Well, this is just embarrassing.
I’ve always held out the option that I would revisit a topic sometime. I thought it would most likely be taking some essay from one of my earliest A-to-Z’s where, with a half-decade’s more experience in pop mathematics writing, I could do much better. And at the request of someone who felt that, like, my piece on duals was foggy. It is, but nobody’s ever cared enough about duals to say anything.
So I went looking at what previous T topics I’d written about here. Usually I pick them the Sunday or Monday of a week, since that’s easy to do. This week, I didn’t have the time until Thursday when I looked and found I wrote up “Tiling” for the 2018 A-to-Z. In about November of that year, too. And after casting aside a suggestion from Mr Wu of the Singapore Maths Tuition blog, although that time at least I was responding to a specific topic suggestion. 2020, you know?
Well, now that the deed is done, I can see what I learned from it anyway. First is picking out the archive pieces before I write the week’s essay. Second is how my approach differed in the 2020 essay. The broad picture is similar enough. The most interesting differences are that in the 2020 essay I look at more specifics. Like, just when Robert Berger found his aperiodic tiling of the plane. And what the Wang Tiles are that he found them with. Or, a very brief sketch of how to show Penrose (rhomboid) tiling is aperiodic. This changes the shape of the essay. Also it makes the essay longer, but that might also might reflect that in 2018 I was publishing two essays a week. This year I’m doing one, and somehow still putting out as many words per week.
I like the greater focus on specifics, although that might just reflect that I’m usually happiest with something I just wrote. As I get distance from it, I come to feel the whole thing’s so bad as to be humiliating. When it’s far enough in the past, usually, I come around again and feel it’s pretty good, and maybe that I don’t know how to write like that anymore. The 2018 essay is, to me, only embarrassing in stuff that I glossed over that in 2020 I made specific. Not to worry, though. I still get foggy and elliptical about important topics anyway.