This paper takes part in the series essay competition of “great science” of Recordunkown.
The center of the solar system is a huge star, the sun, whose mass accounts for 99.86% of the total mass of the solar system. Strong mass brings strong gravity. In front of the sun, the eight planets and other small bodies all add up to be very small.
In the face of strong gravity, the eight planets can only bow to the sun and do regular circular motion around it. The sun has become the number one in the solar system. Management maintains the stability of the whole solar system, brings light and warmth to the solar system, and brings the source of life to the earth.
Without the sun, the early Earth could not have formed a perfect ecosystem, let alone the birth of primitive life 3.8 billion years ago. Without the sun, even if the earth is born with life, it will not be able to go through a long evolutionary process and finally give birth to human beings. Therefore, in a sense, the sun is the mother of all life on the earth.
The sun has given the earth a very suitable position, which is the key to the continued evolution of life on earth. You know, the planet in the habitable zone is not only earth, but also Venus and Mars. According to the research of scientists, Venus and Mars may be as beautiful ecological planets as the earth in the early days, and may also have given birth to early primitive life.
However, in the later development process, Venus became a purgatory planet with a surface temperature as high as 400 degrees Celsius, and life could not survive. Mars has also lost liquid water on its surface and turned into a desolate desert planet. Only the earth in the middle still maintains a beautiful ecological environment, which provides a guarantee for the evolution of life on earth.
The main reason why the three planets in the same habitable zone had the same fate in the early stage, but different fates in the later stage was the location. The difference of position makes the ecological environment of the three planets change greatly in the later evolution process.
This shows how important the sun is to life on earth and to human beings. Theoretically speaking, as long as the distance between the earth and the sun does not change significantly, we can always maintain a suitable environment. Life on earth can survive all the time, and so can human beings.
So can the earth always be the home of mankind? The answer is no, it’s mainly about the evolution of the sun. As we all know, the sun is a star, and its combustion is the energy released by the internal nuclear fusion reaction. Unlike chemical combustion, the combustion of nuclear fusion is a spontaneous fusion reaction under strong mass pressure.
The mass of the sun is 330000 times that of the earth. Its main component is hydrogen, which accounts for three-quarters of the mass of the sun. The rest is basically helium, as well as a small amount of other elements. At present, the sun is engaged in hydrogen nuclear fusion reaction. Every four hydrogen nuclei are aggregated into one helium nucleus, which consumes 600 million tons of hydrogen per second and converts into 596 million tons of helium.
Through this data comparison, you can see that every second, hydrogen lost about 0.04 tons of mass in the process of fusion into helium. The loss of this part of the mass is released in the form of energy, that is, every second, the nuclear fusion in the center of the sun releases about 4 million tons of hydrogen energy.
This number looks very large, but it is insignificant compared with the mass of the sun. Although it is insignificant, the mass of the sun is constantly consuming. This means that the sun is not eternal, it also has a life span. According to the current research, the life span of the sun is about 10 billion years. At present, it has gone through half of the years.
In another 5 billion years, the sun’s hydrogen will all be consumed, and hydrogen helium fusion will stop. When all the hydrogen inside the sun is consumed, the core of the sun will collapse, and the gravitational field will no longer be able to bind the shell. The whole sun will continue to expand and evolve into a red giant.
The constant expansion of the sun will engulf mercury, the orbit of mercury and the earth, and may eventually extend to the orbit of Mars and engulf Mars. Even if the expansion of the sun will not engulf the earth, the distance between the earth and the sun will be greatly shortened at that time, and the temperature of the sun will also rise, so the temperature of the earth will naturally rise, becoming the second purgatory planet.
When the sun evolves into a red giant, it also means that the earth is no longer suitable for human survival. What should human do at that time? Life on earth will go extinct because of the expansion of the sun, but human beings may not, because we are intelligent life with the help of science and technology.
With the help of science and technology, as long as the sun’s orbit does not reach the earth’s orbit, we can not leave the earth. Some people may have said that the temperature of the sun is so high at this time, and the irradiation on the earth will also make the temperature of the earth rise sharply. How can human beings survive? Under normal circumstances, human beings can’t survive on the earth.
But we should not forget that mankind is a technological civilization. At that time, we could rely on the power of science and technology to build huge sunshades on the earth’s orbit, which could block the redundant solar radiation for us, so as to keep the temperature of the earth warm. Life on earth and human beings can continue to survive.
Of course, with the passage of time, the expansion of the sun will be closer and closer to the earth, and the sun visor can no longer play an important role. At this time, we have to leave the earth and go to Mars for a temporary life. It is believed that with the strength of human science and technology, Mars will be transformed into a beautiful planet suitable for human survival in billions of years.
Of course, the population of mankind in the future, a small Mars will not be able to meet all the living needs of mankind. At this time, we don’t have to worry. In addition to living on Mars, we can also build some large migration spacecraft. People can live on the spacecraft and move away from the sun at any time.
When the expansion of the sun to the end of the sun’s shell out of the explosion, to the white dwarf evolution time. The solar system can’t survive any more. At this time, human beings can only collectively migrate to the outer galaxy and abandon the solar system that we have lived for billions of years.
Anyway, as long as human science and technology continue to develop, we will not have to worry about the trouble that the sun will bring after burning hydrogen in billions of years. The power of science and technology is enough to solve all these difficulties. Of course, this is an ideal development model for human beings. After all, billions of years is a very long time. In this long time, no one can give an answer to where human development will go.
If in the future development of mankind, the scientific and technological civilization disappears because of a disaster and returns to the era of primitive civilization. At that time, in the face of the expanding sun, human beings will have nothing to do but stay on the earth and meet the final destiny with all life.