Two mathematicians have proved that a straightforward question — how hard is it to untie a knot? — has a complicated answer.

A reader from West Alabama this week sent me an email saying he couldn’t quite grasp the slip cork knot I mentioned in last week’s column. It occurred to me he might not be the only one, so I figured ...

A group of chemists from Manchester have successfully tied a series of microscopic knots using individual molecules for the first time, ushering in the advent of a form of nano-scale weaving which ...

A Q&A with a veteran knot theorist discusses the strange origins of the discipline, as well as its modern-day applications. This field of mathematics, rich in aesthetic beauty and intellectual ...