This disturbing theory may explain why we haven’t found evidence of intelligent extraterrestrial life

Over the centuries, the question of whether intelligent life could exist elsewhere in our universe has long intrigued researchers. In ancient times, the philosopher Epicurus (c. 341-271 BC) hypothesized that “there are infinite worlds both alike and different from this world of ours”, sentiments similar to those expressed by Nikolas Krebs much later in the 15th century, when he espoused the idea that “life, as it exists on earth in the form of men, animals and plants, found, we suppose, in higher form in the solar and stellar regions”.

Today, the search for intelligent extraterrestrial life remains one of the most difficult pursuits in modern astronomy. In the 1960s, Frank Drake calculated the likelihood that intelligence could be discovered among the stars, noting that while it should exist in abundance in our galaxy, searches continue to be met with an almost deafening silence. As unlikely as this prospect may seem to some, such fruitless research has led others to ask the difficult question: what if life on Earth really is something entirely unique to the Universe?

Now, a recent paper by team members at NASA’s Jet Propulsion Lab in Pasadena, California attempts to answer that age-old question by offering new insights into an old idea.

Known as the “Great Filter” theory, it suggests that distant civilizations on alien worlds may have existed throughout the history of the cosmos, but may have destroyed themselves before to have been able to achieve a level of technological capability that would facilitate communication with any future. interstellar neighbors.

During the Cold War, as the nuclear arms race escalated, many wondered about the true prospects that life on Earth might be able to wipe itself out. “Most of the human survivors were starving to death,” said astronomer Carl Sagan says famous, adding that “the extinction of the human species would be a real possibility”. Sagan and several colleagues then co-wrote an article that examined what are the effects of a nuclear winter could mean for life on Earth.

Now, in an article by authors Jonathan H. Jiang, Philip E. Rosen, Kelly Lu, Kristen A. Fahy, and Piotr Obacz, they revisit the question of whether humanity might be on an equally dark path, destined for us. filter out of existence just as Sagan and others have expressed concern over the past few decades.

“The silence of the universe beyond Earth reveals a pattern of both human limitation and unwavering curiosity,” the authors write in their recent paper. “Although ambitious programs such as SETI aim to solve technological challenges, the results have so far proven to be void of any signs of life in the galaxy.

In their paper, the team goes on to propose how “existential catastrophe may lurk as our society moves exponentially toward space exploration”, which in this case would act as the “Great Filter”, the authors characterize “a phenomenon which annihilates civilizations before they can meet, which may explain the cosmic silence.

The authors offer several scenarios that describe how this could potentially happen, ranging from human-induced factors like nuclear wars or the creation of a form of artificial intelligence that could eradicate humanity, to natural events with potentially cataclysmic effects, such as an unstoppable asteroid impact.

Some of these problems, the authors concede, could be avoided through “reforms of individual, institutional, and intrinsic behaviors”, although they note that “each of these categories has diverse influences but lacks critical fit for each other.” adapt to their high risk”.

Basically, the authors argue that even if life on Earth were not entirely wiped out, the kinds of existential considerations they present in their paper could still significantly impede our technological progress, potentially setting humans back decades, if not centuries. depending on the scenario and its end.

The authors propose “a necessary period of introspection” as well as the adjustment of our collective worldviews and strategies for the future to help “respond to the challenges and methods in which we may be able to mitigate the risks to humanity and the nearly 9 million other species on Earth”. .”

The team’s new paper isn’t alone in asking such tough questions in recent years. In 2020, one of the study’s co-authors, Jonathan H. Jiang, also co-author of an article which examined the potential self-annihilation of complex life forms as a potential limiting factor in the search for intelligent extraterrestrial life. In this study, the team’s models found that such a scenario had been “the most influential parameter determining the amount and age of galactic intelligent life”.

In their recent paper, Jiang and his co-authors stress the need to recognize potential developments that could have such a “filtering” effect not just for intelligent extraterrestrial life on other worlds, but for life here on this one. this.

“To overcome these obstacles, both the individual and the institution must bring about awareness and, in turn, reform toward higher ideals,” the authors write. “Indeed, by striving to achieve far-reaching goals, we as a species can disentangle ourselves from historical issues.”

The team’s article, “Avoiding the ‘Great Filter’: Extraterrestrial Life and Humanity’s Future in the Universe”, was published on the arXiv preprint website and is currently awaiting peer review.

Micah Hanks is editor and co-founder of The Debrief. Follow his work on and on Twitter: @MicahHanks.

Sharon D. Cole