Ocean and the future of mankind

Ocean explores the future of mankind: returning to the ocean

David Wang

If the future of mankind needs to go beyond land, where will mankind go? The moon? Or Mars? Let's go back to the sea! Because life originated there, human beings will get new development there. According to experts' prediction, the world population will exceed 20 billion in the middle and late 20th century. How can the limited land space meet the needs of human normal life? Building a marine city and living in the sea has become a new dream of mankind.

How to build a marine city

Should marine cities be built on the sea, in the sea or under the sea?

There are different opinions among marine architects: some imagine to build a "mirage" on the sea with a water depth of 100 m to 200 m with tens of thousands of steel columns as support; Some imagine strengthening the island and establishing an "island country" at sea; Some people also imagine floating the city on the sea. When encountering severe weather such as tornadoes, they will close and sink to the bottom of the sea, and then surface when the weather is good, just like submarines.

The first country to build a marine city was Japan. More than 20 years ago, Japan built the world's largest marine city on the coast of Kobe, which can accommodate more than 20,000 people, showing a broad and bright prospect for the development of marine cities in 2 1 century. The future maritime city will be a highly developed and industrialized new human activity community, and there will be a large number of submarine farms and offshore oil fields around the maritime city. Submarine farms and offshore oil fields will provide food and agricultural products for coastal cities, raw materials for factories in coastal cities and energy for the whole city. How to achieve self-sufficiency in hydropower supply in coastal cities? Scientists say that solar energy, wind power, waves or underground undercurrent power generation, seawater temperature difference power generation and other ways can be used for power supply; Use seawater desalination or purification to supply fresh water.

Where are the future mineral deposits of mankind?

The rich fish in the ocean provide delicious food for people, and deep-sea oil and natural gas also provide abundant energy for human beings.

Scientists have found that there are countless potato-sized manganese nodules and a considerable number of non-ferrous metals, such as iron, nickel and cobalt, scattered everywhere in the deep seabed. These minerals are scattered over a large area of the Pacific Ocean. These manganese nodules were formed in the past 10 million years. In addition, as a new resource, seawater itself has attracted more and more attention.

At present, Japan is exploring the development of deep seawater resources by using the three characteristics of "low temperature", "rich nutrition" and "clean". The so-called deep seawater usually refers to seawater with a water depth of less than 200 meters and no sunlight. Deep seawater has accumulated a lot of nutrients and few harmful pathogens, which has important development value.

What are manganese nodules?

The so-called manganese nodules are very abundant on the seabed. Manganese, the main component of manganese nodules, is an important metal with great commercial value. It is indispensable in steelmaking, aluminum alloy and modern aircraft manufacturing industry. A jumbo jet needs at least 65,438+0 tons of manganese.

At present, the cost of mining and refining manganese from near-seabed mineral deposits is very high, because manganese compounds are rare in shallow water. Manganese nodules have not been mined at present, on the one hand, because the reserves are not proved, on the other hand, because they are in the deep sea. They are usually scattered on the deep seabed of the ocean, and can generate hundreds of kilograms of pressure per square centimeter, which is enough to scrap mining equipment. However, it is only a matter of time before the exploration and production equipment for manganese nodules is completed. Experts predict that these non-ferrous metal deposits with trillions of tons of reserves on the seabed will be enough for us to dig for more than a century!

Can humans imitate marine life to build nests?

"Since corals and clams can build nests with seawater, why can't humans follow suit?" A scientist once said this. He believes that seawater is rich in magnesium, calcium, carbon and other elements, so humans can use seawater to make limestone, and then use limestone to build houses, just like many marine life.

In addition, with the help of high-power microscope, materials scientists found that the hard shell of abalone was like a carefully piled "brick wall". Calcium carbide crystals absorbed from seawater can play the role of this "brick wall". Although the chemical composition of this shell is very simple, it is as hard as the most advanced artificial ceramics, but not as brittle as ordinary ceramics. It is also found that when the ceramics are destroyed, cracks will appear, and the calcium carbide in the abalone shell will slide on the organic protein layer, so the abalone shell will not be seriously damaged, which shows that the abalone shell is deformed. From this point of view, it is like a metal material. If people can use the characteristics of these materials to design, they can produce epoch-making new ceramic compounds. The well-arranged structure of abalone shells improves the strength of calcium carbide by 20 times. If people can improve the strength of current ceramics by 5 times, then people will get better materials than today.

Can you breathe freely like a fish?

1993, the United States built the world's first underwater hotel. Experts believe that this new type of submarine building will become the prototype of underwater city in 2 1 century.

This hotel is located in the shallow sea bottom of Kira, Florida, USA. The top of the hotel is 9 meters above the water. The hotel is made of metal synthetic materials and covers an area of 90 square meters, including living room, bedroom, bathroom and bathroom. Equipped with modern household appliances such as video recorder, color TV, stereo, telephone and microwave oven. The most attractive thing is that you can see the fish and shellfish in the sea from every window, just like visiting the Crystal Palace.

This underwater hotel is called "Verne Underwater Hotel". Verne was a French science fiction writer in the19th century. He wrote magical science fiction novels such as Two Wan Li under the Sea. Now many of his fantasies have come true. But this only meets the needs of underwater sightseeing, and it can't be called a real "underwater city" because it doesn't have many functions of the city, for example, people can't just go shopping and stroll the streets like on land. That is, if humans can breathe directly in the sea like fish, then underwater cities are truly "free".

Dr. Peter Beinert, an American diving physiologist, discovered this liquid carbon chloride that can be used for breathing; German scientist Michelson also successfully developed an artificial scuba for divers by using carbon chloride. Take this diving respirator and dive 30 meters underwater. You can breathe directly in the sea like a fish. After 40 minutes, it will still feel good.