So maybe just stick right to the paper itself and its clearly stated motivation?
> Perhaps unusually, the authors of this paper are not convinced of the correctness of their proposed hypothesis. Were it to be true it would have profound implications and not just for astrobiology. However, most readers do not need to be told that it is always a bad idea to decide on the truth or falsity of an idea based on the consequences of it being true. While we strongly doubt that any previous industrial civilization existed before our own, asking the question in a formal way that articulates explicitly what evidence for such a civilization might look like raises its own useful questions related both to astrobiology and to Anthropocene studies. Thus, we hope that this paper will serve as motivation to improve the constraints on the hypothesis so that in future we may be better placed to answer our title question.
[0]https://www.cambridge.org/core/journals/international-journa...
On a much more recent timescale, one of the dominant theories of the emergence of civilization places the ancestors of the Sumerians in a stupendously fertile valley at the bottom of what is now the Persian Gulf, eventually flooded during the retreat of the glacial maximum and covered in Tigris & Euphrates sediment. It could be the very origin of regional flood and primordial garden myths. But it's all buried.
dude wind hundreds of thousands of years into future, sands of time, etc. modulo two warring biological descendants of humans not full diff species tho
I also use the Carboniferous Period as a metric as to why "Advanced alien life" isn't more abundant (and I believe it should be factored into the Fermi equation)...
All those trees growing, soaking up sun, dying and just laying there to be compressed and buried without anything to decompose them, and then humans using them like solar batteries to power civilization (i.e. burning the coal), is one of those million-to-one things that enabled the human race to develop beyond basic society.
We needed all that coal and oil (and gas) based power to get to the point - industrially and technologically - where we could even build solar panels or nuclear to replace them, so its not like you could start from first principals and jump straight to modern power generation either.
The odds that the same sequence of events - fungus and bacteria not having the tools to decompose lignin (or whatever the alien equivalent is) - to happen on an extra-solar planet is ... pardon my pun ... astronomical :D
(yes, I used a dash to separate ideas in a sentence, deal with it...)
"One hundred million years from now:
The universe has a surprise in store for the corvins, though. Their first moon landing included among its goals the investigation of some odd surface features, too small to be seen clearly by Earth-based equipment. That first lander thus set down on a flat lunar plain that, a very long time ago, was called the Sea of Tranquillity, and so it was that the stunned corvin astronauts found themselves facing the unmistakable remains of a spacecraft that arrived on the moon in the unimaginably distant past.
A few equivocal traces buried in terrestrial sediments had suggested already to corvin loremasters that another intelligent species might have lived on the Earth before them, though the theory was dismissed by most as wild speculation. The scattered remnants on the Moon confirmed them, and made it hard for even the most optimistic corvins to embrace the notion that some providence guaranteed the survival of intelligent species. The curious markings on some of the remains, which some loremasters suggested might be a mode of visual communication, resisted all attempts at decipherment, and very little was ever learnt for certain about the enigmatic ancient species that left its mark on the Moon."
1. https://www.resilience.org/stories/2013-09-05/the-next-ten-b...
Jokes aside, what is the evidence, beyond "Ancient mystical texts"?
[0] http://www.myths.com/pub/fiction/science-fiction/Asimov/Nigh...
I know about Yellowstone, Campi Flegrei, etc, but I haven't heard about a supervolcano below the Atlantic. What's that referring to?
Our knowledge is becoming holographic such that to prevent the reemergence of civilization one would have to wipe out all of us at once.
So there could have been this hypothetical civilization 55 million years ago already. And they've only just disappeared (if they did) 10'000 or so years ago? Without a trace?
Also, no, a conspiracy cannot be the answer to a question we've not yet asked. The word has a clear meaning, it requires people to conspire to hide something from you.
I do not understand this statement, I thought an area in Quebec was around 3 - 4 billion years old. I looked, seems Australia may have the oldest area:
https://www.bbc.com/travel/article/20220126-is-the-pilbara-t...
But I say the article could be true, but the only issue I have is the large dinos. I would think they could be an impediment to any organized settlements.
One other thing, didn't most of our fossil fuels come from the Carboniferous era ?
