According to NASA, a black hole is a "place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying."
Albert Einstein first predicted the existence of black holes in his general theory of relativity, and the term 'black hole' was coined by American astronomer John Wheeler. The three types of black holes are: stellar black holes, supermassive black holes and intermediate black holes. The first one was discovered in 1971.
There a lot of myths surrounding black holes and these are the most common.
1. Black holes are not real
Although black holes cannot be seen because light can not escape from them, the effects can be seen in the space around them. "While we can't actually see them directly, mathematically we have known about black holes since Albert Einstein's time, since the early 1900s," Dr Amanda Bauer, an astronomer at the Australian Astronomical Observatory, said.
With the use of modern telescopes, astronomers can see the effects of black holes to stars orbiting around them. "We have something at the centre of our Milky Way galaxy called SgrA* that doesn't produce any light, and we can watch individual stars going around it, not in nice circular orbits, but in highly elliptical, elongated paths. And you find that there is something there that's over four million times the mass of our Sun but in a tiny area that produces absolutely no light. There's nothing else we think that it could be other than a black hole" Dr Bauer said.
2. The Sun will turn into a black hole eventually.
Since our Sun is not as massive as the other stars, no it cannot turn into a black hole. In four billion years, when the Sun will run out of nuclear fuel in its core, it will die a quiet death.
3. Black holes will suck up everything in the universe like a vacuum.
No, not likely, because you have to be very close to a black hole to actually feel the strength of its gravity.
"If the Sun could magically turn into a black hole (which as we already pointed out it can't), then all its stuff would get shoved down into a tiny little volume maybe a couple of kilometres across. Think about what would happen to Earth, the Sun would still have the same mass if it were a black hole instead of a star. Earth also still has the same mass and still be the same 150 million kilometres away from it, and gravitationally speaking the only things that matter are your mass and how far away you are," Bauer said.