Newton or Einstein—who got gravity right? 🌌 Neil deGrasse Tyson breaks down how classical physics evolved into relativity, ...

Einstein was awarded the 1921 Nobel Prize for a theory that half of the people might not even have heard of. His Theory of ...

How astronomers used gravitational lensing, a space-time trick predicted by Einstein, to detect a black hole measuring 30 ...

The sharpest black hole collision ever detected just gave Einstein another win—and raised hopes that the next one might ...

When someone proclaims anything with absolute certainty, I cringe. And when a politician does it, I double over in laughter.

One such mystery, described in a recent paper in The Astrophysical Journal Letters, concerns circumbinary exoplanets—or rather, the shortage thereof—in the now 6,000+ exoplanets confirmed to date.

Different measurements of the Hubble constant, the rate of space-time expansion, refuse to agree – meaning we may have to look beyond Einstein’s theories to explain the universe ...

Most physicists doubt that time exists. On this page 40 years ago, we published scientific ‘proof’ of time being illusory. We pointed out that none of the equations of physics, from Newton’s laws to ...

A newly detected gravitational wave, GW250114, is giving scientists their clearest look yet at a black hole collision—and a powerful way to test Einstein’s theory of gravity. Its clarity allowed ...

Scientists pushed photons across the universe to test the speed of light—and found Einstein’s cosmic speed limit still holds ...

This puzzle is known as the problem of time, and it remains one of the most persistent obstacles to a unified theory of ...

Friedmann accepted this new term but pointed out a radical alternative: the universe did not have to be frozen. He argued that Einstein’s static universe was merely a special case and that the cosmos ...