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 ...

This is the first time that disk-jet co-precession has been clearly observed in a black hole system, which is truly exciting, ...

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 ...

Time dilation. Length contraction. The fact that time moves faster at your face than it does at your feet. These are all experimentally verified consequences of the Special Theory of Relativity, ...