Previous technological civilizations?

[lpetrich]

Worse than Lovecraft: What if the Old Ones were real, but they’re all extinct? by PZ Myers

One of my commonly made arguments against the likelihood of finding extraterrestrial intelligence is that it seems to be remarkably rare on our planet ...

But what if I’m wrong? What if intelligent life had arisen on Earth multiple times? Would we be able to recognize it in the geological record?

...
I think I just gave myself nightmares. What if we launched a SATI (Search for Ancient Terrestrial Intelligence) program, found multiple instances, and learned that our peculiar niche is more common than we thought, and always leads to our decline and disappearance? Would that knowledge allow us to change, do better, and escape our doom, or would it tell us that any attempt would be futile?

noting
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.

Authors Gavin Schmidt and Adam Frank note a curious paradox. The longer that our industrialism lasts, the more that it will end up using sustainable practices, like renewable energy and recycling. These will reduce a civilization's garbage and emissions footprint.

They then get into what would be a good geological marker, and they decide on variations in isotope fractions. For instance, biological carbon is depleted in C-13 relative to C-12, and a big injection of biological carbon into the atmosphere makes its C-13 fraction go down.

Humanity's domestic animal and plant species would become well-represented, and also commensal and nuisance species like pigeons and rats.

We have produced a lot of synthetic organic compounds, including halogenated ones. Carbon-chlorine ones are stronger than carbon-carbon ones, meaning that halogenated organics could survive in sediments.

The discussion neglected what macroscopic artifacts could survive. On land, they would be vulnerable to erosion, but those on continental shelves and other sediment-receiving areas could preserve a variety of objects, especially ones that do not rot or corrode. Rock-like ones like bricks and cinderblocks and glass objects and ceramic objects could survive very well. Concrete may also survive fairly well, as may the less reactive metals like copper and silver and gold. The more reactive metals will likely corrode, though aluminum may be protected by what happens now: becoming covered by a thin layer of aluminum oxide. Iron, however, will produce big rust spots. Wood could get fossilized if its gets mineralized, in the fashion of petrified logs.

The authors then discussed events like the Paleocene–Eocene thermal maximum (PETM) oceanic anoxic events, and similar events. The PETM and similar events were big warming events, with lots of biological carbon released into the atmosphere as CO2 and CH4 and the like.

At least since the Carboniferous (300–350 Ma), there has been sufficient fossil carbon to fuel an industrial civilization comparable with our own and any of these sources could provide the light carbon input. However, in many cases this input is contemporaneous to significant episodes of tectonic and/or volcanic activity, for instance, the coincidence of crustal formation events with the climate changes suggest that the intrusion of basaltic magmas into organic-rich shales and/or petroleum-bearing evaporites (Storey et al., 2007; Svensen et al., 2009; Kravchinsky, 2012) may have released large quantities of CO2 or CH4 to the atmosphere. Impacts to warming and/or carbon influx (such as increased runoff, erosion, etc.) appear to be qualitatively similar whenever in the geological period they occur. These changes are thus not sufficient evidence for prior industrial civilizations.

The authors are rightly concerned that a previous-civilization hypothesis may be poorly defined.

We are aware that raising the possibility of a prior industrial civilization as a driver for events in the geological record might lead to rather unconstrained speculation. One would be able to fit any observations to an imagined civilization in ways that would be basically unfalsifiable. Thus, care must be taken not to postulate such a cause until actually positive evidence is available. The Silurian hypothesis cannot be regarded as likely merely because no other valid idea presents itself.

Finally, "We name the hypothesis after a 1970 episode of the British science fiction TV series Doctor Who where a long-buried race of intelligent reptiles ‘Silurians’ are awakened by an experimental nuclear reactor."

 

[lpetrich]

A New Study Suggests There Could Have Been Intelligent Life on Earth Before Humans - VICE - summarizes that article and introduces a science-fiction story based on it.

Under the Sun - VICE - "One of the world's leading climate scientists has written a work of fiction about his latest blockbuster paper—on the possibility that intelligent life may have preceded humans on Earth. "

I remember thinking of what would make UFO contactee George Adamski's accounts even halfway plausible given what we now know about the Solar System, and I decided that the best way to illustrate that would be to write some science-fiction stories based on it. Yes, Venus being superhot figures in it. Like this: "Hardly any of my fellow Venusians, however. When the Earthers discovered my homeworld's surface conditions, they were scared away," said Kalna, laughing.

