Talk:Regular Polytopes (book)

fullerenes

Siobhan Roberts' biography quotes Sir Harry Kroto, codiscoverer of fullerenes: "I knew Buckminster Fuller's work, but I didn't know the Coxeter connection. Certainly, Coxeter's book Regular Polytopes would have been helpful." If there's anything in Regular Polytopes about the truncated icosahedron, let alone the higher Goldberg polyhedra, I can't find it! —Tamfang 01:45, 16 April 2007 (UTC)

Reads like an advertisement

It praises the book too much. Not enough citations for all the circlejerking. — Preceding unsigned comment added by 96.231.116.47 (talk) 15:48, 29 September 2012 (UTC)

the illo

The stereographic {5,3,3} from Jenn3d is not the most appropriate choice. This is a representation of a curved object, a tiling of S3 (positively-curved 3-space); Regular Polytopes is about objects with flat boundaries in flat 4-space. While conflating the two is a convenient way to visualize the convex 4-polytopes, I think Coxeter would object. Better a flat projection. —Tamfang 05:23, 2 July 2007 (UTC)

I've changed the image and tweaked the caption. Actually, both images are projections of the 120-cell into 3-space, so the underlying object is the same - the difference is that one projection preserves angles, the other preserves straight lines. Gandalf61 08:40, 2 July 2007 (UTC)

Good change. Maybe a lores photographed book cover would be nice too? (I have a paperback copy at least). Tom Ruen 16:26, 2 July 2007 (UTC)

I found my mislaid new copy! —Tamfang 18:11, 20 August 2007 (UTC)

The Jenn figure can be seen as the result of two projections – a gnomonic projection from E4 to the S3, followed by a stereographic projection from S3 to E3 – but what angles does it preserve? The angle between edges is 108° (the pentagonal angle) in the polychoron, 109.5° (the tetrahedral angle) in the projection; the angle between faces is 116.6° in the polychoron, 120° in the projection; the angle between cells is 144° in the polychoron, 180° in the projection. (Naturally I'm getting some of these figures from Coxeter's table!) —Tamfang 06:16, 5 July 2007 (UTC)

Tamfang, that must be a rhetorical question, as you seem to know the answer already. If you don't like the new illustration then find your own. I tried to help out, and you just produce more complaints. I can't read your mind to work out what you want here, so I am done. Gandalf61 10:07, 5 July 2007 (UTC)

Did I say I'm unhappy with the new picture?? Au contraire! I'm asking for clarification of something you said about the old one, if that's not too much trouble. —Tamfang 05:17, 6 July 2007 (UTC)

I'm interested in the topic, mostly since I've been annoyed how best to explain/label what the diagrams are. I'd call the Jenn curved diagrams as uniform 3-sphere surface tessellations, viewed by stereographic projection from 4-space into 3-space. ANYWAY to Tamfang's question (maybe), I see the curved projection is preserving angles from the 3-sphere surface tessellation, not the 4-space regular polytope. (Sometime I'd like to get some regular polyhedron stereographic projections, curved and linear edges for comparsion as well.) Tom Ruen 17:23, 5 July 2007 (UTC)

That's how I see it too. —Tamfang 05:17, 6 July 2007 (UTC)

book cover

Does someone want to give a fair use rationale for the cover? I don't know if there is one, and I'm not particularly motivated, even though I'm the one who scanned it. —Tamfang (talk) 23:01, 21 December 2009 (UTC)

The warning message says this, so how about just uploading a smaller image? Tom Ruen (talk) 02:43, 22 December 2009 (UTC)

This non-free media file should be replaced with a smaller version to comply with Wikipedia's non-free content policy and United States copyright law.