We all know we live in three-dimensional space. But what does it mean when people talk about four dimensions? Is it just a ...

Mathematicians say knots cannot exist in four-dimensional space because the extra dimension allows a rope to move around itself and untangle, revealing surprising insights into geometry and topology.

Zsuzsanna Dancso does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...