The Silurian hypothesis

[Dutch Uncle]

Modern human beings, Homo sapiens sapiens, have been around for about 300,000 years. Although fossils have been found, no records of civilizations older than about 10,000 years have been found. While it's possible human beings just lived in primitive tribes for 290,000 years, considering the advancements humans have made in the last 6,000 years, it's also possible that humans advanced to modern levels before being knocked back to the stone age. Hence, the Silurian hypothesis of looking for evidence of such advancements even further back than 300,000 years.

An Evolutionary Timeline of Homo Sapiens

Scientists share the findings that helped them pinpoint key moments in the rise of our species

www.smithsonianmag.com

Our ancestors used stone tools as long as 3.3 million years ago and by 1.75 million years ago they’d adopted the Acheulean culture, a suite of chunky handaxes and other cutting implements that remained in vogue for nearly 1.5 million years. As recently as 400,000 years ago, thrusting spears used during the hunt of large prey in what is now Germany were state of the art. But they could only be used up close, an obvious and sometimes dangerous limitation.

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? | International Journal of Astrobiology | Cambridge Core

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? - Volume 18 Issue 2

www.cambridge.org

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record?​

If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.

 

[AProudLefty]

 

[Dutch Uncle]

View attachment 34250

What if we're the aliens?

 

[AProudLefty]

What if we're the aliens?

That would explain a lot.

 

[Cypress]

What if we're the aliens?

A bold hypothesis. But I'm skeptical.

We now have a very good record of atmospheric gases going back 800k years, and I would think there would be isotopic anomalies in our atmospheric
gas samples if there had been periods of extensive industrialization.

Our DNA is a genetically related to all life on earth, and can be traced back to a last universal common ancestor four billion years ago. So I don't think it's plausible we are a recent arrival from an alien world.

 

[Dutch Uncle]

A bold hypothesis. But I'm skeptical.

We now have a very good record of atmospheric gases going back 800k years, and I would think there would be isotopic anomalies in our atmospheric
gas samples if there had been periods of extensive industrialization.

Our DNA is a genetically related to all life on earth, and can be traced back to a last universal common ancestor four billion years ago. So I don't think it's plausible we are a recent arrival from an alien world.

Agreed on skepticism.

Beyond my expertise, but that's assuming such a civilization used our type of tech. What if they used biotech and avoided fossil fuels or other polluting technology? Of course, that would become a problem in trying to detect such civilization.

Life could be the alien.

 

[Cypress]

Agreed on skepticism.

Beyond my expertise, but that's assuming such a civilization used our type of tech. What if they used biotech and avoided fossil fuels or other polluting technology? Of course, that would become a problem in trying to detect such civilization.

Life could be the alien.

Anything that involves widespread burning/combustion of plant matter, whether through coal or petroleum, or through deforestation is going to leave a chemical footprint in the atmospheric carbon isotopes.


Agreed, ancient life here could have been seeded by amino acids found in meteorites.

 

[Dutch Uncle]

Anything that involves burning plant matter, whether through coal or petroleum, or through deforestation is going to leave a chemical footprint in the atmospheric carbon isotopes.


Agreed, life here could have been seeded by amino acids found in meteorites.

Agreed. Again, what about a civilization that lives in harmony with the biosphere instead of seeking to exploit and dominate it? The Bible states man was given dominion over the Earth, but that doesn't mean permission to shit all over it and exploit it.

Agreed on the theory but that still leaves the question of how life began from those amino acids. Especially since we haven't found life elsewhere...so far.

 

[Cypress]

Agreed. Again, what about a civilization that lives in harmony with the biosphere instead of seeking to exploit and dominate it? The Bible states man was given dominion over the Earth, but that doesn't mean permission to shit all over it and exploit it.

Agreed on the theory but that still leaves the question of how life began from those amino acids. Especially since we haven't found life elsewhere...so far.

Hard to understand how we can find stone tool relics in the Pleistocene archeological record, but not extinct cities and advanced civilizations.

Agreed, it is a long, long way from amino acids to proteins, DNA, and cellular biology. How life was able to come from non-life is a mystery.

 

[Dutch Uncle]

Hard to understand how we can find stone tool relics in the Pleistocene archeological record, but not extinct cities and advanced civilizations.

Agreed, it is a long, long way from amino acids to proteins, DNA, and cellular biology. How life was able to come from non-life is a mystery.

One thought is that during periods of maximum glaciation, not only would they have rolled over and crushed cities underneath the ice sheets, but the sea levels would have dropped up to 410' (125m). Since humans habitually build along coasts, cities and villages existing on the coast then would be over 400 feet underwater now. Perhaps more underwater mapping of ancient coastlines would be more revealing.

