Help me write a report on space immigration, and thank the moon immigrants.

Moving to another planet is a long-cherished dream of mankind. Stephen Hawking, a famous physicist, recently accepted the Copley Medal awarded by the Royal Society, saying that human beings must emigrate to other planets in order to get rid of the fate of extinction. Hawking believes that as long as human beings are trapped on a unique planet, their long-term survival is in danger. Threats such as asteroid impact on the earth and nuclear war will destroy us sooner or later. However, if we expand into space and build self-sufficient settlements, our future should be secure. There is no place like the earth in the solar system, so we must look for another planet and use more advanced space rockets to help people move to a planet suitable for survival. This is the second time in six months that he has made such amazing remarks. Griffin, director of NASA, also said that historically, species on a single planet cannot survive forever. "We have conclusive evidence that, on average, every 30 million years, species on earth will suffer massive destruction; One day we will definitely immigrate to another planet, but I don't know when that day will be. "

What difficulties need to be overcome in emigrating to another planet, and when will it be realized? The first level of immigration: where to migrate. At the beginning of the 20th century, some people thought that Mars and Venus might be good choices, but NASA soon found that other planets around the sun were not suitable for our survival. People on the surface of Venus must live at a temperature high enough to melt lead. As for Mars, living on it is like living twice as high as Mount Everest. Dr. Margaret Tenbar, an astronomer at the Carnegie Institute in Washington, DC, summed up four criteria of "the most suitable galaxy for life": 1, at least 3 billion years, enough to form planets and show complex life; 2. The volume of the central star should not exceed 1.5 times that of the sun, otherwise it is difficult to produce planets suitable for life; 3. There should be enough iron to form Earth-like planets; The central star should be neither a red giant nor a white dwarf, so that the complex life on the surrounding planets can exist for a long time. According to this standard, he concluded that there are five galaxies in the universe that meet the standard: one is BetaCVn, the dog constellation 26 light years away from the earth; The second is HD10307; , 42 light years away from the earth; 3. HD 2 1 14 15, and its metal content is about half that of the sun; The fourth is Scorpio SCO18; ; Fifth, Pegasus 5 1. Level 2: How do humans get to these planets? According to calculation, Alpha Centauri, the closest star to the Earth, is about 42.3 light years. According to the current speed of the space shuttle, it will take 1.58 million years to arrive. This requires the vehicle to reach the speed of light. The American sci-fi movie Star Trek has such a background: in the mid-265,438+century, engineer Cochrane invented a "warp drive" that can surpass the speed of light. Because "warping technology" is the threshold to enter the galactic civilization family, human beings have been brought into the interstellar Federation, and the degree of civilization has reached a new level. In fact, scientists are moving towards this goal. According to New Scientist magazine, the US Air Force and NASA are currently secretly studying a "hyperspace engine". It is said that scientists are expected to make a prototype of the "hyperspace engine" and test it within five years. Once the "hyperspace engine" is proved to be feasible, it only takes three hours from the earth to Mars, and it only takes 80 days from the earth to the planet with a distance of 1 1 light-year. Some scientists predict that the time when a suitable spaceship can really be built and set off for the destination planet is in the 26th century, and the estimated arrival time is 12500. The third level: how to solve the problem of life security after human beings arrive at the planet. The United States, Russia and other countries have cultivated peas, wheat, corn, rice, onions, orchids and other plants 100 in the space station. Animals such as fruit flies, spiders and fish can also grow and reproduce in weightlessness. If this technology can be applied to the future planet, the problem of human survival will be solved. But living in weightlessness for a long time, it is also a question whether human beings can reproduce. A French scientist found that the important structure of living cells could not be formed normally under weightlessness. This means that human beings cannot survive and reproduce for a long time in near weightlessness. However, some scientists say that after human beings settle on another planet, their race and body structure will also change with the environment, and perhaps the problem of reproduction can be completed in another way.

According to a recent report by Future City Network, American scientist O 'Neill proposed a space city named "Island No.3" in his book "High Frontier: Space City for Humanity", and imagined that people could live and live in this space city in the future.

This future space city is a cylindrical city with a length of 32 kilometers and a diameter of 6.4 kilometers. The living area inside is 1.3 million square kilometers, which can accommodate 1.0 million people. It takes six or seven hours to walk from one end of the city to the other. The plan to build a "space city" at a cost of 654.38+300 million Malaysian dollars was put forward by Malaysia.

Fully enclosed, the living environment is exactly the same as the earth. The gravity of the space city is the same as that of the earth, otherwise people and things living there will float in the air because of weightlessness, and there is no place to go up and down. How can we generate gravity? Spin. This cylindrical space city rotates once a minute with the central axis as the rotation axis, causing a centrifugal force on the inner wall of the cylinder, which is exactly equal to the gravity on the earth's surface. The inner wall of the cylinder is exactly the ground of the city. Therefore, people living in the space city, standing on this land, feel the same as standing on the ground of the earth In the space city, no matter where you stand, your head is right on the central axis of this cylinder.

