@mathandcobb.bsky.social
Professor of Mathematics, number theorist (arithmetic geometry), author, Hagoromo chalk ambassador, bonsai amateur. Views expressed are my own.
Dimension one? 😍
21.02.2026 02:11 — 👍 1 🔁 0 💬 0 📌 0
Let's play once again "SHOULD THAT REALLY BE NAMED AFTER NEWTON??" Today: "Newton's Cradle"...
youtube.com/shorts/vswX-...
You know what's really cool? Visualizing what's happening geometrically as we do row reduction operations on a linear system of equations! #math #linearalgebra #rowreduction
youtube.com/shorts/wTYfM...
Aristotle used a theorem in geometry that characterizes spheres in order to give very strong evidence that the earth is spherical... some 2300 years ago! Let's see the proof of the theorem. #math #sphere #geometry #aristotle
youtu.be/SpGXoYh-c5Y
In this video we learn how to analyze a row reduced echelon form (RREF) to deduce properties about the solution set of a linear system
youtube.com/shorts/XPtQ1...
Would Erdős hate that mathematicians are using AI/LLM's as assistants to find new proofs? I'm not sure sure! #math #ai #erdos
youtube.com/shorts/0SXdv...
Now that Erdős and Erdős' problems are trending, it's time once again to show off my paper plate with his handwriting on it! Is this an Erdős problem?
youtube.com/shorts/9aUrA...
This semester I'm teaching multivariable calculus and recording my lectures, plus adding other short/reel videos to clarify concepts or add examples. Hope this is useful to students! Here is the playlist of videos as they are uploaded. #math
Multi-Variable Calculus: www.youtube.com/playlist?lis...
What is multivariable calculus all about? #math #calculus #multivariablecalculus
youtu.be/IAKwooA9yvc?...
Why do we diagonalize matrices? #math #linearalgebra
youtu.be/DgkTeTWkikI
An example of matrix diagonalization #math #linearalgebra
youtu.be/1LXnF92yE7I
Are mathematicians "cooked", like the kids would say, because AI has found solutions to open problems in mathematics? I'm here to address the doom and gloom and tell you that Mathematicians are more relevant than ever! #math #ai
youtube.com/shorts/LeFV0...
Hey @amermathsoc.bsky.social still convinced it's a good idea to have #ICM2026 in the USA?
14.01.2026 15:50 — 👍 17 🔁 5 💬 2 📌 0
Mathematics education research is mathematics research. It's just one of the areas of study within math #math #research #mathed
youtube.com/shorts/XmSjZ...
We are so excited this is happening! Ask me any questions, #TCSSky #MathSky!
Also, we are looking for a couple more project leaders, so if you want to know more about what that involves, please get in touch.
🚨🚨 BREAKING NEWS🚨🚨 in AI and MATH! AI has solved 3 open problems more or less autonomously... is this a big deal? Is this a HUGE deal? Let's see what happened and decide #math #ai
youtu.be/5GkiLtnlcoY
Say more
13.01.2026 04:10 — 👍 1 🔁 0 💬 0 📌 0
LOVE this comment! Watch until the end for some ideas on how to prepare for Calculus 3 (and also for an unexpected visitor)
youtube.com/shorts/8WtWH...
Not transitive, ironically.
11.01.2026 12:49 — 👍 7 🔁 0 💬 0 📌 0
Teaching a large lecture of Calculus 3, multivariable calculus is daunting but also really exciting! The material of Calc 3 is really cool so can't wait. #math #calculus #multivariablecalculus
youtube.com/shorts/PEZF_...
Graphic announcing AMS-Simons research enhancement grants awarded to PUI faculty with molecular network design on blue background.
Applications for the AMS-Simons Research Enhancement Grants for Primarily Undergraduate Institution Faculty are now open. Learn more and apply today: https://www.ams.org/grants-awards/ams-simons-pui-research
09.01.2026 14:00 — 👍 7 🔁 3 💬 0 📌 1
Let's learn how to row reduce matrices because it's a FUNDAMENTAL skill to do well in an intro to linear algebra class! On top of that, let's also figure out how to compute the null space of a 3x3 matrix #math #linearalgebra
youtube.com/shorts/4WVBL...
What is a kernel? What is a null space? How are the two related? How do you compute them? Very important questions in linear algebra! So let's go thru the definitions and examples #math #linearalgebra #kernel #nullspace #rowreductionmethod
youtu.be/njjWbGjmJ3g
When was Calculus invented? Or was it discovered? Who invented it? Or were there multiple discoveries throughout history? The answer is a lot more complicated than "Leibniz" or "Newton" #math #calculus
youtube.com/shorts/OiseB...
Can high school students find research level math problems to work on? #math #research #highschoolmath
youtu.be/3q_JeKg9rg0
It was Newton's birthday recently... so let's *remove* Newton's name from the "Newton's method" which, in fact, should be called the Viete-Raphson-Simpson method instead! #math #newton #newtonsmethod
youtu.be/x7plcVWcGbI
I don't know exactly how this works but given the answers I got on several iterations it really looks like it was trying things out itself.
26.12.2025 20:40 — 👍 1 🔁 0 💬 1 📌 0back in my 2^n - 2*n era
for the first time since n=10
For full disclosure, I've been asking AI and humans for interesting expressions for 2026 and ChatGPT 5 came up with this one while a human (someone in the comments... no proof of humanity) came up with
2026 = 2^(22/2) - 22
2026 = 2^11 -2*11
26.12.2025 19:33 — 👍 18 🔁 2 💬 2 📌 1
