When human beings did not go out of the earth and see the vast universe, the plan of exploring extraterrestrial civilization began. So is it possible for an alien civilization to exist? When we have a general picture of the universe, we will have an answer to this question.
The galaxy where the earth is located is the solar stellar system, a small galaxy only about 2 light-years in diameter. Beyond the solar system is the Milky way, which has a diameter of 150000 light-years. There are hundreds of billions of stars in the Milky way. Each star has its own stellar system, and there are different numbers of planets around it.
According to the preliminary calculation of scientists, the number of earth like planets in the galaxy will not be less than 40 billion. And the Milky way is only one member of the Virgo supercluster, which is hundreds of millions of light-years in diameter. There are too many galaxies like the Milky way to be counted. The Virgo supergalaxy is just a speck of dust in the universe, and the observable universe is about 92 billion light-years.
Within this observable range, even if there is a very small probability of the birth of intelligent civilization, the number of civilizations in the universe will not be a small number. When we really understand the vastness of the universe, do you have any doubts about the possible problems of alien civilization? I believe you have no doubts. Every astronomer and physicist is basically a staunch supporter of the existence of alien civilization.
Maybe someone here will say, if there are a lot of alien civilizations in the universe, why can’t we find one? In fact, the universe is too vast. The distance of the universe is measured in light years. The nearest star system to the solar system, biling galaxy, is 4.2 light years away from the earth. Even if we fly at the speed of light, it will take us 4.2 years to get there.
If it is at the speed of our current spacecraft, it will take hundreds of thousands of years to reach the neighboring galaxy. Therefore, even if there are a large number of alien civilizations in the universe, they can’t find each other because they are far away from each other and have no ability to navigate the galaxy. This is actually the same as the development of human beings in the earth age.
Before human civilization entered the era of science and technology, there was very little contact between the East and the West. Especially in ancient times, it was normal that the East did not know the existence of the West. Due to the obstruction of the sea and the limitation of transportation, we have no idea how many species there are on earth. We may even think that only the East is inhabited in this world.
When mankind enters the era of science and technology, with the rapid transportation, the earth has become a global village, and we can detect every corner of the surface. At this time, how many countries and places on earth are inhabited is no longer a secret. Now we are looking for extraterrestrial civilization in the universe, in fact, the same is true.
Even if there is an alien civilization in beling, we don’t know it at all. If there were alien civilizations in the universe, would they be in the stone age or the technological age? I believe many people are very curious about this. In the eyes of many people, alien civilizations are very powerful. In particular, many alien science fiction movies and novels mislead us, that is, human beings are weak in the face of alien civilization.
Is that really the case? Let’s first analyze the situation of the Milky way. With a diameter of 150000 light-years and a number of 40 billion earth like planets, is it true that only human civilization exists in the Milky way? This possibility is very small. If there are many intelligent civilizations in the galaxy, why don’t we meet them alone? Human beings can not take the initiative to find alien civilization, that is because we do not have the ability of interstellar navigation, the galaxy can not be regarded as the back garden of human beings.
However, when a civilization grows into an advanced civilization, the distance between the universe will no longer be a problem, which is the same as the development of human beings on the earth. We now think that Lightyear is an insurmountable gap, because our technology is just at the beginning. But if there is a technological civilization in the galaxy that has developed for tens of thousands or even millions of years, then the rate of such civilization has broken the speed limit and can carry out interstellar navigation.
Even if we can’t traverse the universe, we don’t think there is much problem in traversing a small galaxy. But what we see is that no alien civilization has come to earth to contact us. Isn’t that very strange? This is also the Fermi paradox that Fermi once proposed. For this problem, the scientific community has many conjectures.
One of the most important conjectures is that the strength of alien civilization is not strong, and it may not be as strong as human beings. In other words, there may not be any advanced civilization capable of interstellar navigation in the galaxy. They may still be in the stone age or the age of science and technology similar to human beings. Perhaps in an unknown galaxy, some alien civilization has focused the telescope’s field of vision on the solar system and also seen the beautiful planet earth.
This civilization may also guess that there may be intelligent civilization in the solar system. However, due to the distance is too far away, and there is no relative speed limit, so we can not really come to the solar system to enter the confirmation. If this is the case with the galaxy, then other galaxies in the universe may be no exception. We should know that the birth time of the galaxy is almost the same as that of most other galaxies.
If the Milky way has not yet developed a powerful advanced civilization, then the probability of other galaxies is similar. So, we can’t really discover the alien civilization. If things are really as we guess, it’s actually good news for human beings. You know, the law of the jungle probably exists among civilizations. If there are many advanced civilizations in the universe, especially the Milky way, the existence of the solar system and the earth may have been discovered.
Human beings and other intelligent civilizations are totally different civilization races, different intelligent life bodies. It is very difficult for different civilizations to really live in peace. We should know that even if there are constant contradictions within human beings, let alone expect other civilizations to treat human beings peacefully. So, once the earth is discovered by advanced civilization, our ending may not be very good.
Now we haven’t found any alien civilization, which is great news for human beings. Only when we make continuous efforts to develop science and technology, and when we become a powerful interstellar civilization in the future, we can go out of the solar system and explore various galaxies in the galaxy. I believe that at that time, we will find a lot of intelligent civilizations. However, at that time, it is difficult to say what kind of attitude human beings will take towards alien civilization.