Expanded Truncated Icosahedron III

Image

Expanded Truncated Icosahedron III

This version of an expanded truncated icosahedron was made in a similar fashion to the one two posts ago — but with the augmentation-by-prisms step altered by using prisms of somewhat greater height, with the goal being to make the rectangular faces closer to “squareness.”

As a result, this polyhedron is closer than the others to being a near-miss to the Johnson Solids — a category of polyhedra which has been discussed on this blog before. “Near-misses” are almost Johnson solids, and must therefore have faces which are regular (as the hexagon and pentagons here are) are nearly-regular (as the rectangles and triangles come close to being).

Is this a near-miss, or is it not? That’s difficult to answer, for that set of polyhedra has no precise definition, and cannot have one — it only has a “fuzzy” definition.

In my opinion, it isn’t quite a near-miss, for the triangles are too non-equilateral to qualify, to my eye — but others might disagree. In the unlikely event that mathematicians wish to start talking about “near-near-misses,” I offer this as a member of that set.

(Software credit:  see http://www.software3d.com/stella.php for a free trial download of the software used to make these polyhedral images.)

 

Expanded Truncated Icosahedron II

Image

Expanded Truncated Icosahedron II

In this version of an expansion of the truncated icosahedron, the faces are simply moved far apart — but with nothing filling the space between them.

Like the last post, this was made using Stella 4d, which you may download and try for free (as a trial version) at http://www.software3d.com/stella.php.

Expanded Truncated Icosahedron

Image

Expanded Truncated Icosahedron

To create this polyhedron, I started with a truncated icosahedron (soccer ball shape), then augmented each face with prisms, then took the convex hull of the resulting non-convex figure.

All of this was done in about two minutes with Stella 4d, a program which makes manipulating polyhedra both quick and easy. You can try it here: http://www.software3d.com/stella.php.

For Tumblr-Refugees

Image

For Tumblr-Refugees

If you’ve never had a Tumblr-blog, you probably won’t get the joke here. If you have, though, you will.