My 2023 Birthday Star

Today is the day I turn 55, so here is a 55-pointed star to mark the ocassion. It’s composed of eleven five-pointed stars, which works because (5)(11) = 55.

One of Many Faceted Versions of the Rhombic Triacontahedron

I made this using Stella 4d: Polyhedron Navigator, which you can try for free at http://www.software3d.com/Stella.php.

Playing Around With the Pentagonal Icositetrahedron

This, above, is the pentagonal icositetrahedron — one of the Catalan solids, and the dual of the snub cube. If faceting is used to remove square-based pyramids, the result is the solid shown below — a chiral polyhedron with six square faces, and 24 faces which are isosceles trapezoids.

I use a program called Stella 4d: Polyhedron Navigator (available here) to perform these polyhedral manipulations. This program has a “try to make faces regular” function, and the solid shown below is the result of using that function on the polyhedron shown above.

The “try to make faces regular” function appeared at first to leave the squares as squares (which it did), but turn the trapezoids into kites (which it did not; the yellow quadrilaterals’ longer sides are actually of two slightly different lengths). Lastly, I used Stella to create the compound of the polyhedron above and its dual. The result is shown below.

A Chiral Polyhedron Featuring Pentagons and Isosceles Trapezoids

I made this chiral polyhedron using Stella 4d, which you can try for yourself — free — at this website. It is a faceted form of the pentagonal hexecontahedron, which is the dual of the snub dodecahedron.

The Four Gas Giants on the Faces of a Dodecahedron

These images of Jupiter, Saturn, Uranus, and Neptune were all acquired by NASA. I placed them on this polyhedron, and created this rotating .gif, using Stella 4d, which you can try for free at this website.

The Galilean Moons of Jupiter on a Rotating Rhombic Dodecahedron

These images of Ganymede, Io, Callisto, and Europa were all acquired by NASA. I placed them on this polyhedron, and created this rotating .gif, using Stella 4d, which you can try for free at this website.

Two Views of a Faceted Dodecahedron

This is one of many possible facetings of the dodecahedron. It’s colored by face type above, and is shown in “rainbow color mode” below. I made both rotating images using Stella 4d, which you can try for free at this website.

A Tessellation Featuring Regular Enneagons and Triangles, as Well as Concave Octagons and Six-Pointed Stars

Image

Four Polyhedra with 7-Fold Pyramidal Symmetry

I made these four polyhedra using Stella 4d, which you can try for free right here.

A Caffeinated Rhombic Dodecahedron

This image of a caffeine molecule comes from this website. I put it on the faces of this rhombic dodecahedron, and created this rotating model, using Stella 4d: Polyhedron Navigator, which you can try for free right here.