Since modern times, one of the most discussed topics of the universe and the starry sky is aliens. Before mankind left the earth, although some people continued to discuss topics related to aliens, at that time, people still had many doubts about the existence of aliens.
It wasn’t until human beings really walked out of the earth to see the vast universe that this kind of questioning continued to disappear. Some people may say that humans have been searching for alien civilizations for more than half a century, not to mention alien civilizations, it is the simplest. We haven’t found the form of life at all. Why do people still believe that aliens exist?
In fact, this problem is very simple. When the frog is at the bottom of the well, its vision is very narrow and its cognition is also very limited. It will also question whether there will be other life in the world beyond the bottom of the well. But when the frog jumped out of the well and saw the vast world outside the well, the original doubts disappeared.
The same is true for human development and cognition. Before we walked out of the earth, we had very limited knowledge of the starry sky above our heads. We also didn’t know how big the world outside of the earth was and what kind of world it was. At that time, we questioned the outside world. The existence of star people is very normal.
But when we really walked out of the earth and saw the vast space of the universe, this kind of questioning disappeared. From the perspective of the universe, stars, planets, galaxies, etc. are too many to describe with numbers. In the huge base Next, as long as the probability of alien existence is greater than zero, then the number of alien civilizations in the entire universe will also be a very large number.
What’s more, it has been 13.8 billion years since the birth of the universe, and human beings were born only a few million years ago. Even from the perspective of the age of the universe, we don’t have to doubt the existence of alien civilizations. Moreover, with the continuous advancement of human technology and the continuous improvement of cognition of the universe, there have been more and more discussions about aliens in recent years.
Through observation, we found that when people discuss alien-related topics, an inherent view is that aliens are always better than humans. Whether it is people’s discussions or in many sci-fi materials, aliens are powerful. It is crushing human beings. So some people have this doubt: Why do people always think that aliens are better than humans? Are there no aliens weaker than humans?
In fact, people’s ability to have this kind of cognition is mainly determined by the vast distance of the universe. Why do you say that? We all know that light-year is the most basic unit of distance in the universe, which is equivalent to using meters to measure distance on the earth. In the vast universe, distance is a very exaggerated number, and only light years can be used for better statistics and calculations.
A light-year is the distance that light travels in a year at the speed of light. One light-year is approximately 9,460,730,472,580 kilometers. Seeing this number, I believe everyone can intuitively understand how exaggerated the distance of the universe is. It is the vast distance of the universe that makes the distance between stars and stars relatively large, on average more than a few light-years. For example, the nearest neighboring star is 4.2 light-years away.
We are looking for alien civilizations. Naturally, we cannot do without communicating with exaggerated distances. According to current observations and explorations, there is no second intelligent civilization in the solar system, so we can only find alien civilizations in other galaxies outside the solar system. . However, the exaggerated cosmic distance hinders our exploration. Although we can observe the distant starry sky through astronomical telescopes, it is only a very obscure observation. It is really difficult to observe the planets in the solar system in a comprehensive manner. To.
Therefore, it is very difficult to observe whether there is an alien civilization outside the system through an astronomical telescope. Unless the alien civilization builds a huge thing in its own galaxy, such as the Dyson sphere, it will be possible to pass the transit. Japanese law is observed by us. Of course, even if we observe such a scene, we cannot be sure that it must be a civilized creation.
It can be seen that the vast distance of the universe hinders mankind’s search for alien civilizations. With the current technological strength of mankind, we cannot actively search for alien civilizations, but can only passively expect alien civilizations to visit. If one day, we observe the existence of aliens, basically aliens have come to the solar system and come to the earth on their own initiative.
Alien civilizations that can cross the interstellar to the earth must be ahead of humans in their technological level. As for how many years ahead, it depends on how far away the parent galaxy the alien civilization is from us, if it comes from a galaxy near the solar system. , The distance may be at most dozens of light years, so the technological level of aliens may only be ahead of us by hundreds or thousands of years.
If the aliens come from more distant galaxies, such as thousands of light-years or more than tens of thousands of light-years away from us, then their technological level is unimaginable, and may be at least tens of thousands or even hundreds of thousands of years ahead of us. the above.
Some friends may say, is it possible that alien civilizations that are very far away from the earth can’t be ahead of us in science and technology by more than a few hundred years? The reason why some friends think so is that they think that alien civilization will cross the long interstellar distance and spend a long time to visit the solar system.
If aliens want to cross the interstellar to the solar system, the speed of the spacecraft must be at least sub-light speed. If it is an alien civilization near the solar system flying at sub-light speed, it may take decades or hundreds of years to reach the solar system. This time is actually not long, because the rapid development of technology can also extend the life of intelligent life. If aliens have a life span of thousands of years, it will take decades or hundreds of years to travel between stars.
But if it is an extraterrestrial civilization that is very far away from the solar system, they want to come to the solar system in a short time, sub-light speed is not enough, they must master the ability to fly faster than light. Some friends may say that if an alien civilization has the technical ability to build a “generational spacecraft”, it can also spend a long time entering the door for interstellar travel.
“Generation spacecraft” refers to a spacecraft that can provide a long-term stable ecological environment. Aliens can multiply in one generation after another, and have a long-term survival guarantee in the space. “Generation spacecraft” is very sensitive to speed. The requirements can be less high, just keep flying towards the target.
As the problem of ecological survival is solved, the “generational spacecraft” can theoretically travel in interstellar space forever as long as they are not destroyed. It can take hundreds of thousands of years, millions of years or even longer to reach the solar system from distant galaxies. But there is a question: Why does the alien civilization take such a long time to cross the interstellar to the solar system?
If mankind masters the technology to build “generational spacecraft” in the future, will we spend hundreds of thousands of years, millions of years to travel to a distant galaxy? I am afraid that as long as there is no problem with the brain, such a thing will not happen. Even if the parent galaxy of aliens has come to an end and can no longer survive, there is a high probability that they can find a place to survive in nearby galaxies or make some modifications to other galaxies to meet the needs of survival.
It can be seen that if there are extraterrestrial civilizations coming to the solar system from a distant galaxy in the future, then they are likely to have the ability to fly faster than light, otherwise they will not cross the vast interstellar to visit the solar system. In either case, as long as alien civilizations come to the solar system and to the earth, their scientific and technological strength must be at least hundreds of years ahead of mankind.
Of course, this is not to say that there are no aliens weaker than humans in the vast universe. In fact, judging from current observations and research, in the vast universe, the strength of humans may not be weak. Perhaps most of the alien civilizations are still less powerful than human civilizations, even if there are alien civilizations that are truly stronger than humans. , Is also rare, otherwise the solar system would not be so quiet.
After the development of human technology to interstellar civilization, we can initially go out of the solar system to explore the surrounding galaxies. At that time, we may be able to discover other intelligent civilizations. For the same reason, if humans can go to nearby galaxies to discover alien civilizations, The technological strength of aliens is also lower than that of humans, otherwise they would have come to the solar system earlier instead of waiting for us to visit.