And someone is saying there could have been an entire advanced civilization 400 million years ago, large and powerful enough to cause climate change, and that no traces of it would possibly be left? Like, billions of individuals, cities, factories, metals, concrete, mines, wells, roads and bridges and tunnels, stone sculptures!, plastic, waste dumps, farms, agricultural land, billions and billions of artifacts of all materials, most of them entirely artificial. All gone because "nothing resists 400 my" and, "oh btw, check this dinosaur footprint and this fossilised piece of skin, how cool"?
400 million years ago is as distant as the stars. The Earth was a different planet then, in a sense.
It’s also yet another Fermi paradox answer. Even if our civilization lasts for millions of years, that’s a blip. We are searching both space and time and both are incomprehensibly vast.
Not really, because none of this passes the smell test if you know even a tiny bit about geology and paleontology. The most solid arguments are religious texts, there is not really any substance other than that.
Though I'm kind of disappointed the last section did not end with fusion power, stellar migration and artificial intelligence...
Nah, you way off on that, coastlines have remained relatively same last million years, def not subducted into an ocean trench
We have plenty of fossil evidence from, from your example, a million year old hominids. Far more than we would need to expect to see evidence of civilization.
Subduction makes up for a tiny tiny proportion of where coastal land "goes" in any age.
You'd need an enormous set of coincidences for a past civilization of hominids to go unnoticed.
Also, just as we "engineered" animals and plants through selective breeding, previous animals/plants could have been the results of selective breeding by a previous civilization: There'd be no way to tell just as there'd be no way to tell our "tampering" a few million years in the future.
Places where there is suddenly a vast collection of foreign rocks from the other side of the world that can't be explained by glaciers.
Radioactivity from nuclear tests that can't be explained by stellar phenomena and leave a layer of weird isotopes and isotope ratios all around the world, as we already have done.
And while we aren't to the point we'd have found this quite yet necessarily, evidence on the Moon where unlike Earth evidence probably would in fact persist for millions of years, especially if it ever attained any scale, e.g., "a large complex of cities" might still leave a visible mark on the surface easily visible to modern satellites and clearly with no other explanation available as to what caused it.
People get stuck on the idea that the only way to determine there was intelligent life earlier is to find a super complicated artifact which obviously can't survive, but there are footprints we've left in the world that are way, way larger than a cell phone or even a major city.
I don't find it hard to believe we've lost entire human civilizations. In fact I'd call it the smart bet. Maybe those civilizations were even a bit more sophisticated than we'd have thought, with maybe an earlier and entirely unknown Iron Age popping up somewhere for some period of time or something. But this is the first major technological civilization this planet has ever seen, even across geological time scales. And those lost human civilizations never reached to the level where they took all the easy resources like we have, because if they had, we wouldn't be able to get them. Some resources we call "non-renewable" do replenish on a few million year time scale, but we also pull lots of resources out of billion-year-old rocks, such as copper mines in northern Michigan which are pulling resources out of pre-Cambrian rocks. Clearly nobody else has been there, at scale.
"they found a single forerunner to their idea of deep time. It came not from science, but from science fiction. At this level of conjecture, there’s little difference. It was an episode of Dr. Who" also betrays an ignorance of the trope originator.[0]
For me, it's carl sagan's "invisible dragon" comparison that sticks in the back of my head. If there's intelligent life out there (or in earth's ancient past) but there's no physical way to detect or know it... Then like the invisible dragon in mu garage, it's the same as not existing.
Maybe we'll develop new techniques and gather new evidence, but until we figure out how to bend spacetime for FTL anything, or find clear evidence, we should act as if it isn't/wasn't there.
So TFA says that 55M years ago there was a climate fluctuation that looks similar to the anthropocene one. Good start. But interpretation of ancient stories across cultures is practically the definition of anthropic bias. We have to wait until there is real evidence that the temperatuee bump was dragonfire and not my heating system acting up, to ascribe cause.
The counter-counter argument is that while we’ve been here for a comparative blink of an eye, we’ve left behind 4 orders of magnitude more stuff than just nests, bones, and a feather or two.
The fossils we do have are of highly successful species in that geography. It’s a matter of chance, leaving behind a fossil, after all.
And unlike biological matter that can fossilize, industrial structures etc do not. All our manufactured stuff has very short life once it reaches the crust and starts getting compacted.
The more time you add, the better the odds we’d find this evidence lost.
And if this wasn’t a global, but more localized pre-human civilization, the evidence would be thinner still.
Which is why this isn’t a scientific hypothesis really. It’s more showing you the limits of scientific inquiry into the deep history of Earth.
