What's up in
General relativity
Latest Articles
Black Hole Echoes Would Reveal Break With Einstein’s Theory
Gravitational waves have opened up new ways to test the properties of black holes — and Einstein’s theory of gravity along with them.
How Einstein Lost His Bearings, and With Them, General Relativity
By 1913, Albert Einstein had nearly completed general relativity. But a simple mistake set him on a tortured, two-year reconsideration of his theory. Today, mathematicians still grapple with the issues he confronted.
To Test Einstein’s Equations, Poke a Black Hole
Two teams of researchers have made significant progress toward proving the black hole stability conjecture, a critical mathematical test of Einstein’s theory of general relativity.
Physicists Find a Way to See the ‘Grin’ of Quantum Gravity
A recently proposed experiment would confirm that gravity is a quantum force.
Newfound Wormhole Allows Information to Escape Black Holes
Physicists theorize that a new “traversable” kind of wormhole could resolve a baffling paradox and rescue information that falls into black holes.
A Defense of the Reality of Time
Time isn’t just another dimension, argues Tim Maudlin. To make his case, he’s had to reinvent geometry.
What Sonic Black Holes Say About Real Ones
Can a fluid analogue of a black hole point physicists toward the theory of quantum gravity, or is it a red herring?
A Debate Over the Physics of Time
According to our best theories of physics, the universe is a fixed block where time only appears to pass.
From Einstein’s Theory to Gravity’s Chirp
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.