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

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

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 ...

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

In October 2015, a young mathematician named Clemens Sämann was flying home to Austria from a conference in Turin, Italy, when he had a chance encounter. He found himself seated beside Michael ...

After Albert Einstein published his special theory of relativity in 1905, he spent the next decade trying to come up with a theory of gravity. But for years, he kept running up against a problem. He ...

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, ...

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 ...