This paper takes part in the series essay competition of “great science” of Recordunkown
The earth is our common home, but our understanding of life on the earth is only superficial, far less than our understanding of the ocean, atmosphere and even the universe. Because the deep underground is a place that human beings have never been to, which can be called “dark world”. The earth’s crust is so tightly wrapped that we have no way to start. It is extremely difficult for us to explore the earth’s interior – the crust. Then someone can’t help asking, “is there life in the deep crust?”
This is a map of the earth’s crust
Exploring the depths of the earth’s crust: the silent “dark world”, full of all kinds of strange life
In the vast universe, the earth is a different planet, because in this blue planet bred a lot of life. Since the birth of human beings on the earth, exploring the earth has always been the goal of human progress. Countless life can be bred on the surface of the earth. Will life also be bred in the deep earth, that is, in the crust?
In history, the former Soviet Union also designated the plan of “digging the earth’s core” to explore whether there will be life inside the earth through some mechanical tools. However, the plan was forced to terminate in the middle of the process. The reason is very simple. First, the construction facilities for deep excavation of the earth’s crust are limited, making it even more difficult to dig deep. Moreover, the whole project costs a lot of money. The Soviet Union had to stop in the middle of the implementation of this plan, but the relevant scientific research team has a new understanding of the earth. Because when digging deep underground, Soviet researchers found that there was life deep in the earth’s crust. These lives were just microbes.
The picture shows the Soviet geocentric plan
With the development of science and technology, human beings gradually have the ability to explore the “dead dark world”. If we refer to the earth’s ecosystem, it is difficult to imagine that there will be life thousands of meters or even tens of thousands of meters deep in the earth. Deep underground in the dark for a long time, not only no sunlight, but also full of high temperature and high pressure, no oxygen, these life is how to survive? Scientists have pumped a lot of underground water at different depths. After research, they were surprised to find that there is a “dark biosphere” deep in the earth’s crust, in which there are all kinds of strange life.
For example, there is a mining area called “mbonege” in Africa. The whole mining area has been explored to 2800 meters underground. The whole underground environment is high temperature all year round. Even the underground water temperature is more than 60 degrees Celsius on average. Because there is no sunlight and no oxygen for a long time, the pressure is extremely high. However, scientists have found a very interesting life here. This is a very interesting life Life is a gold bacterium.
What is the main survival of the underground peculiar organism, the gold bacteria?
“Gold bacteria” is a kind of microorganism, a member of the bacterial family. It has been isolated from the world for a long time, and has no contact with any other living body in the earth. In other words, this kind of bacteria exists independently. Unlike us, food, clothing, housing and transportation are closely related, transportation is indispensable when we go out, tableware is indispensable when we eat, and so on. All things are self-sufficient. It can survive independently in extremely harsh environment, even if the temperature in the deep underground has reached more than 60 degrees Celsius, without light and oxygen, it doesn’t matter for the gold bacteria, and it can still survive in harsh environment. So what do gold bacteria rely on for energy?
We should know that the essential process of all life on earth is completed by energy conversion, and the energy conversion of life on earth can be divided into two basic ways, one is photosynthesis, for example, plants and some algae, including some bacteria, convert carbon dioxide into carbohydrates, and finally release oxygen. The process of energy conversion is chemical energy, and another is energy The way of quantity conversion is the conversion of organic chemical energy, which is the basis of the survival of the earth. However, it is neither photosynthesis nor the use of organic chemical energy, it is converted by a third party energy. In other words, it mainly uses the sulfur and water produced by the decomposition of ore by radiation to directly absorb the sulfate and hydrogen peroxide produced by sulfur and water. In the absorption process, it slowly generates the energy for survival. The gold bacteria use the energy generated by the interaction of these small molecules to synthesize organic matter. Relevant scientists believe that this kind of microorganism can survive in Mars.
The picture shows the bacteria of gold mine
2. If we put the bacteria on the earth’s surface, can they survive for a long time?
In the space full of sunlight and oxygen, gold bacteria can not survive. Because we mentioned earlier that the gold ore bacteria belong to an alternative organism, and its survival is completely isolated from the world. Scientists call this organism “inorganic autotroph”. It’s just like fish can’t survive without water. We humans need to breathe continuously and absorb oxygen to survive and maintain our life. That fish in the water, it is by absorbing dissolved oxygen in the water can survive. They also need to breathe, they need to metabolize. If we have to put the fish on the land, the fish that leave the water will die within a few minutes, because water resources are the basic conditions for the survival of the fish. Similarly, the basic condition for the survival of the gold bacteria is “isolation from the world” in the deep underground.
