Black Holes: A certain region where matter falls forever, as Einstein predicted

In the illustration, the supermassive black hole at the center is surrounded by matter flowing into the black hole in what is called an accretion disk.

Albert Einstein’s theory of general relativity has received another concrete confirmation: astronomers have observed, for the first time, a “dipping zone” in a black hole. This region, located at the edge of the black hole, is where matter can no longer remain in its orbit and falls forever toward the center, as Einstein predicted.

The discovery, published in the journal Monthly Notices of the Royal Astronomical Society, was made by a team of astronomers using telescopes capable of detecting X-rays. The observed black hole is located in a system called MAXI J1820 + 070, and it consists of a star smaller than the Sun and the black hole itself, and its mass is estimated at 7 to 8 solar masses.

“Like the edge of a waterfall”

Astronomers used NASA’s NuSTAR and Nicer space telescopes to collect data and understand how hot gas, called plasma, is sucked from the star into the black hole. NuSTAR orbits Earth, while NISER is located on the International Space Station.

“Around these black holes are large disks of material orbiting nearby stars,” said Andrew Mummery, a researcher at the University of Oxford and lead author of the study. “Most of them are stable, which means they can flow smoothly. They’re like a river, while the diving area is like the edge of a waterfall – all your support disappears and you fall head first. Most of what you can see is the river, but there’s this little area at the end, which is in “Basically what we found.”

Unlike the event horizon, which is closer to the center of the black hole and does not allow anything to escape, including light and radiation, in the “dipping zone” light can still escape, but the matter is doomed to the strong gravitational pull, Mummery explained.

The discoveries could help understand how black holes form

The study results could help astronomers better understand the formation and evolution of black holes. “We can really learn about it by studying this area, because it’s right on the edge, so it gives us the most information,” Mummery said.

Next step: imaging a black hole

While the study wasn’t able to take an actual picture of a black hole because it’s so small and distant, another team of Oxford researchers is working on something even better: the first movie of a black hole. To achieve this, the team will first need to build a new observatory, the Africa Millimeter Telescope in Namibia, which Mummery hopes will be up and running within a decade.

Confirmation of Einstein’s genius

The discovery of the “dipping zone” is another important step in confirming Einstein’s theory of general relativity, which has already been strengthened by other observations, such as the first image of a black hole in 2019 and the detection of gravitational waves.

Implications for future research

According to Christopher Reynolds, a professor of astronomy at the University of Maryland, College Park, this is a measurement of the rotation rate of these celestial bodies and a study of high-energy X-ray emissions from the “dipping zone.”

“This is going to be a major place for discovery over the next decade or so,” said Dan Wilkins, a research scientist at Stanford University. “We look forward to the next generation of X-ray telescopes that will give us more detailed measurements of deeper regions outside the event horizons of black holes.”