Galaxy is likely full of dead civilizations, study says

Galaxy is likely full of dead civilizations, study says


Astronomers suggest that many extraterrestrial civilizations have already arisen in our galaxy during its history. On the other hand, they also argue that most have probably already disappeared.

Proposed in 1961 by Dr. Frank Drake, the Drake Equation is a formula for estimating the potential number of extraterrestrial civilizations in our galaxy. The equation takes several factors into consideration: the number of stars that form annually in our galaxy, the share of stars with planets, or the expected number of potentially life-sustaining planets per star. It also takes into account the part of these planets where life actually appears, the part of these planets where intelligent life appears and the part of these planets capable and willing to communicate. Finally, the equation considers the average lifespan of a civilization (in years).

The problem, however, is that at the time of thinking this equation, none of these factors were actually known for sure. So, taking into account this degree of uncertainty, the Drake equation estimated that between one and one hundred million the number of technological civilizations developed in the Milky Way. In other words, the fork was huge.

In a recent article, physicists from Caltech, Calif., Roughly updated this equation using modern astronomical data and statistical modeling. “We have learned a lot, notably thanks to the Hubble and Kepler telescopes, on the densities [of gas and stars] in the Milky Way, on the rate of star formation and exoplanets or on the rate of occurrence. supernova explosions, ”says Jonathan H. Jiang, co-author of the study.

Late humans

In their work, the authors considered several factors that could influence the development of intelligent life in the galaxy, such as the prevalence of Sun-like stars harboring Earth-like planets, the frequency of deadly supernovae and explosive, the probability and time needed for intelligent life to evolve if the conditions are right and the possible tendency of advanced civilizations to self-destruct.

By modeling the evolution of the Milky Way over time and considering all of these factors, the researchers found that the probability of emergence of life peaked at around 13,000 light years from the galactic center and eight billion years ago. after its formation of the galaxy. By comparison, Earth is about 25,000 light years from the galactic center, and human civilization did not appear on the planet’s surface until about 13.5 billion years after the formation of the Milky Way (although simple life appeared shortly after the formation of the planet).

In other words, we are probably a “frontier civilization” in terms of galactic geography, but also laggards compared to other “conscious inhabitants” of the Milky Way.

Many have already destroyed themselves

The authors also estimate that while the galaxy reached its “civilizational peak” more than five billion years ago, most of the civilizations that existed at the time have probably already self-annihilated due to scientific and technological progress in the past. origin of climate change or wars.

However, the authors do not exclude the idea that there may still exist advanced civilizations in the galaxy. If so, they point out, on the other hand, that these are probably young, like ours, due to the fact that intelligent life is likely to develop over long periods of time.