Embed <iframe src="https://www.npr.org/player/embed/4254287/4254288" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player"> NPR's ...

Imagine you're a mapmaker, ready to finish your masterpiece map of the world. The only thing left to do is add the colors. But how many colors do you need for the countries if you want to make sure no ...

As an undergraduate at the University of Chile, Bernardo Subercaseaux took a dim view of using computers to do math. It seemed antithetical to real intellectual discovery. “There’s some instinct or ...

Let G = (V, E) be a strongly connected, aperiodic, directed graph having outdegree 2 at each vertex. A red-blue coloring of G is a coloring of the edges with the colors red and blue such that each ...