Joe Clinton's Equal Central Angle Conjecture about Goldberg polyhedrons is front page at the moment on bfi.org.
Adrian Rossiter has made some new computer images of a 15 frequency tetrahedral Goldberg and a 20 frequency icosahedral Goldberg. I'm placing them here in the dome section for obvious reasons. Nice work, Adrian and Joe! Next is a mathematical proof. Any volunteers?
Rossiter wrote:
"I made my program more efficient, using a different algorithm, and it turns out that this Goldberg doesn't have a minimum edge length.
Here is one with a shorter edge length (all equal to 10 significant figures) and a good tesselation"
http://www.freewebtown.com/adrian/tmp/tet15e1.gif
"So, all is still well with the conjecture!
Surprisingly, this one has a slight twist. I don't know if
the twist would disappear if I ran the program for longer.
Here are some views of an equal edge spherical Goldberg based on the dual of an F30 tetrahedron."
http://www.freewebtown.com/adrian/tmp/tet15f1.gif
http://www.freewebtown.com/adrian/tmp/tet15f2.gif
http://www.freewebtown.com/adrian/tmp/tet15f3.gif
"This "concentric" tiling appears to be sustainable at higher frequencies, which bodes very well for the conjecture.
I guess I should have a go at an icosahedral one now...Minimal distortion on an F20.
http://www.freewebtown.com/adrian/tmp/ico20g1.gif
All looks good for the conjecture!"
http://www.bfi.org/node/608
Adrian Rossiter
adrian@antiprism.com
Home: http://antiprism.com/adrian
Adrian writes:
Rearranging a cube into a half-volume stellation of a rhombic
dodecahedron (2.4Mb)
http://www.freewebtown.com/adrian/misc/anim_cube_x05.gif
(see also http://www1.ttcn.ne.jp/~a-nishi/y_cube/z_y_cube.html )
Rearranging a cube into a double-volume rhombic dodecahedron (2Mb)
http://www.freewebtown.com/adrian/misc/anim_cube_x09.gif
Adrian's new a-module rotation transformation from one tet dual to the other.
http://www.freewebtown.com/adrian/misc/anim_tet_v2f02.gif
http://en.wikipedia.org/wiki/Module