What are black holes, and is it true that the laws of physics collapse inside black holes? Why is it black and what happens to us if we enter a black hole ... In this article, I will answer these questions and work to clarify the mysterious matters related to black holes
Note: In this article, I am modestly trying to describe this natural phenomenon within my capabilities, but it must be known that the issue of black holes is still under discussion and our information on the subject is constantly evolving. I hope this article is interesting and useful, and I hope it is classified within the general culture dissemination about black holes, not a research article on the topic ...
About black holes
Stars are very large atomic reactors in which billions of trillions of atoms explode and nuclear fusion processes take place that results in everything we see around us of matter. Yes, you and I, the trees, the water, and the mountains, we are all formed from elements that have melted inside the stars, but why does the star not explode once and its atoms scatter in space and evaporate? The reason is that the enormous mass of the star forms a great gravitational force that holds the star together.
Imagine a star, not a specific one, and imagine the huge explosions that happen in it. Let the mass of this star be ten times greater than the sun. This means that this star is 3,333,000 times larger than the Earth. In childhood, the star performs nuclear hydrogen smelting processes, but due to the huge mass of stars, a conflict forms between the nuclear fuses that in their nature emanate from the star's core to the surface, and between the gravitational force of the star. With the passage of time the star burns a large amount of hydrogen, which reduces the force of its melting points and increases the force of gravity.
After a while, gravity takes over the star and becomes the dominant force, then the star begins to collapse in on itself. If certain conditions are met in this collapse (the size of the mass with the force of gravity) the star turns into a point of enormous gravity so that everything that passes near the star is directly attracted and decomposes inside it. Scientists call this process macaroni effects spaghettification
It is important to note that nothing can escape the gravitational influence of a collapsing star. Even the light can't go out and so we can't see what's inside this avalanche. That is why we call these collapsing stars "black holes" due to our inability to see what is inside them. So, although we are not able to see a black hole directly, we can monitor the effect of black holes on everything close to them due to the force of gravity.
I will return to black holes to explain more phenomena, but let us go back a little bit and talk about some physical matters that must be understood before continuing in this article.
Matter and gravity:
In 2012, a basic element called the Higgs was discovered. The Higgs field is responsible for giving the material its mass, but we will not go into these details in this article.
All that we see in the universe is made up of basic elements. I will not go into details in this article, that these elements (quarks) have electrical charges, and these electrical charges determine the type and size of the nucleus in every substance. The mass of matter is directly related to the interaction of this substance with gravity. But what is gravity?
Gravity is not what some perceive as an energy that attracts objects to each other. Gravity is a curvature of space due to the mass of objects. So, the size of the mass of the nucleus directly affects the amount of curvature in spacetime .. But what is spacetime?
Let's imagine we have a large fabric hood over the mouth of a large barrel. If we put a metal ball in the middle of the cap, we would have a circular curve in this cap. Now if we put several balls and make them revolve around the metal ball, these balls will rotate several rounds and then go in the bend formed in the cover until all the balls hit each other and meet in the center of the cover. The reason the balls are attracted to each other is not due to the energy of attraction between them, but rather as a curvature of the fabric cover. The cloth cover represents space-time.
Now let's imagine that this cover is the space area in our solar system and that the sun is the metal sphere in the middle and that the small metal spheres are the planets in our solar system.
The large mass of the sun is the reason for the curvature of the space cloth and the earth, and the rest of the planets revolve around the sun due to the curvature of the space space. Of course, in space there is no friction between the objects, so the objects remain in the same orbit without their speed slowing down.
This idea is the most important achievement of Albert Einstein and is called the theory of general relativity.
Space-time - time and place:
Imagine with me that we are on an island in the Pacific Ocean and want to move to another island. We know that the journey from our island to the other island will take a specific time and that the duration of the trip depends on the amount of speed. Assuming we can fly at 340 meters per second (about the speed of sound). This means that we will cover the distance between the two islands (6 km) in approximately 18 seconds.
Let's take a second example ...
Suppose we spot a thunderstorm coming towards our island. We see lightning, and after a certain period of time, we hear the sound of thunder. If we want to know the distance between us and the storm, we have to do a simple (mental) math. All we have to do is time the difference in time between lightning and thunder. Sound moves at a speed of 1 km approximately every 3 seconds. The moment we see the lightning, we start counting in seconds until we hear the sound of thunder. Suppose we heard the sound of thunder 9 seconds after witnessing the lightning. This means that the storm is about 3 km away from us from the direction of the lightning.
In this universe there is a cosmic truth, which is that the transition between two points, whatever the size of the mass of matter, this transition must take a certain time regardless of the speed of transmission. There is no such thing as teleportation between two different places. So time is an integral part of space. Without place there is no time and without time there is no place.
Time and space in physics represent one and indivisible dimension, and for this we call it space-time. (Space-time)
By virtue of the fact that the speed of light is the maximum speed in the universe, this means that the movement from place to place is related to the speed of light, and for this reason the speed of light is used in measuring space distances.
Time and place are two parts from one dimension.
Gravity escape velocity:
I mentioned earlier that gravity is not an energy that affects objects at a distance, but rather a curvature in spacetime. She also explained what is space-time in a simple way and explained the relationship between speed, time and space. Now I would like to explain how objects can escape gravity or how to exit the spacetime.
If we imagine ourselves stuck in a hole and we have to get out of this hole. The only way out is by accelerating out of the hole. If the speed is not appropriate we go up a little on the walls of the hole and then stop and return to the bottom of the hole. Now let's imagine that gravity is in the hole and we want to get out of the hole.
Note: the spacetime curvature is not a hole from the bottom up because there are no directions in space ...
We first need to calculate how convex the walls of the hole are and then work out the velocity needed to exit the hole. The convexity of the walls is due to the mass of the material that originally formed the convexity (gravity).
So, to get out of the space-time crater formed by the Earth (Earth's gravity) we have to launch at speed = or more than 11 kilometers per second. All spacecraft must launch at this speed to exit from the Earth's atmosphere to outer space.
The speed needed to escape the moon’s gravitational pull is 3 kilometers per second
The speed required to escape the gravitational pull of Mars is 5 kilometers per second
The speed required to escape from Saturn's gravity is 36 kilometers per second
The speed required to escape from the sun's gravity (from its surface) is 618 kilometers per second
In a black hole, we need a speed of more than 300 thousand kilometers per second (the speed of light) to escape from the black hole’s attraction, and for this nothing can escape the attraction of black holes….
The escape velocity from the gravity of the 67P comet that landed on the ESA is 1 meter per second.
Side final idea:
Black holes are not gulps ... Many people imagine black holes as attracting everything around them. In fact, this is not true, and only matter that crosses the point of no return enters the gravitational field of the black hole. For example, if the planet Earth turns into a black hole, this will not affect the moon's orbit. The moon will remain in its place because the distance between the earth and the moon is a safe distance compared to the speed of the moon’s rotation (otherwise the moon would have hit the earth).
Of course, the Earth's gravity still has an effect, but the farther away we are from the center of the Earth, the slower the escape velocity and the closer we get, the greater ... When meteors approach the Earth at a speed less than the escape velocity, this means that they will be attracted to the Earth.
So the point of no return with respect to the Earth depends on the velocity of the object orbiting it ...