We think we're the first advanced earthlings—but how do we really know?

April 16, 2018, University of Rochester
How do we really know there weren't previous industrial civilizations on Earth that rose and fell long before human beings appeared? That's the question posed in a scientific thought experiment by University of Rochester astrophysicist Adam Frank. Credit: University of Rochester illustration/Michael Osadciw

Imagine if, many millions of years ago, dinosaurs drove cars through cities of mile-high buildings. A preposterous idea, right? Over the course of tens of millions of years, however, all of the direct evidence of a civilization—its artifacts and remains—gets ground to dust. How do we really know, then, that there weren't previous industrial civilizations on Earth that rose and fell long before human beings appeared?

It's a compelling thought experiment, and one that Adam Frank, a professor of physics and astronomy at the University of Rochester, and Gavin Schmidt, the director of the NASA Goddard Institute for Space Studies, take up in a paper published in the International Journal of Astrobiology.

"Gavin and I have not seen any evidence of another industrial civilization," Frank explains. But by looking at the deep past in the right way, a new set of questions about civilizations and the planet appear: What geological footprints do civilizations leave? Is it possible to detect an industrial civilization in the geological record once it disappears from the face of its host planet? "These questions make us think about the future and the past in a much different way, including how any planetary-scale civilization might rise and fall."

In what they deem the "Silurian Hypothesis," Frank and Schmidt define a civilization by its energy use. Human beings are just entering a new geological era that many researchers refer to as the Anthropocene, the period in which human activity strongly influences the climate and environment. In the Anthropocene, fossil fuels have become central to the geological footprint humans will leave behind on Earth. By looking at the Anthropocene's imprint, Schmidt and Frank examine what kinds of clues future scientists might detect to determine that human beings existed. In doing so, they also lay out evidence of what might be left behind if industrial civilizations like ours existed millions of years in the past.

Human beings began burning fossil fuels more than 300 years ago, marking the beginnings of industrialization. The researchers note that the emission of fossil fuels into the atmosphere has already changed the carbon cycle in a way that is recorded in carbon isotope records. Other ways human beings might leave behind a geological footprint include:

  • Global warming, from the release of carbon dioxide and perturbations to the nitrogen cycle from fertilizers
  • Agriculture, through greatly increased erosion and sedimentation rates
  • Plastics, synthetic pollutants, and even things such as steroids, which will be geochemically detectable for millions, and perhaps even billions, of years
  • Nuclear war, if it happened, which would leave behind unusual radioactive isotopes

"As an industrial civilization, we're driving changes in the isotopic abundances because we're burning carbon," Frank says. "But burning fossil fuels may actually shut us down as a civilization. What imprints would this or other kinds of industrial activity from a long dead civilization leave over tens of millions of years?"

The questions raised by Frank and Schmidt are part of a broader effort to address climate change from an astrobiological perspective, and a new way of thinking about life and civilizations across the universe. Looking at the rise and fall of civilizations in terms of their planetary impacts can also affect how researchers approach future explorations of other planets.

"We know early Mars and, perhaps, early Venus were more habitable than they are now, and conceivably we will one day drill through the geological sediments there, too," Schmidt says. "This helps us think about what we should be looking for."

Schmidt points to an irony, however: if a civilization is able to find a more sustainable way to produce energy without harming its host planet, it will leave behind less evidence that it was there.

"You want to have a nice, large-scale civilization that does wonderful things but that doesn't push the planet into domains that are dangerous for itself, the civilization," Frank says. "We need to figure out a way of producing and using energy that doesn't put us at risk."

That said, the earth will be just fine, Frank says. It's more a question of whether humans will be.

Can we create a version of that doesn't push the earth into a domain that's dangerous for us as a species?

"The point is not to 'save the earth,'" says Frank. "No matter what we do to the planet, we're just creating niches for the next cycle of evolution. But, if we continue on this trajectory of using and ignoring the climate change it drives, we human beings may not be part of Earth's ongoing evolution."

Explore further: Earth as hybrid planet: New classification places Anthropocene era in astrobiological context

More information: Gavin A. Schmidt et al. The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record?, International Journal of Astrobiology (2018). DOI: 10.1017/S1473550418000095

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TheGhostofOtto1923
2.7 / 5 (11) Apr 16, 2018
Funny - they start off with what seems to be an innocent science thought experiment and end up with a typical anti-human diatribe.

