Ancient Clues, Hidden Histories
What if an advanced civilization lived on Earth millions of years ago, long before humans? Would we even know? The Silurian Hypothesis explores this mind-bending idea, questioning what clues such a civilization might leave behind.
What’s The Silurian Hypothesis?
The Silurian hypothesis is an idea that explores whether modern science could find proof of an advanced civilization that was present millions of years ago. The best evidence for such a civilization might come from things like carbon traces, radioactive materials, or temperature changes.
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It Starts With Exploring Ancient Civilization Evidence
Astrophysicists Adam Frank and Gavin Schmidt introduced the Silurian Hypothesis in a 2018 paper that discussed whether evidence of an advanced civilization before humans could be found in Earth's geological record. Here’s what they discovered.
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Fossils Dating Way Back
They suggested that enough fossil carbon has existed since the Carboniferous Period (about 350 million years ago) to support an industrial civilization. However, finding direct proof, like ancient technology, is unlikely because fossilization is rare. The primary issue is that geological processes (erosion, plate tectonics) erase evidence over time.
Subtle Clues Of Past Civilizations
Instead of direct proof, scientists might find clues like unusual sediment layers or traces of nuclear waste. The hypothesis also suggests that if an ancient civilization existed, its artifacts might still be on the Moon or Mars, where erosion and geological activity are much slower.
Speculation Shaping Scientific Inquiry
According to Frank and Schmidt, they highly doubt any industrial civilization existed before humans. Still, they believe exploring the idea helps raise important questions about astrobiology and the impact of human civilization on Earth's history.
Indirect Evidence Of Past Civilizations
Over long periods of time, the researchers concluded that humans would be more likely to find indirect clues rather than direct artifacts. These could include signs of geothermal energy use. Let’s understand more about the clues that can indicate an ancient civilization.
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First Stop, Chemical Traces
The chemical traces from artificial fertilizers or isotope anomalies can be great clues. For example, plutonium-244 doesn’t occur naturally on Earth except from a supernova, so finding it could suggest the presence of a past advanced civilization.
Los Alamos National Laboratory on Wikimedia
Second Stop, Buried Traces Of Past Technology
Possible evidence of past civilizations could also include plastics and nuclear waste buried deep underground or on the ocean floor. Frank and Schmidt also reference the natural nuclear reactors at Oklo, Gabon, which were active around two billion years ago.
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Nuclear Fission Occurred
Although the transuranic elements they produced have since decayed, scientists confirmed that nuclear fission had occurred by studying the depletion of uranium-235 and the unique isotope ratios of the fission byproducts. In the next slide, we will dive even deeper into this intriguing concept.
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Searching Beyond Earth For Clues
Frank and Schmidt suggest that if such a civilization existed, it might have traveled to space and left artifacts on the Moon or Mars. Finding evidence on these celestial bodies would be easier than on Earth, where erosion and tectonic activity could have wiped out most traces over time.
Third Stop, Climate Records
Frank initially reached out to Schmidt to explore how alien civilizations might be detected through their impact on climate with the use of ice cores and tree rings. They soon realized that the same idea could be applied to Earth’s own history.
No Clue, No Story
Since modern humans have existed for approximately 300,000 years but have only utilized advanced technology for a few centuries, the possibility of earlier civilizations having existed and leaving behind subtle traces has become an increasingly intriguing and thought-provoking question.
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Tracing Humanity's Future Footprint
The Silurian hypothesis helps us identify the kinds of traces our civilization would leave behind if we vanished, which is going to allow future researchers, millions of years from now, to detect evidence of our existence.
The Silurian Hypothesis Presents A Paradox
That paradox is that the more advanced and sustainable civilization is (using cleaner energy and efficient resource management), the less impact it leaves on the planet. However, this also means there would be fewer traces in the geological record, which makes it even harder to detect its existence.
But Plastics Are There As A Lasting Trace
The more plastic and long-lasting synthetic materials we create, the more likely future civilizations will find evidence of us. Today, we produce nearly 300 million tons of plastic annually, almost equal to the weight of the entire human population!
Radioactive Particles Would Also Prove Humanity’s Legacy
Even if human civilization were to disappear due to a nuclear catastrophe, radioactive particles would remain in the soil for millions of years. This would leave behind a clear sign that we once existed on Earth.
The Duo Needs Advanced Methods To Detect Past Civilizations
More importantly, there are gaps in our current scientific tools. As Frank explains, if an earlier species had only a brief period of industrial activity, our existing methods wouldn’t be able to detect it in ancient sediments.
This Calls For More Studies And New Techniques
According to him, to find evidence of a past civilization, scientists would need to conduct studies that haven’t been done before and develop new techniques. For example, they would have to analyze the rock record in much greater detail to detect subtle traces that current methods might miss.
You Miss It If You Aren’t Looking For It, Insinuates Frank
While Frank and Schmidt don’t actually believe an industrial civilization existed before ours. According to Frank, the key lesson of the Silurian hypothesis is that if you’re not actively looking for something, you might completely miss it.
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Ancient Civilizations In The Fiction Universe
The name "Silurian" comes from an intelligent species in the BBC sci-fi show Doctor Who. In the series, they built an advanced civilization before humans. However, the name is not related to the actual Silurian geological period.
The Silurian Solution | Warriors Of The Deep | Doctor Who by Doctor Who
Books And TV Shows
The idea of civilizations before humans has been featured in books like Inherit the Stars. The concept has also been entertained by TV shows like Quatermass and the Pit and Space: 1999. Many sci-fi stories have played with this idea—namely...
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The Green Marauder
In Larry Niven's 1980 short story The Green Marauder, an alien, over 700 million years old due to relativistic travel, recounts its last visit to Earth. It describes a desperate plea from an ancient anaerobic civilization, which was struggling to survive against the rising threat of chlorophyll-based life.
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Distant Origin
In the 1997 Star Trek: Voyager episode Distant Origin, the crew encounters the Voth, an advanced, spacefaring species that may have evolved from dinosaurs on Earth millions of years ago. Chakotay discusses this theory with a Voth scientist.
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Distant Origin (Cont.)
Chakotay speculates that their ancestors might have originated on an isolated continent that was eventually destroyed by a massive cataclysm, which left no visible evidence behind as it was buried beneath the ocean or deep underground.
