A black hole is a thing or place in space where the gravitational pull is so much that it absorbs light in itself and even the light can not escape. The gravity there is so strong because the matter is squeezed into a very tiny space.
Black holes can only get formed by a star that is dying. After the formation of a black hole, it continues to grow by absorbing mass from its surroundings which makes the black holes dangerous for any other star, comet, asteroid, or planet.
NASA, which is the world’s biggest space agency, has a current watch on different black holes. NASA is using satellites and telescopes that are traveling in space to learn more about black holes. These spacecraft help scientists answer questions about the universe and the black holes.
Birth of the universe from a black hole
The birth of our universe may have come from a black hole. Most science experts and astronomers agree that the universe might have started as an infinitely hot and dense point called a singularity.
According to scientists, there is a point of infinite density at the center of the black hole which is known as the “singularity.” Scientists say that the singularity in a black hole can give birth to a new universe anytime. There is no proven evidence of this but scientists still think that there is a possibility that a black hole can form a new baby universe.
How big a black hole can be?
Black holes can be as small as just an atom or can be as massive as the sun. But even the smallest black holes can have the mass of a large mountain.
Because mass is the amount of matter in an object.
A kind of black hole called “stellar” has a mass of 20 times the mass of the sun. There can be many stellar-mass black holes alone in our galaxy called the Milky Way. The simplest or the smallest black holes have mass but neither any electric charge nor any angular momentum.
After their formation, by absorbing other stars and merging with other black holes, supermassive black holes can get formed. Supermassive black holes are the largest kind of black holes. Scientists have expected that the mass of these black holes can be more than a million suns together.
According to scientists, every large galaxy can contain a supermassive black hole at the center. There is also a supermassive black hole at the center of our galaxy which is called “Sagittarius.” It has enough size to hold inside it a few million Earth and has a mass equal to about 4 million suns.
How do scientists find a black hole if they are invisible?
Since even the light can not get out of the black hole, people can not see black holes. In simple terms, they are invisible. It is impossible to see a black hole with human eyes because of its strong gravity which pulls all of the light into its middle. But scientists can study the behavior of stars and gas around the black hole due to the strong gravitational pull of the black hole. Scientists can study if stars are flying around or orbiting a black hole.
Only special tools can help humans find black holes as the special tools can see how stars that are close to a black hole behave differently than other stars away from the black hole.
Scientists use space telescopes and satellites to see the high-energy light known as the “quasars”, some of the brightest objects in the universe which is produced when a black hole and a star are close to each other. Also if some stars are orbiting a black hole, their orbits can be used to determine the black hole’s mass and location by scientists.
Can someone survive a black hole?
Nothing escapes a black hole. A trip into a black hole would surely be one way. A black hole would stretch the human body into a thin ribbon because the gravitational pull on the feet would be so much stronger than on the head. The length of the human body will increase due to different gravitational pulls at different parts of the body that we can not even imagine.
The gravitational pull of the black hole is so strong that even the light can not get out of it so it is simply a truth that no one can come back in space and time after entering the black hole. So if you are thinking that someone can survive a black hole, it is impossible.
Will the Sun ever become a black hole and destroy the earth?
No, it is impossible that the sun will ever turn into a black hole. The reason behind this theory is that the sun is not a big enough star to make a black hole.
The sun would need to be about 20 times bigger to end itself as a black hole. But with this size, the sun will end up as a white dwarf that is a small remnant that glows from the heat left in it. And that white dwarf will not be capable of becoming a black hole.
Even if a black hole having the same mass as the sun were to take the place of the sun, the Earth would not fall in the black hole because the black hole would have the same gravity as the sun and the planets would normally orbit it as they orbit the Sun now.
Also, at present, there is no black hole close enough to the Earth or the solar system for the earth to fall into it. So we can say that earth is safe from black holes at present.