Astronomers have found many supermassive black holes in the universe that are much larger than the Sun.
These supermassive black holes have billions to hundreds of billions of solar masses.
This supermassive black hole is typically located in the center of the Milky Way galaxy and is called an AGN.
They possess massive mass and strong gravity, capable of engulfing all the gases, dust, and stars around them.
As the black hole accretes, a disk called an accretion disk appears, which releases a large amount of energy and emits strong radiation.
1. Stellar evolution
The formation of black holes is driven by the evolution of stars.
When a planet runs out of nuclear energy and cannot continue nuclear fusion, it goes through a series of evolutionary processes until it finally becomes a black hole.
In the later stages of stellar evolution, as the core collapses to a certain point, a very dense type of star - neutron star is produced.
A neutron star is an extremely dense celestial body, with an inner core that may be tens to tens of times that of a star, but its volume is compressed to tens of kilometers.
This is because the matter in the inner core is squeezed by strong gravity, and the electrons are squeezed into protons, forming neutrons, so the density is very high.
However, when the mass of the star is larger, it will exceed the so-called Ptolemaic limit, which is three times the mass of the Sun, and its gravity will be crushed inward, eventually forming a black hole.
After a black hole is formed, its matter gathers at an infinitesimal point, the so-called singularity, and around this singularity, there is an inescapable gravitational field, known as the "event horizon".
Black holes are created by gravity, and at a certain point, gravity can no longer be counteracted by other forces, so they collapse to the singularity.
At present, there is no complete theory of quantum gravity about the singularity in black holes and the nature of singularities.
So, black holes have always been the most mysterious and fascinating objects in the universe.
2. The black hole of terror
One of the most famous is the black hole in the center of M87, which is hundreds of billions of times more massive than our sun.
In addition, we have also observed supermassive black holes in other galaxies, which is of great significance for our understanding of the evolution of the universe, the formation of galaxies, and the physics of black holes.
Black holes are intimidating in large part due to their unique properties.
Black holes have such a strong gravity that they can swallow even light.
In the Event Horizon, gravity is so great that no object, not even light, can escape. This is the black hole that is the most powerful gravitational capture in the universe.
Black holes have a boundary called the "active boundary", in which neither matter nor information can escape.
When an object passes through the active boundary, it can no longer return to where we can observe, so we can't directly observe a black hole.
A black hole may be billions of suns in size or larger.
With such a large mass, black holes can have a great impact on the objects around them, including the bending of space and the devouring of matter.
The internal structure of black holes remains a scientific mystery.
Within the event horizon of a black hole, matter is compressed to an infinite density of singularities, which is beyond the scope of our existing physical theories.
We don't yet fully understand the physical processes inside black holes, which adds to the mystique and horror of black holes.
Despite these terrible properties, most black holes do not pose a direct threat to our lives or the planet.
They usually exist in faraway parts of the universe, and the distance between us and them is very far.
In addition, the range of influence of black holes is limited, and their gravitational pull will only have a noticeable effect on the surrounding matter if they are close to the black hole.
3. Impact
For Earth, black holes usually don't have a significant impact on our lives directly.
This is because most black holes exist in distant parts of the universe and are very far away from the Earth.
Even if there are massive black holes, their gravitational impact on the Earth is negligible.
Despite the strong gravitational pull of black holes, the gravitational pull of the Sun is still the dominant force for Earth.
The gravitational pull of the sun is very important for the movement and orbit of the earth, while the gravitational pull of a black hole has a relatively small effect on these processes.
Some black holes may produce intense radiation and jets, which are created as a result of the black hole devouring the surrounding material.
However, this activity usually occurs in distant galactic centers, millions of light-years away or more from Earth, and the impact on Earth is negligible.
Black hole activity may produce cosmic rays, which are streams of high-energy particles.
However, the Earth's atmosphere can effectively shield cosmic rays, protecting life on Earth from their effects.
4. Significance
The study of black holes is of great significance for our understanding of the evolution and physical laws of the universe.
Black holes are an important prediction of general relativity.
By observing and studying black holes, we can test Einstein's theory of general relativity, which is a theory that describes gravity.
The existence and nature of black holes are consistent with the predictions of general relativity, which further strengthens the reliability of this theory.
The powerful gravitational field of a black hole offers a unique opportunity to study gravity.
By observing the movement and radiation of matter around a black hole, we can better understand the nature of gravity and its role in the universe.
Black holes play an important role in the evolution of the universe, and their formation, growth, and interaction play an important role in the formation and evolution of the structure of the universe.
Through black holes, we can learn about the formation and evolution of galaxies in the universe, the clustering of galaxies, and the distribution and evolution of supermassive black holes in the universe.
Revealing the singularity of matter and energy, the singularity inside a black hole is where the density of matter and energy is infinite, beyond the scope of our existing physical theories.
Studying black holes can help us better understand the nature of singularities and possible physical laws, which can advance physics.
Black holes are one of the most extreme celestial bodies in the universe, with enormous mass and gravitational pull.
Studying black holes can help us understand the behavior of matter and energy under extreme conditions in the universe and reveal the wonders of the universe.
The universe is vast, and there are so many secrets in it.