Scientists have proved the possibility of the existence of extinct intelligent beings
Climatologist Gavin Schmidt of the Goddard Institute for NASA Space Studies and astrophysicist Adam Frank from the University of Rochester put forward a "Silurian hypothesis" according to which the ancient developed civilizations of the Earth had to leave traces of their stay on the planet. The article was published in the International Journal of Astrobiology.
The researchers named their hypothesis in honor of the Silurians - intelligent reptiles from the British science fiction series "Doctor Who", which in the story were the first developed beings on Earth.
Scientists did not try to provide an accurate proof of the existence of other intelligent forms of life before humanity, but only show that there is such an opportunity. The "Silurian hypothesis" is a mental experiment that should help answer the question whether it is possible to find evidence of the existence of developed civilizations that died millions or billions of years ago.
According to Schmidt and Frank, humanity came into the anthropocene era, when the biosphere has a significant impact on the part of civilization. Thus, people's activities are "recorded" in geological sediments, and these tracks can be found and studied by researchers of the distant future.
However, in this case, according to scientists, there is a paradox. Civilization, which can exist for a long time, should create a sustainable economy that will not overload the natural ecosystems. On the contrary, a noticeable geological trace can be left by those civilizations that quickly reached a peak in development and declined due to depletion of resources and global changes in the biosphere.
Thus, the "Silurian hypothesis" suggests that geological traces, such as those that humanity is leaving now, could be found, since it is far from entering the path of sustainable development. Such testimonies include, for example, mass extinction of animals, plastic debris, synthetic contaminants and steroids that can persist for millions of years, and variations in the ratio of different isotopes indicating an increase in the concentration of atmospheric carbon from the combustion of fossil fuels.
At the same time, the creation of synthetic substances can not be regarded as a common sign of all intelligent civilizations. The remaining traces can be explained by natural causes, such as increased volcanic activity and other tectonic processes, the fall of the asteroid or fluctuations in the global carbon cycle. Therefore, scientists come to the conclusion that to detect traces, if they are, can only be more thorough studies than those conducted so far.