A Powerful New ‘QR Code’ Untangles Math’s Knottiest Knots

Mathematicians have long tried to untangle exactly what makes a knot a knot. There are several ways to define a knot’s characteristics, referred to as ‘invariants’, but “most invariants are either very strong but impossible to compute, or easy to compute but very weak,” says mathematician Daniel Tubbenhauer. Now researchers Dror Bar-Natan and Roland van der Veen have proposed what they dub “a fast, strong, topologically meaningful, and fun knot invariant” — or Θ for short — that can describe even very complex knots as a rather lovely 2-dimensional pattern.