Matt Macauley

I used to post long #VisualAlgebra threads on #MathTwitter before realizing that I was actually in #TheBadPlace. I'm going to make my debut #MathSky thread today, with visuals that I've never publicly shared. (Can you guess the topic?) I'm excited to show you, and I hope you enjoy! 1/19 🧵👇

This is a fully visually evident proof of the fact that the diagonal of a regular unit pentagon is the golden ratio. arxiv.org/abs/2610.18903

I was interviewed by the NPR show On Point, with things I said dropped in a couple of places into an illuminating conversation between Steven Strogatz and Meghna Chakrabarti about AI and math: www.wbur.org/onpoint/2026...

Rutherford's puzzle about 'Napoleon's theorem' was published in 𝘛𝘩𝘦 𝘓𝘢𝘥𝘪𝘦𝘴' 𝐷𝑖𝑎𝑟𝑦: 𝑜𝑟 𝑊𝑜𝑚𝑎𝑛'𝑠 𝐴𝑙𝑎𝑚𝑎𝑛𝑎𝑐𝑘. Interestingly, this woman's magazine was an important forum for math problems before more 'serious' math journals appeared in the UK in 1830.

www.nytimes.com/2026/09/22/s...

Chaim is bringing the fire 🔥

For anyone wondering what Navier-Stokes is all about and what the recent proof did and didn’t do, watch @QuantaMagazine’s excellent new explainer video: youtu.be/PsWR1rQEWYo

September fruit from my orchard. I picked these all today. Fuyu persimmons, flying dragon citrus, and red & green muscadines.

This fall I am co-teaching a brand-new class – ENGR 009: Fabricating Tessellations and Tilings. It's roughly equal parts math and design, filtered thru an engineering perspective. The syllabus and all assignments are freely available to the public at mzucker.github.io/e9_f2026/

Here's a thoughtful blog post about math and AI by Matt Baker. mattbaker.blog/2026/09/10/s...

A recent Washington Post article titled "This may be the first academic profession to see its work taken over by AI," ponders if AI can solve mathematical problems, what is left for mathematicians to do? What do you think? Leave your comments below! Full story link in comments.

My 7-year-old daughter heard me say that Dolly Parton died, and got visibly very sad. I was surprised she even knew that name. “You know Dolly Parton?” In the sweetest timid voice, she replied: “Well, I don’t _know_ know her. But she sent me books.” 🥹😢😭

Academics, to "celebrate" the start of a new semester, post a WayBack Machine snapshot of your workplace from when you were applying to college (or a later milestone if you missed the dawn of dot edu) #WayBackCollegeChallenge

Nothing quite melts my heart like my 7-year-old daughter asking in earnest after dinner: “Daddy, can we do some abstract algebra?”

It took 62 days of playing, but today I finally got my first perfect score in #MapTap! (Albany, Athens, Singapore, Bangkok, Gaborone.) www.maptap.gg August 9 100🎯 100🎯 100🎯 100🎯 100🎯 Final score: 1000

When you get over 150 pounds of fresh figs in 3 weeks, you have to get creative. This is a cast iron skillet with wheel of Brie cheese, fresh figs, nuts, fresh rosemary, honey, balsamic glaze, and raw cane sugar. Baked for 30 minutes.

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!

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

Someone made a list of math problems solved by AI: 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 Riemann Hypothesis is false.

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.

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.

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

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)

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.

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!

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.

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.

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

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

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

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! 🥰