Relativity

After years of downtime for upgrades, the world’s premier gravitational-wave observatories are coming back online with big hopes for transformative discoveries

Solving a notorious quantum quandary could require abandoning some of science’s most cherished assumptions about the physical world

Using machine learning, researchers have now created a much sharper portrait of the supermassive black hole at the center of the galaxy M87

The hunt for dark matter is in crisis, and it’s time for radical new ideas to explain our universe

Quantum telepathy, laser-based time crystals, a glow from empty space and an “unreal” universe—these are the most awesome (and awfully hard to understand) results from the subatomic realm we encountered in 2022

Elegant experiments with entangled light have laid bare a profound mystery at the heart of reality

The MICROSCOPE mission tested the weak equivalence principle with free-falling objects in a satellite

In the far future, we could reveal detailed views of distant worlds by turning our home star into a gravitational lens

Weighing in at seven times the mass of our sun, the dark object is by far the best-yet candidate for a free-floating stellar-mass black hole

Subtle signals from black hole mergers might confirm the existence of “Hawking radiation”—and gravitational-wave detectors may have already seen them

The atom interferometry technique uses the effects of time dilation to reveal subtle changes in gravity’s strength

Runaway success and underfunding have led to growing pains for the preprint server