I’ve been hinting all month about **rotation**, and the time has finally come to dig into the topic. As mentioned, my interest began with wanting to understand what it means to rotate a **tesseract** — particularly what’s *really* going on in a common animation that I’ve seen. What’s the math there?

This interest in rotation is part of a larger interest: trying to wrap my head around the idea of a fourth *physical* dimension. (Time is sometimes called the fourth dimension, but not here.) To make it as easy as possible, for now I’m focusing only on tesseractae, because “squares” are an easy shape.

After chewing at this for a while (the tesseract post was late 2016), just recently new doors opened up, and I think this journey is almost over!