A Möbius strip is a curious subject in the field of mathematics. Named after nineteenth century German astronomer and mathematician, August Ferdinand Möbius, Möbius Strips only have one side and one edge — a lot like a bagel. Somehow.
So, if you imagine a rubber band or a similar loop, it will have two sides and two edges. But if you add a half twist, it becomes a Möbius strip. I actually think I've encountered this before with the elastic waistband on a pair of pajamas. No matter how I twisted the band, it never sat flat. Very annoying.
It turns out that many highschools now ask their students to attempt Möbius strips using bagels. And in the video, one student demonstrates (with surprising ease) a Möbius strip using a raisin bagel and a plastic knife (added obstacles). There's also a video of how it works in an ideal world — without bagel crumbs and lumpy raisins. I have enough trouble cutting a bagel in half, so prepare to be impressed by the amazing bagel cutting stylings of a high school student named Kirill.