Einstein’s claim that the speed of light is constant has survived more than a century of scrutiny—but scientists are still ...

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

A bizarre "cosmic glitch" in the theory of how the gravity of the universe works may have been mended. The strange glitch in Einstein's description of gravity in his theory of general relativity may ...

The universe’s accelerating expansion has long puzzled physicists. For decades, dark energy, an unseen force thought to make ...

Quantum theory and Einstein's theory of general relativity are two of the greatest successes in modern physics. Each works ...

Long and winding road: The Juice space probe taking the long way to Jupiter and its moons - Copyright NASA/AFP/File NASA Long and winding road: The Juice space probe ...

A century after Albert Einstein sketched out his radical picture of gravity, astronomers have now watched a black hole ...