In the middle and latter part of the last century, with the help of science and technology, mankind finally realized the dream of flying out of the earth and began to explore the universe. The vast universe is a completely unfamiliar space for human beings. We don’t know how the universe came from? How big is the universe?
There are countless mysteries in the vast universe waiting for us to solve, and for human beings who have just walked out of the earth, the most interesting thing is the existence of aliens. I believe that every person who sees the vastness and mystery of the vast universe will be curious about whether there is an alien civilization in the universe.
Some people may be very arrogant to believe that there is only one intelligent civilization in the universe, but more scholars believe that the existence of the earth as a living planet and the existence of human beings are the best evidence for the existence of alien civilization in the universe. The vast universe cannot be the only beautiful ecological planet Earth, and every beautiful ecological planet has the possibility of birth of life. Coupled with the infinite space of the vast universe, we can imagine that there is a high probability that an alien civilization will exist. of.
If alien civilizations exist, why haven’t we encountered them so far? Regarding this question, Fermi once had a big doubt, and this doubt became the later famous Fermi paradox. In other words, theoretically speaking, alien civilization must exist. The universe should be a very lively civilized family, but what we have seen is that the universe is very strange, and we have not encountered any aliens. .
Where are the aliens? Do they exist? The mystery of aliens is an eternal and unchanging topic in the human world, and is a topic that many people discuss every day. Through constant discussion of conjectures, scientists have proposed six possible conjectures about our inability to meet aliens, and each of them makes us feel scared.
The first guess: Alien civilization is also waiting
After human beings walked out of the earth, they began the exploration project of extraterrestrial civilization. We hope to be able to contact extraterrestrial civilization through various means. Then there is a possibility that alien life is also constantly searching for other intelligent civilizations and waiting for us to take the initiative to contact them?
This possibility is quite high. We use astronomical telescopes to search for exoplanets that may have extraterrestrial life, and use radio waves to search for possible extraterrestrial civilizations. Alien civilizations may also be technological civilizations that have just stepped out of their home planets. They are also very curious about whether there are other civilizations, and it is possible to find other intelligent civilizations in the same way as humans.
The second guess: time is not enough
This point is actually connected to the first conjecture. After we walked out of the earth, the main reliable way to search for extraterrestrial civilizations is through radio waves. We must know that the vast universe uses light-years as the basic unit of distance. The distance between stars ranges from a few light-years to hundreds of millions of light-years. Without the ability to fly faster than light, it would be impossible for civilizations to pass the direction of visitation.
Before being incapable of reaching for contact, the most likely way to communicate between civilizations is through radio waves. Any intelligent civilization, as long as it enters the age of science and technology, will develop radio wave technology. With radio wave technology, we have sent various human radio wave signals to the universe many times, hoping to be received by alien civilizations.
In the same way, alien civilizations may also send radio waves to the earth and the solar system in this way. However, with traditional radio waves, its fastest speed is the speed of light. If the civilization planet closest to the solar system is far away from us, for example, it is more than a hundred light-years away from the earth. So whether it is a signal sent by us or a signal sent by an alien civilization, it will take at least a hundred years to reach the galaxy where the other party is located.
It has only been more than 60 years since human beings walked out of the earth. The earliest radio signals we sent are still decades away from the time of a hundred years. Therefore, it is possible that the human civilization signal is still in the process of reaching the target and has not been received by the alien civilization. In the same way, we have not received the signal sent by the alien civilization, so we can’t know each other’s existence.
Perhaps as long as we give humans more time, we may receive alien civilizations. In the future, humans will find evidence of the existence of extraterrestrial civilization, most likely through radio pulse signals.
The third conjecture: aliens may already be by our side
I believe that when many friends search for topics related to aliens on the Internet, they will see many stories about aliens abducting people on Earth from all over the world. Of course, these stories are basically false, but we cannot be sure that all of them are false. Among so many stories of aliens kidnapping Earthlings, as long as one case is true, the possibility that aliens will be around us will be very high.
