There were many hypotheses and assumptions, and with each era, depending on the accumulated knowledge, this or that assumption of the great minds of that time became relevant.
Question of all time
The question of how the Earth was born and life on it excited the mind of a person throughout its existence. From the moment he learned to think and speak, in the distant past he began to reflect on his origin and everything around him.
Not understanding the forces of nature and seeing the powerful power of various elements, people ranked what was happening as divine manifestations. All this is reflected in the myths that have come down to us of various peoples of antiquity.
Ancient world views
For example, the ancient Egyptians believed that the planet arose from a sacred egg created by the god Khnum from ordinary clay. According to the beliefs of the Greeks, everything came from the original Chaos, filled with water, earth, air and fire. Everything revolved, shuffled, and at a certain moment the planet Gaia was born. Together with her, the god of heaven, Uranus, was created. Together they worked for a long time to fill the space with a different life.
How did the earth originate? What did ancient China think about this?
A similar myth existed in the territory of ancient China. Chaos Hun-tun, containing a mixture of earth, water, wood, metal and fire, flew through the infinite Universe until the god Pan-Gu was born. Glancing around, he saw emptiness and darkness. This saddened him greatly. Having gathered and thought, he broke the shell of Chaos and freed Yin and Yang. Yin descended and formed the Earth, and Yang turned into sky.
Modern hypotheses
In the modern world, how the Earth was born, the popular cosmogonic hypothesis of Schmidt explains. It is known as the theory of the cold formation of the planets of the solar system from a gas-dust cloud. The scientist’s hypothesis today explains more fully how planet Earth and other components of the cosmos originated.
This process had two stages, first intermediate bodies, about one hundred kilometers in size, were formed from the gas-dust cloud. Then, under the influence of gravitational forces, large objects united, attracting other, smaller ones. After the formation of the planets, they acquired orbits in the plane of the gas-dust cloud. Warming up was due to strong compression and collision with other large objects in the nascent solar system. What was the value of the Schmidt hypothesis? It was this approach that made it possible to explain how the Earth was born and what is the regularity of the distribution of planetary masses in the solar system.
In addition, the period of formation of rocks was consistent with the age of our planet.
A story using the Schmidt theory of how the Earth originated for children will be an exciting and uncomplicated method of knowing the world around it.
The time of the appearance of life on the planet
After a strong warm-up, in the process of compression, the period of cooling of the planets and newly formed bodies of our system began. And after about five hundred million years, the surface cooled to temperatures when water could be in a liquid state. According to scientists, in the process of intense bombardment by comets, water was brought in.
In the cooled atmosphere, condensation of water vapor formed the primary ocean. It was during this period that the process of the appearance of the first living organisms began in the aquatic environment.
The hypothesis is confirmed, but there are many questions
The question of how life was born on Earth has been raised repeatedly, and there is no definite answer to it. There is a generally accepted theory of the biochemical evolution of Oparin, proposed to the scientific world in 1924. The essence of this hypothesis is that the appearance of living organisms was preceded by a long chemical evolution. In the process of a number of conditions and time, the complication of chemical elements — “bricks” of the building material of a living organism — took place.
Young American scientist Stanley Miller undertook to prove Oparin's theory in 1953. He reproduced in a glass flask the conditions and composition of the gases, fairly close to the state and composition of the Earth of that period. One of the additional conditions was the transmission of electric charges, some imitation of lightning strikes in the young atmosphere of the planet. The experiment lasted for a week.
At the end, amino acids — glycine, alanine, asparagine, and glutamine — were found in the flask.
However, despite the fact that the theory has been partially confirmed, there are opinions about other versions of how life was born on Earth. The version about panspermia is quite popular. Its essence is that certain proto-organisms or microorganisms were brought from outer space. A number of experiments prove that microorganisms can survive for a long time in extreme conditions and airless space.
There are many opinions, but the fact is obvious.
Along with other hypotheses, there is a theory of creationism. In fact, it assumes that all living organisms were created in a certain period of time by God, the Higher Mind or the Great Cosmic Force. This theory has no scientific confirmation. However, this hypothesis is quite widespread not only in religious circles, but also in scientific ones. It finds application to explain the most complex issues of biochemical and biological evolution, the formation of organelles and organs such as the eyes.
Whatever the hypothesis about how the Earth originated and how life came about on our planet, you and I are direct evidence of the possibility of the existence of biological life in the Universe.