Just discovered espanso, a snippet expander: https://espanso.org/ It's all configured with regular YAML files, works perfectly on Linux and macOS. It's super easy to use and really nice -- I do :shrug and get 🤷. I was grading last week and leaving feedback comments and it was nice to automate […]

CS folks: I have a bit of extra professional development funds and am looking to buy some good books. What are some of your all-time favorite books related to CS, programming, and so on? (For me, I might mention "On Lisp", and "Algorithms to Live By") I'm especially interested in books on CS […]

I made a Norwegian resistance hat! #crochet #iceout #twincities

What would you say is the difference between "fraction" and "rational number"? (Context: teaching an intro programming course and we have an example class for...these things. The existing materials call it "Fraction", but somehow I feel like RationalNumber or Rational would be better, but I […]

NYT article on how giving prompts to an AI chatbot with code examples riddled with security problems turns the entire chatbot into a...very bad "person"/misaligned model […]

I recently was trying to use `gtasks` for command-line access to my Google Tasks, and didn't like how it did some things. I look at the repo, see it's in #golang, but decide to actually use Claude to implement a feature. It was super easy -- and along the way, I looked at bit at the Go -- it […]

🧵 1/3 A public service announcement...and a story about a very frustrating, subtle, weird problem: I'm on macOS and am making html slides from markdown. I have a makefile that does the conversion, and it has a "clean" target to remove the generated html files. I'm a little chary, and figure […]

I'm interested in learning about formal methods and zero-knowledge proofs, particularly for their use in verifying software. I know very, very little about this, but it would be very useful if I knew more. What are some good basic introductions? I'm going to poke around a bit with Lean and […]

What is this polyhedron? I made this modular origami piece, and I want to know what polyhedron it represents. The units all have three arms, so the underlying graph is 3-regular, and all the faces are pentagons and hexagons. So, there's necessarily 12 […] [Original post on mathstodon.xyz]

A while back someone gave me some AirTags. Now I want to use one...but I can't find them. #irony

Once again I went down a rabbit hole figuring something out, and now you -- yes, you, random person on the internet -- can benefit from my work. I write slides for my classes in markdown and turn them into reveal.js slides. Sometimes I want to post the slides, but I want to strip out speaker […]

Analogs of binomial coefficients: q-binomial, Stirling numbers, and Eulerian numbers https://www.johndcook.com/blog/2025/07/24/analogs-of-binomial-coefficients/

Very proud of my fellow Minnesotans and Twin Citians: yesterday was brutally, viciously cold -- high temperature was -9 Fahrenheit (-22 Celsius). That was the HIGH temperature. And in that brutal weather, tens of thousands of people went outside to protest […] [Original post on mathstodon.xyz]

I know I posted about this but can't find it -- but today I learned of the --human-numeric-sort option to the GNU "sort" command! "sort -h" is smart about suffixes: it knows that 999K is less than 1M, and so on. It's obviously designed to handle input from things like "du -h", which means du […]

RE: https://graz.social/@publicvoit/115944406944516221 I use emacs *and* vim...and I also use a cargo bike *and* a regular bike...I love this analogy. I might also compare vim to a fixed-gear bike; riding a fixed-gear bike is a bit different than a regular bike, since you have to learn how to […]

#emacs vs. #vim Real World Analogy: #cargobike Vs. #foldingbike https://karl-voit.at/2026/01/23/Emacs-vs-vim-Cargo-Folding-Bike/ This isn't supposed to deliver fuel to the gratuitous #editorwar. It's supposed to clear up a few things why the two tools are so fundamentally different. HTH […]

I found this lovely little utility by @mjd -- it reads lines on stdin, gives you a little menu to choose some of them, and echoes those to stdout. I'm more of a Python person, so I tried asking a chatbot to convert the code. It went very well. Get a Python version at […]

🧵 1/N I was struck by this artwork at the Minnesota Museum of American art. It was part of an exhibit called Queering Indigeneity. I noticed the fractions, and pondered what that would have to do with queerness. Well, being queer could be viewed as being […] [Original post on mathstodon.xyz]

From Matt Haig's great book "The Humans": "Listening to music, I realized, was simply the pleasure of counting without realizing you were counting."

I just completed "Gift Shop" - Day 2 - Advent of Code 2025 #AdventOfCode https://adventofcode.com/2025/day/2 I did this part in Racket. Oh, Racket, you are so lovely. #racket #adventofcode

I just completed "Secret Entrance" - Day 1 - Advent of Code 2025 #adventofcode https://adventofcode.com/2025/day/1 (I'm in academia, so I'm always too busy in December to do Advent of Code. But I have time now!)

TIL a fun thing about Unicode, text, and emojis. I ran into a very weird encoding / text display thing with checkboxes: I saw both ☑︎ and ☑️ But emacs said both of those were the same: Unicode codepoint U+2611. I couldn't figure out why they were shown differently. Thanks to […]

My friend @gobfrey sent me this photo. It looks like an origami crease pattern! Also, he knows exactly the kind of geometric images that I find irresistible. #origami #pylons

The other evening I started reading Daniel Temkin's "44 Esolangs": https://danieltemkin.com/Esolangs I just read the introduction and skimmed a few of the languages. In the following eight hours, I thought of three esolangs of my own! This book may be slightly deadly to my productivity […]

Second derivatives in the news:

One thing about being a human using the internet in 2025 is that you have to prove that you are a human all the time, often by doing a CAPTCHA. One interesting thing I realized about proving you are human: it can be good to make mistakes! Today I was proving my humanity by clicking on all the […]

@ddrake here’s our education policy! https://wizardzines.com/education/

New Yorker magazine should have a diaresis over one of the zeros in its 100-year anniversary logo.

