Henry Segerman

Museum preparator Michael King was testing the mounting system today and invited me along to check it out!

A doorway into the safe, with a pattern of light and shadow visible inside.

A 3D-printed sphere is patterned with triangular holes. It casts shadows onto the wall.

Closeup of the 3D printed sphere. It is mounted on a pipe coming down from the ceiling, which also holds an LED light.

The OSU Museum of Art is in a beautiful old building that used to be a post office. They have a small but heavily-fortified room that used to be a safe. Not such a great location to view paintings, but will work nicely for light-based sculpture, like "(5,3,2) triangle tiling", by @saulsch and me.

Giant cardioid: version 2.5. Version 1.0 was made using Pex tubing and grommet tape. Version 2.0 was made from laser-cut pieces. The wood was too fragile, and it broke during construction. In version 2.5, I made the pieces wider and I used thicker wood. Success, I'd say! The diameter is about 5 ft.

Understanding geometry through model making

Everyone is invited to attend the SCULPT 2025: Show & Tell, a digital gathering that celebrates creative exploration across art, geometry, design, and fabrication.
Date: Friday, November 7, 2025
Time: 8:00 – 10:30 AM (PST)
Zoom Link: cca.zoom.us/j/9826107944...

Every Artist Has a Favorite Subject. For Some, That’s Math.

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...

A dark-themed event poster titled "EXPLORING ZETA FUNCTION VISUALIZATIONS." The poster includes an abstract about visualizing the Riemann Zeta function. A colorful, three-dimensional plot of a mathematical function dominates the right side. The bottom features a circular photo of the presenter, Grant Sanderson from 3Blue1Brown. The event is scheduled for Friday, October 10, with times listed, and will be held on Zoom.

The #illustratingMath Seminar Online returns on Friday, October 10th, 9 am Pacific / 12 pm Eastern / 6 pm Europe. @3blue1brown.com will be "Exploring Zeta Function Visualizations." Gabriel and Jim will provide some "Show and Ask" input. See you online on Friday!

@robertfathauer.bsky.social ?

Submissions are now being accepted for the Exhibition of Mathematical Art to be held as part of the Joint Mathematics Meetings, Washington, DC, in January of 2026. Apply online through October 15 at gallery.bridgesmathart.org. pic.x.com/MGSEyexSzo

This sounds like a similar idea to a project by Jeffrey Ventrella, see archive.bridgesmathart.org/2024/bridges... I don’t think he looked at fairness, and he made polyhedra with the points as vertices rather than faces.

Correct. And rigging up the slider at that angle would not be easy either!

Photograph of a camera with a probe lens mounted on a slider.

Just added a post with some of the behind the scenes details and unused footage from this video on my Patreon: www.patreon.com/HenrySegerman

You can buy these at www.mathartfun.com/DiceLabDice....!

Dice with greek letters on the faces, on a sheet of paper with a very long equation on it.

New dice from The Dice Lab (me and Robert Fathauer), which may (?) be useful if you regularly write equations. youtube.com/shorts/fgMox...

It’s a single loop.

In this image, our algorithm fills the sphere much more completely than Thurston's does, despite using ten times fewer edges.

The black curve is our recreation of Thurston's original algorithm to approximate Cannon-Thurston maps. The boundary between the green and purple regions is an approximation generated by our new algorithm based on veering triangulations.

A very squiggly black curve on a sphere. The sphere is divided into green and purple regions by a less squiggly, but more sphere-filling curve.

This image (made with Saul Schleimer) shows two different ways to approximate the Cannon-Thurston map associated to the figure-eight knot. Cannon-Thurston maps are space-filling curves, a bit like the Hilbert curve except that these fill a sphere rather than a square.

Submissions are now being accepted through September 14 for SCULPT 2025. Accepted work will be presented in a ZOOM Show and Tell event on November 7. In addition, works will be digitally showcased in the exhibition section of SCULPT 2025 and in a proceedings volume.

I learned thumb then index then middle. That seems like the most natural order to count your fingers.

Bathsheba mostly worked in bronze infused sintered steel. That process is no longer available from any supplier, according to Bathsheba: mathstodon.xyz/@bathsheba/1...

A person is giving a talk, with a split screen showing them and a slide with a hand-drawn diagram of a perfectly smooth torus with the title "The Perfect torus?".

A split screen shows a person presenting and a slide with a hand-drawn diagram illustrating the difference between "Mathematical Precision" and "Mathematical Imprecision" when constructing a torus.

A split screen shows a speaker and a slide with a hand-drawn diagram explaining the "Gauss map/Normal map," using a torus and a sphere to illustrate the concept.

A person presents with a split screen, showing them and a slide with a sketch of M.C. Escher's "Hand with Reflecting Sphere" and the word "Torus" written below it.

Starting the #illustratingMath talks at the @icerm.bsky.social today is Elliot Kienzle, who aims to settle the question how "To draw a torus." Like all good answers, his is based on differential geometry, taking the geometry of the torus into account when drawing. And Escher's there, too😄

Today, the one-week #illustratingMath workshop at @icerm.bsky.social starts. It is a week, packed with great talks on #images, #animations, #textiles, #sculptures, #dance, and #3dPrinting. All talks are being live-streamed, so go check out the schedule at icerm.brown.edu/program/topi... and join in!

I added a second post on my new Patreon, about my plans for a three-dimensional expanding racks design based on the srs net (also known as the Laves graph). See www.patreon.com/posts/135832...

The space-filling curve is the Cannon-Thurston map for a veering triangulation (with veering isosig gLLAQbecdfffhhnkqnc_120012). We prove that veering triangulations have Cannon-Thurston maps in an upcoming paper with Jason Manning.

I never got around to posting this animation I made with Saul Schleimer.This animates successively better approximations to a space-filling curve. (Or rather, you can tile the plane with the shape, and that gives the approximation to the space-filling curve.)

They generally do this by having health/damage numbers generally be very small: your attack might do three damage. Then an item that increases an effect by one makes a real difference to how you play, and feels like a real reward.

This allows the game makers to mete out many tiny rewards, although few that really make much difference to the game. There is however something of a movement (particularly in indie games) to have the items you get be meaningful upgrades, and the numbers involved be really meaningful.

There is perhaps a parallel in video game damage/health numbers. There are many games that measure how much damage your sword (or whatever) does in hundreds or even thousands. This allows for a large number of items to collect that modify your damage output by one or two percent here or there.

Come to mathstodon, where the sources of timeline bugs are presumably less opaque!