As such it seems impossible for life to have reached interstellar travel anywhere in the Milky Way before at most a few million years ago, otherwise we would see it.
Which is weird because life surely can’t be that rare in the entirety of space time.
Of course the galaxy could be teaming with non interstellar life, but once you reach mankind’s level of sentience and technology it dormant seem a massive jump to interstellar, and once that happens there’s no way to put the genie back in the bottle.
If humanity vanished today, in 1 million years almost all of our artifacts would be gone or burned under miles of subduction.
In 10 million years there would literally be nothing left.
This is what I always say to "Why haven't we found any aliens yet??"
Hell, we wouldn't even have known about the existence dinosaurs, lifeforms on THIS VERY PLANET, if we hadn't chanced upon their remains.
How so? We know how it forms, there is no real gap in understanding there. What could lead to the kind of distribution of oil and gas fields we can observe?
Of course we haven't discovered everything. But it seems very likely that if there were a civilization's worth of slag from 500m years ago, we would have discovered it.
A more interesting question is the civilizational technology of domestication, especially since that is short-term technology coupled with long-term evolution. It does seem possible (but purely fantastical) that Earth had talking dinosaurs with sophisticated ideologies and mythologies, feeding dumber dinosaurs and curating the growth of nutritious plants, the descendants of which all died 65m years ago.
Civilisation implies large scale agriculture.
Large scale agriculture implies specific pollen signatures.
We don't see any of these signatures in the pollen records dredged up from lakes and seas.
There was no previous civilisation in the last 1.4m years (this is the depth of the pollen records we have I think).
Why is it obvious that none of them can survive? Ordinary bones can become rocks (fossils) that are preserved. If mining of iron ore is visible, things would have been made out of iron -- wouldn't a large structure made out of iron leave some trace? Or even a small one? Why are there dinosaur fossils galore, but not so much as a pre-human fidget spinner to be found?
At that age we can be pretty sure they did not have industry but they could have been like tribal hunter gatherers. If they did not build a lot and at large scale we’d have basically zero chance of finding anything. Stone, wood, animal skins, pottery, arrow heads, tools, etc., all that would be long gone. Metal would too but it might leave diagnostic traces, as would synthetic chemistry (plastics) or large scale fuel use.
Birds, the modern still living closest relatives of dinosaurs, are often strikingly intelligent especially relative to their brain mass. Dinosaurs had small brains relative to body size but while there is a correlation there with intelligence it’s not perfect. There’s exceptions, animals with small relative brain sizes that seem very smart, like elephants.
I think this is it: the point of this argument is to inspire some awe in the listener, making them realise how vast Earth's time is compared to our horizons.
But in practice, the argument is wrong. A dead animal's skin is expected to lasts weeks to months- and yet we have fossilised specimens. A footprint typically lasts hours, and yet we have ones that are hundreds of millions of years old. Even if the expected lifespan of our artifacts is nothing in comparison with these timespans, a small percentage of artifacts will either be preserved or leave recognisable traces- exactly as it happened for soft tissues and footprints. It's extremely naive to think that none of this will leave traces.
That is completely incorrect. We have sedimentary rocks from 100 M years ago on the Earth’s surface right now, that never underwent any kind of subduction.
Subduction only occurs at plate boundaries and is not nearly this fast. Continental plates float on top like foam and do not get subducted. It's the oceanic plate that is created at mid-ocean ridges and gets subducted at the margins.
I want to point out that the silurian hypothesis is specifically about civilizations removed from us by geologic time. Advanced human precursor civilizations are much more effectively ruled out by the current evidence. Basically, a hypothetical precursor society either has to look very different from any we know about and materialize out of nowhere like alien colonists, or they didn't exist.
For example, we know they weren't using large amounts of fire because nothing in the global charcoal records points to that. We know they weren't using plants that produce pollen because we don't find phytoliths with domestication indicators. We know they weren't using surface metals, because there was lots of that still around when the classically ancient civilizations started. We know they didn't contribute significantly to the gene pool. We have no material culture from them. We don't have a location on Earth they would have lived in. Etc.
