Search found 83 matches

by oxenholme
Mon Jan 21, 2008 5:50 am
Forum: Polyhedra
Topic: What was your introduction to polyhedra?
Replies: 21
Views: 57751

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...
by oxenholme
Mon Jan 21, 2008 5:45 am
Forum: Polyhedra
Topic: What was your introduction to polyhedra?
Replies: 21
Views: 57751

Re: What was your introduction to polyhedra?

Dinogeorge wrote:Yike! A blast from the past! Did you use my computer-generated nets for the yog-sothoth?
I wondered whether it might be you!!!

Yes, I used them, and I still have them. My yog-sothoth is approx 23.25 inches circumspherically.
by oxenholme
Sat Jan 19, 2008 5:19 pm
Forum: Polyhedra
Topic: What was your introduction to polyhedra?
Replies: 21
Views: 57751

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...
by oxenholme
Sat Jan 19, 2008 2:18 pm
Forum: Polyhedron Models
Topic: Posting Images
Replies: 6
Views: 20126

Squeaky!

There are many packages for manipulating images - I find Irfanview to be excellent.

That torus looks wonderful...
by oxenholme
Sat Jan 19, 2008 6:58 am
Forum: Polyhedra
Topic: What was your introduction to polyhedra?
Replies: 21
Views: 57751

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...
by oxenholme
Wed Jan 16, 2008 4:03 pm
Forum: Stella Feature Requests
Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
Replies: 5
Views: 16944

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 - ...
by oxenholme
Wed Jan 16, 2008 8:22 am
Forum: Stella Feature Requests
Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
Replies: 5
Views: 16944

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...
by oxenholme
Wed Jan 16, 2008 6:15 am
Forum: Stella Feature Requests
Topic: "Branko Grünbaum" Vertically Transitive Polyhedra
Replies: 5
Views: 16944

"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...