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From: lab@qubix.UUCP (Q-Bick)
Newsgroups: net.math
Subject: Re: Archemedian polyhedra: the EPCOT ball
Message-ID: <1395@qubix.UUCP>
Date: Tue, 2-Oct-84 00:44:25 EDT
Article-I.D.: qubix.1395
Posted: Tue Oct  2 00:44:25 1984
Date-Received: Wed, 3-Oct-84 05:44:52 EDT
References: <3732@decwrl.UUCP>
Organization: Qubix Graphic Systems, Saratoga, CA
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I guess I qualify as an engineer. During my first visit to EPCOT (8 Oct
1982), I studied the ball in an attempt to determine its basic geometric
construction. I don't know if I still have the notes, so I'll pass along
what I can remember.

Side point to return to later: each triangle of the geodesic dome is
covered by a triangular pyramid, thus multiplying the total number of
triangles on the dome by 3. Back to the basic dome.

The ground perspective made it difficult to correlate with the most
obvious similar structure - an icosahedron. As you enter EPCOT, you can
immediate see a couple of super-triangles, 8 units per side, on the
front. Further, there is a trough extend from the top of one to the top
of the dome. At that vertex and at the ends of common edge of the first
two triangles, you can see the intersection of FIVE basic triangles.

But waitaminnit - if the dome was based on an icosahedron, I should not
have been able to see as much as I did above and below those first two
triangles (even accounting for curvature). Hmmm...new theory is called for.

It became apparent that there had to be places where SIX curved
triangular faces met. With planar faces, this would be obvious; the
curved faces could conceal this well. I came up with a 30-face
construction; with 8 units per side, this put 1080 on the basic dome and
3240 on the entire ball, minus a few for the base.

Will check my EPCOT photos (I have some from both sides of the dome) and
report back later. However, I am also notoriously absent-minded - if you
don't hear anything in a week or two, nag me about it. (BTW, although
disk cameras are rotten for capturing facial detail, they did VERY well
with the ridges and troughs on the dome!)
-- 
		The Ice Floe of Larry Bickford
		{amd,decwrl,sun,idi,ittvax}!qubix!lab

You can't settle the issue until you've settled how to settle the issue.