Black holes are a fascinating phenomenon in our colossal universe. The only way to detect the existence of a black hole in this far-reaching universe is the way a star behaves in close proximity to it. Black holes are tiny spaces where gravity pulls with such great force that matter gets squeezed in such a way that light cannot find its way out of there. It was Albert Einstein who had first predicted the existence of black holes back in 1916. However, it was Karl Schwarzschild, who put Einstein’s general theory of Relativity to prove that a compact mass of sufficient strength can indeed deform space-time, resulting in the formation of a black hole. The term, however, was coined many years later by the American Astronomer, John Wheeler. It is impossible for even light to escape such a strong gravitational pull. As a result, black holes remain perpetually invisible.
The existence of black holes
It is only with the help of powerful scientific tools that scientists can gauge the existence of black holes. The strong gravity emanating from the center of the black holes affects the stars and gas around them. Scientists are yet to know if there are fixed orbits for stars around black holes. Also, when a star gets too close to a black hole, a light of unfathomably high energy is generated. This light, too, is invisible to the naked eyes. Thus, special telescopes are used by scientists to be able to see the light.
Black holes vary in size. The smallest of black holes are just the size of an atom. However, the biggest black holes are called supermassive black holes. Their size exceeds the size of 1 million suns put together. It is often debated that the supermassive black holes are as old as the galaxy they are in. They are supposed to have existed since the inception of the galaxy they are residing in.
Is there a black hole at the center of every galaxy?
Scientists have found evidence to prove that there exists a supermassive black hole at the center of every galaxy that there is. The supermassive black hole at the center of the Milky Way is Sagittarius A. It is approximately the size of 4 million suns put together. Not just do black holes exist in all galaxies, a supermassive black hole is sure to occupy the center of every galaxy that exists. In 2019, the Event Horizon Telescope released a picture of a black hole at the center of Galaxy M87, while examining an area past which nothing escapes the black hole. It took them two years of research even after they got the images. Black holes are formed of huge stars which have either collapsed or have fallen into themselves. Sun is not a big enough star to become a black hole someday.
How many black holes are there?
There are numerous small black holes populating the wide space of the universe. However, research suggests that supermassive black holes are more in number. They are as massive as a billion times the size of the sun, but the same in diameter. Hence, these are considered to be at the center of every galaxy. Supermassive black holes are speculated to have been formed either as a consequence of thousands of small black holes merging together, or large gas clouds collapsing together, or a group of stars all falling together.
Are black holes real?
The image released in 2019 proves the existence of black holes. They have three layers: the outer event, and inner event horizon, and the region with the mass, called the black hole’s singularity. It is the point where the entire mass of the object is concentrated. It is impossible for scientists to see the black holes, but they are certain of their existence on the basis of the detection of the radiation that takes place from within the black holes in the form of dust and gas. Sometimes, the supermassive black holes can get covered by thick layers of dust and gas, and the emissions may get blocked.
The Black Hole Theory
Black Holes have the ability to stretch the length of anything that falls into it. This phenomenon is known as Spaghettification. According to the Black Hole Theory, it is possible that Black holes can actually give birth to new universes. The singularity at the center of the black holes is known to not abide by the standard laws of physics, hence can easily make alterations in the present universe and create a new one. Black holes are the reservoirs of energy. The amount of energy generated by the Sun is nothing compared to that of a single black hole. Due to the great rotating speed of the black holes, they are very heated up, and the average temperature is supposed to be approximately billions of degrees Fahrenheit.
Black holes are supposed to be able to slow down time. According to the general theory of relativity, if an object was to move in a black hole, it would have moved quickly. Thus, the lesser the time it takes to travel, the younger the object remains.
The Hawking Radiation
A fascinating discovery was made by the physicist, Stephen Hawking, which he later named the Hawking Radiation. By this phenomenon, a black hole can be evaporated. It would stop existing. This proved that black holes are not indestructible in nature. Even with the myriad mysteries that are yet to be unleashed, black holes are not beyond the powers of man. Again, theoretically, it is possible for anything to turn into a black hole only if it has a very dense core and a huge gravitational pull. In reality, however, only the collapse of an extremely massive celestial object can result in the formation of black holes.
Unknown things about black holes
There are things still not known about black holes, and research is being done to know the unknown. There are newer speculations coming up about black holes every other day. It keeps getting mysterious by the day, with every new fact being revealed. The more one tries to solve, the more convoluted it gets. However, with the incessant pursuit of the scientists at solving this jigsaw of the universe, one can guess it is a matter of time before we get to know about the black holes in their entirety. Till then, just like all other celestial wonders that bless our universe, black holes remain a part of the unknown, unrevealed, and dark.