Physicists have measured Albert Einstein's theory of general relativity, or more specifically, the effect called time dilation, at the smallest scale ever, showing that two tiny atomic clocks, ...

For those who watch gravitational waves roll in from the universe, GW250114 is a big one. It's the clearest gravitational wave signal from a binary black hole merger to date, and it gives researchers ...

General relativity stands as one of the bedrock theories in modern physics. Its strange view of relative time and space has been confirmed by countless experimental and observational tests, from ...

Monisha Ravisetti was a science writer at CNET. She covered climate change, space rockets, mathematical puzzles, dinosaur bones, black holes, supernovas, and sometimes, the drama of philosophical ...