The accelerating expansion of the universe is usually explained by an invisible force known as dark energy. But a new study ...

One hundred years ago this Wednesday, Albert Einstein gave the last of a series of presentations to the Prussian Academy of Sciences, which marks the official completion of his General Theory of ...

The geometry of spacetime forms the very foundation of modern gravitational theory, where the elegant interplay between curvature and matter is described by Einstein’s field equations. In this ...

Why the universe is expanding faster and faster remains one of the biggest open questions in physics. Current theories cannot ...

General Relativity, Einstein’s seminal theory of gravitation, remains a pillar of modern physics by describing gravity as the curvature of spacetime. Nonetheless, persistent questions—ranging from the ...

Shortly after Einstein proposed his general theory of relativity, a German physicist called Karl Schwarzschild found one of the first and most important solutions to Einstein’s field equations. Now ...

It stands among the most famous theories ever created, but the general theory of relativity did not spring into being with a single, astonishing paper like the special theory of relativity in 1905.

Finally, scientists have their finger on the pulse. Spinning dead stars, known as pulsars, blast powerful beams of radio waves into space. As a pulsar spins, its beams sweep past Earth, producing a ...