Theory of Relativity

A group of physicists has measured gravity using the effects of time dilation — the slowing of time imparted by increased velocity or gravitational force — on atoms.

Scientists tested seven different predictions, in one of the most ambitious and involved challenges to general relativity ever undertaken — and the theory passed with flying colors.

Once again, physicists have confirmed one of Albert Einstein's core ideas about gravity and relativity — this time with the help of a neutron star flashing across space.

Physicists dropped objects on a satellite for two years to test Galileo's theory of falling objects.

Warps in the fabric of space-time can act like magnifying glasses, and that may help solve a cosmic mystery about the rate of the universe's expansion, a new study found.

The three architects of supergravity are getting some high-profile recognition, more than four decades after they developed the influential theory.

Scientists created a computer simulation to test an alternative theory to the evolution of the cosmos.

While it's tough for humans and spaceships to travel near light speed, tiny particles do it all the time. Here are three ways that's possible.

One hundred years ago today, in the wake of the first World War, a British astronomer watched a solar eclipse for signs that a German physicist may have been right about warps in the universe.

A dancer gliding across a stage was so well synced with the projection around him that the performer appeared to trigger ripples coursing through the fabric of space-time.

The botched launch of two global-positioning satellites four years ago has proven to be a real gift to physicists.

Once again, a decades-old theory of gravity has survived a modern scientific onslaught. Einstein wins again.

The discovery of wobbling "hotspots" circling the drain of a massive black hole offers exciting new evidence for the behemoth that lies at our galaxy's center.