BOULDER- Black holes, time travel and E= mc^2. They are all related to Albert Einstein's Theory of Relativity. How many of us, though, can actually explain any of it? This year, Einstein's theory ...

For over 100 years, two theories have shaped our understanding of the universe: quantum mechanics and Einstein’s general relativity. One explains the tiny world of particles; the other describes ...

A record-breaking gravitational wave signal let scientists "listen" to a distant black hole merger and put Einstein's gravity ...

110 years ago today, Albert Einstein published his General Theory of Relativity, which redefined the relationship between matter and gravity. Suddenly, our mysterious universe made a little more sense ...

An international team led by Japanese researchers has made a 3D map of 3000 galaxies 13 billion light years from Earth, and found that Einstein’s general theory of relativity is still valid. Since it ...

New research suggests Einstein's general relativity explains the rarity of planets orbiting two suns. In tight binary systems ...

The discovery in 1998 that the Universe is expanding faster over time shook the foundations of cosmology. This finding challenged deep-seated assumptions about how space behaves on the grandest scales ...

Physicists artificially slowed down time to reveal the bizarre Terrell-Penrose effect, a consequence of special relativity. This image from the experiment shows a sphere seemingly moving at 99.9 ...

A newly detected gravitational wave, GW250114, is giving scientists their clearest look yet at a black hole collision—and a powerful way to test Einstein’s theory of gravity. Its clarity allowed ...

Addressing a controversy first raised around 1910, two physicists have performed experiments with the aid of an engineer that validate anew the special theory of relativity’s limitations on the speed ...

General relativity helps explain the lack of planets around tight binary stars by driving orbital resonances that eject or destroy close-in worlds. This process naturally creates a “desert” of ...