A new, Silurian hypothesis examines the possibility of the existence of another technologically advanced civilization in the distant past of the planet.
If on Earth once upon a time there really was another technologically advanced civilization of intelligent animals, then in tens of millions of years all direct evidence should have disappeared. The continents have changed, the ocean floor has been renewed, but traces may have survived in ancient geological rocks. And while there is no evidence yet, University of Rochester professor Adam Frank and his NASA colleague Gavin Schmidt suggest taking a closer look.
In an article published in the International Journal of Astrobiology, scientists set up a curious thought experiment. Indeed, the paradox of the absence of any evidence of the existence of another intelligent civilization in the Universe can be explained by a variety of reasons. Life on the planet may simply not arise, not develop to complex forms, not reach the level of intelligent beings - and if this did happen, civilization simply may not exist long enough, disappearing as a result of a global nuclear war, climatic or other catastrophe. After all, our own technogenic culture is several hundred years old, but nothing guarantees that it will last even as long.
In this regard, Frank and Schmidt raise the question of what kind of trace humanity can leave on geological time scales - tens and hundreds of millions of years. “Gavin and I did not find any traces of other industrialized civilizations,” emphasized Adam Frank. Their Silurian Hypothesis, named after a mythical ancient land, proved to be a highly instructive thought experiment.
Today we have entered an era that many experts confidently call the "Anthropocene" - a period when human activity has a significant impact on the entire planet, changing its lithosphere, atmosphere, ocean. This era is characterized by the massive use of fossil fuels and nuclear energy. The authors highlight other aspects, traces of which could persist for an indefinitely long time: global warming and large-scale use of fertilizers, erosion as a result of agricultural activities, the accumulation of plastic pollution.
Separately, scientists pay attention to the period of the Paleocene-Eocene thermal maximum, which happened shortly after the extinction of the flightless dinosaurs. "Soon" - by geological standards: these events are separated by about five million years, during which time on Earth (theoretically) civilization could well have developed and died. The abnormal rise in temperature of that era, in principle, could be the result of the activities of a developed civilization, all traces of which have been erased over the next tens of millions of years. And although there is no evidence of this after all, the Silurian Hypothesis forces us to take a fresh look at the chances of finding intelligent beings on other planets - and at the fragility of our own world.