We don’t know why the universe appears to be expanding faster than it should. New ultra-precise distance measurements have only intensified the problem.

Lauren Williams has charted an adventurous mathematical career out of the pieces of a fundamental object called the positive Grassmannian.

Over the past two years, astronomers have rewritten the story of our galaxy.

Catherine Dulac is overturning preconceptions about “male” and “female” instincts and opening new avenues to treating postpartum depression.

The goal of the “busy beaver” game is to find the longest-running computer program. Its pursuit has surprising connections to some of the most profound questions and concepts in mathematics.

Mathematicians have long pondered the reach of a grazing goat tied to a fence, only finding approximate answers until now.

The simple insight that most changes are random had a profound effect on genetics, evolution and ecology.

Jelani Nelson designs clever algorithms that only have to remember slivers of massive data sets. He also teaches kids in Ethiopia how to code.

The result highlights a fundamental tension: Either the rules of quantum mechanics don’t always apply, or at least one basic assumption about reality must be wrong.