Albert Einstein was right: There is an area at the edge of black holes where matter can no longer stay in orbit and instead falls in, as predicted by his theory of gravity.
Using telescopes capable of detecting X-rays, a team of astronomers has for the first time observed this area - called the “plunging region” - in a black hole about 10,000 light-years from Earth.
Many of Einstein’s other predictions have turned out to be correct over the years. “He’s a tough man to bet against at this point,” said Andrew Mummery, lead author of the study published last week. “We went out searching for this one specifically - that was always the plan. We’ve argued about whether we’d ever be able to find it for a really long time,” Mummery told CNN. “People said it would be impossible, so confirming it’s there is really exciting.”
“Around these black holes there are big discs of orbiting material (from nearby stars),” Mummery said. “Most of it is stable, which means it can happily flow. It’s like a river, whereas the plunging region is like the edge of a waterfall - all of your support is gone and you’re just crashing headfirst. Most of what you can see is the river, but there’s this tiny region at the very end, which is basically what we found,” he added, noting that while the “river” had been widely observed, this is the first evidence of the “waterfall.”
Unlike the event horizon, which is closer to the centre of the black hole and doesn’t let anything escape, including light and radiation, in the “plunging region” light can still escape, but matter is doomed by the powerful gravitational pull, Mummery explained.
The study’s findings could help astronomers better understand the formation and evolution of black holes.