Astronomers Estimated the Lifespan of Alien Civilizations, and It’s Not Looking Good for Us

For decades, humans have scanned for signals of alien technology emanating through the galaxy. The search highlights the contradiction between the abundance of planets and stars that stretch across space and time and the lack of intelligent life, also known as the Fermi Paradox.

A team of physicists from Sharif University of Technology in Tehran, Iran, set out to resolve the juxtaposition between the high probability of alien civilizations and the complete lack of evidence that one exists. A recent study, available on the preprint website arXiv, examines a harsh reality: if we haven’t made contact with a technologically advanced civilization yet, that may be because intelligent life is short-lived. Indeed, the scientists behind the new paper, Sohrab Rahvar and Shahin Rouhani, estimate that advanced civilizations last no longer than roughly 5,000 years.

Where is everybody?

Physicist Enrico Fermi first proposed the question in 1950, suggesting that life is common throughout the universe and yet our search for extraterrestrial intelligence keeps turning up empty. The Fermi Paradox prompted several explanations for the lack of evidence: either space is too vast for alien signals to be detected, intelligent civilizations are intentionally shielding themselves from being found, or maybe we are all alone in the cosmos, among many other proposed resolutions to the paradox.

The new study came up with a different explanation. The authors used the Drake equation, a formula used to estimate the number of active extraterrestrial civilizations in the Milky Way, and paired it with the electromagnetic reach of our current technology. Today’s radio telescopes have the ability to listen to a region of space that covers nearly 100,000 years of the galaxy’s history (it takes about 100,000 years for light to travel across the galaxy). Therefore, our technology should have allowed us to detect any civilization that existed within that time period, according to the study.

The numbers indicate that technologically advanced civilizations last for around 5,000 years. That would explain why we have not detected radio signals from another planet; any advanced civilization that may have existed in the Milky Way either died out, or their short-lived stint in the cosmos hasn’t come up yet.

The clock is ticking

Earth has been an advanced civilization for around 300 years. Over the last 100 or so years, we’ve been capable of emitting technosignatures that could be detected by intelligent life on another planet. As our modern world continues to grow, our doom is also fast approaching, the new research would seem to suggest.

The authors of the new paper list a number of threats that could spell out destruction for advanced civilizations: a large asteroid impacting the planet, volcanic eruptions, climate change, pandemics, nuclear war, and artificial intelligence.

Although the study does not necessitate that civilizations must die out once they hit their 5,000-year mark, it suggests that it is highly unlikely that they last longer than this given timespan. Sooner or later, civilizations tend to bring about their own demise.