Collected from notes made prior to and during the 2020 pandemic; spurred by 3b1b's Summer of Math Exposition
3b1b SoME1 submission.
I live outside, so…the effects of that are going to show here. Despite it needing a lot of work, I hope you take away something useful.
Here, ongoing research, NOT part of the 2021 contest. I’ll fix the thing above here too.