Xingyu science fiction.
2019-6-615:54Author of online text, representative work "Abyss Starlight".
First of all, I believe that there must be other alien beings in the universe besides humans, and some of these alien creatures have evolved into civilizations.
Let's not talk about the entire universe, the universe is too big, more than 90 billion light years, and the number of stars and planets is too large to be counted, let's talk about things in the galaxy first.
The number of stars in the Milky Way is about 200 billion to 400 billion, and according to estimates, the number of planets and the number of stars are basically the same, even if we follow the idea of earthlings, the generation of life is extremely harsh on the environment, but the number of planets is not large, even if one of the 100 million planets is similar to the earth, or there is a less harsh natural environment to produce life, there are 2000 life planets in the galaxy, but the real number should be far greater than this number.
Of course, life may not necessarily evolve into civilization, I believe that the generation of life is easy, but the evolution of civilization is difficult, our earth has life billions of years ago, but the generation of civilization is only a few thousand years, in the galaxy, there may be some life planets that have produced life for more than 10 billion years, but they may not be able to evolve civilization, the base of civilization is far less than the base of life planets.
As for why the civilization of other planets has never been to the earth, there are many reasons for this, the first may not be able to reach the technology, because there are many development routes of civilization, not necessarily all scientific and technological civilizations, and there are actually many restrictions for civilization to leave the home planet, if the earth's gravity is a little bigger, and the types of elements are a little less, no matter how high our rationalization is, we may never be able to leave the earth, and there may be such a tragic civilization in the galaxy. Especially those civilizations that have evolved in liquids, and their use of energy is even more difficult.
Second, even if it is a scientific and technological civilization, it is extremely difficult to cross the vast desert space of the universe that is often measured in light years, and it is impossible to cross this kind of moat distance if you do not master those science fiction technologies, such as dimensions, wormholes, etc.
The third is necessity, if it costs countless manpower, material and financial resources just for curiosity, it is economically unacceptable.
Fourth, just like the ** in the three-body problem of Teacher Liu, the law of the dark forest, no one knows the strength of the other party, and no one dares to take the lead, once the strength of the other party is not as good as the other party, it is likely to be eaten by the other party.
The fifth is that they may have been here a long time ago, but because we have developed like ants, they don't bother to come into contact with us.