Everything you want to know about black holes

Written By طقس العرب on 2023/10/28

This article was written originally in Arabic and is translated using a 3rd party automated service. ArabiaWeather is not responsible for any grammatical errors whatsoever.

Arabia Weather - Black holes are one of the strangest and most mysterious phenomena in the universe. These massive masses are characterized by their high density and intense gravity, which greatly affects the galaxies and space around them. In 1916, famous scientist Albert Einstein presented his general theory of relativity that predicted the existence of black holes. Years later, American astronomer John Wheeler coined the term "black hole" for this phenomenon.

For decades, black holes were considered only theoretical objects, not based on direct evidence. However, the first physical black hole was discovered in 1971, proving its existence. In 2019, a major breakthrough was reached when the first image of a black hole was taken, thanks to a major international collaborative project using a group of ground-based telescopes. This image enhances our understanding of black holes and opens a new horizon for research and exploration in astronomy.

What are black holes?

Black holes are locations in space that have gravity so strong that it prevents even matter and light from escaping. This massive gravitational force is caused by huge amounts of matter packing into a very small space, with everything being pulled towards the center of the black hole. Black holes occur at the end of the life of some massive stars, as these stars collapse on their own due to gravity, resulting in this strange astronomical phenomenon.

To humans, a black hole is barely visible because it cannot be seen directly with the naked eye, because it does not emit any light since the black hole absorbs everything, including light. However, space telescopes equipped with dedicated instruments can be used to detect signals coming from the vicinity of black holes. These telescopes enable us to study the behavior of stars near black holes and observe the enormous gravitational effects that black holes impose on their surroundings.

Types of black holes

Classification of black holes helps understand the diversity and different properties of these fascinating cosmic phenomena.

Supermassive black holes: These black holes are distinguished by their enormous mass, which may reach masses as large as the sun. They are often found in the centers of the largest galaxies and have a major influence on the formation of galaxy structures.
Intermediate mass black holes: This type can have a mass ranging from one hundred to one million solar masses. Although the existence of this species has not been directly proven yet, there are indirect evidence of its existence.
Stellar black holes: These black holes are the result of the collapse of a massive star with its end. Its mass ranges from 5 to 100 solar masses and can be observed when nova explosions or star collapses occur.
Micro black holes or quantum mechanical black holes: This type of black hole was introduced by scientist Stephen Hawking. These holes are believed to follow quantum laws and appear on a very small scale. These tiny holes interest physicists because of their potential effects on quantum and stellar physics.

How do black holes arise?

So far, astronomers have identified three main types of black holes. These types include supermassive black holes, intermediate-mass black holes, and stellar black holes. We'll take a look at how each type is formed individually:

Supermassive black holes: These holes can form as a result of the merger of hundreds or thousands of small black holes, or they may arise from the accumulation of gas and matter at an amazing speed to form a huge mass. These holes may also form from the collapse of massive stellar clumps or from huge pools of dark matter that can be detected through gravitational effects on other objects. Once formed, supermassive black holes collect more gas and dust around them, allowing them to grow to enormous sizes due to the vast amounts of matter available at the centers of galaxies.
Intermediate-mass black holes: These holes typically form when several stars collide in a star cluster as part of a chain reaction. These intermediate-mass black holes coalesce at the center of the galaxy over time, forming intermediate-mass black holes.
Stellar black holes: This type of black hole is formed when a large star collapses due to intense compression. These holes are dark and dense, with masses several times higher than the Sun. These holes have a very strong gravity that pulls objects around them to keep them growing.

Basic components of a black hole

Black holes consist of five main parts:

Event horizon: This region surrounding the black hole is characterized by containing the boundaries through which matter and electromagnetic radiation can pass towards the black hole without matter being able to exit it. This area is a critical turning point.
Center of the hole (eye of the hole): This place represents the center of the black hole, where the curvature becomes infinite and absolute.
Photon sphere: This boundary represents a surrounding sphere of intangible thickness. This ball moves the photons vertically to the ball trapped in an elliptical orbit with respect to the shape of the black hole.
Ergosphere: This part allows things to move in it as a result of a phenomenon known as tire drag. Simply put, this part is surrounded by the event horizon part.
Circular orbit: On this orbit, particles rotate steadily at different distances from the black hole.

Examples of the most famous black holes

Cygnus X-1 black hole: It is considered one of the first black holes to be discovered. It has a stellar mass and is an X-ray source. It is located about 6,500 light-years from Earth and forms a binary system containing a blue giant variable star.
Sagittarius A:* It is considered one of the supermassive black holes and is located in the heart of the Milky Way Galaxy. It is distinguished by its enormous mass, which is approximately 4 million solar masses.
M87 Hole: It is located in an elliptical galaxy and has a mass of about 3.5 billion solar masses. It is located in the heart of the galaxy and is surrounded by a disk of very hot material. It is characterized by the characteristic of emitting and the flow of hot materials around it. It is about 5,000 light-years away from the heart of the galaxy.
Centaur Hole Galaxy: This galaxy has a giant spiral shape and a strongly active core. It is characterized by the presence of a black hole with a mass estimated at about 55 million solar masses in its core. Material flows towards it at approximately half the speed of light across a distance of one million light-years of space.