Have there been other civilizations on Earth? Who could have preceded humans?

 The so-called Silurian hypothesis suggests that millions of years ago on Earth there may have been a civilization (not necessarily human) capable of transforming the world, which was destroyed in some cataclysm. Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, and astrophysicist Adam Frank of the University of Rochester base their theories on a phenomenon known as the "Paleocene-Eocene thermal maximum."

This dramatic climate change marks the end of the Paleocene and the beginning of the Eocene. It occurred about 56 million years ago and may have been artificially induced. At that time, the average temperature of the Earth was 15 degrees higher than today. There was virtually no ice on the entire surface of the Earth, and the climate at the poles was almost tropical.

This is all the more interesting because geological research shows that in the centuries preceding this period, there was a sharp increase in carbon dioxide emissions, comparable to what researchers expect after the Anthropocene - the geological epoch of humanity that will replace the current Holocene. Do these events prove the existence of an inhuman industrial civilization?

The Silurian Hypothesis is not a widely accepted scientific theory, but rather a thought experiment that has been proposed as a way to explore potential scenarios for the development of life on our planet. There is little empirical evidence for or against this hypothesis. If this extinct civilization really existed, it is quite possible that no trace of it remains. Keep in mind that most fossils found date back thousands or hundreds of thousands of years, not millions. It is possible that the remains of hypothetical factories and buildings from that time are just dust today.

As the researchers note, an industrial civilization that lived 100,000 years, or 500 times longer than ours, would leave absolutely nothing behind. The search for evidence of such civilizations would require new and specialized detection methods. Let's not forget that complex life on Earth emerged relatively quickly geologically.

This could mean that intelligent living organisms could be a much more common occurrence on our planet. Proponents of this hypothesis also point to the fact that many of the conditions necessary for the evolution of advanced life, such as a stable climate and plate tectonics, have existed on Earth for billions of years.

One of the main challenges to support this hypothesis is the complete lack of physical evidence to support the existence of an earlier technological civilization. There is no known archaeological or geological evidence to indicate the presence of such a civilization. It is worth noting here, however, that many of the traces of human activity we see today, such as buildings, are relatively short-lived geologically.

Another challenge to the Silurian hypothesis is that the evolution of complex life on Earth was not a straight line, but was characterized by numerous extinctions and periods of relative stagnation. It is possible that the emergence of advanced life on Earth was a relatively rare and unlikely event, and the existence of an earlier civilization is even less likely.

While the Silurian hypothesis is an interesting and thought-provoking idea, there is currently no conclusive evidence for or against the possibility of an earlier technological civilization on Earth. The hypothesis remains a subject of debate and speculation in the scientific community.