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

It’s often said that you don’t need a drill bit; what you need is a hole. How you make that hole is up to you, but it’s a given that you want to make it as efficiently as possible. The drill bit, ...

With close to a decade of writing and editing experience, Maisha specializes in service journalism and has produced work in the lifestyle, financial services, real estate, and culture spaces. She uses ...