physicsfun on Instagram: "Mystery Braid: a fun math puzzle challenge- how can three strands be braided if both sets of ends are connected? A favorite in my collection of “impossible objects”, this leather key fob is braided from a single piece of leather, constructed by making two parallel slits but not cutting the ends. The solution (demonstrated here with red felt) is well known to those in the field of leatherwork- due to a twist of topology it’s possible to make this braid if the number of l