Rahul Narain @narain@mathstodon.xyz

Far more entertaining than it has any right to be: Newton's Pendulum (Gangnam Style)
https://youtu.be/YB7KUGdP7wI
via https://www.metafilter.com/195343/Newtons-cradle-Gangnam-style

@Breakfastisready Looks like you meant \( k \mapsto a^k \bmod n \). That sheds a little light, thanks!

@Breakfastisready Interesting. What does the Fourier transform have to do factoring integers? (Disclaimer: I only know of, but do not know, Shor's algorithm.)

@johncarlosbaez @thosgood I remember figuring this out for myself after reading your "Rosetta stone" article. The way I like to think of it, knowing functional programming but no Hodge theory, is that "the cross product is the curried form of the determinant" (at least, if you think of the determinant as a function on three column vectors in ℝ³, and identify V → ℝ with V).

I had not realized that buying colourful curtains would turn my apartment into a Cornell box (http://www.graphics.cornell.edu/online/box/history.html).

@tpfto You probably already know this, but I found the halfway shape between the rounded dodecahedron and the rounded icosahedron by taking linear combinations. It's... a sphere.

More interestingly, I was stunned to discover (though it's easy to check in retrospect) that the cross-section of all these dodecahedral Goursat surfaces in the xy-plane is a perfect circle.

The three genders

Time for another edition of: Song Stuck In Head Please Help
https://austramusic.bandcamp.com/track/beat-and-the-pulse

@ColinTheMathmo I think we talked about this before (probably because I'm the only loser still posting Wordles :) ). But yes it's hard mode, as indicated by the asterisk. Sometimes you get stuck in a bad situation, but overall I prefer it. Especially when you manage to claw your way out anyway (I haven't lost a game yet!)

Good grief

Wordle 282 6/6*

⬜⬜⬜⬜⬜
⬜🟩🟩🟩🟩
⬜🟩🟩🟩🟩
⬜🟩🟩🟩🟩
⬜🟩🟩🟩🟩
🟩🟩🟩🟩🟩

So our TAs prepared a spreadsheet with the final marks for all the students

And they flagged the students who were found committing plagiarism in the assignments

For those students, they wrote down

the phrase

"plag in ass"

Beware the ides of March

and shun

the frumious bandersnatch

@jsiehler Kudos is just some site that lets authors post layperson-friendly summaries of their papers for broader dissemination. I've never bothered with it, but other than the self-congratulatory name there doesn't seem to be anything too icky about it, and it's clear that it's the authors talking about their own work. The Wikipedia article is definitely weirder, to me.

A whole Wikipedia article singing the praises of a certain 1D root-finding algorithm, which was published in 2020, and has only 3 citations. Is this a new avenue of self-promotion by the authors?
https://en.wikipedia.org/wiki/ITP_method

@mjd My favourite version of this is "infinity isn't a number, it's a concept!" As if numbers aren't concepts, genius

@ColinTheMathmo That seems like it'll waste a guess on something that'll likely give you very little information? The most likely outcome is that none of the letters match, and then you haven't narrowed down the set of possible words very much.

What you describe may be a good strategy for Absurdle though. https://qntm.org/files/absurdle/absurdle.html