What does it mean to be to space-time? The seemingly simple question gets to the essence of twentieth-century physics and has driven a hundred-year debate between philosophy and science. In Einstein’s ...

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

For those who watch gravitational waves roll in from the universe, GW250114 is a big one. It's the clearest gravitational ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Two cutting-edge atomic clocks — the most accurate ever ...

Relativity Space, the 3D-printing rocket builder, is making another big bet: Developing a fully reusable rocket, designed to match the power and capability of SpaceX's workhorse Falcon 9 rockets.

Two blind spots torture physicists: the birth of the universe and the center of a black hole. The former may feel like a moment in time and the latter a point in space, but in both cases the normally ...

Whether space-time exists should neither be controversial nor even conceptually challenging, given the definitions of “space-time,” “events” and “instants.” The idea that space-time exists is no more ...

Astronomers have long faced a strange contradiction: most stars are born in pairs, and ...

"The singularity is the most mysterious and problematic part of a black hole. It's where our concepts of space and time literally no longer make sense." When you purchase through links on our site, we ...

Quantum mechanics and relativity are the two pillars of modern physics. However, for over a century, their treatment of space and time has remained fundamentally disconnected. Relativity unifies space ...

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