Message #1753

From: schuma <>
Subject: 4D Playground
Date: Sun, 29 May 2011 20:42:09 -0000


Yesterday when I walked through a playground, this climbing structure immediately caught my eye:

It really looks like a projection of a 4D polychoron! It’s not one of the six regular ones but some truncated polychoron. With my wife by my side and some kids on it, I started examining the structure. At the center there’s a truncated octahedron, surrounded by several (should be eight) truncated octahedra, just as in the space-filling tessellation <>. I was a little bit disappointed because that means not all cells are transitive. But it could still be something like a prism. I don’t remember the structure of the outskirts.

I don’t know what the designer was planning to build, but I really like this structure. I may go there another day and take a closer look, and, climb it. How does it feel to walk into a 4D structure (actually on the surface of it)? I really want to find it out. If there’s a 120-cell playground climbing structure, it would really worth a trip to go into it.