What did the Earth look like?

This book introduces that, in 4.6 billion years, the Earth has changed its appearance many times. From a planet that was black when it first formed and then turned blue, went through the glacial process to become the white Earth, and over time it became the image we still see today . With the constant change of the Earth, life gradually sprouted. The best thing about this book is that the author has threaded the interaction between life and non-life through the evolution of the planet, in other words, without life there would be no Earth of the Earth. present.

Stage 1: Black Earth covered with basalt rock

About 4.6 billion years ago, after the birth of the Solar System, some cosmic debris and dust began to collide continuously, and slowly mixed together through gravity to form the original Earth. . But our planet at that time had a rather terrible environment, everywhere there were red rifts, magma could suddenly erupt from the ground at any time. Along with constantly colliding with asteroids and comets from the outside world, the temperature of the entire Earth now exceeds 1,200 degrees Celsius. In essence, the Earth now resembles a mass of mud with high temperature, high pressure and constantly impacted by objects in outer space. Geoscientists often liken this initial 500-million-year period of the Earth to a living hell.

In essence, the Earth right now is like a mass of mud with high temperature, high pressure.

During this time period, the temperature of outer space is much lower than that of the Earth, so after each collision, the surface of the Earth also rapidly cools and turns yellow. black, like red iron bars dipped in water. Over time, a layer of rock formed on the Earth's surface and became the original crust of the entire planet. Since the crust at that time was mainly composed of basalt and black, the author described the first 500 million years of Earth's formation as a Black Earth.

Stage 2: The green earth is covered with water

When it was about 4.4 to 4.3 billion years ago. Over time, the overall temperature of the Earth gradually decreased, and the water vapor ejected from the ground slowly cooled, and part of it remained in space. gas, forming an atmosphere containing water vapor. Another part fell to the surface to form the ocean, and the Earth began to slowly turn blue with the appearance of liquid water. This is the second change of the face of the Earth - Green Earth. 

We often say that water is the source of life, and there is a very important reason that water has two outstanding advantages.

This is the second change of the face of the Earth - Green Earth. 

First: Water is a super-solvent, so the inorganic substances in the water will have many opportunities to combine into organic matter and then create life.

Second: The density of liquid water is greater than that of solid state, in other words, ice will float on top of liquid water, and form a very important protective umbrella for life. Just imagine what would happen if the ice sank underwater? When it's cold, the surface of the water will freeze, and then the ice will continue to sink, and the top water will continue to freeze in direct contact with cold air, so all the water on our planet we will be frozen and life will be very difficult to spawn and evolve.

Water on Earth helped form life, and that life continued the process of transforming the Earth, and its appearance is closely related to the creatures that appear on our planet.

Stage Three: Oxidized Red Earth

With the appearance of the first life, some more intelligent cells, such as algae, have developed the ability to capture solar energy into energy. This is the initial process of photosynthesis. It didn't take long for these creatures to grow strong enough to have an impact on the planet's climate. 

Oxygen will cause the oxidation of substances.

They only absorb solar energy and fix the carbon element of carbon dioxide in the air to release oxygen. Oxygen will cause the oxidation of substances. As a result, these tiny creatures have produced a lot of oxygen for our planet, and the entire surface of the Earth is now undergoing extremely drastic changes.

The most abundant element on Earth is iron, and when it encounters high concentrations of oxygen in the air, the bundle will rust. In a short time, rust red covered the entire Earth. The Earth's Oxidation Age lasted from about 3.5 to 1.8 billion years ago. And this process turns the Earth into a red globe.

Stage Four: Snowball

With the abundant growth of plants, the oxygen in the carbon dioxide continues to be released into the atmosphere, and the carbon is gradually accumulated in the ground. As the amount of carbon in the atmosphere decreases, the greenhouse effect weakens, and the Earth slowly cools down accordingly. As the planet's temperature dropped, ice began to spread from the poles to the equator. 

For millions of years, the entire Earth, except for a few areas around the equator, was covered in ice, this period is known by the author as the Snow Earth - Snow Earth. During the Snow Earth period, almost all ecosystems were frozen, and a lot of life on our planet was wiped out. 

 In 150 million years, the Earth cycles between these two extremes at least three times.

However, over time, the Earth's lava core, along with the movement of plate tectonics, combined with the eruption of volcanic gas. A large amount of carbon dioxide also accumulates in the gas. atmosphere, and the greenhouse effect started again due to the mass extinction of algae. As the Earth warmed, the algae started exploding again, then the carbon dioxide levels started to drop again, and the Earth started to freeze again. In 150 million years, the Earth cycles between these two extremes at least three times.

Stage Five: Green Earth

After the above freezing period, due to the constant movement of the Earth's plates and the restoration of ecosystems, the Earth's climate seems to have maintained a rare balance in the past. 1.4 billion years later. The environment on our planet right now is neither too hot nor too cold, extremely favorable for the development of life. Biodiversity explosion also followed, as happened in the Cambrian 560 million years ago, life became more and more abundant, and after many iterations, the emergence and The evolution of countless organisms has formed the ecosystem with the plants and animals we see today. And this period is also the current Earth phase - Green Earth.

So, it can be said that if there was no life on our planet, there would be no Red Earth, Snow Earth or Green Earth phase like today.