Achievement unlocked: I have ridden a bicycle with square wheels. This is from earlier this week at our department's "block party" for our majors and interested students.
I'm proud (and a bit intimidated TBH) to work in the same department as Stan Wagon, the mathematician who made the square wheel bike -- and the surface on which you can ride it.
https://www.macalester.edu/mscs/multimedia/squarewheeledbike/squarewheelbike/
