What is a Black Hole?
Black holes, also called black holes, are one of the great mysteries of the Universe.
Astronomers study these cosmic giants, and although it has not been possible to decipher all their secrets, there is some information that has been established for lovers of the Cosmos.
The US space agency, NASA, defines it as a region in space where the force of gravity is so strong that nothing, not even light, is able to escape.
Gravity is so powerful because the matter has been squeezed into a tiny space.
Black holes are invisible: As light cannot escape the gravity of black holes, they are not visible to the eyes.
From the beginning of all time: NASA maintains that the so-called primordial black holes were formed in the early Universe, shortly after the Big Bang, which gave rise to everything we know.
However, astronomers have developed space tools capable of detecting them. The NASA agency explains that they can observe the behavior of the material and the stars that are very close to the black holes.
A black hole is a theoretical concept of Einstein’s general theory of relativity introduced by John Wheeler in 1967.
Today we know that there are cosmic objects that come very close to this concept and, in fact, that they are black holes is the best explanation we have.
This is the case with Sagittarius A*, an astronomical source of luminous and very compact radio waves in the center of the Milky Way, which is the location of what is believed to be a supermassive black hole about 4.5 million times the mass of the Sun.
Scientists support the hypothesis that black holes are generated when a massive star dies and its mass falls or implodes at a proportionally smaller point in space.
How do black holes form?
Stellar black holes form when the center of a very massive star’s galaxy collapses in itself, explains NASA.
This collapse also causes a supernova. Scientists believe that supermassive black holes form at the same time as the galaxy that houses them.
Can a black hole destroy the Earth?
Although there is a black hole in our galaxy, in theory, there is no danger to our planet. In addition, NASA makes it clear that far from what most people believe, black holes do not wander around the Universe swallowing worlds at random.
If one day the Sun were replaced by a black hole, the Earth would not be dragged but would continue to orbit around it.
Holes are Invisible
A black hole is not visible to the naked eye because gravity literally devours light. Scientists identify a black hole in space when they find stars whose behavior is affected by massive gravitational forces indicating that they are near a black hole.
Gravity in a black hole is highly concentrated due to the large amount of mass accumulated in a tiny space.
It’s like putting all the mass of the sun in a small room. The room may contain the mass, but it does not prevent it from generating gravitational waves affecting its environment.
What is the size of the black holes?
Not all black holes are giants in the cosmos. Scientists think the tiniest black holes are as small as an atom.
These may be really tiny, but they have the mass of a big mountain. These are called primordial black holes.
The most common class is the medium sized black stellar holes, which means a mass 20 times greater than that of our Sun. The supermassive ones are the biggest, with a million times the mass of our star.
Different hole sizes
The black holes can be of different sizes. Scientists divide them into 3 sizes:
- Small: black holes the size of an atom, but with the mass of a mountain.
- Stars: black holes containing masses equivalent to 20 times the sun. These are the most common black holes in our galaxy: the Milky Way.
- Supermassive: are black holes containing masses equivalent to more than 1 million times the sun.
It is believed that every large galaxy has a supermassive black hole at its center. The supermassive black hole in the center of the Milky Way is called Sagittarius A and is made the analogy of 4 million suns on a ball.
The heart of galaxies
One of the most accepted hypotheses is that in the center of each large galaxy there is a supermassive black hole.
In fact, our own Milky Way also has its own giant black hole at its center. It is located 26 000 light years from the Solar System, in a region called Sagittarius A, and has a mass equal to 4 million suns.
The British physicist and scientist Stephen William Hawking was one of the most important contributors to this issue of spatial-temporal uniqueness and were also the first to speak about the emission of radiation into the black hole.
He has even written a book, published in 1988, History of Time: from the Big Bang to the Black Holes, which deals precisely with the subject of the formation of black holes.
According to studies by Hawking and other scientists, it is believed that in many galaxies, including the Milky Way, there are black holes.
Key facts about black holes
They are also called’black holes’ and are finite regions of space that generate a gravitational field from which no particle, not even light, can escape.
Black holes, according to their mass, are classified into three types: supermassive, stellar mass and micro black holes.
It is believed that in the center of most galaxies there are supermassive black holes.
what happens when someone falls into a black hole?
You probably think you’d end up crushed, or maybe smashed to pieces. But the reality is much stranger than that.
The moment you enter the black hole, reality will split in two. In one of them, you would be incinerated immediately. And in the other you’d dive into the hole, totally unharmed.
Black holes are places where the laws of physics as we know them to lose their meaning. You’re gonna have to be a little patient to understand.
Can a black hole be created?
Scientists believe it would be so small that it would fade in a fraction of a second in order to pose a danger.
The Large Hadron Collider (LHC), launched in 2008, is capable of producing small black holes through high-energy collisions that produce new particles that govern the rules of fundamental forces: electromagnetism, weak force, strong force, and gravity.
The LHC is powerful enough to create a black hole comparable to that of elementary particles. However, it’s all a theory.
Scientists believe that it would pose no risk because if it were to be created, it would be so small that it would fade in a fraction of a second and this is too little time to pose a danger.