We've all heard of relativity, but what is it? How does it relate to light and motion? So we've all heard of relativity, right? But... what is relativity? And how does it relate to light? And motion?

Einstein's theory of general relativity has passed its toughest test with flying colors, a new study reports. General relativity, which Einstein proposed in 1916, holds that gravity is a consequence ...

For the first time ever, researchers have watched a star race past the supermassive black hole at the heart of the Milky Way, verifying that its motion showed the effects of general relativity, as ...

As new and powerful telescopes gather fresh data about the universe, they reveal the limits of older theories like Einstein's relativity. When you purchase through links on our site, we may earn an ...

The stars of the Milky Way orbit a gargantuan black hole called Sagittarius A*, which is generally quiet as viewed from Earth, except for ripping apart the occasional object that ventures too close.