Reposted
I learned this folding technique yesterday, so I had to make something with it.
November 30, 2025 at 4:39 PM
I learned this folding technique yesterday, so I had to make something with it.
Reposted
εεεεδεεεεδεεεεδεεεεδ...
Every four ε, there is a δ.
Every four ε, there is a δ.
November 30, 2025 at 1:28 AM
εεεεδεεεεδεεεεδεεεεδ...
Every four ε, there is a δ.
Every four ε, there is a δ.
Reposted
non-Euclidean geometry proofs where the two columns eventually meet 💡
November 30, 2025 at 1:31 AM
non-Euclidean geometry proofs where the two columns eventually meet 💡
Reposted
lotta math classes teach about completing the square without ever asking why the square felt incomplete in the first place 😔
November 30, 2025 at 1:34 AM
lotta math classes teach about completing the square without ever asking why the square felt incomplete in the first place 😔
Reposted
Sunday night seems the right time to post a gallery of (I hope!) every one of Catriona's geometry puzzles.
notes.mathforge.org/notes/publis...
Give it a moment to load ... there's a *lot* of them!
#GeometryPuzzles #UKMathsChat #mathsky
notes.mathforge.org/notes/publis...
Give it a moment to load ... there's a *lot* of them!
#GeometryPuzzles #UKMathsChat #mathsky
Puzzle Gallery in Notes
notes.mathforge.org
November 16, 2025 at 6:24 PM
Sunday night seems the right time to post a gallery of (I hope!) every one of Catriona's geometry puzzles.
notes.mathforge.org/notes/publis...
Give it a moment to load ... there's a *lot* of them!
#GeometryPuzzles #UKMathsChat #mathsky
notes.mathforge.org/notes/publis...
Give it a moment to load ... there's a *lot* of them!
#GeometryPuzzles #UKMathsChat #mathsky
Reposted
We're disappointed to see Ben Barres's powerful book "The Autobiography of a Transgender Scientist" among the ~400 titles removed from the Naval Academy Library. Needless to say, we're proud to have published his book and will keep it — and his memory — alive.
The Coming Out of a Transgender Scientist
"I know that I am making the right decision because whenever I think about changing my gender role, I am flooded with feelings of relief."
thereader.mitpress.mit.edu
April 8, 2025 at 8:24 PM
We're disappointed to see Ben Barres's powerful book "The Autobiography of a Transgender Scientist" among the ~400 titles removed from the Naval Academy Library. Needless to say, we're proud to have published his book and will keep it — and his memory — alive.
Reposted
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.
November 9, 2025 at 4:34 PM
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.
Reposted
Understanding geometry through model making
November 6, 2025 at 5:51 PM
Understanding geometry through model making
Reposted
Hi Blue Sky! I edit the Journal of Humanistic Mathematics. We publish articles, essays, #fiction & #poetry on doing, teaching & living of #mathematics. So far we had more than 850K full-text downloads of our content - why not check us out? scholarship.claremont.edu/jhm/ #math #openaccess #mathart
Journal of Humanistic Mathematics - an online-only, open access, peer reviewed journal | Current Journals | Claremont Colleges
Journal of Humanistic Mathematics - an online-only, open access, peer reviewed journal published by the Claremont Colleges Library.
scholarship.claremont.edu
September 30, 2025 at 4:42 PM
Hi Blue Sky! I edit the Journal of Humanistic Mathematics. We publish articles, essays, #fiction & #poetry on doing, teaching & living of #mathematics. So far we had more than 850K full-text downloads of our content - why not check us out? scholarship.claremont.edu/jhm/ #math #openaccess #mathart
Reposted
Reposted
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
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
October 29, 2025 at 3:38 PM
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
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
Reposted
I met with my knot theory independent study students today. The topic: braids. I broke out these "BraidTiles" that I made several years ago. You can download a printable pdf here (recommendation: print them on cardstock): divisbyzero.com/2019/05/01/b...
October 29, 2025 at 7:09 PM
I met with my knot theory independent study students today. The topic: braids. I broke out these "BraidTiles" that I made several years ago. You can download a printable pdf here (recommendation: print them on cardstock): divisbyzero.com/2019/05/01/b...
Reposted
😃 Now you can define colors in the @desmos 3D calculator that depend directly on coordinates.
www.desmos.com/3d/s40shr66rn
www.desmos.com/3d/s40shr66rn
October 28, 2025 at 8:30 PM
😃 Now you can define colors in the @desmos 3D calculator that depend directly on coordinates.
www.desmos.com/3d/s40shr66rn
www.desmos.com/3d/s40shr66rn
Reposted
🌈 😃 Now you can now define colors in the @Desmos 3D calculator that depend directly on coordinates.
www.desmos.com/3d/42d0f0d88f
www.desmos.com/3d/42d0f0d88f
October 28, 2025 at 8:38 PM
🌈 😃 Now you can now define colors in the @Desmos 3D calculator that depend directly on coordinates.
www.desmos.com/3d/42d0f0d88f
www.desmos.com/3d/42d0f0d88f
Reposted
Free Online Math Materials
A blog post on linear algebra, taken from the students' preface to my free (gratis) book, with links to interactive software for matrix multiplication and exploring the geometry of linear transformations.
www.diffgeom.com/blogs/about-...