Rapid glaciation and a two-step sea level plunge into the Last Glacial Maximum - Nature

Details of the drops in sea level associated with glaciation during the Last Glacial Maximum are revealed using a coral proxy from the Great Barrier Reef.

www.nature.com

 

[Cypress]

One thought is that during periods of maximum glaciation, not only would they have rolled over and crushed cities underneath the ice sheets, but the sea levels would have dropped up to 410' (125m). Since humans habitually build along coasts, cities and villages existing on the coast then would be over 400 feet underwater now. Perhaps more underwater mapping of ancient coastlines would be more revealing.

Rapid glaciation and a two-step sea level plunge into the Last Glacial Maximum - Nature

Details of the drops in sea level associated with glaciation during the Last Glacial Maximum are revealed using a coral proxy from the Great Barrier Reef.

www.nature.com

A good point.

Humans also build cities along or near to navigable rivers, well inland from any ocean, aka the Assyrian Empire, the Hittite Empire, the Zhou dynasty. I would think an advanced coastal civilization would figure out how to move its cities and populations inland during times of rising sea levels.

The point you make is a good one though, there is still a lot of archeology buried under 200 feet of seawater.

 

[Dutch Uncle]

A good point.

Humans also build cities along or near to navigable rivers, well inland from any ocean, aka the Assyrian Empire, the Hittite Empire, the Zhou dynasty. I would think an advanced coastal civilization would figure out how to move its cities and populations inland during times of rising sea levels.

The point you make is a good one though, there is still a lot of archeology buried under 200 feet of seawater.

True, but that's if given time. If they suffered a collapse worse than the collapse of the Bronze Age, they wouldn't have time or the organization to move cities. Plague and famine would prevent such efforts and then time would have buried what was left.

If I read the Silurian Hypothesis correctly, we're not talking Homo sapiens but some other intelligent race that existed millions of years ago. The thought experiment is to ask the question "Would we be able to detect such a civilization?" Climate changes and different types of civilizations would be obstacles to such detections.

 

[Cypress]

True, but that's if given time. If they suffered a collapse worse than the collapse of the Bronze Age, they wouldn't have time or the organization to move cities. Plague and famine would prevent such efforts and then time would have buried what was left.

If I read the Silurian Hypothesis correctly, we're not talking Homo sapiens but some other intelligent race that existed millions of years ago. The thought experiment is to ask the question "Would we be able to detect such a civilization?" Climate changes and different types of civilizations would be obstacles to such detections.

I get what you are saying, but it seems a little too convenient to invent a list of reasons for why we haven't found their fossils, found their archeological footprint, found their cities.

If we push the timeline back millions of years into the Pliocene and Miocene epochs, the Earth was warmer then and I don't think it had the sustained ice ages of the Pleistocene. So the archeological remains of an unknown hominid should be under 200 feet of sea water.

I agree that it is fine to say that there is a lot we don't know about Earth's geologic past.

 

[Dutch Uncle]

I get what you are saying, but it seems a little too convenient to invent a list of reasons for why we haven't found their fossils, found their archeological footprint, found their cities.

If we push the timeline back millions of years into the Pliocene and Miocene epochs, the Earth was warmer then and I don't think it had the sustained ice ages of the Pleistocene. So the archeological remains of an unknown hominid should be under 200 feet of sea water.

I agree that it is fine to say that there is a lot we don't know about Earth's geologic past.

The same for inventing a list of reasons why Fermi's Paradox exists. If life is so ubiquitous then why is it only found on Earth? I'm not buying the "Because Jesus only wanted life on Earth" excuse.

Again, the Silurian Hypothesis is a thought experiment about how we could detect such a civilization even if it had existed.

Could an Industrial Prehuman Civilization Have Existed on Earth before Ours?

A provocative new paper suggests some ways to find out

www.scientificamerican.com

One of the creepier conclusions drawn by scientists studying the Anthropocene—the proposed epoch of Earth’s geologic history in which humankind’s activities dominate the globe—is how closely today’s industrially induced climate change resembles conditions seen in past periods of rapid temperature rise.

“These ‘hyperthermals,’ the thermal-maximum events of prehistory, are the genesis of this research,” says Gavin Schmidt, climate modeler and director of the NASA Goddard Institute for Space Studies. “Whether the warming was caused by humans or by natural forces, the fingerprints—the chemical signals and tracers that give evidence of what happened then—look very similar.”

The canonical example of a hyperthermal is the Paleocene-Eocene Thermal Maximum (PETM), a 200,000-year period that occurred some 55.5 million years ago when global average temperatures rose by five to eight degrees Celsius (nine to 14 degrees Fahrenheit)....

