(ORDO NEWS) — If a technologically advanced civilization had existed on Earth before us, it might have left some kind of trace.
An article published in the Journal of Astrobiology proposes an interesting hypothetical question about whether it would be possible to find “geological footprints” of a past civilization that lived and died millions of years ago.
In 2018, two scientists from the University of Cambridge conducted a study titled “The Silurian Hypothesis: Is it Possible to Detect an Industrial Civilization in the Geological Record?”.
“One of the key questions in assessing the likelihood of finding such a civilization is understanding how often, given that life has arisen and that some species are intelligent, does an industrial civilization develop?” – write in the media.
“Humans are the only example we know of, and our industrial civilization has lasted (so far) for about 300 years (since, for example, mass production methods began). This is a small fraction of the time we have existed as a species, and a tiny fraction of the time that complex life has existed on Earth’s land surface.”
“This short amount of time raises the obvious question of whether it could have happened before.”
In addition to being an interesting hypothesis to think about, finding the answer to this question can also help us look for signs of advanced civilizations on exoplanets.
As noted in the study, humans have left visible footprints on the planet that will undoubtedly persist for many years, influencing the planet’s climate and ecosystem.
However, this does not mean that these changes will be noticeable in millions of years. In fact, the record we leave, for example, is in sedimentary rocks that can be only a few centimeters thick.
“The longer human civilization has been around, the more signal one would expect in the recording,” the researchers write. “However, the longer a civilization exists, the more sustainable its practices would have to become in order to survive.
The more sustainable a society is (for example, in energy generation, manufacturing or agriculture), the less its impact on the rest of the planet. But the smaller the footprint, the less signal will be reflected in the geological record.”
The team is discussing other markers that we might have left for the species millions of years from now (or that may have been left for us).
Some of them will be indistinguishable from natural phenomena, such as anoxic phenomena in the Cretaceous and Jurassic oceans, but others will be clear signs that we have been here and we have completely destroyed this place.
“We hypothesize that there are some specific indicators that would be unique, in particular persistent synthetic molecules, plastics, and (potentially) very long-lived radioactive fallout in the event of a nuclear catastrophe,” the scientists write.
“In the absence of these markers, the uniqueness of an event may well be seen in a multitude of relatively independent fingerprints, as opposed to a consistent set of changes associated with a single geophysical cause.”
The team does not provide a definitive answer in the paper, but suggests that if other ancient evolved species were found, they would have been discovered by studying elemental and compositional anomalies in the sediments.
“While we strongly doubt that any previous industrial civilization existed before ours, the formal framing of the question, which clearly articulates what the evidence for such a civilization might look like, raises its own useful questions related to both astrobiology and Anthropocene research. “, they conclude.
“We hope that this article will serve as motivation to improve the constraints of the hypothesis so that we can better answer our main question in the future.”
Contact us: [email protected]