One of the oldest problems in low-dimensional topology is the unknot recognition problem, posed by Max Dehn in 1910: Is there an algorithm to decide if a given knot can be untangled? You know that this is a challenging problem if you owned a pair of earphones that are tangled! The unknot recognition problem was highlighted by Alan Turing in his last article in 1954, and the first solution was given by Wolfgang Haken in 1961. However, it remains widely open whether there exists a polynomial time algorithm to detect the unknot. The current state-of-the-art is Lackenby’s announcement for a quasi-polynomial time algorithm, which puts it in similar standing to the graph isomorphism problem. I will discuss what is known about the unknot recognition, how it is related to the theory of foliations on three-dimensional manifolds, as well as recent developments on related algorithmic problems.