Quantum gravity

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

If a theory can’t be tested, is it still science?

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.

Imagine the fabric of space-time peeled back layer by layer.

New tools may reveal how quantum information builds the structure of space.

A bold new idea aims to link two famously discordant descriptions of nature. In doing so, it may also reveal how space-time owes its existence to the spooky connections of quantum information.

If string theorists can show that their framework is the only consistent theory of quantum gravity, does that make it true even without tangible evidence?

Scientists report the possible discovery of primordial gravitational waves, ripples in space-time that carry a record of how the universe began.