Quantum gravity

The unprecedented experiment explores the possibility that space-time somehow emerges from quantum information.

Physicists have discovered that the ring of photons orbiting a black hole exhibits a special kind of symmetry, hinting at a deeper meaning.

Einstein’s description of curved space-time doesn’t easily mesh with a universe made up of quantum wavefunctions. Theoretical physicist Sean Carroll discusses the quest for quantum gravity with host Steven Strogatz.

Vijay Balasubramanian investigates whether the fabric of the universe might be built from information, and what it means that physicists can even ask such a question.

Physicists are devising clever new ways to exploit the extreme sensitivity of gravitational wave detectors like LIGO. But so far, they’ve seen no signs of exotica.

Physicists are reexamining a longstanding assumption: that big stuff consists of smaller stuff.

In a quest to map out a quantum theory of gravity, researchers have used logical rules to calculate how much Einstein’s theory must change. The result matches string theory perfectly.

Physicists have been busy exploring how our universe might emerge like a hologram out of a two-dimensional sheet. New clues have come from the symmetries found on an infinitely distant “celestial sphere.”

Time was found to flow differently between the top and bottom of a single cloud of atoms. Physicists hope that such a system will one day help them combine quantum mechanics and Einstein’s theory of gravity.