"Only the Sea Saw When it Sank" www.desmos.com/3d/qnjd3qwwv... #desmos #mathart #mathplay

I'll try making some simple @desmos.com art with my students today. The only "math" part of this is the geometric dilation with a list of scale factors: the rest is just drawing with the Geometry polygon tool. So, mostly fun, but some learning too! www.desmos.com/geometry/why... #iTeachMath #MathSky

Here's a Halloween-themed @desmos.com geometry activity, in case anyone is looking for one. Task: transform the black witch's hat onto the orange one. The first few screens use constructions, and the rest use coordinate transformations. classroom.amplify.com/activity/690... #iTeachMath #MathSky

The new surface-colouring option in @desmos.com 3D allows a cute way of visualizing conic sections. www.desmos.com/3d/fiv5gnltdl (The option to have translucent surfaces doesn't save with the graph itself, so needs to be re-toggled on. It's important for seeing the full curves) #MathSky #iTeachMath

Have you noticed a change of colors? 🍁 You can now define colors in the 3D calculator that depend directly on coordinates. 📝 Learn more in the Desmos Help Center: help.desmos.com/hc/en-us/art... #iteachmath #mathsky

I saw this poster in NYC, and was struck by how it (unintentionally) embodies a key tension in the philosophy of free will. We tend to be determinist when forgiving people we feel sympathy for, and libertarian when criticizing views that we dislike.

Some Halloween @desmos.com art 🎃 www.desmos.com/calculator/z... #iTeachMath #MathSky

New yardbird! Harris’s Hawks aren’t terribly uncommon but this is a first for our east Tucson yard ☀️🪶🌵

Complex function domain-colouring of roots of unity, in @desmos.com Here's the graph: www.desmos.com/3d/hadt9rebbe They recently enabled colouring a surface using functions, so far only in 3D grapher. Side-effect: allows complex domain colouring, using 3D tool as a 2D one! #iTeachMath #MathSky

Timeline palate-cleanser: some pretty geometry in @desmos.com www.desmos.com/geometry/wgp... #iTeachMath #MathSky

There's a nice article by Siobhan Roberts about the Bridges 2025 conference in Eindhoven in the NY Times. I can now say that I am in The NY Times! (A photo credit for the shot of Chaim Goodman-Strauss and Edmund Harriss,... but still!) www.nytimes.com/2025/10/10/s...

Borromean rings in @desmos.com 3D: www.desmos.com/3d/nje29p8eqp #iTeachMath #MathSky

It looks like the Wikipedia page for Mary Brunkow got created literally just this morning, after her Nobel Prize was announced. I had heard that women in academia tend to be somewhat under-represented on Wikipedia, but this is a particularly stark example. en.wikipedia.org/w/index.php?...

I just finished a new website on fractal self-replicating tiles ("reptiles") based on polyominoes, polyhexes, and polyiamonds: www.mathartfun.com/fractaldiver...

I think my geometry students will enjoy making an infinite zoom effect, using the dilation tool in @desmos.com Geometry. Here's an initial attempt. Don't stare at it for too long! 😀 www.desmos.com/geometry/x46... #iTeachMath

Lorentz attractor in @desmos.com 3D #iTeachMath www.desmos.com/3d/mnm7duxhew

Is this a new piece of Kenny Scharf graffiti on W 57th St? I walked past it this morning and don’t recall seeing it before.

Here is a @desmos.com activity about the symmetry-preserving transformations of a square, inspired by my colleague Tom Jameson. classroom.amplify.com/activity/68c... For a really great intro to how this relates to group theory, see this by @stevenstrogatz.com archive.nytimes.com/opinionator....

Making pretty patterns is fun. And it can help you to learn geometry! I made a short video about how to make a snowflake in @desmos.com Geometry. Comments and suggestions welcome! #iTeachMath ❄️ www.youtube.com/shorts/EI1RN...

Seen at the MoMA Design Store. @momanyc.bsky.social . It’s a nicely designed light, but it’s not a hexagon! #

Great to see the NYT launch another math-related puzzle, after their Numbers game got beta-tested and then dropped a couple of years ago

In a new op-ed, Cornell Tech professor Tanzeem Choudhury and postdoctoral associate Dan Adler argue for a new labelling system for AI-driven mental health tools. Read more in STAT: www.statnews.com/2025/08/20/c...

This talk by Erik Demaine was great. And I very much enjoyed the talk by Dave Richeson on the game Left, Center, Right too!

Am enjoying attending the @momath.bsky.social MOVES conference at @nyucourant.bsky.social Any other BlueSky folks here? momath.org/moves-confer...

@mathtechcoach.bsky.social I was messing around with conics and ran across your GeoGebra inscribed one. I’m curious: do you happen to know what the point H is called, and how one might prove that the tangent-to-vertex lines are concurrent there? Thanks!

Check out the replies to the post below for an ever-growing list of great resources for math teaching! #iTeachMath #MathSky

Messing around with circle inversions in the complex plane in @desmos.com. #iTeachMath #MathSky www.desmos.com/calculator/m...

