Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Most of us have struggled with the mathematical puzzle known as the "moving sofa problem." It poses a deceptively simple question: What is the largest sofa that can pivot around an L-shaped hallway ...

For decades, mathematicians tried to come up with the optimal sofa shape to move around a corner. Post-doctoral student Jineon Baek posted a 100-page proof that claims to solve the problem. In a scene ...

A Korean researcher who solved the “Moving Sofa Problem,” a mathematical challenge that had puzzled mathematicians for nearly 60 years, was selected as one of the top 10 mathematical innovations of ...

In a scene from the classic sitcom, "Friends," the characters Ross, Rachel and Chandler struggle to heft a new couch up the stairs of their apartment building. As they try to get the sofa around the ...