4-Dimensional Cross-Polytope

When bad news gets me down, I often get insomnia. I wake up in the middle of the night, start thinking about how we’re all doomed, and can’t easily stop. To break out of these doom loops, I do elaborate visualization exercises. They don’t really put me to sleep, they just calm me down. Then later I can fall asleep.

Here’s what I’ve been doing this week. I visualize this shape made of two interpenetrating tetrahedra, called the ‘stella octangula’ or ‘stellated octahedron’. Then I imagi...