In order to make the big cylinder have enough sunshine, scientists imagine dividing the wall of the big cylinder into six areas: three residential areas and three skylight areas. Residential areas and skylight areas are staggered, and one residential area is opposite to one skylight area. The skylight area is made of huge glass, and three huge plane mirrors are installed outside the skylight area. The mirror is controlled by a computer and rotates according to a certain rule, reflecting the sunlight shining on it to the space city at different angles. The mirror rotates with the big cylinder. By adjusting the reflection angle of the mirror and the color of the skylight glass, the residents of Space City can not only see the blue "sky", but also watch the sunrise and sunset.

100000 people living in a vat will feel crowded? Of course not. Because 1300 square kilometers of living area is equivalent to half of Switzerland. Space City is divided into administrative area, residential area, cultural area and commercial area, and the largest is tourist area. There are winding green hills and gurgling green water in the tourist area; Flowers and plants are everywhere, and fruit trees are forests. No noise, no exhaust gas running on the road, no dust. The environment is much stronger than the earth! Can you imagine? There are white clouds in the sky, white sails on the river, birds singing in the Woods, deer and rabbits playing on the grassland. In addition, there is a special sight here-people can see the "ground" overhead through the clouds in the sky, where the peaks, trees, houses and pedestrians are upside down. Space City has large supermarkets, theaters, cinemas, concert halls, hospitals, libraries, gyms and nightclubs. In a word, space residents can enjoy everything that earth residents can enjoy, but there are no "man-made disasters" that today's society suffers, such as crowded houses, air pollution, traffic jams, lack of water resources and violent incidents. The whole space city is a huge closed ecological circulation system, which can solve the problem of circulating supply of air and water. Radiation protection can be solved by the metal structure shell of the living room.

In Space City, people grow their own food and vegetables, raise livestock, set up factories, and recycle air and wastewater. Space city, like the earth, is a self-enclosed ecosystem, and the only reliance is the sun. There are many factories in the space city, including heavy industry, light industry and high-tech industrial zone. Heavy industry includes steel, cement, glass, rocket fuel and various chemicals. Industrial raw materials can come from the moon and some asteroids. If minerals shipped from the moon and asteroids are smelted, steel, cement, rocket fuel and chemical products can be produced. Light industry includes textiles, food and various household appliances. High-tech industries are mainly precision instruments, information technology and communication equipment. Because the waste water and waste gas discharged by the factory will pollute the environment, the factory is located at both ends of the cylinder, far away from the living area and isolated from the living area. The central axis of the cylinder has no centrifugal force and is a weightless area. The factories here can just use the special conditions of weightlessness to produce things that cannot be produced on earth. For example, smelting refractory metals, refining very pure large crystals, processing round steel balls, making foam steel light enough to float on the water, metal wires thin enough to be seen with a magnifying glass, and transparent metal films. The top of the cylinder also has a large circle of teacup-like structure. What is that? That is an automated farm. The crops planted here can be harvested four or five times a year, and the output is several times higher than that of the earth; Livestock and poultry may also grow bigger than the earth because of weightlessness. The farm has fruits and vegetables all year round, and there are often fish and shrimp. Fresh vegetables, fruits, chickens, ducks, fish, meat, eggs and milk are also provided. Self-sufficiency in agricultural products is no problem. Experts estimate that in order to solve the problem of feeding100000 people, the agricultural area only needs 400 square kilometers of effective cultivated land, which is equivalent to 40 square meters of cultivated land per capita. In order to greatly increase the output of crops, we must vigorously develop new space agricultural technologies. The Space City also has well-equipped scientific stations and observatories. From here, we can see the whole picture of the earth and comprehensively study the problems of agriculture, geology, astronomy, meteorology, soil, earthquake and environmental pollution on the earth. There are no clouds, rain, snow and atmosphere in space, and the light and radio waves emitted by the sun and stars will not be absorbed and reflected, making it the best place for astronomical observation and research. There is also a space dock at the top of the cylinder, which can dock spacecraft from the earth or other space cities.

How was such a good space city built? It's hard. At least several million tons of building materials. It is better not to transport so many materials from the earth, but it is more cost-effective to take local materials from the moon or asteroids near the earth. After analyzing the moon rock samples, scientists found that the moon rock is rich in elements such as aluminum, iron, titanium, silicon and oxygen. 95% of the building materials of Space City can be found on the moon. The gravity of the moon is much smaller than that of the earth. An object should leave the earth at a speed of11200m/s, while it only takes 2,400m/s to leave the moon. Sending the same weight into space can save 95% energy from the moon than from the earth. Before building a space city, we should first develop the moon and use the resources on the moon to build a space city. Scientists estimate that as long as 150 people are sent to the moon, more than10 million tons of ore can be mined every year. Ore is thrown into a space smelting furnace by a magnetic launcher, heated, smelted and processed into various building materials and components such as aluminum and glass by solar energy, and then a group of migrant workers, mainly space robots, are put into orbit for unparalleled aerial work and assembly to build a space city.