If one day, the earth doesn't exist, what should we do?

One day in the future, we may have to leave the earth for the survival of mankind, even if this planet is so suitable for our survival and reproduction. As we all know, this huge blue planet will not be a refuge for mankind forever. One day, we will be threatened. This threat may cause worldwide destruction, and human beings may be included in it, but if human beings become a species distributed on multiple planets, it will be conducive to maintaining human survival. As the late Stephen Hawking said, it is very difficult to avoid disasters on the earth in the future 100, not to mention the future 1000 and1000. Humans should not put all their offspring in a cradle or a planet.

The possibility of a global disaster at some time in the future is very high, and becoming a species living on many different planets will be the best choice. Many scientists think that the sooner we realize this, the better. But without the earth, where will we go? In order to leave the earth better, we need great progress in space technology. It will not be a short and easy journey to immigrate to a distant planet we want to go across the Milky Way. Take the nearest star, A Centauri, for example, about 4. 3 light years from the solar system. Even if we can build a spaceship big enough to carry many people, ensure their long-term survival, and develop new horizon technology to visit Pluto at a corresponding speed. Back in 20 15, we reached a speed of about 36,000 miles per hour, but it still took more than 70,000 years to reach Pluto.

Therefore, in order to explore the Milky Way and look for alternative planets for the earth, we need to make major breakthroughs in propulsion system, spacecraft sustainability and life support technology. Before humans can even imagine flying to the unknown, it should be the best choice to find it in the solar system closer to our home until we make greater technological progress. Before trying the interstellar route, the first and most obvious place to try immigration was Mars. This crimson planet has been the focus of scientists' attention for many years. Because the most livable place in the solar system is the earth, and it is not easy to live on this red planet, there is controversy. The surface conditions on Mars are far from the ideal conditions of human beings, accompanied by a greatly reduced air pressure environment.

Although Mars has only 0. 1% oxygen, incredible low temperature and eternal radiation, it is possible to colonize Mars. At present, Mars colonization needs complex facilities to maintain human life activities. Living in an artificial environment, we will have to rely on our technology to protect our lives. Elon Musk and his space exploration technology company are preparing a manned space mission to Mars, which may turn the fantasy of Mars colonization into reality in the next few decades. Musk has publicly talked about his dream, that is, to build a city with a population of one million on the surface of this red planet (Mars) to increase the chances of human survival. A possible long-term choice is to try to transform Mars to make its surface and climate more suitable for human habitation and colonize it. But this process needs a lot of resources and a long time, which may take hundreds of years. At the current level of technology, we may have another choice, that is, to choose a gas giant planet.

Take the satellite Titan (also known as Titan) for example. It runs around Saturn and is rich in elements for human use. Titan is considered as one of the most livable planets in the outer solar system, because it has some common features with the earth, such as wind, rain, volcanic structure and many other earth features. There may be liquid water under the frozen crust, which is transported to the surface through the activity of cold precipitation volcano and may be used to form breathable oxygen. However, Titan is still not a suitable place for human habitation. The average temperature of this satellite is-179 degrees Celsius. The atmosphere is mainly composed of nitrogen and methane, and its surface pressure is 60% higher than that of the earth. Therefore, in order to establish a colony on Titan, we must use and rely entirely on advanced technology again. The future goal of the solar system may be our sister planet Venus. But Venus's environment is as bad as hell, and it is still not a place where human beings live. Its surface temperature can be as high as melting objects, and there is sulfuric acid rain on the surface. In addition, Venus's atmosphere is very dense, which makes people feel like breathing underwater.

Venus has not been earthized, which will take hundreds or even thousands of years, and it will require great progress in technology. But it is possible to live in a floating city 32 miles from its surface, which is lighter than air. The air pressure there will be slightly lower than the sea level of the earth, and you will be protected by radiation from the universe. Because Venus has a thick atmosphere, people in the colonies may be able to walk outside the floating platform only wearing oxygen masks, instead of wearing a full set of pressure suits as on Mars. But living in the cloud world of Venus will also present some problems, such as how to establish the first floating colony and how to find raw materials necessary for survival, such as water, which does not exist on this hellish planet. Venus is still a very mysterious world, worthy of our study and exploration, but it does provide a potential place for future human beings to live, and the idea that the earth is on the surface of Mars may be only temporary. Therefore, this red planet seems to be the best place for us to open up a new world in the solar system. According to many previous studies, Mars is close enough to us, which is the most unsuitable environment for living.

However, if we have the technical ability to travel through light years to a strange new world, finding an exoplanet similar to Earth will be the best choice. After studying the average data of millions of stars, it is a rule, not an exception, that each star will be bigger than the stars around it. According to the mission data of Kepler galaxy, the number of earth-sized planets far exceeds Jupiter, and there are more than 40 billion earth-sized planets in the Milky Way orbiting sun-like planets and red dwarfs, which are in livable areas. Isolated exoplanets, such as Voyager 1e or Kepler 62-f, may one day become the next place for human colonization. But the first exoplanet that humans may visit and hopefully civilize its surface will be neighboring star B.

This mysterious exoplanet can be locked in the livable zone of proxima centauri. Proxima centauri is a red dwarf, the closest star to our solar system, about 4.2 light years away. However, for the understanding of this alien world, scientists are not sure whether it has an atmosphere, let alone a magnetic field or flowing liquid water. The only known thing is that it runs in the "Gudiroko planet" region of the star, which means that there may be liquid water on its surface. Scientists hope to find more similar exoplanets, which have the same conditions to support life as the earth, and in the near future, humans will one day be able to boldly enter these areas that have never been set foot in, explore strange new worlds, and settle here to expand our species distribution.

But before the technology is greatly improved, we have to rely on NASA's James Webb space telescope and other technologies. The technology is planned to go online on March 30th, 20021year. This incredible telescope will be used to study all stages of the universe-from the first light after the Big Bang to the formation of the solar system and living planets (such as the Earth). One day, we will become a multi-planet species to ensure the survival of mankind. In the future, mankind will still remember that the earth is the planet where human civilization originated. I hope you like this video. If you like it, remember to like it and subscribe. Thanks for watching. See you next time.

relevant knowledge

The Big Bang theory is a cosmological model of Hubble volume evolution from the earliest known period to the later large-scale evolution. The model describes how the universe began to expand from the initial state of high density and high temperature, and provides a comprehensive explanation for a wide range of observed phenomena, including rich light elements, CMB radiation and large-scale structure.

Most importantly, the theory is compatible with Hubble's law, that is, the farther the galaxy is observed, the farther it is from the earth. This theory uses known physical laws to calculate the backward expansion of the universe in time, and describes a high-density state before singularity, in which space and time are meaningless. There is no evidence of this phenomenon before the singularity. The detailed calculation of the expansion rate of the universe shows that the Big Bang occurred about 65.438+0.38 billion years ago, so the age of the universe is also considered to be 65.438+0.38 billion years.