The general theory of relativity (or general relativity for short) is a major building block of modern physics. It explains gravity based on the way space can 'curve', or, to put it more accurately, ...

What is time, and why does it seem to flow in only one direction? This video explores modern physics’ take on time—from the ...

EVER since Arthur Eddington travelled to the island of Príncipe off Africa to measure starlight bending around the sun during a 1919 eclipse, evidence for Einstein’s theory of general relativity has ...

OUR most accurate clocks are probing a key tenet of Einstein’s theory of relativity: the idea that time isn’t absolute. Any violation of this principle could point us to a long-sought theory that ...