Acronym | ... |
Name |
n-fold dissected icosahedral polytwister, n-fold dissected ikter, icosaswirlic 20n-choron |
Circumradius | ... |
Face vector | 12n, 72n, 80n, 20n |
Especially | trap-600 (n=30) |
Confer |
The Hopf fibration of the icosahedron maps its vertices to according great circles, its edges into twisted (i.e. non-flat but smoothly curved) faces (then looking like a Möbius strip), and the faces get mapped into twisters, which are solid rings bounded by those twisted faces and having thereby throughout the polygonal cross-section of the pre-image, i.e. are triangular here. Further each twister then gets dissected into n identical chiral antiprisms. This isochoric construction moreover happens to come out to be isogonal as well, so in total provides a noble polychoron.
This polychoron will have 2 types of edges, one describes the right-up lacing edges of the antiprisms (y), while all its remaining edges belong to the other type (x), simply because the neighbouring twister attaches its cross-secting base polygons next to the left-up lacings of the former. That is, the whole polychoron happens to be chiral in general.
In fact, right this connectedness of the mutually swirling individual twisters does further restrict that n after all. This thus brings back into play the former vertex figure of the starting polyhedron – in addition to the so far only considered faces thereof (the cross-sections of the twisters, i.e. the bases of the antiprisms). Because there also is a full inversion symmetry of the outcome of that fibration, we thus finally have to consideder n = LCM(p, q, 2) for a starting polyhedron {p, q}, i.e. n = LCM(3, 5, 2) = 30 in here.
For that specific value this swirlchoron then becomes trap-600. Then the edge length ratio can be evaluated as y : x = sqrt[(15-3 sqrt(5)-sqrt[30+6 sqrt(5)])/12] = 0.376683.
12n | 2 10 | 15 5 | 10 ----+---------+---------+---- 2 | 12n * | 5 0 | 5 y 2 | * 60n | 2 1 | 3 x ----+---------+---------+---- 3 | 1 2 | 60n * | 2 3 | 0 3 | * 20n | 2 ----+---------+---------+---- 6 | 3 9 | 6 2 | 20n chiral trap variant
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