#MathSky #ITeachMath
A blog post on linear algebra, taken from the students' preface to my free (gratis) book, with links to interactive software for matrix multiplication and exploring the geometry of linear transformations.
www.diffgeom.com/blogs/about-...
#MathSky #ITeachMath
October 27, 2025 at 11:19 PM
Free Online Math Materials
A blog post on linear algebra, taken from the students' preface to my free (gratis) book, with links to interactive software for matrix multiplication and exploring the geometry of linear transformations.
www.diffgeom.com/blogs/about-...
#MathSky #ITeachMath
A blog post on linear algebra, taken from the students' preface to my free (gratis) book, with links to interactive software for matrix multiplication and exploring the geometry of linear transformations.
www.diffgeom.com/blogs/about-...
#MathSky #ITeachMath
Reposted
About to do triangle congruency methods, which is the exact topic that Jesse Spano overdosed on caffeine pills to study
October 23, 2025 at 8:05 PM
About to do triangle congruency methods, which is the exact topic that Jesse Spano overdosed on caffeine pills to study
Reposted
new @cshor.org pset 🏃💨
drive.google.com/file/d/1NaXQ...
screenshots of PDF pages 1, 2, 3, and 10 below
cc #iTeachMath ♾️
bcc #MathSky 🧮
drive.google.com/file/d/1NaXQ...
screenshots of PDF pages 1, 2, 3, and 10 below
cc #iTeachMath ♾️
bcc #MathSky 🧮
October 19, 2025 at 11:04 PM
new @cshor.org pset 🏃💨
drive.google.com/file/d/1NaXQ...
screenshots of PDF pages 1, 2, 3, and 10 below
cc #iTeachMath ♾️
bcc #MathSky 🧮
drive.google.com/file/d/1NaXQ...
screenshots of PDF pages 1, 2, 3, and 10 below
cc #iTeachMath ♾️
bcc #MathSky 🧮
Reposted
It is *still* unknown whether or not every triangle admits a periodic billiard trajectory. Every triangle with rational angles does. And so does every obtuse triangle of at most 112.4 deg. "112.5 appears to be a natural barrier."
gwtokarsky.github.io. #MathSky #Mathematics #Geometry #Billiards
gwtokarsky.github.io. #MathSky #Mathematics #Geometry #Billiards
October 18, 2025 at 12:15 AM
It is *still* unknown whether or not every triangle admits a periodic billiard trajectory. Every triangle with rational angles does. And so does every obtuse triangle of at most 112.4 deg. "112.5 appears to be a natural barrier."
gwtokarsky.github.io. #MathSky #Mathematics #Geometry #Billiards
gwtokarsky.github.io. #MathSky #Mathematics #Geometry #Billiards
Reposted
Announcing the next MAA President and Vice President!
Edray Goins will serve as MAA President-Elect and Yvonne Lai as Vice President starting July 1, 2026. Learn more about their vision and leadership: https://maa.org/news/announcing-the-next-maa-president-and-vice-president/
Edray Goins will serve as MAA President-Elect and Yvonne Lai as Vice President starting July 1, 2026. Learn more about their vision and leadership: https://maa.org/news/announcing-the-next-maa-president-and-vice-president/
Announcing the Next MAA President and Vice President – Mathematical Association of America
maa.org
October 15, 2025 at 6:13 PM
Announcing the next MAA President and Vice President!
Edray Goins will serve as MAA President-Elect and Yvonne Lai as Vice President starting July 1, 2026. Learn more about their vision and leadership: https://maa.org/news/announcing-the-next-maa-president-and-vice-president/
Edray Goins will serve as MAA President-Elect and Yvonne Lai as Vice President starting July 1, 2026. Learn more about their vision and leadership: https://maa.org/news/announcing-the-next-maa-president-and-vice-president/
Reposted
Today I realised that “integrates like” is the phrase I’ve been missing for talking about spotting the structure of an integral. #ALevelMaths #MathsToday
October 15, 2025 at 4:32 PM
Today I realised that “integrates like” is the phrase I’ve been missing for talking about spotting the structure of an integral. #ALevelMaths #MathsToday
Reposted
Timeline palate-cleanser: some pretty geometry in @desmos.com
www.desmos.com/geometry/wgp...
#iTeachMath #MathSky
www.desmos.com/geometry/wgp...
#iTeachMath #MathSky
October 15, 2025 at 7:29 PM
Timeline palate-cleanser: some pretty geometry in @desmos.com
www.desmos.com/geometry/wgp...
#iTeachMath #MathSky
www.desmos.com/geometry/wgp...
#iTeachMath #MathSky
Reposted
I recently worked on a fun problem involved the Pokémon TCG. Here's a post about the problem and my thought process/solution. jclevelandtran.com/2025/10/15/s...
October 15, 2025 at 8:10 PM
I recently worked on a fun problem involved the Pokémon TCG. Here's a post about the problem and my thought process/solution. jclevelandtran.com/2025/10/15/s...
Reposted
a million years later, this is still the neatest thing I've ever made, with huge help to the person at TMC13 (!) who figured out how to make the planets orbit www.desmos.com/calculator/d...
October 13, 2025 at 8:10 PM
a million years later, this is still the neatest thing I've ever made, with huge help to the person at TMC13 (!) who figured out how to make the planets orbit www.desmos.com/calculator/d...