Hooraaaay flexagons! Happy October.
Historical Note: This video is based on a true story. Arthur H. Stone really did invent the hexaflexagon after playing with the paper strips he'd cut off his too-wide British paper, and really did start a flexagon committee (which we'll hear more about in the next video). The details and dialogue, however, are my own invention.
This video is based on, and in honor of, Martin Gardner's first Mathematical Games column from 1956, "Hexaflexagons," which can be found here: maa.org/pubs/focus/Gardner_Hexaflexagons12_1956.pdf
October 21st is Martin Gardner's birthday, which is why every October the recreational mathematics community celebrates his life and work. This year we're having hexaflexagon parties. You can join in too: puzzles.com/hexaflexagon/
You can find more about hexaflexagons all over the internet. flexagons.net has a lot of patterns for different kinds of flexagons, or here's the wikipedia page: en.wikipedia.org/wiki/Flexagon
My personal website, which you might like: vihart.com