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 ...

Spacetime is often described as the stage on which the universe unfolds, a four-dimensional blend of space and time that ...

A century ago, Albert Einstein became famous. Sure, he was already well-known among physicists. But the world at large learned his name only after November 1919, when news broke that his theory of ...

One of the best-performing models in cosmology is also one with the least physical rationale behind it. Columnist Leah Crane ...