We all know that everything is composed of various elements. So have you ever thought about how so many elements are produced?
This needs to start from the beginning of the birth of the universe.
In the early days of the universe, it was filled with hydrogen element and a small amount of helium element . The two together formed the most primitive nebula.
Due to the difference in temperature density, the original nebula will gather towards a denser place under the action of gravity. After a long time, the temperature pressure in the core area becomes higher and higher, which will trigger nuclear fusion to form the most primitive star.
When the hydrogen fuel is exhausted, if the mass of the star is large enough, the helium element will continue to fusion and become heavier elements, such as carbon, oxygen, etc.
However, nuclear fusion cannot continue to fusion. When the fusion reaches the iron element, it will come to an abrupt end. No matter how big a star is, it cannot allow the iron element to continue to fusion, because the fusion of iron element requires energy absorption rather than energy release, which is exactly the opposite of other elements.
When a massive star fusion reaches the iron element, nuclear fusion stops. Since there is no energy to compete with the star's own gravity, the star begins to collapse inward sharply, which triggers a violent supernova explosion , producing elements heavier than iron.
It is necessary to emphasize here that nuclear fusion cannot produce elements that are more important than iron. The process of supernova explosion in the process of producing elements that are heavier than iron is not nuclear fusion.
How does supernova explosion produce heavy elements?
In layman's terms, it is brute force. With super-strong temperature pressure, it strongly combines iron elements with neutron to form a heavy core. This process is also the process of "neutron capture".
Because there is no external thrust generated by nuclear fusion, the inward gravity generated by massive stars themselves completely let go of their hands and feet, pulling all the stellar matter into the direction of the core. The temperature pressure in the core area rose sharply in a short period of time, forcibly combining iron elements with neutrons. The process of
neutron capture is actually very complicated, but the basic principle is this.
In addition to supernova explosions, there is another violent event in the universe that can produce elements heavier than iron, that is, the collision of neutron star , which is also an extremely violent cosmic event.
can be seen that the colorful world we see today, every cell in our body, every atom , actually comes from the primitive stars at the beginning of the birth of the universe, and our sun is just the third generation of stars.
