A growing body of theoretical and experimental work in physics is converging on a striking possibility: time, the dimension humans experience as a constant forward flow, may not be a fundamental ...

A cluster of recent theoretical papers has laid out mathematical frameworks for propelling spacecraft at speeds ranging from a significant fraction of the speed of light to, in the most ambitious ...

General relativity and quantum mechanics seem to describe all of observable reality. Between them, general relativity and quantum mechanics seem to describe all of observable reality.

We've all heard of relativity, but what is it? How does it relate to light and motion? So we've all heard of relativity, right? But... what is relativity? And how does it relate to light? And motion?

New impressions A visualization of a curved space–time “sea” from the general-relativity simulations carried out by the authors.(Courtesy: James Mertens) From the Genesis story in the Old Testament to ...