In fact, the legend about the alien civilization already existed on the earth has existed for a long time. In some ancient records in the history of human civilization, there are also some related records, but the ancient people’s view of aliens is different from ours. The ancients regarded aliens as gods. And the myths and legends that appeared in the ancient times of the earth, are they the evidence that alien civilizations visited the earth, or the existence of aliens on the earth?
The fourth conjecture: they have been watching us
Among the many conjecture theories about alien civilization, one is more famous, and that is the zoo concept. Some scientists speculate that the earth and even the solar system may be a laboratory set up by alien civilizations. Humans are the main objects in this laboratory, and it is a common phenomenon for animals to be enclosed and isolated in a limited space for observational research.
We will also put all kinds of wild animals in a limited range and install various cameras for observation. We basically do not interfere with the living habits of these wild animals. Through such observations, we can better understand wild animals and explore the mysteries of life.
Humans will set up a range to observe wild animals. Will powerful alien civilizations also regard humans as wild animals and observe them? This possibility is not completely absent. After the zoo theory was put forward, it received the support of many scientists. In other words, many scientists believe that the earth may be the biological laboratory of alien civilization.
In fact, this is not difficult to understand. If mankind becomes an interstellar civilization in the future and can cross all corners of the universe, we will also find a variety of life planets. At that time, humans might also house a certain galaxy or a certain life planet in captivity, and then conduct various biological observations.
The fifth conjecture: the law of the dark forest
The dark forest theory became popular because of the novelist Liu Cixin. In the novel, the author compares the universe to a forest at night. Different civilizations are on guard against each other for fear that the other side will know their own existence. Once the intelligent civilization knows the other side’s existence, then interstellar wars may break out, and weak civilizations will be wiped out or enslaved by advanced civilizations.
From the perspective of the earth’s biological world, we can understand the law of the dark forest, because the natural world of the earth is such a world. There is a law of the weak eating the strong among creatures. Even within human civilization, there has been a strong eating of the weak since ancient times. It is normal for a weak country to be bullied and annihilated by a powerful country.
The sixth conjecture: human beings are looking for the wrong direction
The universe is a vast three-dimensional space, and no one knows how big the universe is. Even in the current observable universe, if we don’t know the specific direction and location of an alien civilization, it is tens of thousands of times more difficult than finding a needle in a haystack. Even if there is a slight change in the coordinate data of the alien civilization, it may be reflected in the space of a few light-years.
Therefore, in the vast universe, in order to truly reach the target position, there must be a certain and accurate position coordinate, there can be no difference. For more than half a century since mankind has searched for outer civilization, the direction of exploration is mainly concentrated in a few space regions, if there is no alien civilization in this direction. Then no matter how hard human beings work, there will be no gain. Therefore, we may be searching in the wrong space area.
Of course, because humans know nothing about aliens, they have very little knowledge of the universe. Therefore, our search for alien civilization is actually an act of luck. If one day, humanity’s luck is bursting, perhaps an extraterrestrial civilization will be discovered by accident. Of course, before we have become an interstellar civilization, it is impossible to go out of the solar system to explore other galaxies.
Before that, we wanted to determine the existence of alien civilizations. There were only two methods. One method was that the alien civilization spacecraft came to the earth on its own initiative. At that time, I believe that no one would doubt the existence of aliens anymore. Another method is that the wireless signal sent by the alien civilization is received by us, and we have successfully cracked the signal. At that time, even if we have not yet met with aliens, we can be sure of the existence of alien civilizations.
No matter which method it is, it mainly needs the support of science and technology. If there is no strong scientific and technological power, even if there are many alien civilizations sending signals to the earth, we may not be able to receive them, and even if they are received, we cannot crack them. And for a signal that cannot be deciphered, it is difficult for us to determine its attributes, whether it is a signal of civilization or a natural signal of celestial bodies. So, let humans work hard! Technology is the foundation of everything.