Hey #MathSky. I’m teaching introductory linear algebra this fall for the first time in over a decade. What materials should I be aware of? I know I’ve seen a few posts about this sort of thing, but I don’t remember from whom or when. I don’t even know what (open) textbook(s) to use yet. Thank you!
Matt Macauley
@visualalgebra.bsky.social
Associate Professor (Clemson) | AIMS Lecturer (South Africa) | Author: "Visual Algebra" (forthcoming) | YouTuber | First Gen | Homesteader | Dad to Ida & Felix | 🔱
I know that \(…\) is supposedly “better” than $…$, but over the last 20+ years, I’ve shared LaTeX files with dozens of people, and I’ve NEVER seen ANYONE use \(…\) in the wild. Does anyone actually do this in practice? Or know anyone who does? Who are these mythical people?
Made some water kefir with my fresh figs. Added a little sugar in the raw and basalmic vinegar. Fermentation process takes 48 hours. Gonna crack it open tomorrow!
Got 7 pounds each of the last two days. Would have been much more, but the rain caused many to ripen and rot quickly and get attached by bugs and bees. Up to 98 pounds in 13 days
Picked 8 pounds each of the last two days. Up to 83 pounds in 11 days, all from a single Celeste tree that I planted in 2015. (Including a 2 lb basket I forgot to include in my last photo.)
Someone made a list of math problems solved by AI: vibemathed.com
VibeMathed - tracking math problems solved by AI models
A website tracking mathematical problems solved by AI models - from famous conjectures to the Erdős problems at erdosproblems.com - each with a checkable source, a verification label, and a notability...
vibemathed.com
Picked 8 pounds each of the last two days. Up to 83 pounds in 11 days, all from a single Celeste tree that I planted in 2015. (Including a 2 lb basket I forgot to include in my last photo.)
The distribution is not unimodal! Back up to 7 pounds yesterday and 8 pounds today. Now over 65 pounds of figs in 9 days, all from the same tree that I planted in 2015.
G-sets need to be taught in every abstract algebra class. It’s criminal at how absent they are from some of the most popular books.
Buckle up, kids — we're taking the factorial of a G-set! For a natural number n, n! = n(n-1)(n-2)⋯1 counts two subtly different structures on the set [n] = {1,2,...,n}: ① the bijections [n]→[n], ② linear orderings of [n]. For a group G acting on a finite set X, we'll try to understand ②. 🧮 1/
The distribution is not unimodal! Back up to 7 pounds yesterday and 8 pounds today. Now over 65 pounds of figs in 9 days, all from the same tree that I planted in 2015.
Not quite as much the last 2 days: 4.5 pounds and 6 pounds, respectively. But that’s brings last week’s total haul to just over 50 pounds.
In 44 days of playing this, I’ve never gotten a perfect score. Today was the closest I’ve come. And the one I missed was in an “easy round”. 😣 www.maptap.gg July 22 99🔥 100🎯 100🎯 100🎯 100🎯 Final score: 999
🎯MapTap Daily Geography Game
Play MapTap - the daily geography game! Find 5 world locations on a 3D globe with historical stories. Free browser-based daily game for geography lovers.
maptap.gg
The Gaussian Moments Conjecture is a pretty conjecture connected to probability and quantum field theory. Two days ago we suddenly learned it's false! - since it implies the Jacobian conjecture. Let me explain this conjecture - it's pretty simple as these things go. (1/n)
The Gaussian Moments Conjecture and the Jacobian Conjecture
We first propose what we call the Gaussian Moments Conjecture. We then show that the Jacobian Conjecture follows from the Gaussian Moments Conjecture. We also give a counter-example to a more general ...
arxiv.org
Not quite as much the last 2 days: 4.5 pounds and 6 pounds, respectively. But that’s brings last week’s total haul to just over 50 pounds.
Picked 6 pounds today, which means that this one tree gave me 40 pounds of figs in just 5 days!
The World Cup Final, when tied after regulation, should be Golden Goal. No shootout no matter what. Give each team one extra sub every 15 minutes. What’s the counter-argument to this?