@b0rk I have your debugging zine and it's great! I want to give it to my students as a reading / resource in my intro programming class. Your zines store mentions teams and companies -- what are your thoughts on use in educational settings?

How do you pronounce hexadecimal numbers? You just say the "digits", right? But that sounds a bit weird, in English, especially the letters -- for example, 0xAC, 0xCD, 0xCF match up with acronyms for alternating current, compact disc, and the Latin "conferatur" for "compare". In the middle of […]

Neat paper on statistics and medical conditions, and the danger of round numbers: https://www.nature.com/articles/s41746-025-02079-y You have, say, a condition you can treat. There's some test or biomarker you can examine to determine the risk from the condition. You have a treatment which […]

@divbyzero @JenJen now you've got me experimenting with square twist tessellations. The pattern on this paper looks neat with the twists.

I want to combine my usual geeky topics with my political ones, specifically my disapproval (to put it very lightly) of Trump's racist insults of the Twin Cities' Somali community. Last summer I read "Don't Teach Coding Until You've Read This Book", which makes a strong case that programming […]

Having just replied to @pixelate on actual good uses of chatbots and AI, here's another: agriculture. Cool article in Communications of the ACM on this: https:/dx.doi.org/10.1145/3760437 Agriculture is (ahem) ripe for AI applications -- think of things like taking sensor data and using that to […]

Today I learned another way in which Macalester College takes its Scottish heritage very seriously. When you get tenure here, the way you find out is...bagpipes. Typically there's some department meeting or other gathering, where, unbeknownst to the newly-tenured professors, members of the […]

A tiny thing that you only will know if you live in a city where you get lots of snow: The first time you get a good snow that completely covers lawns and roofs and so on, your bedroom at night suddenly is not as dark. It's the reflectivity of the snow and all the streetlights -- before the […]

Why nobody told me that #lisp #racket is sooo cool! Lang of choice for #adventofcode2025 ?

Git folks: I'm looking at @b0rk's Oh Shit, Git thing for when you commit to the wrong branch and want to move the top commit elsewhere. For a commit to main, you have: # create a new branch from the current state of master git branch some-new-branch-name # remove the last commit from the […]

Thinking of a comment from @inthehands on this Black Friday -- "I never thought I'd say this, but I miss consumer capitalism." I agree -- right now, I could sure go for an economy and culture relentlessly promoting spending and consumption. Instead, we have a few AI-related companies sloshing […]

Ugh, I hate bad UI like this: I'm ordering some energy-efficient stuff and I get a discount through my local electrical utility. On the checkout page, I have to enter my account number to get the discount. The field for that has this text below: "Your utility account number is shown in the red […]

I really like the old-school, text UI style of this cookie popup on the JetBrains website. II usually click reject cookies -- or even click "manage" and decline them there, which surely puts me in rare territory -- but I liked this enough that I accepted the […] [Original post on mathstodon.xyz]

A while back I wrote about how anyone who cares about their digital data and access to it (which is, basically, everyone these days, right?) should choose tools that cannot be taken away, and to use data formats that can be used by many tools: https://ddrake.prose.sh/choosing_tools […]

There's an old joke about emacs users and foot pedals to help them handle the crazy key combinations used by emacs. I just discovered that you really can get foot pedals! Check out the Duckypad Pro: https://www.tindie.com/products/dekunukem/duckypad-pro-macro-scripting-beyond-qmkvia/ I have a […]

Waymo started testing their autonomous taxis in Minneapolis...today: https://www.startribune.com/driverless-ridesharing-company-waymo-expanding-to-minneapolis/601527735 https://www.cbsnews.com/minnesota/news/waymo-driverless-taxi-fleet-coming-to-minneapolis/

Yesterday I gave a presentation at a nearby senior center called "AI for the confused" -- I've been inspired to do some outreach to educate less-technical people on just what AI is these days, how to use it, what to know about it. An interesting thing: one of the attendees was deaf. She had an […]

RE: https://mastoxiv.page/@arXiv_csHC_bot/115575733396796885 This looks really interesting -- how can you present code in a way that reduces cognitive load for blind and low-vision users? Of course, in the spirit of universal design, my first suspicion is that if you can reduce cognitive load […]

🧵 1/N Imagine a graphics/paint program that worked with 24-bit RGB values, and which had a color selection where you could type in the numerical values for the three channels. Now imagine that program would let you type in numbers bigger than 255, or negative values. And it wouldn't tell you […]

Just went down a rabbit hole to fix a weird bug and feel like (1) I should post about it so that others can find it (or, these days: so it can get sucked into LLM training data), and (2) so I can vent about how irritating it is. Problem: using Ptyxis, the default terminal in GNOME 49 / Ubuntu […]

Texas A&M makes it a thought crime, basically, to "advocate" race or gender ideology: https://www.nytimes.com/2025/11/13/us/texas-am-gender-race-ideology-rules-classroom.html?unlocked_article_code=1.1E8.DhKk.wCdC1ptnYqDO&smid=url-share There's quotes from leadership claiming that the policy […]

Infinitely More is a substack by Joel Hamkins. Lots of interesting essays on math and the philosophy of the infinite: https://www.infinitelymore.xyz/ I subscribed, and have several gift subscriptions I can give away. If you're interested, DM me and I'll give you one.