Here's Gavin on why he decided to take a stab at exploring new scientific findings through fiction:

"This story comes from me thinking playfully about the what-if's that arise when you consider the Earth from an astrobiological standpoint. Work that I did in describing the very long term impact of the Anthropocene on the geology of the Earth lead directly to thinking about the potential causes of similarly abrupt changes in the past, or what fingerprints we might eventually look for on Mars, or even Venus—both of which were likely habitable early in Solar System history.

Wouldn't it be interesting if the first non-human civilizations we discover were not extra-terrestrials at all?"

PCB's found in rocks from the Paleocene-Eocene Thermal Maximum (PETM), about 55 million years ago when the average temperature went up about 8 C. Then transuranic-element nuclides. Then something very unsettling about one of them.

 

[Bronzeage]

In an infinite universe, anything is possible. The problem with with proposals like this is it quickly spins into a Hitchhiker's Guide to the Galaxy scenario.

I remember a Boy Scouts project where we were making a map of our camping reserve, using aerial photographs. Although the pictures were mostly tree tops, any man made object stuck out from the back ground. If there has been a previous technological civilization there would be some discernible remains, somewhere on the planet.

 

[Loren Pechtel]

A past intelligence would most certainly show up in the fossil record.

 

[lpetrich]

A past intelligence would most certainly show up in the fossil record.

How so? I'm not saying that it wouldn't. I want some reason to suppose that that would be the case.

Like where I state that I think that bricks and cinderblocks and glass objects and ceramic objects will survive.

 

[Cheerful Charlie]

A civilization so widespread and advanced it wiped itself out would leave lots of evidence in the fossil record. Things that do not decay over even millions of years. Ancient toilets, bricks, broken ceramic dishes. Lots of evidence of ancient open pit mining efforts. Gold objects. Remnants of concrete roadways. Ancient trash dumps. And fossils of some creatures with big brains and opposable thumbs that could have lead up to such a species. And a thousand and one further similar objections.

This is as dumb an idea that has ever been proposed.

 

[skepticalbip]

The 'theory' seems to be awfully anthropocentric. It makes the assumption that any intelligent life would have to mimic human technical achievements. I can easily imagine an intelligent species that focused on philosophy rather than technology. Assuming that their farming and animal husbandry focused on 'working with nature', their buildings were only of wood then no or very little sign of them would remain after a few tens of thousands of years. Such an intelligent species could have lived much like the ancient Greeks (or even greatly exceeded the Greeks in their philosophies) minus the stone monuments and metal tools and weapons.

 

[Gun Nut]

In an infinite universe, anything is possible everything is certain.

there. that's better.

 

[Bronzeage]

A past intelligence would most certainly show up in the fossil record.

How so? I'm not saying that it wouldn't. I want some reason to suppose that that would be the case.

Like where I state that I think that bricks and cinderblocks and glass objects and ceramic objects will survive.

We have plenty of evidence of civilizations which existed before use of metal became a thing, and all they left behind were mud bricks and stacked stones.

Nature abhors a vacuum and straight lines. While finding a vacuum is interesting, anytime you find a straight line in nature, it's a good sign someone has been there before you.

In an infinite universe, anything is possible everything is certain.

there. that's better.

On the planet Sqornshellous Zeta. mattresses grow wild in marshes. The discovery of this led to a Galaxy wide economic depression when it was realized in an infinite universe, anything that could be manufactured also grew wild, somewhere. Investment in manufacturing screeched to a halt for fear any factory could be bankrupted by discovery of a tanning booth planet.

 

[Sarpedon]

Didn't we have this thread before?

I made the same points as the authors last time around: Industrial societies can create products (and wastes) that last far beyond that of natural materials. Our waste will be here long after we are gone. The idea that could have happened on earth before and left no trace is implausible.

 

[Loren Pechtel]

A past intelligence would most certainly show up in the fossil record.

How so? I'm not saying that it wouldn't. I want some reason to suppose that that would be the case.

Like where I state that I think that bricks and cinderblocks and glass objects and ceramic objects will survive.

If nothing else, brain capacity. (Not proof of intelligence, but it's lack is proof of a lack of intelligence.) Also, where's the branch they evolved from?

