Can we really live underground in the future?

  High temperature, heavy rain, cold wave, storm… After the earth entered the “Era of Escape”, the surface of the earth is no longer a beautiful home for human beings. In order to survive, 3.5 billion people have entered the underground city. People extract oxygen from the soil, use simulated natural light to grow crops, and reproduce the blue sky and white clouds through the holographic screen – this is the scene of people living underground in “The Wandering Earth”. In fact, not only “The Wandering Earth”, but also in sci-fi works such as “Three-Body Problem” and “Gloomy City”, the underground has become the future home of mankind. After reading these works, I wonder if you have such a question: In a few years, can the underground really become a habitat for human beings?
  The real underground city
  In fact , the underground city is not the patent of science fiction works, and people in reality have a long time to think about the underground. Whether ancient or modern, people have left many buildings underground.
  No.1 Ancient Underground Architecture
  In without advanced science and technology and equipment, people have already expanded their activity areas underground. Today, many magical underground architectural relics have become tourist check-in places.
  Cappadocia Underground City
  In 1963, a resident of Derinkuyu village in Cappadocia, Turkey found a hole in his home. The hole was as big as a well and could not be seen to the end. With the help of a ladder, he went down from the entrance of the cave and discovered that there was actually a huge underground city under the entrance of the cave. This underground city covers an area of ​​2,500 square meters, is about 55 meters deep, and is divided into 8 floors. Bedrooms, kitchens, dining rooms, transportation, schools, etc. are all available, and there is a reservoir on the bottom floor. It is said that there are many similar underground cities in the local area, and they have become famous local tourist attractions, attracting many tourists every year. There are also many caves that have been transformed into unique cave hotels, providing a real underground life experience for tourists who come here.
  Margate Shell Palace
  In Margate, a seaside town in Kent, England, an underground palace made of shells also amazes the world. The palace was stumbled upon by a farmer in 1835, and is estimated to have been built around 3,000 years ago. When you are in this palace and look at the exquisite patterns made up of shells of various conch, mussels, oysters, etc., you can imagine how 3,000 years ago, when these shells had not faded their colorful colors How magnificent and stunning this palace should be.
  No.2 Modern underground buildings
  In modern times, with the emergence of various advanced equipment, people have developed more underground buildings, and more and more underground buildings have appeared in our lives.
  Underground transportation
  hub Building a transportation hub underground is undoubtedly a great invention in the development of human society. It is said that ancient Babylon has mastered the technology of building tunnels 4,000 years ago. Today, this technology is used in the construction of subways. The appearance of the subway has provided a lot of convenience for people’s travel. In the morning and evening travel rush hours, in the face of crowded ground traffic, the smooth subway has become the first choice for many people’s travel.
  Underground living facilities and entertainment venues
  With the increase in population and above-ground buildings, ground resources in many places have become very limited and expensive. In order to obtain more space and more favorable rents, many living facilities and entertainment venues have been moved underground, such as the familiar underground parking lot and underground shopping malls built on the negative floor.
  Underground warehouse The environmental characteristics of
  underground constant temperature and humidity make it the first choice for many warehouses. Whether in rural or urban areas, people like to open up a part of the underground space to store things. In addition, many well-known storage institutions are also built underground, such as the International Seed Vault on Svalbard, Norway, which stores more than 1 million biological seed backup samples. The warehouse is built at a depth of about 160 meters. underground.
  underground research institute
  In order to get rid of the interference of cosmic rays, many research institutions are built deep underground. For example, CERN’s Large Hadron Collider is built in a circular tunnel more than 100 meters deep underground near Geneva, at the junction of Switzerland and France; the Gran Sasso National Experiment affiliated with the Italian National Institute of Nuclear Physics. The laboratory is located at a depth of 1,400 meters under the rock formations of Mount Sasso in Italy; my country also has a Jinping underground laboratory built at a depth of 2,400 meters underground, which is also the underground laboratory with the deepest rock coverage, the smallest cosmic energy and the largest available space in the world. Laboratory, and the laboratory is undergoing a second phase expansion, the future available space will increase to 300,000 cubic meters.
  What conditions must be met for permanent underground residence
  Of course , these underground buildings are far from meeting the conditions for human beings to live underground for a long time. If you want to build an underground city that can be permanently inhabited by humans, there are many practical problems that must be solved first.
  Oxygen The survival of
  human beings is inseparable from oxygen. Without oxygen, human beings cannot breathe, and nature cannot continue life. In the unseen underground, if there are no plants, photosynthesis cannot be carried out, and humans must find a way to produce oxygen.
  Water is the source of life, and it is also indispensable to human existence. Although there are aquifers with rich water content underground, when a large number of human beings live underground, how to ensure the rational distribution and utilization of freshwater resources in the aquifers, how to deal with domestic sewage, and how to ensure that water resources are not polluted, etc. Humans are required to come up with reasonable solutions.
  ”people are iron, rice is steel”, no matter where human beings live, they have to fill their stomachs. But in the underground, how to fill the stomach will become a problem. In the underground where the sun does not shine, traditional farming cannot be carried out normally, and animal husbandry cannot be sustained without fodder to feed livestock. If we can’t find a suitable substitute for sunlight like in “The Wandering Earth”, human beings may not be able to live underground for a long time.
  Living underground also has security risks, not only to resist the impact of the surface, but also to guard against threats from deeper parts of the earth, such as magma. We know that the earth is composed of the crust, the mantle and the core. The mantle is divided into the upper mantle and the lower mantle. The magma we are familiar with exists in the upper mantle and the deep crust. If we build cities deeper underground, there may be magma infiltration like in “The Wandering Earth”, which will bring major disasters to human life.
  In addition, there are energy problems, environmental problems, psychological problems, etc., which are all problems that human beings need to face when they live underground.
  If these practical problems related to human survival can be solved in the “underground future” planned by various countries
  , there are still many benefits to building a city underground.
  The most obvious benefit is of course that it can improve land utilization and alleviate urban land shortage. In addition, living underground can save a lot of energy for cooling and heating because the temperature fluctuation range is much smaller than that of the surface. If the underground city is built deep enough, for example, it is built at a depth of more than 1,000 meters in the “Three-Body Problem”, the thick soil above the head is a good natural protective layer, which can help humans to block the disasters, including radiation.
  In view of the advantages of building underground cities, many countries have begun to utilize underground resources and formulate construction plans for underground cities. For example, in Singapore, due to the lack of surface space and the high cost of reclamation, the Singapore government has turned its attention to the underground. Singapore has reportedly built underground expressways and an advanced underground air conditioning system. In the future, they will use 3 areas as pilots, use 3D technology to make underground maps, and continue to build underground cities. In addition to Singapore, Canada, Finland and other countries have their own underground urban planning.
  China is no exception. Nanjing is constructing the largest and most integrated urban underground space in Jiangbei New District at present. The maximum excavation depth is about 51 meters, and the total construction area of ​​the underground space is about 1.98 million square meters. This underground city not only has facilities such as transportation, commerce, and rail, but also introduces wind, light, water, and green to make people feel more comfortable underground.
  It is foreseeable that with the development of science and technology and the gradual scarcity of human living space, there will be more and more underground cities in the future. Maybe one day, we will live underground or study and work underground like in sci-fi movies. Are you looking forward to that day?