I’m at @unm.edu for a camp my kid is at, and I popped into their meteorite museum. It didn’t look like much, until the amazingly knowledgeable person working there told me more. This fragment of the Murchison meteorite is 7 billion years old: the oldest object on Earth! It contains amino acids!

My "Math, Revealed" series is freely available to anyone -- no paywall! -- in the thread below.

I just now stumbled across the website of @malinc.bsky.social. It's full of really wonderful interactive pieces on math education and geometry. Thanks so much for having created such a great resource! www.malinc.se #iTeachMath #MathSky

If you want to see a truly wonderful piece of mathematical communication, check out the thread by @stevenstrogatz.com, replying to my question below. My question was in response to his article, wonderful in itself: www.nytimes.com/interactive/... A welcome reminder of good things in the world!

I was playing around with distance loci in @desmos.com. This one is sort of fun: it looks like the orange blob avoids the black dot by looping around it. #iTeachMath #MathSky www.desmos.com/calculator/k...

My latest for @nytimes.com -- please repost so your followers can see this for free. www.nytimes.com/interactive/...

Did someone say folders?! 📂 👀 You now have more options when saving and sharing. 🎉 Access all your saved graphs across tools in a refreshed view. Share your graphs with more control. Quickly switch between tools. And did we mention folders? 🗒️ Learn more: help.desmos.com/hc/en-us/art...

Woah! @desmos.com have added folders to sort your shared graphs!

Dear #mathsky, if you repost this, it will let people see the article for free. Thanks! www.nytimes.com/interactive/...

Some photos from the exhibition that opened at the National Museum of Mathematics Thursday, on 5th Ave in NYC. The other artists/mathematicians in the exhibition were Nicolas Belmonte, Chaim Goodman-Strauss, Edmund Harriss, Stepan Paul, Henry Segerman, and Steve Trettel.

Explore sketches that use AI to create generative arts, games, and more! Joe's AI curation is one of those to surface all the great sketches on OpenProcessing that we can learn a lot from. Now featured on the activity page! openprocessing.org/curation/88218

The great Alfred Brendel has passed away at 94. There was no piece of music in the world he loved more than Mozart's Concerto No. 9 in E flat, K. 271. Here he is, in his piece. God bless Herr Brendel. www.youtube.com/watch?v=DP8i...

I was playing around a bit with @desmos.com Geometry, and I stumbled upon yet another rearrangement way of demonstrating the Pythagorean theorem. I don't recall seeing this particular version before, so I figured I'd make an animation of it. #iTeachMath #MathSky www.desmos.com/geometry/863...

Despite everything (or maybe because of it?), sometimes it's nice just to play with some silly code. Here's an early-stage game using @q5play.bsky.social for physics, and ml5.js for face-tracking. Your task is to catch fruit with your mouth, but not the germs! 🦠 openprocessing.org/sketch/2664137

I got an email from someone asking for my "Essential Trigonometry for Calculus" cheat sheet, which I give to my calculus students. So, I thought I'd put it on GitHub for anyone to download (compiled PDF and source code). github.com/divisbyzero/...

Is there a name for this arrangement of circles? They pass through the incircle's tangent points and center, and the vertices. Their existence is not at all deep, but they are quite pretty! Is there a name for them, or are they too trivial to have one? #iTeachMath www.desmos.com/geometry/n0a...

In important news, we have a new winner in the hotly contested category: Most Silly Website for a Restaurant: sketch.london Don't miss the animated spinning entrance when you click on a menu! (The restaurant itself looks really good, though).

Here's how AI systems scored on Part 1 of an old Regents Geometry exam. Wide variance: Gemini won by a lot! #iTeachMath (pp.2-11 of www.nysedregents.org/geometryre/8...) ChatGPT: 9 / 24 chatgpt.com/share/683598... Claude: 13 / 24 claude.ai/public/artif... Gemini: 22 / 24 g.co/gemini/share...

Dynamic window size in @desmos.com means that we only need 1 parabola now! Hooray! www.desmos.com/calculator/z...

Our R01 was part of yesterday's "mass termination" at Harvard; 1 of ~1000 NIH grants in Trump's "fight". The irony of how many Jewish (& non-Jewish) researchers/scientists/physicians/patients/students will be harmed in the name of "fighting antisemitism" is sickening.deliberately cruel. #AcademicSky

Here's a simple hand puppet, made with the wonderful library p5play @q5play.bsky.social, which provides sprites and a physics-engine, and hand-tracking via ml5.js (from @shiffman.lol and his colleagues). You can run it in a web-browser and explore the code here: openprocessing.org/sketch/2652482

If you're in science, read this. I used to be in neuroscience, and was NSF-funded. (I'm now much happier as a math teacher, but that's me). So, I've been hearing about the huge cuts. However, the public hasn't heard. They don't know that medical research is being gutted. Time to spread the word.

With a high degree of confidence, we can confirm new inference tests are now live! 🎉 🗒️ Learn more in the Desmos Help Center: help.desmos.com/hc/en-us/art... #mathsky #iteachmath #statistics