 

[Loren Pechtel]

Nature abhors a vacuum and straight lines. While finding a vacuum is interesting, anytime you find a straight line in nature, it's a good sign someone has been there before you.

Except when some crystalline process is involved. Such things are always fairly small scale, though.

Reminds me of the Florida Man I encountered out on the trails last spring. He was determined to summit the local highest mountain before going home--but kept being blocked by snow. He pulled out his paper map (he didn't have electronic maps of any kind) and asked me about the third trail the map showed, would it be more accessible? Hey, we are about 4 miles in (assuming he took the shortest route) and half a mile above the trailhead. You don't get far out there without encountering switchbacks. You think there's an arrow-straight trail around?? (His "trail" was a boundary line of the ski resort.) It was several weeks before the peak was accessible to hikers!

 

[Bronzeage]

Nature abhors a vacuum and straight lines. While finding a vacuum is interesting, anytime you find a straight line in nature, it's a good sign someone has been there before you.

Except when some crystalline process is involved. Such things are always fairly small scale, though.

Reminds me of the Florida Man I encountered out on the trails last spring. He was determined to summit the local highest mountain before going home--but kept being blocked by snow. He pulled out his paper map (he didn't have electronic maps of any kind) and asked me about the third trail the map showed, would it be more accessible? Hey, we are about 4 miles in (assuming he took the shortest route) and half a mile above the trailhead. You don't get far out there without encountering switchbacks. You think there's an arrow-straight trail around?? (His "trail" was a boundary line of the ski resort.) It was several weeks before the peak was accessible to hikers!

In Florida, the highest peak is a fireant mound.

 

[steve_bank]

There are cable shows on this topic.

There is an old claim that an artifact from the ancient world was actually a battery.

The Star Gate TV shows had an ancient space faring civilization as the origin of us humans as the premise.

 

[Jimmy Higgins]

I work in a field that is entirely underground and unseen. The question is, could resource acquisition and infrastructure been created without leaving any trace. Hundreds of millions of years is a long time. But one would have to think that within the Devonian and post Devonian rock, there would be debris found.

 

[steve_bank]

The latest show I watched said there is archaeological evidence f organized cultures with technology like civil engineering and construction much older than previously thought, but nothing about a technological civilization.

Ancient fire pits with piles of animal bones have been found. We have a fossil record of evolution.
We know something about Neanderthals, but there is zero evidence o four kind of technology.

 

[Bronzeage]

The latest show I watched said there is archaeological evidence f organized cultures with technology like civil engineering and construction much older than previously thought, but nothing about a technological civilization.

Ancient fire pits with piles of animal bones have been found. We have a fossil record of evolution.
We know something about Neanderthals, but there is zero evidence o four kind of technology.

The fire pit is the hole in this silly idea. Advanced civilizations are built on metallurgy and even on a small scale, this requires a lot of energy in the form of fuel. Any fuel more powerful than charcoal requires a technology that scars the landscape on a geological scale. In the thousand years (give or take) we've never opened a coal deposit and found someone beat us to it.

 

[lpetrich]

Yes, no evidence of mineshafts or strip mining. No evidence of mining tools or mining machines or mining vehicles or mining infrastructure or mining camps.

Also, no evidence of drilling or extraction of liquids, like drilled holes with rusted pipes in them.

 

[Jokodo]

Yes, no evidence of mineshafts or strip mining. No evidence of mining tools or mining machines or mining vehicles or mining infrastructure or mining camps.

Also, no evidence of drilling or extraction of liquids, like drilled holes with rusted pipes in them.

How long before a rusted pipe becomes just an area of rock with slightly heightened iron oxide content?

 

[steve_bank]

The latest show I watched said there is archaeological evidence f organized cultures with technology like civil engineering and construction much older than previously thought, but nothing about a technological civilization.

Ancient fire pits with piles of animal bones have been found. We have a fossil record of evolution.
We know something about Neanderthals, but there is zero evidence o four kind of technology.

The fire pit is the hole in this silly idea. Advanced civilizations are built on metallurgy and even on a small scale, this requires a lot of energy in the form of fuel. Any fuel more powerful than charcoal requires a technology that scars the landscape on a geological scale. In the thousand years (give or take) we've never opened a coal deposit and found someone beat us to it.

Unless thy had lien technology that did not require the stuff e have today...or so cable TV shows say..