Isn't that where most all academie soft science efforts usually end up?
carbon_unit
4.3 / 5 (13) Apr 16, 2018
They tend to wind up at "anti-human" because our civilization's activities tend to wind up being "anti-human" - the tragedy of the commons. While the authors seemed to focus on disruption of planetary environmental cycles, I would think that some of our large scale engineering projects, such as highway cuts through mountains, would be noticeable for millions of years. Also possibly tunnels and stuff that we buried. While the things in a landfill might not be identifiable after along time, I would think they would make an odd pocket in the layers of earth.
rrwillsj
1.5 / 5 (10) Apr 16, 2018
These writers are using terms for Human societies that are prejudicial. Such as conflating 'civilization' when they mean a 'technologically based culture'.

The root meaning of 'civilization' is a stratified culture of aristocrats and priests ruling an enslaved population. "I am civilized. You are my slave. Those people over there are barbarians until I have enslaved them."

The fabulous claims of this article are speculating without any supporting evidence.

An 'advanced' society that did not leave any traces of mining or metalworking? Roadwork cutting through hills and bridging rivers?

We could fantasize a pre-tech agriculture based society. But no signs of dams? Maybe canals instead of roads?

Qanats, stepwells, and terraces for cultivation should leave some sign even after tens of millions of years.

Perhaps the K2 monster fell exactly where a nascent society of morris-dancing dinosaur farmers just happen to be?

Try getting that image out of your head!
KBK
2.3 / 5 (10) Apr 16, 2018
Look up the book 'forbidden archeology', by Micheal Cremo.

He backs up everything he explores. It is a serious work, and has over 900 (alt version: +1000pg) pages of densely packed information.

https://en.wikipe...cheology

You will find the standard claim of 'pseudo science' thrown at it.

There are hundreds of other works available and there are hundreds of sites you can go to today, RIGHT NOW, (get on a plane in hours), and in approx than 1-2 days, be staring right in the face at evidence of ancient extreme technology civilizations. With your own eyes and you own hands, in person. In 1-2 days.

So, it exists and it exists a hundred fold, a thousand fold. The evidence is completely overwhelming.

But it is uncomfortable for the weak, and impossible for oligarchy to maintain their parasite like control - if true... so they attack it instead and exist in a form of cognitive dissonance, which is forced upon all others.
doogsnova
1.4 / 5 (10) Apr 16, 2018
Don't tell me what to think.
WCFTSATFM
https://billymeie...21-0.pdf
Whydening Gyre
not rated yet Apr 16, 2018
The "https://fabbiosa....ffle-us/ would look like for extraterrestrials...

never saw that one before...
Interesting.
gculpex
4.2 / 5 (5) Apr 16, 2018
Don't tell me what to think.
WCFTSATFM
https://billymeie...21-0.pdf

It takes a critical eye to find the lie.
robweeve
2 / 5 (8) Apr 16, 2018
Examples of ancient high technology cover the planet. One that constantly amazes me are the 1.5 million pound blocks of cut stone that lay on the ground at Baalbek,
Lebanon. Another is an Egyptian obelisk still in the ground at the quarry in Aswan. While partially carved it was abandoned when a large crack was discovered running longitudinally through it. At 137 feet in length the weight of the obelisk is 1200 tons or 2,400,000 pounds. Both the obelisk and the blocks of stone at Baalbek we're carved and were meant to be moved. We're talking about "primitive" ancient civilizations who somehow had the ability to move what we as a modern society are not capable of doing. No machine exists today that could even budge let alone lift and transport 2,000,000 pounds.
Mimath224
5 / 5 (2) Apr 16, 2018
The "https://fabbiosa....ffle-us/ would look like for extraterrestrials...

never saw that one before...
Interesting.

