Category Archives: mathematics

Weird and slightly alarming – the chaos game

by Matthew Cobb This video from the excellent Numberphile YouTube channel shows a very simple game that has the most unexpected outcome. My only criticism of this video is that I’d like to be shown the explanation, even if it’s complicated! Maybe readers can help me.

More security lunacy: mathematician pulled from plane for . . . doing math

From Marginal Revolution, courtesy of reader Jósef, we have a bizarre tale of how our nation is being protected from terrorists. Here it is in its entirety (I’ve added the link to his university site): “Guido Menzio an economist at the University of Pennsylvania–author of Block Recursive Equilibria for Stochastic Models of Search on the Job among […]

Does the beauty and effectiveness of math in understanding the world prove anything?

One of the disadvantages of shopping for food early Sunday morning is that Krista Tippett’s “On Being” program is on National Public Radio at 7 a.m. And, of course, I have to listen, cursing to myself for an entire hour. Why do I do it, you ask? I could say that I need to keep […]


I win! And happy Pi Day!

An algebraic limerick

by Matthew Cobb Spotted on Tw*tter. I’ll give the source later, along with the explanation. Post your explanations below. If you know the answer already, please refrain from posting – if you work it out, go ahead! [EDIT: The correct answer appears in the first comment below! If you want to spend some time working […]

Some surprising sums—and a challenge

by Matthew Cobb This was tw**ted earlier today: 1+2+34–5+67–8+9 =100 12+3–4+5+67+8+9 =100 123–4–5–6–7+8–9 =100 123+4–5+67–89 =100 123+45–67+8–9 =100 123 –45 –67+89 =100 — Simon Pampena (@mathemaniac) December 9, 2015 There are five other sums (equations?) that give the same answer. Can you find them? Post your answers below.  

Two Google Doodles: one for a holiday, one for science

Today’s doodle in the U.S., and probably Mexico, features the Day of the Dead (click screenshot below), but I find the one in Ireland, sent by reader Grania, much more interesting, as it’s science-related. First, Dia de Muertos (yesterday and today), which I was lucky to see first-hand a few years ago in Mexico City: […]

Dave Gorman, perfect numbers, and why he left university

I don’t know the British comedian Dave Gorman, but this bit on perfect numbers makes me like him. He explains what a “perfect number” is in the sketch, but you can also read about those weird numbers here. When you look at Euclid’s formula for generating even perfect numbers, which shows a one-to-one correspondence with primes, then you realize […]


I really like this photo sent in by reader Barry.  The possibilities are endless!

Google Doodle honors mathematician Emmy Noether

Google Doodles these days to be concentrating on the contributions of women in science and technology, and today’s features Emmy Noether, a mathematician born on this day in 1882 (died 1935). If you click on the screenshot below, it will take you to the Google page, and there clicking on the picture itself takes you to a […]