The curious minds at What If examine overwriting Einstein’s theory of relativity with time travel, imagining paradoxes, ...

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.

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 ...

Their tests spanned the entire life cycle of the collision: inspiral, merger, and ringdown. Remarkably, the constraints were ...

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 ...

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

General relativity doesn’t just bend light, it can influence planetary orbits enough to wipe out entire systems.

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

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

Time feels like the most basic feature of reality. Seconds tick, days pass and everything from planetary motion to human memory seems to unfold along a single, irreversible direction. We are born and ...

A century ago, Erwin Schrödinger came up with an equation that says how the quantum world behaves. Now scientists are asking ...