What just happened? A group of mathematicians created a "new" polygon previously known to exist only in theory. It's a 13-sided shape that they dubbed "the hat," even though it only vaguely resembles ...

The Penrose tiling pattern is a type of quasicrystal, which means that it has an ordered yet never-repeating structure. The pattern, composed of two shapes, is a 2D projection of a 5D square lattice.