Birth of the sun
And now the nebula has acquired a completely different look. A huge dark, slightly flattened cloud rotates majestically in the middle, and around it at different distances floating in circular orbits located approximately in the same plane, small “satellite clouds” detached from it. Follow the central cloud. It continues to condense. But now a new force begins to struggle with the force of gravity – the force of gas pressure. Indeed, in the middle of the cloud, more and more particles of matter are accumulating. There arises a “terrible crowding” and an “incredible crush” of particles. They rush about, striking each other harder. In the language of physicists, temperature and pressure rise in the center. At first it gets warm, then hot. Outside, we don’t notice this: the cloud is huge and opaque. Heat does not come out. But something happened inside! The cloud stopped shrinking. The powerful force of the increased gas pressure from heating stopped the work of gravity. There was a sharp smell of unbearable heat, like from the mouth of a suddenly opened furnace! In the depths of the black cloud began to faintly shine tearing out clubs of dull red flame. They are getting closer and brighter. The ball boils majestically, mixing the escaped fire of the nucleus with the black fog of its outskirts. The scorching heat makes us pull back even further. However, bursting out, hot gas weakened the resistance to gravity. The cloud began to shrink again. The temperature in its center began to rise again. She has already reached hundreds of thousands of degrees! Under these conditions, the substance cannot even be gaseous. Atoms fall apart. The substance goes into a plasma state. But even plasma – a frantic crush of atomic nuclei and electrons – cannot endure heating indefinitely. When its temperature rises above ten million degrees, it kind of “ignites”. The impacts of particles against each other become so strong that the nuclei of hydrogen atoms no longer bounce from each other like balls, but crash, squeeze into each other and merge with each other. The “nuclear reaction” begins. Out of every four nuclei of hydrogen atoms, one helium nucleus is formed. At the same time, huge energy is released. Such a “nuclear burning” of hydrogen began in our red-hot ball. This “fire” can no longer be stopped. The “plasma” was raging. Gas pressure in the center began to work with tenfold strength. Plasma bursts out like steam from a boiler. With monstrous force, it presses from the inside onto the outer layers of the ball and stops their falling to the center.
A balance has been established. Plasma cannot break the ball, scatter its fragments to the sides. And gravitation fails to break the plasma pressure and continue to compress the ball. The dazzlingly luminous white-yellow ball entered a stable stage. He became a star. Became our Sun! Now it will be billions of years old, without changing its size, not cooling and not overheating, to shine with an equally bright white-yellow light. Until all the hydrogen burns out inside. And when it all turns into helium, the “backup” inside the Sun disappears, it will be compressed. From this, the temperature in its bowels will rise again. Now, up to hundreds of millions of degrees. But then helium will “ignite”, turning into heavier elements. And the compression will stop again.
The stars have several more nuclear reactions that require ever higher pressures and temperatures for their start. The nuclei of increasingly complex and heavy elements are “boiled” in them. In the end, all possible reactions will be exhausted. The star will shrink and become a tiny “white dwarf”. Then it gradually cools down, fades. Finally, it goes off completely. Silent invisibility will float in space “black dwarf” – a cold “firebrand” left over from the once raging powerful bonfire. As we see from the starting material – hydrogen – in the bowels of stars, in the nuclear fusion reactions, the nuclei of atoms of all elements are “boiled”. And perhaps we can say that it is there, in the bowels of the stars, that the beginning of life is laid. After all, it is there that the nuclei of the “atom of life” carbon arise. And behind them are the nuclei of atoms of all the other elements of the periodic table necessary for life. Not necessarily this valuable “brew” is then buried in cooled “black dwarfs”. In many stars formed from larger clumps of nebulae, nuclear burning is too violent. Gas pressure is much stronger than gravity. It inflates a star, tears it to shreds, scattering it in all directions. These grandiose explosions in the starry world are sometimes observed from the Earth and are called flashes of “supernovae”. As a result of the explosion, the star scatters in interstellar space, enriching it with heavy elements. This is the main source of that mysterious, vital impurity that we spoke about before. Now about the allocation of this impurity.