....Frank came to his office to discuss the idea of studying global warming from an “astrobiological perspective”—that is, investigating whether the rise of an alien industrial civilization on an exoplanet might necessarily trigger climate changes similar to those we see during Earth’s own Anthropocene. But almost before Frank could describe how one might search for the climatic effects of industrial “exocivilizations” on newly discovered planets, Schmidt caught him up short with a surprising question: “How do you know we’re the only time there’s been a civilization on our own planet?“

 

[Cypress]

The same for inventing a list of reasons why Fermi's Paradox exists. If life is so ubiquitous then why is it only found on Earth? I'm not buying the "Because Jesus only wanted life on Earth" excuse.

Again, the Silurian Hypothesis is a thought experiment about how we could detect such a civilization even if it had existed.

Could an Industrial Prehuman Civilization Have Existed on Earth before Ours?

A provocative new paper suggests some ways to find out

www.scientificamerican.com

One of the creepier conclusions drawn by scientists studying the Anthropocene—the proposed epoch of Earth’s geologic history in which humankind’s activities dominate the globe—is how closely today’s industrially induced climate change resembles conditions seen in past periods of rapid temperature rise.

“These ‘hyperthermals,’ the thermal-maximum events of prehistory, are the genesis of this research,” says Gavin Schmidt, climate modeler and director of the NASA Goddard Institute for Space Studies. “Whether the warming was caused by humans or by natural forces, the fingerprints—the chemical signals and tracers that give evidence of what happened then—look very similar.”

The canonical example of a hyperthermal is the Paleocene-Eocene Thermal Maximum (PETM), a 200,000-year period that occurred some 55.5 million years ago when global average temperatures rose by five to eight degrees Celsius (nine to 14 degrees Fahrenheit)....

....Frank came to his office to discuss the idea of studying global warming from an “astrobiological perspective”—that is, investigating whether the rise of an alien industrial civilization on an exoplanet might necessarily trigger climate changes similar to those we see during Earth’s own Anthropocene. But almost before Frank could describe how one might search for the climatic effects of industrial “exocivilizations” on newly discovered planets, Schmidt caught him up short with a surprising question: “How do you know we’re the only time there’s been a civilization on our own planet?“

Shakespeare wrote: "There are more things in Heaven and Earth Horatio, than are dreamt of in your philosophies."

I think you are right to be skeptical of the reach of our knowledge.

 

[Dutch Uncle]

Shakespeare wrote: "There are more things in Heaven and Earth Horatio, than are dreamt of in your philosophies."

I think you are right to be skeptical of the reach of our knowledge.

Given the lengths of time involved, it's difficult to be certain about the history of advanced life on our own planet much less that of exoplanets.

Example: https://useruploads.socratic.org/l3S6oXWKSwihGmsSnaj4_earth_history.jpg

 

[goat]

Modern human beings, Homo sapiens sapiens, have been around for about 300,000 years. Although fossils have been found, no records of civilizations older than about 10,000 years have been found. While it's possible human beings just lived in primitive tribes for 290,000 years, considering the advancements humans have made in the last 6,000 years, it's also possible that humans advanced to modern levels before being knocked back to the stone age. Hence, the Silurian hypothesis of looking for evidence of such advancements even further back than 300,000 years.

An Evolutionary Timeline of Homo Sapiens

Scientists share the findings that helped them pinpoint key moments in the rise of our species

www.smithsonianmag.com

Our ancestors used stone tools as long as 3.3 million years ago and by 1.75 million years ago they’d adopted the Acheulean culture, a suite of chunky handaxes and other cutting implements that remained in vogue for nearly 1.5 million years. As recently as 400,000 years ago, thrusting spears used during the hunt of large prey in what is now Germany were state of the art. But they could only be used up close, an obvious and sometimes dangerous limitation.

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? | International Journal of Astrobiology | Cambridge Core

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? - Volume 18 Issue 2

www.cambridge.org

The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record?​

If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.

Bro, shouldn't this be in conspiracy theories?

 

[Hawkeye10]

Bro, shouldn't this be in conspiracy theories?

I am pretty sure I saw where the whole Big Bang story is almost certainly not true.

 

[goat]

I am pretty sure I saw where the whole Big Bang story is almost certainly not true.

Neanderthal date back at least 300,000 years but they weren't building anything abstract.

 

[Hawkeye10]

Neanderthal date back at least 300,000 years but they weren't building anything abstract.

All these claims should be something like "This is the current best guess, we might very well have a different guess around next week".