Recently, some scientists have come up with the bold idea that all living things in the universe except Earth are extinct, and that humans located on Earth are the last generation of civilizations in the entire universe, a statement that naturally has no basis in reality and therefore will not be believed by most people. In 1961, when NASA invited british atmospheric scientist James to discuss the survival of extraterrestrial life, James proposed a general theory, which is completely different from the remarks of scientists today.

The theory that life can only continue to exist and develop under the interaction of life and environment, in recent years, this theory has gradually attracted the attention of meteorologists, when a highly developed civilization develops to a certain extent, we will reflect on it, because human beings will think of themselves as the most special and important people on this planet, so they will not have the knowledge of cherishing other life and environments on earth. Whether or not these theories are true, we cannot deny that if humans no longer value the environment in which they live with animals, it will undoubtedly become an important cause of accelerating the extinction of life on Earth.
Cosmic space is not only huge, for the visible universe, its diameter has reached 90 billion light years, and there is a long history, 13 billion years of the universe is enough to make the stars it formed burn, faint, and eventually die several rounds, once enough heavy elements are formed, any new stellar cycle can be used as a preparatory place for the creation of terrestrial planets and life habitable, which indicates that the possible time span of extraterrestrial life is very long, and it is necessary to be with them to communicate with them.
How long is the overall life cycle of intelligent species? As far as the current experience of scientists is concerned, it is difficult to guess that the history of mankind is a civilization that is constantly repeated or destroyed, and most civilizations have lasted for hundreds of years, and today's technological development has reached today, and the self-destructive ability of human beings has far exceeded any previous era, can we obtain this information in 500 years, 5000 years, 50,000 years? Does it still exist?
One possibility is that millions or hundreds of millions of years ago, alien civilizations existed, prospered, and transmitted information into space and then went to self-destruction, a process that would happen hundreds or millions of years from now, so to communicate with aliens, you have to achieve the ability to communicate with them at any time.
In 1977, a radio telescope in Ohio, USA, somewhere in the constellation sagittarius, detected a strange signal that lasted 72 seconds, which was a very strong signal, and this change in the strength of the signal, just like the signal sent by scientists imagining aliens, that night, the scientists on duty recorded and printed it out, and the signal was "Wow". Unfortunately, this signal never appeared again, and there is no exact interpretation of it, nor can it be clearly defined as some kind of alien.
Scientists replied to the message in 2012, but have not received any information since then, and scientists speculate that perhaps alien civilizations are deliberately avoiding, they are just observing the process of our natural evolution, just as humans observe the evolution of other animals, we seem to be staying in the cosmic zoo, and they may be masters of many high-tech species, just listening and not talking.