Yesterday I wrote about the maypole braid group and left two questions for homework. Here are the solutions. The first question was to show that the following maypole braids could not be represented as products of . Observe that each time we apply , one strand moves clockwise and one moves counterclockwise. Thus there is…
The maypole braid group
Over the weekend I attended a May Day party thrown by one of my colleagues. During the party they had a traditional maypole dance. An example of a maypole dance is shown at left. A maypole is a tall pole with colorful ribbons attached to the top that are fanned out in a cone shape….
Mathematical Google logos
Google loves to celebrate holidays and events by displaying custom logos on their website. All of their past custom logos are now available for browsing at Google Logos. I was happy to see that there are several mathematical ones. Here are some that I found (there are many science and technology-related logos that I’m not…
Recommended readings (4/27/09)
Barack Obama speaks to the 146th Annual Meeting of the National Academy of Sciences Calculus Made Easy: Being A Very Simplest Introduction To Those Beautiful Methods Of Reckoning Which Are Generally Called By The Terrifying Names Of The Differential Calculus And The Integral Calculus (2nd Ed., 1914), by Silvanus P. Thompson ~ What one fool…
Happy birthday Michael Atiyah
There is a article about Sir Michael Atiyah in the Times Online in honor of his 80th birthday, “Maths and the bomb: Sir Michael Atiyah at 80.”
How the arch got its shape
The most recent video podcast episode of Science Friday is a short but nice discussion of the mathematics behind the St. Louis Arch: How the arch got its shape.
PAR scoring in squash
The purpose of this post is to present a possible research topic for a mathematics or computer science student. For the last several years I’ve been an avid squash player. For those of you who don’t know, squash is played in a court like a racquetball court (although smaller). The racket is long and thin….
xkcd in the New York Times
The popular web comic xkcd is coming out in book form. The book will contain 150-200 of the 500 comics and will be sold on the xkcd website (initially, at least). There is an article about the book in the New York Times. Regular readers love the extra joke that appears on a mouse-over. The…
Musings about traffic on the highway
Here’s a neat looking infographic by Stephen J. Beard and Rich Exner from The Plain Dealer that I bookmarked a few months ago. It addresses the question, why do freeways come to a stop? Seeing this graphic reminded me of how much I used to be fascinated by traffic when I was a child (even though I…
Arthur Benjamin: Lightning Calculation and Other “Mathemagic”
I’m continuing to enjoy watching mathematics videos online. This week I saw a few math-related TED talks pop up in my news reader and enjoyed watching them: Math = Letting Dead People Do the Work at Let’s Play Math How calculus is changing architecture at Casting Out Nines In case you do not know what…
David Richeson: Division by Zero 