For thousands of years, people have been constantly making hypotheses, doing experiments, observing and concluding to find answers to their own origins.
Just by looking at our own body, we can understand a part of the history of the universe’s development. The adult human body is an incredibly complex system made up of trillions of cells composed of countless atoms that make up the Earth.
The scientific perspective behind the human body also tells us many things about the evolution, the development of the Earth and the vast universe.
The human body is made up of extremely small components: Atoms. Oxygen is the most abundant element, followed by carbon, hydrogen, nitrogen and calcium.
In 0.1 milligram the human body contains at least 56 elements in the periodic table, including the light and heavy elements, which play an important role in the biological activities of the body.
So what in the universe makes life available on a planet like Earth and orbiting stars like the Sun? We cannot just say “because the universe is like that”. To answer, for thousands of years, people have to make hypotheses, do experiments, observe and conclusions. Those methods gradually reveal the answer we are looking for.
An artist’s design of space around the time of the first star formation. Photo: NASA.
Elements for a perfect universe
The first elements that make up life are chemical atoms. Studying the universe from the big stars to the Big Bang helps determine where most of the elements come from.Elements for a perfect universe
After the Big Bang, only hydrogen, helium and a little lithium were formed. Although in the early post-explosion phase, the universe was in the hottest state, with many high-energy protons and neutrons, but there were also many photons right now. Each time protons and neutrons bond together, these light particles come in and separate them, so only light elements are created.
Only when the universe has expanded and cooled, can protons and neutrons combine to form heavier elements. But at that time, matter was so dense and energetic that it wasn’t until some time later that the stars began to form, and heavy elements appeared.
It took tens, even hundreds of millions of years for the universe to cool and gravity could gather all kinds of matter from all over, forming the first stars.
To do that, the environment in the universe must be imperfect. Some places must have a denser material density than usual.
In addition, the medium must be cool enough for free electrons and ionized nuclei to combine to form stable atoms.
The next is to attract enough matter into one place for gas clouds to collapse, forming stars.
And finally, the energy generated after the collapse must be enough to form nuclear fusion in the stellar core.
The first factor is one of the proofs for the expanding universe. The second factor is the cause of the cosmic microwave background. The third factor takes tens to millions of years to emerge.
But the fourth factor is a problem. Normally, the gas cools to star formation by releasing energy through heavy elements. At first, the elements didn’t exist, the only way to cool them down was through hydrogen gas, but the process was not as efficient as heavy elements.
As a result, the first stars in the universe, also called type III stars, are very different from present-day stars. Due to their lack of heavy element, Type III stars are 10 times the size of the Sun, which only exist for a short time and die after stellar explosions.
The role of dark matter
Stellar explosions make up most of the heavy element and neutron stars, which collide with each other to form the heaviest elements: gold, iodine, platinum and tungsten. The early stars and their supernovae are crucial.
However, this also raises another issue. Star clusters initially have a low amount of matter, but new star explosions release matter very quickly, leading to the heavy element being ejected into the interstellar medium. But we need to retain those elements to form new generations of stars, rocky planets like Earth, and create life. At this point, dark matter begins to join the story.
Ordinary matter in the universe, gases, cosmic dust or black holes also do not provide enough gravity to anchor heavy elements. A universe containing only ordinary atoms is not enough to form a massive structure like the Milky Way we live in, but requires an additional component: Dark matter.
Dark matter gives primitive star clusters and galaxies enough gravity to hold back the materials ejected from stellar explosions, while also absorbing more matter. Over time, more evolved stars form and contain more heavier elements.
Their mass is lighter, contributing to more elements in the periodic table and white dwarfs. When white dwarfs collide and explode, they form many atoms such as carbon, nitrogen and calcium – important elements in the human body.
Finally, after billions of years, individual galaxies like the Milky Way are so rich in elements that when stars first formed, terrestrial planets like Earth were also created around them.
9.2 billion years after the Big Bang, in a certain area of the Milky Way there will be many new stars, including the Sun. The young star’s protoplanet disc clumped together, forming four inner terrestrial planets and four outer gas giants. The third planet from the Sun named Earth slowly creates life and people multiply here.
The laws that form life in the universe have always been like that. The universe with ordinary matter will create light elements, imperfect matter density creates the first generation of stars, dark matter retains the released matter and forms new stars from heavy elements. .
The new generation of stars will have stars like the Sun and create terrestrial planets similar to Earth, from which life begins, exists and develops.