4D Euclidean space
News Archive
Mar 2018
This month, we continue with our exploration of the so-called ursatopes, a generalization of the tridiminished icosahedron to higher dimensions, by taking a look at the octahedral cousin of last month's Polytope of the Month. This is the octahedral ursachoron:
This polychoron has a surface with an octahedron, 8 tridiminished icosahedra, 6 square pyramids, and a cuboctahedron. Head on over to the octahedral ursachoron page to learn more about the structure of this interesting CRF polychoron. Its full coordinates are available, as usual.
8 Mar 2018:
Added more projections to the sphenocorona page.
7 Mar 2018:
Added the tridiminished rhombicosidodecahedron (J83), a Johnson solid.
Added the gyrobifastigium (J26), another Johnson solid.
1 Mar 2018:
The Polytope of the Month for March is up!
Feb 2018
Yes, the Polytope of the Month is back! We apologize for the 4-year hiatus. Technical troubles and personal situations made it difficult to keep up with the updates. But we're back, and we're bringing you more CRFs (convex regular-faced polytopes) and other polytopes to look at!
This month, we'll resume updates with a modest, but nonetheless interesting addition: the tetrahedral ursachoron, a cute little 4D CRF polytope that generalizes the tridiminished icosahedron to 4D:
This polychoron's surface has 5 tetrahedra, 4 tridiminished icosahedra (J63), and an octahedron. Head on over to the tetrahedral ursachoron page to learn its structure and how it generalizes J63.
As usual, we give its full Cartesian coordinates.
19 Feb 2018:
Added the snub disphenoid (J84), one of the Johnson solids. Full coordinates are provided.
Added the sphenocorona (J86), another of the unusual Johnson solids near the end of Johnson's list. Full coordinates are provided.
16 Feb 2018:
Updated the Johnson solids page to list all 92 solids, along with some explanations of their names.
14 Feb 2018:
Upgraded stylesheet to work better with mobile browsers. Note: if the page layout suddenly looks strange, it's probably because your browser still has the old stylesheet cached. Clear your browser's cache and reload the page, and that should fix it. If not, please let us know.
Upgraded to HTML 5.
9 Feb 2018:
Corrected a typo in the uniform polychora page.
8 Feb 2018:
The Polytope of the Month updates are back! Check out the projections of the tetrahedral ursachoron!
Corrected numerous typos and other errors in several pages. Many thanks to the many nice people who pointed them out!
A technical problem with the contact email address has been fixed. Many apologies for all the bounced mail!