Extra dimensions

An idea derived from string theory suggests that dark matter is hiding in a (relatively) large extra dimension. The theory makes testable predictions that physicists are investigating now.

The concept of dimension seems simple enough, but mathematicians struggled for centuries to precisely define and understand it.

Explore our surprisingly simple, absurdly ambitious and necessarily incomplete guide to the boundless mathematical universe.

Cosmologists have shown that it’s theoretically possible for a contracting universe to bounce and expand. The new work resuscitates an old idea that directly challenges the Big Bang theory of cosmic origins.

The physicist-mathematician Miranda Cheng is working to harness a mysterious connection between string theory, algebra and number theory.

The search for exotic new physical phenomena is being led by huge experiments like the Large Hadron Collider. But at the other end of the spectrum lie tabletop experiments — small-scale probes of hidden dimensions, dark matter and dark energy.

Two leading candidates for a “theory of everything,” long thought to be incompatible, may be two sides of the same coin.

Nima Arkani-Hamed is championing a campaign to build the world’s largest particle collider, even as he pursues a new vision of the laws of nature.

Explore the deepest mysteries at the frontier of fundamental physics, and the most promising ideas put forth to solve them.