re: A cool fractal

[trappe@PHYSICS.UTEXAS.EDU (Karl Trappe)]

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


> This morning I encountered my wife's coffee cup from last night.  It was
> full, sitting undisturbed, and on its surface was a convection pattern.
> But rather than the hexagons commonly seen in "Benard Cell" convection,
> this pattern was different.  It was dark radial branches, starting with
> five or six dark branches in the center.  Further from the center each
> branch split, then split again and again and again, and out at the rim of
> the cup it had grown to a couple of hundred dark branches.  It looked like
> satellite photos of a river drainage basin.
>
> Has anyone else seen similar things?  Do other types of patterns appear?
> I think the flow was made visible because the creamer had settled
> somewhat, leaving a thin transparent layer on top, and where this
> transparent layer was flowing downwards it created dark cracks in the
> opaque muddy coffee.
>
>
> .....................uuuu / oo \ uuuu........,.............................
> William Beaty  voice:206-781-3320   bbs:206-789-0775    cserv:71241,3623
> EE/Programmer/Science exhibit designer        http://www.eskimo.com/~billb/
> Seattle, WA 98117  billb@eskimo.com           SCIENCE HOBBYIST web page

Dr. Karl I. Trappe                              Desk Phone:  (512) 471-4152
Physics Dept, Mail Stop C-1600                  Demo Office: (512) 471-5411
The University of Texas at Austin               Home Phone:  (512) 264-1616
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