You might want to check out the Inga Stone (Brazil) Although not ancient in terms of years it is still of 'archeoastronomical' and contains an, as yet, undecipherable pictograph language. There are a great many artifacts world wide to check out, things that were made or are there, that shouldn't be...but beware of some interpretations. Nonetheless, it does make an interesting diversion if you are looking for some 'light reading /viewing.
Telekinetic
1.6 / 5 (7) Apr 16, 2018
How about the human skeletal remains of eight foot and taller giants unearthed in various places around the world? Most skeptics dismiss all unusual phenomena out-of-hand because they have never seen or experienced anything outside of what's been taught in schools and accept that information without question.
That runs counter to science. "Spooky action at a distance." Even Einstein was fallible.
adave
1 / 5 (5) Apr 17, 2018
Civilization is based on fire and invention. We look like we were made to make things based on just our human form and a matrix of concepts. No other life had that until after the ice age. Even our ancestors were less than Neanderthal. We should find ancient cell phones, mind and body implants, once human gods living thousands of years, nanobots, free electron space lasers extracting billions of watts from the solar wind, ziggurats, lots of life descended from geneticly modified organisms, the cambrian explosion of life written down in a book from the stone age, the holographic universe written down long before 2008, information preceding a big bang universe. There would be a stain left from earlier advanced lords to modify what had taken billions of years to walk on the earth.
ThomasQuinn
5 / 5 (3) Apr 17, 2018
The "https://fabbiosa....ffle-us/ would look like for extraterrestrials...

never saw that one before...
Interesting.


Don't get too excited: https://archyfant...ic-disk/ (see especially Dr. Hammer's statement and the part about Mr. Dona).
aksdad
1.4 / 5 (11) Apr 17, 2018
The real point of this "thought experiment" by prominent alarmist Gavin Schmidt is soft-selling global warming alarmism. Because the fire and brimstone tactics aren't working anymore and the public has become desensitized. Fewer people care as they realize that most of the dire predictions aren't happening. Hysteria gets old.

Then there's this gem:

We need to figure out a way of producing and using energy that doesn't put us at risk.[/q)
We already have. Fossil fuels have produced a miraculous improvement in living conditions for billions of humans. The benefits far outweigh the negative impacts. Then there's nuclear fission; the most efficient, safest, and cleanest form of base load energy production ever invented. But the alarmists want us to revert to centuries-old wind power and unreliable solar power that can't reasonably sustain the needs of humankind.
ThomasQuinn
5 / 5 (4) Apr 17, 2018
If you're calling modern wind energy "centuries-old wind power", then you have to refer to nuclear fission as "an 18th century steam engine". It's a little thing called "being consistent".
antialias_physorg
4.5 / 5 (8) Apr 17, 2018
As soon as we find microchips of an unusual design in amber I'll bite. Unless a civilization is *that* good that it can erase all its traces (even of its own past buried in deep layers) then we're in "any sufficiently advanced technology is indistinguishable from magic"-territory. And if we posit this then we're just speculating idly.

if a civilization is able to find a more sustainable way to produce energy without harming its host planet, it will leave behind less evidence that it was there.

Why stop there? A really advanced civilization would have engineered itself to be immune to the elements and produce any kind of energy it needs on an individual basis - i.e. it would have no tech at all.

"We need to figure out a way of producing and using energy that doesn't put us at risk."

We need to figure this out? I could name half a dozen such technologies that already exist in widespread use.
TheGhostofOtto1923
1 / 5 (1) Apr 17, 2018
As soon as we find microchips of an unusual design in amber I'll bite
These would be from ancient gamecams I would surmise.
https://www.trail...-reviews

-and might preserve invaluable paleontological data
https://www.googl...yr3zC7M:

spencerpencer
not rated yet Apr 17, 2018
I'm just a dumb regular person, so sorry for the dumb question.
Wouldn't steel (or any refined metal for that matter) last longer than animal bones?
TheGhostofOtto1923
1 / 5 (1) Apr 17, 2018
Wouldn't steel (or any refined metal for that matter) last longer than animal bones?
Bones get replaced by something more durable - minerals. As for metals, it would depend on which and where and how. Any steel, even stainless, will eventually rust away in the presence of O2.

But an interesting question is, could steel objects become fossilized? Wood fossilizes. Animal tracks, burrows, and scat fossilizes. So why not Subarus and hammers and transmission towers?

An example might be pseudomorphism

"Another well-known pseudomorph is Chalcedony after coral. In the Tampa Bay in Florida, coral has been chemically replaced by Chalcedony, and its original form is preserved..."

