Though the chart starts out in alphabetical order, there's a break in the pattern that offers a clue... Puzzling Like the Seventeenth Century Ursula Whitcher Mathematical Reviews (AMS) The following chart is taken from the second edition of a German-language arithmetic textbook by Anton Schultze. It was published in LiegnitzRead More →
You could pick up the torus and rotate it horizontally, as though you are taking the lid off of a jar of peanut butter... How to Untwist Your Fractions Diana Davis Phillips Exeter Academy A string around a bagel Here's the problem: your bagel has a torus knot wrapped aroundRead More →
This fall I woke up to a surprise comprehensive exam, with my toddler as the examiner, starting with the demand for a nonconvex regular [simple] polygon. It was 4:30 am. I had not yet had coffee. Everything I Need to Know About Polygons I Learned from My Pre-Kindergartner Courtney GibbonsRead More →
The next time it's pouring rain and you're clinging to that umbrella like it's your most prized possession, take the opportunity to look up and see the beauty of the mathematics above you. Grasping the Math That's Over Your Head Jessica Sidman Amherst College Audrey St. John Mount Holyoke CollegeRead More →
If you’re used to the original versions and want to spice up your life a little bit, you can play Torque (Queens on a torus)… This Queen Loves to Tango! Torque, Twango, and Algebraically Addled Games Courtney Gibbons Hamilton College Whenever I see a new game, I can’t resist thinking,Read More →
The Greeks were wary of infinities of any kind, and nothing like an exact definition of 'ratio' was possible for them... Irrationality Tamed Bill Casselman University of British Columbia Not so long ago, the internet magazine Quanta posted an article titled "How the square root of two became a number".Read More →
We would like to clear out every room over time, but asking guests to leave seems rude. Instead, every day we assign them new rooms using a monotone increasing function… Primitive Recursion and the Disappearing Guests Bevin Maultsby NC State University Hilbert’s Hotel is a well-known thought experiment which challengesRead More →
We’ve seen that semialgebraic Teddy and semialgebraic Lambkin are both images of a four-dimensional ball. Could they be images of each other? The Teddy-Lambkin Theorem Ursula Whitcher Mathematical Reviews (AMS) My given name means bear—it’s the same root as the constellation Ursa Major—so growing up I had a huge collectionRead More →
An automorphic form is, in the simplest sense, like a trigonometric function. Trigonometric functions are inescapable in both mathematics and physics, so it makes sense that we would see generalizations of them in physics applications... Strung Out on Automorphic Forms Holley Friedlander Dickinson College Automorphic forms are highly symmetric functionsRead More →
A natural question in the context of origami mathematics is: What if we make the paper infinitely large? Welcome to the Fold Sara Chari Saint Mary's College of Maryland Adriana Salerno Bates College and the National Science Foundation Origami—from the Japanese words for “fold” (oru) and “paper” (kami)—is the artRead More →