Black holes are one of the most important scientific discoveries of the entire twentieth century.
We call a black hole a region in space that contains so much concentrated mass that no object can escape its gravitational pull.
That is, it is an object with a gravitational field so intense that the escape velocity exceeds the speed of light.
In 1968, American physicist John Archibald Wheeler first used the term "black hole." The term "hole" indicates that events occurring within it are not seen by outside observers, while the term "black" is used because not even light (speed of approximately 300,000 km / s) can escape from within.
A black hole can be any size. Some are formed by mergers of several others, and with only three characteristics:
- angular momentum (spin)
- electric charge
Once formed, the size of the hole tends to zero, so its density tends to infinity.
How a black hole arises
The emergence of black holes is related to the life cycle of the stars. Stars arise from immense clouds composed of tiny particles of matter and hydrogen gas, which is abundant in the universe.
After a long time shining and converting their hydrogen into helium, the stars collapse. So your destinations depend on your size. The most massive ones explode. In place of the supernovae (name given to the celestial bodies arising after the explosions) the star's original nucleus, which served as a "support" for the explosion, contracts. Other times, the nucleus does not stop contracting and a black hole is born.