Math Monday: Sierpinski tetrahedron

Sierpinski tetrahedron

By George Hart for the Museum of Mathematics

A classic 3D fractal is the Sierpinski tetrahedron, which is a tetrahedron of tetrahedra of tetrahedra, etc. This fifth-order model is about 8.5 inches along its edges. It is made from nylon by selective laser sintering. If you have access to additive fabrication machines, you can make your own copy of it using the STL file available here.

The Sierpinski tetrahedron is so elegant that it has inspired many people to construct it in many materials. Alexander Graham Bell made giant kites with wood frames in this form. I love this geekly romantic photo of him kissing his wife in one.

Others have made this structure using materials ranging from soda straws to steel. Above is a ten foot tall flaming straw version by Wayne Tousignant, Darren Stanley, and Thomas MacKay.

And here is a 22-foot tall sculpture, Bat Country, by Gwen Fisher and Paul Brown, made out of 384 aluminum baseball bats bolted together. Why not see what materials you can use to make your own Sierpinski tetrahedron?

More:

• Math Monday: Skewer hyperboloid
• Math Monday: Morton Bradley sculpture
• Math Monday: Tetraxis puzzle
• Math Monday: Giant burr puzzles
• Math Monday: Fractal polyhedra clusters
• Math Monday: Giant SOMA puzzle
• Math Monday: Tie your bagel in a knot!
• Math Monday: Playing card constructions
• Introducing “Math Monday”