»In which we understand the recursion

Two professors at University College London have published their solution to describing a perplexing shape in three dimensions. The Möbius Strip has long fascinated me, from the literature about it to the topological conundrum it presents.

The strip is made from what mathematicians call a 'developable' surface, which means it can be flattened without deforming its shape — unlike, say, a sphere.

When a developable surface is formed into a Möbius strip, it tries to return to a state of minimum stored elastic energy, like an elastic band springing back after being stretched.

But no one has been able to model what this final form will be. "The first papers looking at this problem were published in 1930," says Starostin. "It seems such a simple question — children can make these things — but ask the experts how to model this shape and we've had nothing."