This week’s class featured some folding and cutting. First we watched Vi Hart talk about the history of flexagons. Since she goes to fast for us to follow, we worked through the process slowly on our own — you can follow this video if you want to make one. Vi Hart has a second video on flexagons that we did not watch, and a video warning of the dangers of flexagons that we did watch. After we folded a tri-hexaflexagon we made a hexa-hexaflexagon — you can see how to do that in the Vi Hart videos. Another source on flexagons is this article by Martin Gardner.
After flexagons, we talked about magic tricks where you fold a piece of paper, make a single cut, and come out with a predetermined shape. This is a field that has been researched by Erik Demaine (see the video from the Museum of Math that we watches a bit of in class). Demaine has been able to prove that you can do the “fold and one cut” trick to produce any shape at all! We did the “swan” in class (although it was extra difficult since it didn’t print out right). Here is more information if you are interested, and you can find links to other “one cut” pictures.
We won’t have class again until after break, so try to get a class response done this week rather than waiting until much later when you might have forgotten what we did! You can talk about some of the videos we watched, how the flexigons work for you, or the fold-and-one-cut work (including how frustrating it was!). Feel free to do more looking around on these topics on your own and give me some links in your response. Send your responses in email or wait to hand them to me next class. And have a good break!!