Scientists’ newfound ability to peer near a black hole’s event horizon has profound implications. In a few decades, when astronomers have measured the spins many black holes, they’ll be able to put general relativity to the test as never before. Will Einstein’s theory, now more than a century old, survive the most intense tests we can imagine? Will he still have the last word on gravity?
An animated look at black-hole spin
See what astronomers are talking about with these animations of black holes.