Most people would find this either delicious or disgusting. Toasted sourdough everything (seasoning) bread, butter, fresh figs, and…Marmite.
Picked 6 pounds today, which means that this one tree gave me 40 pounds of figs in just 5 days!
Only 7 pounds today. But that’s still 34 pounds from one tree in 4 days. My LSU Gold and Chicago Hardy trees aren’t even ripe yet.
Happy Emoji Day! 📆 Celebrated today, because today is the date on the calendar emoji.
Only 7 pounds today. But that’s still 34 pounds from one tree in 4 days. My LSU Gold and Chicago Hardy trees aren’t even ripe yet.
And another 11 pounds today! Just from the Celeste. The LSU Gold and Chicago Cold Hardy figs haven’t even ripened yet.
And another 11 pounds today! Just from the Celeste. The LSU Gold and Chicago Cold Hardy figs haven’t even ripened yet.
24 hours later. Over 9.5 pounds! Al from one Celeste tree in my front yard.
24 hours later. Over 9.5 pounds! Al from one Celeste tree in my front yard.
It’s that time of year again!!! Today haul: over 6 lbs. I’ll be getting this much every day for a few weeks.
It’s that time of year again!!! Today haul: over 6 lbs. I’ll be getting this much every day for a few weeks.
Got my first rip Celeste fig of the year this morning. And saw this little guy protecting it.
#Worldle #1622 (01.07.2026) 1/6 (100%) 🔥 Current Win Streak: 140 days 🟩🟩🟩🟩🟩🎉 🧭⭐📍🗺️🚩🗿📜🛡️🔤🗣️💰💸📐 worldle.teuteuf.fr/share
Worldle - Guess the Country
A daily geography game where you guess the country from its shape and get clues with every attempt. Play daily or explore the archive.
worldle.teuteuf.fr
This is a fun daily game I discovered a few weeks ago. When you finish, they reveal 5 neat historical facts about the locations. It seems to frequently feature mathematicians; today it’s Sophie Germaine! This is also my highest score. www.maptap.gg June 27 95🏆 100🎯 100🎯 100🎯 100🎯 Final score: 995
🎯MapTap Daily Geography Game
Play MapTap - the daily geography game! Find 5 world locations on a 3D globe with historical stories. Free browser-based daily game for geography lovers.
maptap.gg
I went to the NAE's webinar on the proposed OMB changes. The intention of this is to stop scientific progress in the United States and cause the financial collapse of research universities. There is no other explanation for the proposed changes.
Russell Vought is an evil man. This plan is nothing short of a personal take-over of federal grant making. It will affect ALL of us. Political commissars will now be in charge of all agencies, reporting to him. But we are not powerless. See what you can do below. 1/ www.thenation.com/article/poli...
This was good. History of mathematics somehow helps me get a deeper understanding. "How Divergence and Curl Were Discovered" youtu.be/11QvV18JGQM?...
Natural Math newsletter is out! This doesn't happen every ::checks notes:: semester. Some amazing math fiction books in the pipeline - check out all the samples and full activities to download! #iTeachMath #MathSky #KidLit #NorthCarolina #Raleigh #Durham #ChapelHill
Factoring is friendship (check this out by 6/30); graph theory activities; Triangle, NC gatherings - June 2026 news - Natural Math
Thank you for checking out what’s new in the Math Maker Neighborhood! In this newsletter, you’ll see: Future Book Club news about three math fiction stories for elementary, middle school, and young ad...
naturalmath.com
I took my kids mushroom foraging in the woods behind my house, and we came home with a bunch of chanterelles.
All on her own, my 7-year-old daughter made me a surprise Father’s Day card with a Cayley Graph and Cayley table! 🥰
Hey #MathSky, I need your advice. Which of the following two pictures should I use to visualize quadratic integer rings? Pro of #1: They highlight the "fundamental domains." Pro of #2: Illustrates how both are "stretched versions" of the Gaussian & Eisenstein integers, respectively. 1/3
The Congo is COD?!? If only there was a more widespread 3-letter abbreviation for the the DRC…