On Monday, Harald Helfgott of the École Normale Supériure in Paris posted a proof of one of the oldest open problems in number theory to the preprint repository arxiv. The ternary Goldbach conjecture, like so many questions in number theory, is easy to state but hard to prove. Every odd number greater than 5 can [...]

Many math teachers have a hands-on approach to their subject, but those hands aren’t usually covered in finger paint. Scott Goldthorp, however, sometimes teaches messy math classes. Goldthorp, a teacher at Rosa International Middle School in Cherry Hill, New Jersey, was the grand prize winner of the inaugural Rosenthal Prize for innovation in math teaching, [...]

Image: Design Shack In the current issue of the Association for Women in Mathematics newsletter (password required), Anne Carlill asks where the female mathematicians are on Twitter: “I found that the only female mathematicians or math educators I followed were Nalini Joshi in Sydney and Fawn Nguyen in California. In contrast there are about 15 [...]

Today I have a piece in Slate about that pi meme that’s been going around. According to the meme, your life story is encoded in pi somewhere. My life story would probably include the word “Evelyn” at some point. (I’m going out on a limb, but stay with me.) In a code that assigns the [...]

There’s a contest going on right now that could reward you for letting your geek flag fly. Spoonflower, a fabric design website, is hosting a “geek chic” design contest that closes April 23. It’s held in conjunction with Robert Kaufman Fabrics, and the lucky winner will get to create a fabric collection for Robert Kaufman. I had [...]

Rather appropriately, April 1st is the 91st day of the year, at least in non-leap years such as 2013. 91 might look innocent, but it’s a sneaky little number because 91=7×13. That might not seem sneaky to you, but I’m here to tell you why it is. Every whole number can be broken down into [...]

March Madness always sneaks up on me. I mean, I know that March has started because my dad’s birthday and my wedding anniversary are right at the beginning of the month, but I always end up scrambling to make my NCAA basketball tournament picks the day before games start. Mathematician Jordan Ellenberg has taken the [...]

On the one hand, I like Pi Day because I get to eat pizza and/or pie, and I like things that get people excited about math, but on the other hand, I’m an adult, and I get to eat pizza and/or pie whenever I want, Pi Day or no. Like Matt at Math Goes Pop, [...]

Last year, in the inaugural Flame Challenge, Alan Alda and the Center for Communicating Science at Stony Brook University challenged scientists to explain what a flame is to an 11-year-old. This year, the subject was time. In particular, we were instructed to “Answer the question — ‘What is time?’ — in a way an 11-year-old [...]

Wrong in Public is a new, hopefully very occasional, series on Roots of Unity. I don’t like being wrong in public, but sometimes I make a mistake in a post, and sometimes mistakes are interesting. In last Friday’s post on the 4-color theorem, I talked about some of the hypotheses of the theorem, including the [...]