Physics

The path from a revolutionary set of equations to the detection of gravitational waves was strewn with obstacles and controversy, explains the physicist Daniel Kennefick — and the struggle continues.

Ripples in space-time have been detected a century after Einstein predicted them, launching a new era in astronomy.

Searching for signs of life on faraway planets, astrobiologists must decide which telltale biosignature gases to target.

The physicist Subir Sachdev borrows tools from string theory to understand the puzzling behavior of high-temperature superconductors.

Bizarre quantum bonds connect distinct moments in time, suggesting that quantum links — not space-time — constitute the fundamental structure of the universe.

Two leading candidates for a “theory of everything,” long thought to be incompatible, may be two sides of the same coin.

The irreversibility of time may be a clue as to what makes up the universe’s dark matter.

If a theory can’t be tested, is it still science?

Scientists are homing in on a warning signal that arises in complex systems like ecological food webs, the brain and the Earth’s climate. Could it help prevent future catastrophes?