-also pseudomorph crystals.
691Boat
5 / 5 (6) Apr 17, 2018
Examples of ancient high technology cover the planet. One that constantly amazes me are the 1.5 million pound blocks of cut stone that lay on the ground at Baalbek,
Lebanon. Another is an Egyptian obelisk still in the ground at the quarry in Aswan. While partially carved it was abandoned when a large crack was discovered running longitudinally through it. At 137 feet in length the weight of the obelisk is 1200 tons or 2,400,000 pounds. Both the obelisk and the blocks of stone at Baalbek we're carved and were meant to be moved. We're talking about "primitive" ancient civilizations who somehow had the ability to move what we as a modern society are not capable of doing. No machine exists today that could even budge let alone lift and transport 2,000,000 pounds.


Google "Taisun crane" and let me know if you are still right....
Also, there are mobile cranes that can lift 1200 tons, FYI
Mimath224
5 / 5 (1) Apr 17, 2018
How about the human skeletal remains of eight foot and taller giants unearthed in various places around the world? Most skeptics dismiss all unusual phenomena out-of-hand because they have never seen or experienced anything outside of what's been taught in schools and accept that information without question.
That runs counter to science. "Spooky action at a distance." Even Einstein was fallible.


I don't think people dismiss such finds out of hand but think the point is that these don't turn up in large numbers and/or various places all over the world. R. P. Wadlow (of USA) at 8 ft. 11 ins. tall is the tallest living on record. There have been a large number over 8 ft tall from various parts of the world and even many more at 7 ft-7 ft 11 ins. So digging up a few skeletons at 8 ft. is really no big deal. The real question is where does this rare gene 'mutation' come from?
Mimath224
5 / 5 (1) Apr 17, 2018
My other thought has been for a long time about the wheel. It is not hard to imagine some ancient chappy sitting on the side of a hill (waiting for his next meal to show up, perhaps) and notices and some stones roll down the hill without much apparent effort then thinks....etc. I'm not saying that's how it happened but was probably something like that. We have become experts in exploiting that from the earliest carts to the modern car. But suppose on another very windy world wind propulsion was the primary idea and circular objects secondary which when combined, facilitated flight first rather than land travel. Perhaps such civilizations might be viewed as superior but then looking at our land conveyance might viewed similarly wonderful by them. Don't mind me, just an old guy's thought that's all, Ha!
Captain Stumpy
4.2 / 5 (5) Apr 18, 2018
@zeph
Do you see this instinctive immediate downvote? Once the proponents of mainstream science cannot explain some artifact, then their first reaction is to dismiss its existence
just so you know, I downrated you because there is exactly zero evidence that this "genetic disc" has been studied at all, in any scientific form

there exists claims from BS sites like yours above, but there is absolutely no proof that it exists as an "artifact" other than by your claim and the claim of the site owner you link

Moreover, to claim something is made of "lydite" without being able to present any empirical evidence smacks of hoax, especially with the claims that this is being investigated by a man that "... has spent more time in the field than many academically acclaimed Archaeologist"

so it's unverifiable, unvalidatable, and the best you can do is show a "pic" of what looks like a pewter disc made by sand mold casting - which is popular in certain S. American areas
Tyrant
1 / 5 (6) Apr 18, 2018
It's just a global warming propaganda piece, 'almost' blaming dinosaurs for their own global warming extinction from driving cars. And besides, the Sleestack had weather control stations.....
dudester
not rated yet Apr 18, 2018
The root meaning of 'civilization' is a stratified culture of aristocrats and priests ruling an enslaved population.


Actually I think the root meaning of civilization is to live in cities. However, it has now been expanded to mean almost anything anyone wants it to mean, beyond living in caves.
Captain Stumpy
3 / 5 (4) Apr 18, 2018
@zeph
Personally I just maintain information about it, but being agnostic I've no reason to promote or dismiss it, until I have more information about it
calling bullsh*t on this
Personally I perceive such a behavior a sign of lower intelligence in a broad sense
that is because you have a vested interest in defending your beliefs

to date, your predominant argument about most astrophysics is to promote a known debunked belief that has absolutlely no evidence whatsoever other than *your belief* that a series of statements may be interpreted (by you alone) as being supportive of your debunked belief

all while ignoring the repeatedly validated experimental evidence that shows your belief to be patently false

the above is the same thing just in another field of interest

.

