When the Earth first formed, it was not what it is now, its geological structure, geographical appearance, surrounding atmosphere, and the animals and plants above it were gradually generated.
Today's Earth, the interior is divided into three layers: the outer layer is called the crust, which is composed of various solid rocks; The middle layer is called the mantle, which is malleable and can flow slowly. The innermost layer is called the core.
When the Earth first formed, its main components were various metal oxides, carbon and carbonates, silicates, metallic iron, nickel, solid water and ammonia, and other substances, mixed with light and heavy substances. At the beginning, the temperature was very low, and all kinds of substances were mostly solid, it was difficult to rise or sink freely, it was difficult to distinguish the layers according to light and heavy, so there was no distinction between the crust, the mantle, and the core. Later, the internal temperature of the original earth gradually increased, and the thermal energy mainly came from the energy released when the internal radioactive elements decayed, and the thermal energy generated by the gravitational contraction of the sphere itself and the meteorite impact made the plasticity of the earth's internal material larger and larger, and the iron-loving elements with a large proportion slowly sank to the core of the earth, forming a core dominated by iron and nickel. The smaller gravity of the pro-lithophilic elements gradually rises, forming the mantle and crust. The original Earth underwent 5 billion years of slow evolution before it gradually became what it is today.
Today, the atmosphere around the Earth is mainly composed of nitrogen and oxygen. The composition of the original atmosphere 5 billion years ago was mainly hydrogen, followed by gases such as nitrogen. Later, the strong wind blew hydrogen and helium gas away and disappeared into the vast universe. When the earth's interior forms three levels, volcanic activity is frequent, the internal material is constantly decomposing, and a large amount of carbon dioxide, nitrogen, methane, water vapor, ammonia, etc. rush out of the ground and become a new atmosphere, which is a secondary atmosphere. The secondary atmosphere is dominated by thick carbon dioxide, similar to the atmosphere of Venus today. Later, there was water on the earth, forming a primitive ocean, and gradually there was life in the ocean, and green plants appeared. The sun's ultraviolet rays decompose water into hydrogen and oxygen, and green plants absorb carbon dioxide and exhale oxygen through photosynthesis, so that the composition of oxygen in the atmosphere increases, and gradually evolves into today's atmosphere.
There was originally no water on Earth, and when the atmosphere evolved into a secondary atmosphere, the water vapor in the atmosphere gradually cooled into raindrops, fell to the ground to form rivers and lakes, and finally converged on a large area of lowland on the ground to form a primitive ocean. This makes up the hydrosphere on Earth.
The earth's surface now has mountains, plains, basins, canyons, rivers and oceans. This is not innate, it is the result of the long and incessant movement of the Earth's crust, forming a "series of old rock formations constantly destroyed and new rock formations constantly formed". The world's tallest Himalayas are just the result of the rise of folds on the ocean floor 30 million years ago. The "Continental Drift Theory" envisages that 300 million years ago there was only one primordial continent and one primordial ocean on Earth, and by 200 million years ago, this continent was torn apart and drifted into the seven continents and four oceans it is now. Today, we have measured that the continents are still drifting, and Europe and the Americas are moving closer to each other at a rate of 1-5 centimeters per year.
There was no life on Earth, but primitive creatures began to appear more than 3 billion years ago. Later, it diverged into animals and plants, from low to high, from water to land and air, until today there are more than 1 million species of animals, more than 300,000 species of plants and more than 100,000 species of microorganisms, forming such a vibrant biosphere today.
The present and present of the earth tell us that everything in nature is in eternal existence and demise.