How many kinds of organisms exist deep in the earth’s crust?
If the “inorganic autotrophic” biological gold bacteria can survive in the deep crust for a long time, there must be other microorganisms. According to the composition of carbon based organisms, without sunlight and oxygen, microorganisms in the earth’s crust can rely on minerals for a long time to survive, such as sulfur dioxide. Research shows that every kilometer of earth depth increases, the temperature will rise by 20-30 degrees Celsius. Underground microbes can use the radiation energy produced by high temperature to obtain more energy. We all know that most of the earth’s surface is the ocean, accounting for about 70%, with an average depth of about 4000 meters, while the depth of the terrestrial biosphere is only within 100 meters. Based on this, we can estimate that there is an environment where microorganisms exist more than 5000 meters underground, and the total weight of underground microorganisms accounts for about 24 billion tons. In other words, this is equivalent to nearly 400 million tons of human mass on earth. It can be seen that the biosphere of the dead and dark world in the earth’s crust is very huge, which is beyond our human imagination.
What is the ultimate heat resistance temperature of living creatures in the dead dark world?
With the increasing depth of the earth, the temperature will continue to rise. Some people can’t help asking, “aren’t the microbes underground afraid of high temperature?” In fact, it’s not. Among the known organisms, the most heat-resistant one can survive normally in the temperature of nearly 121 degrees Celsius. Scientists call this kind of organism “strain 121”.
Strain 121 is known as “the king of high temperature tolerance of the earth”, which grows and reproduces fastest in the high temperature of 100 ℃. This kind of bacteria has super survival ability, even if it is boiled with 100 ℃ hot water, it can not be inactivated, so this kind of bacteria is also called super bacteria. Superbacteria are very terrible. For example, although human beings have entered the “era of antibiotics” in modern society, in the long-term misuse of antibiotics, some superbacteria will produce antibodies, which will not be resistant (incurable) and invade into animals and human bodies from polluted groundwater and soil. The spread speed is faster and faster, and the consequences are unimaginable.
The picture shows “strain 121”
Scientists call strain 121 “extremophiles”, which can reproduce and survive in extreme environments. For example, among many extreme microorganisms, there are high temperature resistant strain 121, radiation resistant Kiwi cocci, which can withstand the strongest radiation, and acid resistant microorganisms, which have strong acid resistance.
If we eat cereals, it is inevitable that we will get sick. Are extreme microorganisms always powerful? Have they ever been damaged? In fact, it has to be said that these extreme microorganisms have super martial arts, just like the Eight Immortals crossing the sea. They have their own iron bell hoods. No matter how bad the living environment is, they can survive tenaciously. Even if their genes are damaged, they will “specialize in their own skills” and carry out their own self-healing and gene repair. In a word, there are all kinds of extremophiles in the earth’s crust, and their number and propagation rate will change with the change of living environment. At present, with the increase of the depth of the earth’s interior, we will know less about it. Due to the limitation of science and technology, we are unable to explore the interior of the earth on a large scale to explore more microorganisms.
Is there another civilization inside the earth? Is there evolution of higher life?
In many sci-fi films, we have seen the existence of lizard man. The lizard man, who is half human and half animal, is two meters high and has red eyes and green scales all over his body. It seems that he can walk upright just like us. And they often appear underground, so will there be lizards in the earth’s interior? The mystery of lizard man is one of the four unsolved biological mysteries in the world. At present, scientists’ exploration and research show that the necessary conditions for the survival of higher life are sufficient sunlight, water resources and oxygen. In the “dead dark world” deep in the earth’s crust, there is no light. It has been in darkness for a long time, and the pressure is very high. There is no oxygen. Under such extremely harsh living conditions, it is almost impossible to evolve higher life, and there will be no other civilization.
Generally speaking, there are all kinds of microorganisms in the earth’s crust. According to the existing science and technology, the maximum depth that humans can find microorganisms is 5000 meters underground, which is one of the largest microbial communities on the earth. We can’t estimate what impact it can bring to human beings. But these huge microbial communities do not need to be exposed to the earth’s surface, because for them, long-term survival in the crust of the dead dark world is the best choice. The world inside the earth is full of many mysteries. Life buried in the earth’s crust is far away from us. We believe that in the near future, with more advanced science and technology, we will find more unknown species of life in the earth’s crust.