Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that ...

Tracking time is one of those things that seems easy, until you really start to get into the details of what time actually is. We define a second as 9,192,631,770 oscillations of a cesium atom.

Did you know that moving a clock one inch toward the ground would result in a slower tick compared to the same clock positioned higher up? Gravity doesn't just pull things; it also bends time.

Tiny “Ferris wheels” made from light and extremely cold particles could allow researchers to test a facet of Albert Einstein’s theory of relativity on unprecedentedly small scales. Theories of special ...

If you're going to Mars you'd best take along a jar of anti-aging cream because while you're there you're going to age faster than on Earth thanks to the Theory of Relativity. It's only 477 millionths ...