When will humans meet aliens? Scientist: It will take at least 200 million years.

A few days ago, we just introduced the alien viewpoint of American scientist Kakumichio, who thinks that human beings are hopeful to find aliens in this century.

Obviously, there are always different opinions about aliens. The result of a recent study is completely contrary to Kakumichio's point of view: human contact with aliens may take hundreds of millions of years. ...

Regarding the existence of aliens, physicist Fermi once asked a famous question: Where are they? This is the Fermi paradox.

In the past 70 years, scientists have done a lot of research and explanation to answer Fermi's questions. Among them, robby henson, a professor at George Mei Sen University and a member of the Institute for the Future of Human Beings (FHI) at Oxford University, put forward the grand filtration theory. He believes that the development from barren space to a civilization capable of interstellar migration requires nine key stages, at least one of which is extremely difficult to achieve, filtering out most of the possibilities of forming an advanced civilization.

Recently, Hansen and his colleagues from the Center for Particle Theory and the Department of Mathematical Sciences of Durham University, the Department of Machine Learning of Carnegie Mellon University and the international trading company Jump Trading conducted a new study, and once again reached a "pessimistic" conclusion. They think that human beings are an earlier civilization in the universe, and we may have to wait 200-200 million years to see other civilizations emerge.

In this study, they adopted a concept called predatory civilization (GCs). This civilization has a similar expansion speed, expanding the space it can rule and preventing the development of other civilizations.

In this model, they put forward three parameters, namely expansion speed, energy and a constant. Through these three parameters, they infer the position of this predatory civilization, how much space it occupies in the universe, and when we can meet them.

To some extent, this parameter is the explanation of Fermi paradox, which is the contradiction between the statistical possibility of the existence of alien civilization and the lack of evidence.

According to current research, the universe was formed 65.438+038 billion years ago, while the earth appeared 4.5 billion years ago, and the earliest life on the earth appeared 4.2-3.8 billion years ago. However, it was not until 200,000 years ago that humans officially appeared, and it was less than 70 years since humans mastered the ability to search for extraterrestrial life in the universe. Considering the comparison between these two sets of figures, we can think how difficult it is to develop from simple creatures to intelligent creatures, and also make many people think that human beings may be the most advanced civilization in the universe.

Moreover, if there really are civilizations in the universe that appeared millions or even hundreds of millions of years earlier than humans, then their capabilities should be enough to occupy a large space. Since nothing has been found at present, it can also be proved from the opposite side that there is no more advanced civilization in the universe than human beings.

What's more, most stars in the universe are red dwarfs smaller than the sun. Their life span is extremely long, and they can even burn 1 trillion years. Considering that civilization may not appear until the middle and late stages of celestial evolution, it may take a long time for civilization around these celestial bodies to appear. It seems that human beings are probably the earliest civilization in the universe.

This parameter comes from the theory that some scientists believe that the evolution of organisms needs to follow certain steps. In addition, the anthropic principle holds that everything we see today has its reasons, and human beings can create civilization to prove that this model has advantages.

In this study, the model they adopted is the big filtration theory put forward by Hansen, which includes nine important stages:

Hansen pointed out that each stage has its own difficulty, so that the difficulty will increase exponentially with each step. This process is just like unlocking a lock, and all the locks need to be unlocked in a limited time to complete the creation of civilization. For this study, Hansen and others also reconsidered these steps and divided them into two levels: difficulty and ease. They also considered the possibility that a certain civilization could develop without being suppressed by other predatory civilizations.

Their conclusion is that most planets like Earth may have completed these nine steps before the end of the life window. Therefore, it's rare to see such advanced Wen Mingzhen as ours. Their calculation results show that predatory civilization only appears once every 654.38+0 million galaxies on average. In other words, there may be other life in the universe, but it is far from the present level.

This parameter represents how long it takes for a newly developed civilization to develop into a predatory civilization. This parameter is based on the Copernican principle.

As we know, Copernicus founded the Heliocentrism and told people at that time that the earth was not the center of the universe, but just an ordinary planet. So people summed up the Copernican principle: we have nothing special, and what we see is also the most common phenomenon in the universe. According to this principle, we can assume that advanced civilization will eventually occupy more space in the universe, but we can't see that this phenomenon is not some special cases, but that there is no such civilization in the universe.

For the present human beings, it is in what they call the "quiet" stage of civilization. In the future, it can also develop into a "echo" civilization, that is, spread human civilization through alien colonization. Of course, there is also a premise that we have to pass all the filters in front of the life window.

Having said that, people naturally want to see the conclusion directly, so let's not keep suspense and just say what they finally found.

Predatory civilizations rise from quiet civilizations at the frequency of every 1 10,000 galaxies 1 time, and they will expand at the speed of about 1/2, occupying 40%-50% of the whole universe, and each predatory civilization can occupy 1 10,000-30 million galaxies.

As for when we are most concerned about finding such a civilization, the answer may be surprising, that is, 200-200 million years later. In other words, it is basically impossible for us to meet even the recent predatory civilization at present. As for the ongoing search for aliens, I am afraid it will also be futile.

Of course, this is just one of many studies on the existence of alien civilization. Who knows, maybe something will happen one day. ...