"Heaven into the earth" has been the dream of human beings since ancient times, and since human beings have realized what is the real heaven and what is the real earth, the mood of wanting to achieve the dream has become stronger and stronger.
What is a day? The sky is the deep space of the universe, what is the earth? The earth is the earth under your feet. It is difficult to go to heaven, because to go to heaven, you must get rid of the gravitational constraints of the earth, at least to reach the first cosmic speed of 7.9 kilometers per second, and humans have done it. Humans have not only escaped the gravitational pull of the earth and entered low-Earth orbit, but have even been able to completely get rid of the gravitational influence of the earth and land and explore the moon 380,000 kilometers away. Since the launch of the first artificial earth satellite, it took only more than 60 years to achieve today's achievements. Human beings have successfully ascended to heaven, so what about entering the earth? Speaking of entering the ground, it was necessary to advance the "Kola ultra-deep drilling" excavated by the Soviet Union.
Why did the Soviet Union dig an ultra-deep borehole? What is the significance of this project?
At that time, it was the Cold War period between the United States and the Soviet Union, the Cold War involved all aspects from the military to science and technology, heaven into the earth is naturally also a competition project, and in this game, the United States took the lead in completing the manned moon landing, since it is inferior to the United States in terms of heaven, then it can only work entering the ground. A project called "Kola Ultra Deep Drilling" officially began on May 24, 1970. Of course, the former Soviet Union to dig through the earth is not just to gamble with the United States, the Kola Peninsula where the project is located is located in the northwest of the Soviet Union, the upper strata in this area are ancient, through excavation research can obtain information about the original geological structure of the earth, if you can really dig the earth through the wish, then its achievements are far better than manned moon landing.
The problem is that "entering the earth" is much more difficult than "going to heaven".
At the beginning, the project was progressing smoothly, and in just 13 years, that is, in 1983, the Kola ultra-deep drilling reached a depth of 120,000 meters, and there is no doubt that the Kola ultra-deep drilling hole at this time has become the deepest human building on the earth. But the deeper the drilling, the more difficult it became, and in the next 6 years, the drilling depth only advanced by more than 200 meters, and then the speed of progress was even slower, and finally, the Cora ultra-deep drilling project was stopped in 1994, and the final step was 12262 meters. Over the next dozen years, scientists thoroughly studied the depth of Kola's ultra-deep drilling and finally sealed the hole with a metal cap in 2008.
Why didn't the dream of the former Soviet Union digging through the earth continue? Will we be able to fulfill this great dream in the future? I'm afraid it's hard.
Korra ultra-deep drilling sounds like just a downward drilling project, but in fact the technical difficulty of this project is very high, first of all, the drilling process will encounter hard rock, so the wear rate of the drill bit is very fast, as the depth increases, the ambient temperature is also gradually increasing, according to the record, at 120,000 meters, the temperature has reached 180 degrees Celsius, which undoubtedly increases the speed of drill bit wear, sometimes a new drill bit just took care of, Put it down and don't drill a few times before it has to be replaced, so the cost of consumables, the cost of equipment, and the cost of labor add up to a huge amount of money, which is a test for a country's economic strength.
Of course, this is not to say that money is enough, and some technical problems are difficult to solve even today.
A depth of 120,000 meters requires an ultra-long drill pipe, and this drill pipe must also have considerable strength, even if you have this super strong drill pipe, to drive it to turn, you also need a super strong motor. 120,000 meters can be solved, but what about 150,000 meters? What about 200,000 meters? And light drilling is not enough, we also need equipment that can monitor and record the situation inside the drill hole without all kinds of interference, which is almost impossible to solve not only in the former Soviet Union, but even today. The former Soviet Union failed to drill through the earth, and there is no way to drill the earth now, so what about the future? No one can give a definitive answer, but it's obviously hard.
The earth is composed of a number of different structures from the inside out, which are the core, the mantle and the earth's crust, of which the earth's crust is the thinnest, with an average thickness of about 17 kilometers, which means that so far human beings have not even dug through the earth's crust, let alone dug through the earth.
Of course, the thickness of the earth's crust is not consistent, and some places are very thin, such as the 10,000-meter deep sea, where the thickness of the earth's crust may be only a few kilometers. However, to drill under 10,000 meters of deep sea under great pressure, the technical difficulty is difficult to achieve with today's technology, so we can only look forward to the future. So since humans have not even drilled through the earth's crust, how do they know the structure of the earth? It was discovered by the former Yugoslav seismologist Moholovic when studying seismic waves, because seismic waves propagate in different underground structures in different ways, and because of Moholovic's contribution, the interface between the earth's crust and the mantle is called the Moho surface.