What's up in

# general relativity

## Latest Articles

### Physics Nobel Awarded for Black Hole Breakthroughs

Roger Penrose, Reinhard Genzel and Andrea Ghez were awarded the Nobel Prize in Physics for their studies of black holes.

### The Physicist Who Slayed Gravity’s Ghosts

Claudia de Rham showed how theories of “massive gravity” could potentially get rid of the need for dark energy.

### Why Gravity Is Not Like the Other Forces

We asked four physicists why gravity stands out among the forces of nature. We got four different answers.

### Black Hole Paradoxes Reveal a Fundamental Link Between Energy and Order

By chewing on the problems posed by “extremal” black holes, physicists have exposed a surprising and universal connection between energy and entropy.

### New Math Proves That a Special Kind of Space-Time Is Unstable

Einstein’s equations describe three canonical configurations of space-time. Now one of these three — important in the study of quantum gravity — has been shown to be inherently unstable.

### Does Time Really Flow? New Clues Come From a Century-Old Approach to Math.

The laws of physics imply that the passage of time is an illusion. To avoid this conclusion, we might have to rethink the reality of infinitely precise numbers.

### The Map of Mathematics

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

### Why the Laws of Physics Are Inevitable

By considering simple symmetries, physicists working on the “bootstrap” can rediscover the basic form of the known forces that shape the universe.

### Black Hole Singularities Are as Inescapable as Expected

For the first time, physicists have calculated exactly what kind of singularity lies at the center of a realistic black hole.