Michael Kinyon

I know it's not a very good picture, but it's hard to take a good one with even a decent phone camera (I have a Pixel 8a). Still, it was fun to watch.

After it was over but before I could go home, I had to fight some bokoblins and lizalfos that had respawned. I hate it when that happens

A photo of the March 3 2026 lunar eclipse, aka, a blood moon

Witness the Blood Moon's rise. When its red glow shines upon the land... the aimless spirits of slain monsters return to flesh

In fact, a little more often than from time to time 🤣

I might have to save that for Wednesday

Tomorrow's history of math lecture is "Leibniz and the Bernoulli Bros.", which sounds like the name of a circus

Yep. The more things change, the more they stay the same

Beats me. I've never read those books and don't even know his name. One of my kids read the first two or three of the books shortly after they were published, but lost interest pretty quick.

It's the main character from the Diary of a Wimpy Kid books

I wasn't aware that qntm had made a novel out of their work on the Antimemetics Division. Good for them!

Really, I just wanted an excuse to use the word "supercilious" today 😁

By coincidence, I was just recently reading about Anton Schultze's quadrivigesimal (what a word!) system. It's very interesting!

Me, writing a proof of a "the following are equivalent" theorem:

"(2) implies (3) is trivial"

No, that's not supercilious enough

"Only a nincompoop would fail to see that (2) implies (3)"

No, that one would never get past the Editor

"(2) implies (3) is, of course, trivial"

Perfect

Great minds, JG, great minds

I don't think very much is known about Prüfer as a person. I've sometimes wondered if he was a heavy smoker since he died rather young of lung cancer. Or perhaps he was just unlucky.

Indeed. Any variety (in the universal algebra sense, i.e., class of algebraic structures axiomatized by universally quantified identities) without nullary operations includes the empty structure. The phrase "single axiom for groups" implicitly refers to nonempty structures satisfying the identity.

As someone who has never used anything beyond H^2, I have only planetesimal thoughts

The simplest known single axiom for groups in terms of multiplication & inverses:

((z * (x * y)^{-1})^{-1} * (z * y^{-1})) * (y^{-1} * y)^{-1} = x

(Source: K. Kunen. Single axioms for groups. J. Automated Reasoning 9 (1992), 291-308)

Describe your favorite games poorly:

Bringing one guy some blue pages and another guy some red pages

It was a joke, Barbara.

I blame the parents

It's associative so it's really just the empty group!

I've seen Blue 3 or 4 times (because J.B.), Red only once, but I respect your choice!

Note that those who attend an AMS Special Session are required to wear blue, but any shade of blue is acceptable.

"You muſt proceed in the firſt Way when x is ſmall enough, but the ſecond Way, when it is ſuppoſed great enough."
-- Isaac Newton, De Analysi

(I love the long s in pre-19th century documents.)

I'm always amazed to learn that there are still people who think π is rational. It's obviously irrational because √5 is irrational, and, of course, π = (3/5)(3 + √5).

If there is an upside to imposter syndrome, at least it allows me to empathize more deeply with my students' struggles.

It's a good way to teach base 60, the best base, of course. 🤪

(Seriously, when I taught precalc, I never had time for it.)

Today I'll be teaching my students how to use "just" properly.
For example, "the field of fractions of the Gaussian integers is just the Gaussian rationals" and so on.

Of course, this is not the full use of "just"; that will have to wait until they learn category theory.