Despite what "enthusiasts" of unidentified flying objects might claim, almost all scientists agree that humanity has yet to receive any messages, nor has anyone "visited" us from beyond our planet. However, within the vast expanse of the universe—estimated to contain around two trillion galaxies—scientists say there is a "100% chance" of life existing somewhere far from Earth. This raises an intriguing question: If extraterrestrial life is indeed common in the universe, why haven't we heard about it?
Professor Frederick Walter, an astrophysicist from Stony Brook University, states, "Life is a biochemical process, and it will happen, but things get more mysterious." He speculates that there is a "100% chance" of some form of life existing in the universe. Nevertheless, scientists are also confronted with the absolute absence of any evidence for life, whether intelligent or non-intelligent. The so-called "Fermi Paradox," named after physicist Enrico Fermi, questions how we can balance the likelihood of life with our lack of evidence for it. As Fermi asked his friends one afternoon in 1950, "Don't you ever wonder where everybody is?"
Dr. Walter continues, "It is possible that the universe, which is 13.8 billion years old, is teeming with life, but everyone is hiding because we are afraid." He gives an example: "If you see a hunter building a fire, will you light a fire yourself to say hello? You don’t know who else is out there, whether they are armed, or what their intentions are. What you know is that if you stay quiet and don’t light any fire, no one can find you."
He explains, "The Dark Forest Hypothesis suggests that if you really want to survive, the only smart decision is to remain silent and shoot anyone you can see. This theory, popularized by Liu Cixin's 'Three-Body Problem' novels and the recent Netflix adaptation, implies that the universe may be in a similar state where civilizations play the role of hunters."
In a report for the Daily Mail, he states, "While humanity is doing its best to reach the stars and communicate with them, there may be other, more powerful forces quietly waiting out of our sight. If that is the case, it could explain why our efforts to communicate with any other civilizations have yet to receive a response."
However, the image of the universe painted by the Dark Forest Hypothesis may be somewhat pessimistic, making it hard for some to believe. Professor Walter points out that although the theory is popular among science fiction writers, he is skeptical of it. "Instead, if we want to explain why no one responds to humanity's messages, we may have to accept that we are the problem. If life is common in the Milky Way as some calculations suggest, extraterrestrials may be spoiled for choice among planets to try to communicate with."
He continues, "In 1977, the 'Golden Record' was sent aboard the Voyager spacecraft as proof of human intelligence. However, some experts suggest that extraterrestrial beings might not be impressed enough to want to talk to us. If this is true, humanity may simply not be interesting enough for aliens to care about."