In the September 2008 issue of the College Mathematics Journal Travis Kowalski presents an neat way to measure an angle using a ruler. He attributes the discovery to a student of his, Tor Bertin. Given an acute angle (the technique can be modified for obtuse angles), measure off a distance on each ray. Then measure…
Category: Math
Shameless self-promotion
If you happen to be in or near Carlisle, PA tomorrow (Friday, October 17, 2008, 6:00-7:30), come by the Whistlestop Bookshop. I’ll be signing copies of my new book Euler’s Gem. Light refreshments will be served.
The eyeballing game
A friend of mine sent me a link to the Eyeballing Game, presumably because it looks mathematical. At a glance it does look like geometry, but really it is a test to see how well you can recognize when geometric images are correctly aligned. Here’s what the creator of the website (a woodworker) wrote: Some…
Lipson’s mathematical LEGO sculptures
Ξ at the the 360 blog just posted a neat LEGO fact: it is possible to snap together two 2×4 lego bricks in 24 different ways. Given six of these LEGOs it is possible to snap them together in 915,103,765 different ways! This inspired me to post a link to a cool website by Andrew Lipson….
Tao on political polls
Fields Medalist and mathematics blogger, Terrence Tao, has an interesting and timely post on political polls on his blog.
Einstein’s math
In a previous post I mentioned that I was hoping to write an article called Mythematics. The idea is that I will investigate famous mathematical myths and either give evidence that they are true or debunk them. One that I had on my radar was the myth that Albert Einstein was bad at math. I…
The US does not produce enough mathematical stars
The New York Times has an article today, “Math Skills Suffer in U.S., Study Finds“, which announces an upcoming article in the Notices of the AMS by Janet Mertz, Jonathan Kane, Joseph Gallian, and Titu Andreescu. The Times writes: The United States is failing to develop the math skills of both girls and boys, especially…
Flatland and other videos about dimension
Not long ago I watched the DVD of Flatland staring Martin Sheen as the voice of Arthur Square. The movie is based on Edwin Abbott Abbott’s 1884 book of the same title. Flatland is a story of polygons living in a two dimensional world and A. Square’s discovery of the third dimension. It is also…
Cutting and folding paper
Inspired by Chaim Goodman-Strauss’s recent video about symmetries, paper snowflakes, and paper dolls, I decided to post a few other paper-related videos. First is a video showing some cutting tricks for a Möbius strip. I show this to my topology class, then have them play around with Möbius strips—twisting them various numbers of times and…
Flash cards are a good idea
I recently came across an article by the mathematician Ethan Akin, whose work in topology and dynamical systems I admire greatly, called “In Defense of ‘Mindless Rote’“. In the article he defends the traditional education model of having students memorize mathematical facts and techniques. He begins with the following quote from Alfred North Whitehead’s Introduction to Mathematics….
David Richeson: Division by Zero 