Why don't the aliens come to us?

Since the beginning of the detailed knowledge of ourselves, human beings have never given up longing for the stars and the imagination of "aliens".

In ancient times, due to the backwardness of technology, such complex and strange feelings could only be transformed into a sigh of relief, and in modern times, although advanced space technology has successfully allowed humans to leave the Earth and embrace the vastness of the starry sky at close range, it still does not let humans stop sighing, because the starry sky is not as lively as it was imagined at the very beginning, but dead silence is its main theme.

This bizarre reality has amazed and frightened scientists because whether in terms of planetary base or cosmic scope, humans cannot be the only intelligent life, but why is there no trace of aliens? Or why don't they come to us?

To solve this mystery, scientists in various fields have come up with hundreds of possible explanations, and the following are five of the most plausible of these explanations.

Physical rules limit

Newton established the classical mechanic's system, then Einstein to propose the theory of relativity, and Schrödinger Bohr and others established quantum mechanics, in just three hundred years, human science has achieved a leap forward, and the understanding of the entire universe has reached an unprecedented degree.

However, no matter how rapid the development of science and technology is, it is still impossible to transcend the universe as a large framework. In other words, no matter how to develop, how fast the development, must honestly comply with the basic rules of physics in the universe, and can not and can not exceed half a step.

Just like no matter how luxurious a car, how amazing the speed is, it still has to follow the basic laws of mechanics. Or no matter what new substance mankind has created in the laboratory, this new substance still cannot escape from the law of conservation of energy.

Thus, we can say with certainty that even if civilization continues to develop for a billion or even billions of years, it will still be limited by the basic rules of physics.

And what is the most desperate thing in the universe? The answer is distance. When the speed of light or FTL cannot be a reality, all civilizations can only emerge from their home planets and then die silently on them, with no chance or possibility to communicate with other civilizations.

Things cannot last forever

The law of entropy tells us that nothing in the universe, not even the universe itself, can exist forever and that they will all die out one day.

Therefore, within a certain time scale, a species or civilization may show the momentum of "eternity", but in a larger time scale, the so-called eternity is just a cycle of countless "birth-death" processes. A cycle.

Based on this theory we can venture to guess: in the universe after birth more than 10 billion years, there have been many different civilizations, because the distance scale is too large, these civilizations simply do not have the opportunity to communicate with each other, and eventually in different periods silently die out, so that humans see the universe is "dead", and the horror is that mankind may also escape the same fate.

Human beings have been found, but do not interfere with human development

In the 1970s and 1980s, the development of space technology sparked concern about intelligent life on alien planets, but the results of the search were so disappointing that the Zoo hypothesis emerged to explain this complex and unique situation.

In the decades of brewing and spreading, it has gained the attention and support of many people, even many influential scientists in related fields.

The hypothesis suggests that alien civilizations have already discovered Earth and humans on it, but in order not to interfere with the natural evolution of humans and to avoid interstellar pollution, the alien civilizations choose to avoid communicating with humans and silently observe them like animals in a zoo.

Based on this hypothesis, John Ball, a radio astronomer at MIT, proposed the laboratory hypothesis in 1973, suggesting that humans might be some kind of experiments, or undergoing some kind of experiments, and that Earth is a huge laboratory.

From the human point of view, these two subversive hypotheses are quite logical.

Imagine that when humans can travel the universe, they suddenly find a backward civilization that can only operate around their home planet, with a technology level far superior to theirs, and they have nothing that humans covet, will they silently observe their development, or will they simply destroy or announce their existence to them?

I'm afraid the answer will only be the former, after all, in the premise that they do not have what humans need, the destruction and the announcement of their own meaningless to humans, but on the contrary, this will make the civilization into turmoil, obviously to the detriment of others.

Humans exist for too short a time

Even if the full calculation, human civilization appeared on Earth in less than 8,000 years, this period and the universe more than 10 billion years, it can be said that even "a moment" can not talk about, not to mention the human search for aliens so far less than 100 years, which is even shorter.

Therefore, some scientists suggest that it is unreasonable and incorrect to say that the universe is "silent" at this time, just like a person who just woke up from his bed, he opened his eyes and saw no one, and no one came to contact him.

It is not that there is no one on earth, but he did not even get out of bed, did not even leave the door, and at the same time the search time is too short. This is the same reasoning as humans looking for aliens in the vast universe.

Human civilization is too low

When people are arguing for many brainstorming conjectures, some scientists put forward a new conjecture, they believe that humans have not received "greetings" from their peers, the fundamental reason is that humans are too backward, and there is no sense of communication.

Just like you will be dedicated to traveling from the plane to the United States, to say hello to the ants there, to communicate with each other? The answer is obviously no. From a certain point of view, the status of humans in the eyes of aliens may not be as good as that of ants in the eyes of humans.

Which of the above five speculations do you think is more reliable? Of course, these speculations are based on the logic of human thinking and may be far from the truth, after all, in the vast environment of the universe, no one knows what kind of strange and weird alien intelligent life will exist.