Human beings are in the vast universe and have always relied on the unique conditions of the earth to reproduce themselves. The most important reason why the earth was able to evolve life is the sun. The sun brings us light and heat, everything we need, but things come to an end, and the sun is no exception. When the sun burns out, what will happen to our planet, and where will humanity go?
The combustion of the sun is achieved through the nuclear fusion of hydrogen. The power of nuclear fusion is great, and we can understand it through the earth-shattering effects of atomic and hydrogen bomb explosions. The reason why the sun has been able to burn for so long is because the volume of the sun is so large that it is enough to support countless hydrogen nuclear fusion reactions. But the energy is going to be exhausted after all, so how long can the sun burn? 5 billion years. Here a friend to ask, 5 billion years? How do you figure it out? Another point of knowledge is involved here, and that is the main sequence of stars.
Stars like the Sun have a main sequence. The main sequence period, as we can understand it, is when the star is at its most stable, neither overextending nor shrinking. And the more massive the star, the shorter the main sequence period. Although the sun is already extremely large for the earth, it is actually a small person among the stars, so it has a main sequence of 10 billion years. It is only during the main sequence that the sun has the conditions to sustain life on Earth. By now, the life of the sun has passed halfway and there is still half left.
And when the main sequence is over, the star will enter the second stage , the red giant , and the final white dwarf , the red giant is, as the name suggests, the red sphere of crazy expansion, and the white dwarf is the remaining product of the red giant stage. We can understand these two phases as the twilight years of the Earth and the period of death. Both stages also mean death for the earth. First of all, red giants, when the sun body consumes almost the same hydrogen element because of nuclear fusion, another kind of nuclear fusion will occur inside the sun - helium fusion.
The super energy released by helium fusion will cause the sun to continue to expand outward, and the volume of the sun will reach 200 times that of the present. At this time, the sun has another name, the red giant star. The Sun, which has become a red giant, undergoes countless thermal pulses, causing the external material to be constantly stripped away, leaving the white dwarf star. Not to mention the last white dwarf, even the influence of the initial red giant stage, the Earth can not hold back.
In the red giant stage, the temperature of the Sun continues to rise as the Sun's hydrogen elements continue to react. The surface of the Sun will have more than twice the intensity of luminescence it now has, and such a heat is absolutely unbearable for life on Earth. And it is not impossible for the sun, which has expanded by a factor of 200, to push the earth out of the solar system, or to directly swallow the earth.
And human beings on Earth, if there were still human beings at that time, would see that the sun in front of us was getting bigger and bigger, getting bigger and bigger, and finally directly close to us, and the sky in front of us was covered with flames.
At this moment, if human beings on the earth cannot evolve high-tech enough to survive, the result will be destruction.
This means that we only have two paths to go, either to transform the earth's own environment or to migrate to other planets. How harsh is the environment of the earth, in the whole galaxy, we have only found one such one. In fact, it is too early for us to care whether the sun will cause the destruction of the earth, because before the sun destroys the earth, if there is a massive asteroid impact near the earth, or other more harmful situations, it is unbearable for us.
So technology is not only productivity, technology is life. But now that technology is evolving rapidly, I believe that we should have enough ability to deal with accidents.