Search found 83 matches
- Mon Jan 21, 2008 5:50 am
- Forum: Polyhedra
- Topic: What was your introduction to polyhedra?
- Replies: 21
- Views: 114476
I wonder .... do you still have copies of your drawings for the net for the four tetrahedra? I do not throw things away, but I have yet to locate them. They will turn up eventually! Meanwhile, I wonder whether compounds obtained this way can be generated by Stella? While I was looking for my drawin...
- Mon Jan 21, 2008 5:45 am
- Forum: Polyhedra
- Topic: What was your introduction to polyhedra?
- Replies: 21
- Views: 114476
Re: What was your introduction to polyhedra?
I wondered whether it might be you!!!Dinogeorge wrote:Yike! A blast from the past! Did you use my computer-generated nets for the yog-sothoth?
Yes, I used them, and I still have them. My yog-sothoth is approx 23.25 inches circumspherically.
- Sat Jan 19, 2008 5:19 pm
- Forum: Polyhedra
- Topic: What was your introduction to polyhedra?
- Replies: 21
- Views: 114476
Five Tetrahedra is second from the right on the top shelf... The compound that you've picked out is Four Tetrahedra - each is rotated 30° by vertex or opposite face from a hypothetical base tetrahedron. I drew the polyhedron on 14th July 1997 from scratch and then worked out the net, again from scra...
- Sat Jan 19, 2008 2:18 pm
- Forum: Polyhedron Models
- Topic: Posting Images
- Replies: 6
- Views: 30028
- Sat Jan 19, 2008 6:58 am
- Forum: Polyhedra
- Topic: What was your introduction to polyhedra?
- Replies: 21
- Views: 114476
What was your introduction to polyhedra?
Around 1961 form master "Bert" Robinson at Bradford Grammar School had some beautifully constructed polyhedra on display in the classroom - the four I remember were Great Dodecahedron, Great Dodecadodecahedron, Great Icosidodecahedron and Icosahedron. His source was Mathematical Models by H Martyn C...
- Wed Jan 16, 2008 4:03 pm
- Forum: Stella Feature Requests
- Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
- Replies: 5
- Views: 27297
I've emailed Branko with a hyperlink for this thread. I have the paper in hardcopy only. If all else fails I will see whether I can get someone to scan it for me. One of the stellations of the pentagonal hexecontahedron (dual of snub dodecahedron) looks very similar to one of the solids concerned - ...
- Wed Jan 16, 2008 8:22 am
- Forum: Stella Feature Requests
- Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
- Replies: 5
- Views: 27297
Vertically is with respect to vertices... http://www.math.washington.edu/~grunbaum/ The polyhedra are not necessarily stellations, though very similar solids can sometimes be arrived at by stellating. I obtained the paper on them from Branko himself, having read about them in a general book on polyh...
- Wed Jan 16, 2008 6:15 am
- Forum: Stella Feature Requests
- Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
- Replies: 5
- Views: 27297
"Branko Grünbaum" Vertically Transitive Polyhedra
I would dearly love to see Stella provide the facial planes for the Vertically Transitive polyhedra described by Branko Grünbaum. Their faces are non-convex pentagons, there are examples of each type for all symmetry groups (tetrahedral, octahedral and icosahedral), and they are chiral - i.e. symmet...