Relativity

According to Albert Einstein’s general theory of relativity, the universe remembers every gravitational wave—and scientists could soon test these cosmic recollections

The Laser Interferometer Space Antenna (LISA) will open a new era in astronomy that brings scientists to the brink of studying gravitational waves from the beginning of time

Light can be reflected not only in space but also in time—and researchers exploring such “time reflections” are finding a wealth of delightfully odd and useful effects

Quantum physics’ oddities seem less surprising if you stop thinking of atoms as tennis balls, and instead more like waves pushing through water

In theory, physicists knew that antimatter should behave just like matter under gravity’s pull. But until now, no one had ever seen it happen

Physicists are on an ever urgent quest to find a fuller understanding of what makes the cosmos tick, which they call a theory of everything

Astronomers are now seeking to pinpoint the origins of an exciting new form of gravitational waves that was announced earlier this year

Voracious black holes feeding on matter in the early universe display the curious spacetime phenomenon known as time dilation

Researchers still hope to discover hundreds of new binary black hole mergers despite technical setbacks that have sidelined key detectors in Italy and Japan

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