General relativity

Physicists theorize that a new “traversable” kind of wormhole could resolve a baffling paradox and rescue information that falls into black holes.

Time isn’t just another dimension, argues Tim Maudlin. To make his case, he’s had to reinvent geometry.

Can a fluid analogue of a black hole point physicists toward the theory of quantum gravity, or is it a red herring?

According to our best theories of physics, the universe is a fixed block where time only appears to pass.

The path from a revolutionary set of equations to the detection of gravitational waves was strewn with obstacles and controversy, explains the physicist Daniel Kennefick — and the struggle continues.

Ripples in space-time have been detected a century after Einstein predicted them, launching a new era in astronomy.

The physical nature of computers might reveal deep truths about their uniquely powerful abstract abilities.

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

By replacing black holes with fuzzballs — dense, star-like objects from string theory — researchers think they can avoid some knotty paradoxes at the edge of physics.