Before the scientific revolution of the 20th century, it was not clear what fueled the fire of the Sun and the stars, nor how extremely stable heavy elements such as gold or silver could have formed. It was only at the dawn of quantum physics that they realized that the fire of stars is not brought to life by chemical processes or gravity, but by something quite different, nuclear fusion. But even that in itself did not explain how elements heavier than iron, which are extremely rare in the universe relative to the universe’s precious material, hydrogen, could have been created. The exploration of the laws of stellar evolution has led us to decipher that all the elements necessary for the building blocks of life on Earth can occur only exceptionally rarely, during the supernova explosion, one of the most powerful energy-releasing phenomena in the universe. Our existence is due to a gigantic stellar catastrophe in the distant past, as well as our gold rings and necklaces.
–
For a long time it was a mystery what heats the Sun.
By the 19th century, astronomy was already so advanced that the mass of the Sun and its distance from the Earth could be accurately determined. Scientists of the age were seriously preoccupied with the question of what the gigantic thermal energy of the Sun, which is almost 150 million kilometers away from us, could come from, which makes the earth pleasant and habitable even from this inexhaustible distance.
Scientists of the 19th century believed that the heat coming from our central star came from a simple chemical combustion. Lord Kelvin was the first of the scientists of the age to seriously question this theory, assuming that even the vast mass of the Sun would not be enough for this in the long run, as sooner or later it would simply burn itself.
Kelvin calculated that the thermal energy of the Sun could also be generated from gravitational contraction, but even this process would not provide solar radiation for more than a few million years. Albert Einstein gave a new perspective to the difficult problem to solve, the famous E = mc published in 1905.2 with the formula (energy = mass multiplied by the square of the speed of light), according to which even a very small amount of matter can be converted into enormous energy.
In the 1930s, Otto Hahn, a Nobel Prize-winning German chemist who discovered nuclear fission, and Nobel Prize-winning Hans Albrecht Bethe and Carl Friedrich von Weizsäcker, a German atomic physicist, created the Bethe-Weizsäcker cycle called practical significance.
The discovery of thermonuclear nuclear fusion has also led to an understanding of the processes taking place inside stars and the formation of heavy elements.
When the size of a star suddenly increases a hundredfold
If we look at the starry sky in the evening, each point of light corresponds to a distant “star-sun” that we see as bright due to the thermonuclear fusion taking place inside them. : there are “celestial phenomena” that shine in white, play in bluish-white, and glorify in orange and red.
The color of the stars can indicate their mass, age, or temperature. Stars form from the vast clouds of gas and dust in cosmic space from matter that condenses due to various gravitational effects, called globules. When the mass of the protostar is large enough for the gravitational contraction to produce enough pressure and temperature inside the nascent celestial body to initiate thermonuclear fusion (the proton-proton cycle), the star will shine and begin to radiate.
Since 99 percent of the universe’s fossil is hydrogen, the mass of young stars is also largely made up of hydrogen. Thus, at the beginning of the star’s life cycle, helium is first formed from the fusion of hydrogen atoms while energy is released.
The star, depending on its mass, consumes its entire hydrogen reserves in a few million or billions of years.
As soon as the amount of helium in the core reaches a certain limit, the fusion of the core stops and the jet pressure ceases, causing the outer layers of the star to be pressed towards the inside of the core by gravity.
The strong contraction causes an increase in pressure and temperature in the core, which, when it reaches 100 million degrees Kelvin, initiates a fusion of helium. As a result of the core heating up again, the star begins to inflate again, only that this process is now much more intense than it was when the star was born.
Due to the rapid inflation, the size of the star can increase up to a hundred times compared to before,
this is how the red giant state is created.
Burning helium in the red giant can take a good few million years, and what happens after the star burns its helium stock also depends on the mass of the celestial body.
A distant star catastrophe to which we owe both gold and our lives
When a star larger than at least four solar masses becomes a red giant, due to the enormous force of gravity, the celestial body begins to shrink again after a while, but much more violently than other stars of lower mass. The core of the collapsing red giant becomes much hotter and denser, causing new nuclear reactions to start inside the star, and the fusion creates more and more difficult elements.
This process temporarily prevents the star nucleus from collapsing until the thermonuclear fusion, as a function of mass, reaches the structure of silicon No. 14, or element 26 of the Periodic Table, iron. After that, however, there is no longer a force that could prevent the core from collapsing due to the tremendous gravity.
Gravitational collapse is an extremely intense and fast process that takes just a few seconds
which culminates in a gigantic thermonuclear reaction, the supernova explosion.
The amount of energy released during a supernova explosion is a good illustration of
that the light of the supernova can also reach the combined light of the 100-200 billion stars that make up a given galaxy for a short time.
The neutrino flood that accompanies the supernova explosion scatters a significant portion of the material of the extinct star in interstellar space. While high-velocity scattering material is exposed to strong neutrino radiation, atoms absorb neutrinos and are transformed into elements heavier than iron.
This creates, among other things, gold with license plate number 79 and all the natural elements of the periodic table that are heavier than iron, up to and including uranium with license plate number 92. So, the heavy elements found on Earth — including the gold and silver that make up the ring or necklace — can be seen as material relics of a past star catastrophe.
But not only gold, but also, indirectly, our existence is due to the supernova explosion in the distant past from which the Solar System evolved. This is because all the natural elements of the periodic table were needed to make up the complex organic molecules that make up the cornerstones of life on earth.
Thus, the death of an ancient star created the possibility for us to exist today. If we look up at the starry sky or stroke the gold ring on our fingers, come to mind this too.
–