and how does that rate in your "field of intelligence" behaviour list?
barakn
4.2 / 5 (5) Apr 18, 2018
No machine exists today that could even budge let alone lift and transport 2,000,000 pounds. -robweeve
You must think we're really gullible. Here's the largest thing I could find that has been transported over land: http://www.almajd...tor.aspx ... a 4891 ton evaporator (that's 9,782,000 pounds). One of the two Missile Crawler Transporter Facilities at Kennedy Space Center was recently upgraded so that it can carry 18,000,000 lb.
Captain Stumpy
3 / 5 (4) Apr 18, 2018
@zeph
Over half of Britons or Americans still don't believe in evolution, which is relatively well proven already
1- so?

2- just because you can find evidence of delusional behaviour doesn't mean you're not projecting the same delusional behaviour, nor does it mean you're not delusional because others do it
It would be complete waste of time - once some people decide to believe or not believe in something, then every attempt for to change it will just lead to backfire effect
Science facts are facts regardless of whether you believe them or not

Science doesn't educate those who choose to not believe or the hypocrites - it educates the ignorant who wish to make something better

this is just one lesson of technology and modern reality
So why do you think
it teaches *the ignorant who wish to advance* how to find facts and think critically when people like you are debunked
barakn
4 / 5 (4) Apr 18, 2018
9 Most Mysterious Ancient Artifacts like the hammer of London, ancient screw or iron nails found in Hungarian fossil cedars for to name just a few...-mackita/Zephir
Your London Hammer link is to a non-English website. When I looked for a website that most phys.org readers wouldn't need to find a translator for, I found this: http://paleo.cc/p...mmer.htm . The hammer and the rock it is embedded is claimed to have been found in Cretaceous, Ordovician or Silurian strata, and also to have been found loose on a ledge, not in any strata at all. The hammer's physical appearance is similar to tools from the 19th century, carbon dates allegedly suggested a range of modern to 700 years old, and World War II artifacts have become enmired in similar limy concretions. It's obviously a recent object, and odds are that it was never found in old strata. Thanks for nothing.
rrwillsj
2.3 / 5 (3) Apr 18, 2018
Such gullibility. Based on crank cult arguments? They are defending the 'scientific' validity of the Cardiff Giant.
barakn
3.7 / 5 (3) Apr 18, 2018
Mackita, your own "ancient screw" link suggests that it is actually the fossilized internal mold of a crinoid stem, something quite natural to find in a 300-million year old rock. And when I look at the "thread" of the "screw," I see no obvious pitch, suggesting a set of rings instead of a continuous thread.
Captain Stumpy
2.3 / 5 (3) Apr 18, 2018
@zeph
A way shittier findings get analyzed and dated by rigorous analytical methods
and per the scientific method, if it can be falsified, it will be
if it's not validated, it's just a singular finding of interest - it isn't scientific fact

and therein lies your entire problem with science
you *ASSume* that a singular study carries the same weight as a validated one (it doesn't)
then you *ASSume* that if it's proven false it's conspiracy (see: https://www.natur...omms9174 ) because you trust [x] persons opinion over the evidence
But in similar way like at the case of overunity or let say cold fusion findings the mainstream science suddenly forgets
no
the mainstream scientists wait for validation from non-related sources and evidence

which never seems to materialise - except, and pay attention here, in *singular* studies that aren't validated

validation trumps belief

make one of your overunity machines and prove me wrong
ThomasQuinn
not rated yet May 04, 2018
https://www.inver...s-pissed "It's a highly dangerous attitude to take" they say.

But dangerous for who? So far only establishment of science feels threatened by it.


Ok, I'll bite. It's dangerous for the historical awareness of the population at large because it's a return to the 19th century horror of armchair idiots coming up with crazy hypotheses without any real study of the subject, putting out those theories and having susceptible fools absorb them, which led to some of the most destructive political movements of the late 19th and 20th centuries (including communism, fascism, nazism, Chinese nationalism and Arab nationalism), which all relied on pseudo-history and pseudo-archaeology to give a veneer of scientific respectability to otherwise insane, immoral and outright evil ideologies, which was gobbled up by the scientifically semi-literate part of the population, which is still just that.

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