Black holes are some of the strangest and most fascinating objects in outer space. They’re extremely dense, with such strong gravitational attraction that even light cannot escape their grasp if it comes near enough. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can’t see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.
Albert Einstein first predicted the existence of black holes in 1916, with his general theory of relativity. The term “black hole” was coined many years later in 1967 by American astronomer John Wheeler.
So far, astronomers have identified three types of black holes: stellar black holes, supermassive black holes and intermediate black holes.Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in.
What do black holes look like? Black holes have three “layers”: the outer and inner event horizon, and the singularity. The event horizon of a black hole is the boundary around the mouth of the black hole, past which light cannot escape. Once a particle crosses the event horizon, it cannot leave. Gravity is constant across the event horizon. The inner region of a black hole, where the object’s mass lies, is known as its singularity, the single point in space-time where the mass of the black hole is concentrated. scientists can’t see black holes the way they can see stars and other objects in space. Instead, astronomers must rely on detecting the radiation black holes emit as dust and gas are drawn into the dense creatures.
The Event Horizon Telescope’s image of a black hole in M87 (released in 2019) was an extraordinary effort, requiring two years of research even after the images were taken. That’s because the collaboration of telescopes, which stretches across many observatories worldwide, produces an astounding amount of data that is too large to transfer by internet.
Sr. Vinayak Mhavalankar