Simple understanding of cosmic black holes and gravitational waves

Knowing that finding gravitational waves is an historical event, but what is the gravitational wave in the end?

Recently, the scientific community has officially announced the discovery of gravitational waves emitted from a "seismic" collision between two giant cosmic black holes .

But gravitational waves and black holes are concepts that only enthusiasts can understand. So how about ordinary people, we will have to understand these two concepts?

1. The black hole of the Universe

Black holes are places of tremendous gravity in the universe, which can suck everything around including light.

Why does a black hole have such strong attraction? First of all, it is important to know that black holes are formed after a massive star collapses.

A star will have the following stages: formation, blossoming into a red giant, and then when it comes to " end of life " it will emit supernova. The explosion will cause the mass of matter in the star to collapse, compressing into a very narrow space, and this is where the black hole is formed.

For simplicity, try imagining you hold . the Earth in your palm and squeeze it, stuffing into a box the size of a grain of sand. In order to do that, it will require an extremely large compressive force, enough to crush all forms of material.

Meanwhile, the condition for forming a black hole is that the star must have a mass of 10 times the Sun. The "stuffing" of such a huge amount of matter into space is so why black holes have such tremendous gravity .

2. Attractive waves

Next, we will come with gravitational waves. This is a concept in the theory of relativity introduced by Einstein in 1915, in which Einstein thinks that the universe is a fixed, space-time space, and has the same characteristics as . pool.

When we touch the water and move, we will see waves of waves spreading throughout the water. So is the universe. According to Einstein, a similar phenomenon occurs when an object has a large mass moving in the universe. That movement will emit energy in the form of waves , and we call that gravitational wave.

In theory, objects with large mass moving in the universe like the Earth and the globes are creating gravitational waves. However, it is the same as when we lightly touch our fingertips to the water surface: the energy emitted is too small and cannot be observed.
It is only when the event "two" black holes occur, forming a source of energy 50 times the total energy of all stars in this universe , can humanity confirm existence. of this phenomenon.

By confirming the existence of gravitational waves, we also formally confirm one thing: space-time can be bent . Now imagine you are simply in Vietnam and want to go to the US to play. Normally, the shortest distance is the bird's wing line. But with the theory of bending space, we can "bend" the world map, bringing the US and Vietnam closer. It is also the solution to the dream of human space travel.