Albert Einstein won the 1921 Nobel Prize in Physics, but not for relativity—the theory that made him famous. This article ...

Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that describe gravity, quantum fields and the structure of spacetime now allow ...

Time feels like the most basic feature of reality. Seconds tick, days pass and everything from planetary motion to human memory seems to unfold along a single, irreversible direction. We are born and ...

Time has an arrow: It only ever seems to move in one direction. The future is always unknown to us, while the past forever remains locked and inaccessible. And yet, the vast majority of the laws of ...

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 ...

In 1905, Albert Einstein revolutionized physics by demonstrating that time is not absolute but relative to the observer's ...