In eight-dimensional
geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...
, a stericated 8-simplex is a convex
uniform 8-polytope
In eight-dimensional geometry, an eight-dimensional polytope or 8-polytope is a polytope contained by 7-polytope facets. Each 6-polytope ridge being shared by exactly two 7-polytope facets.
A uniform 8-polytope is one which is vertex-transitive ...
with 4th order
truncations (
sterication
In geometry, a uniform polytope of dimension three or higher is a vertex-transitive polytope bounded by uniform facets. The uniform polytopes in two dimensions are the regular polygons (the definition is different in 2 dimensions to exclude ver ...
) of the regular
8-simplex
In geometry, an 8-simplex is a self-dual regular 8-polytope. It has 9 vertices, 36 edges, 84 triangle faces, 126 tetrahedral cells, 126 5-cell 4-faces, 84 5-simplex 5-faces, 36 6-simplex 6-faces, and 9 7-simplex 7-faces. Its dihedral angle is c ...
. There are 16 unique sterications for the 8-simplex including permutations of truncation, cantellation, and runcination.
Stericated 8-simplex
Coordinates
The
Cartesian coordinate
A Cartesian coordinate system (, ) in a plane is a coordinate system that specifies each point uniquely by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured i ...
s of the vertices of the ''stericated 8-simplex'' can be most simply positioned in 9-space as permutations of (0,0,0,0,1,1,1,1,2). This construction is based on
facets of the
stericated 9-orthoplex.
Images
Bistericated 8-simplex
Coordinates
The
Cartesian coordinate
A Cartesian coordinate system (, ) in a plane is a coordinate system that specifies each point uniquely by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured i ...
s of the vertices of the ''bistericated 8-simplex'' can be most simply positioned in 9-space as permutations of (0,0,0,1,1,1,1,2,2). This construction is based on
facets of the
bistericated 9-orthoplex.
Images
Steritruncated 8-simplex
Images
Bisteritruncated 8-simplex
Images
Stericantellated 8-simplex
Images
Bistericantellated 8-simplex
Images
Stericantitruncated 8-simplex
Images
Bistericantitruncated 8-simplex
Images
Steriruncinated 8-simplex
Images
Bisteriruncinated 8-simplex
Images
Steriruncitruncated 8-simplex
Images
Bisteriruncitruncated 8-simplex
Images
Steriruncicantellated 8-simplex
Images
Bisteriruncicantellated 8-simplex
Images
Steriruncicantitruncated 8-simplex
Images
Bisteriruncicantitruncated 8-simplex
Images
Related polytopes
This polytope is one of 135
uniform 8-polytopes with A
8 symmetry.
Notes
References
*
H.S.M. Coxeter:
** H.S.M. Coxeter, ''Regular Polytopes'', 3rd Edition, Dover New York, 1973
** Kaleidoscopes: Selected Writings of H.S.M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995,
*** (Paper 22) H.S.M. Coxeter, ''Regular and Semi Regular Polytopes I'',
ath. Zeit. 46 (1940) 380-407, MR 2,10*** (Paper 23) H.S.M. Coxeter, ''Regular and Semi-Regular Polytopes II'',
ath. Zeit. 188 (1985) 559-591*** (Paper 24) H.S.M. Coxeter, ''Regular and Semi-Regular Polytopes III'',
ath. Zeit. 200 (1988) 3-45*
Norman Johnson ''Uniform Polytopes'', Manuscript (1991)
** N.W. Johnson: ''The Theory of Uniform Polytopes and Honeycombs'', Ph.D.
* x3o3o3o3x3o3o3o, o3x3o3o3o3x3o3o
External links
Polytopes of Various Dimensions
{{Polytopes
8-polytopes