"Ancient mystical texts hint at earlier creation, the life that preceded the Garden, prequels to Genesis. These incarnations are not reported in the Bible because they are none of your goddamn business, but the evidence is everywhere. Some students of conspiracy believe there was a time when lizard people shared the earth with modern men, the older race dying as the younger emerged from the forest. The last of the lizards were worshipped as gods; these were the deities of ancient India and Greece. The technology—weapons and machines—created miracles. You can see the lizard kings in carvings from Mesopotamia, the oldest historical records, where humans bow before reptile men. You find them again in the Torah, where they appear as Nephilim..."
So current human population is 400 thousand times the maximum T-rex population at any one time. A few decades are enough to produce more human individuals than the entire T-rexes history. We also have the ability to go (and die) pretty much anywhere, so there will be human skeletons in every crevice, depth and environment on Earth. We also produce an absolutely staggering amount of artifacts of all kinds, from plastic straws to giant tunnels and artificial caves. There are zero chances an advanced civilisation on Earth won't be aware of us in 400 million years.
Yeah, that's the pacific rim, which in some sense is the opposite of a volcano.
I do find it difficult to believe that we would not leave enough fossil and mineral evidence for future paleontologists to find. I get that the surface will churn, but layers of rock routinely become exposed, revealing the geological history of the area. No tea cup shards, no impressions of rusted cars in the mud, no concentration of metal in strangely rectilinear formations that suggests skyscrapers?
While there would probably very little direct evidence of humans after millions of years, there would probably be at least some anomalous evidence someone could find.
I mean, would an ant walking on a highway be able to tell that it's artificial?
Plastic will be gone in ~1000 years,
https://www.activesustainability.com/environment/waste-plane...
tunnels and artificial caves in a few million years at most as they are compressed by the weight of the rocks above them ("tunnel squeezing").
And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
In his monthly column, Conspiracy, Rich Cohen gets to the bottom of it all.
When I was eleven, we lived in an English Tudor on Bluff Road in Glencoe, Illinois. One day, three strange men (two young, one old) knocked on the door. Their last name was Frank. They said they’d lived in this house before us, not for weeks but decades. For twenty years, this had been their house. They’d grown up here. Though I knew the house was old, it never occurred to me until then that someone else had lived in these rooms, that even my own room was not entirely my own. The youngest of the men, whose room would become mine, showed me the place on a brick wall hidden by ivy where he’d carved his name. “Bobby Frank, 1972.” It had been there all along. And I never even knew it.
That is the condition of the human race: we have woken to life with no idea how we got here, where that is or what happened before. Nor do we think much about it. Not because we are incurious, but because we do not know how much we don’t know.
What is a conspiracy?
It’s a truth that’s been kept from us. It can be a secret but it can also be the answer to a question we’ve not yet asked.
Modern humans have been around for about 200,000 years, but life has existed on this planet for 3.5 billion. That leaves 3,495,888,000 pre-human years unaccounted for—more than enough time for the rise and fall of not one but several pre-human industrial civilizations. Same screen, different show. Same field, different team. An alien race with alien technology, alien vehicles, alien folklore, and alien fears, beneath the familiar sky. There’d be no evidence of such bygone civilizations, built objects and industry lasting no more than a few hundred thousand years. After a few million, with plate tectonics at work, what is on the surface, including the earth itself, will be at the bottom of the sea and the bottom will have become the mountain peaks. The oldest place on the earth’s surface—a stretch of Israel’s Negev Desert—is just over a million years old, nothing on a geological clock.
The result of this is one of my favorite conspiracy theories, though it’s not a conspiracy in the conventional sense, a conspiracy usually being a secret kept by a nefarious elite. In this case, the secret, which belongs to the earth itself, has been kept from all of humanity, which believes it has done the only real thinking and the only real building on this planet, as it once believed the earth was at the center of the universe.
Called the Silurian Hypothesis, the theory was written in 2018 by Gavin Schmidt, a climate modeler at NASA’s Goddard Institute, and Adam Frank, an astrophysicist at the University of Rochester. Schmidt had been studying distant planets for hints of climate change, “hyperthermals,” the sort of quick temperature rises that might indicate the moment a civilization industrialized. It would suggest the presence of a species advanced enough to turn on the lights. Such a jump, perhaps resulting from a release of carbon, might be the only evidence that any race, including our own, will leave behind. Not the pyramids, not the skyscrapers, not Styrofoam, not Shakespeare—in the end, we will be known only by a change in the rock that marked the start of the Anthropocene.
It was logical for Schmidt and Frank to turn their attention from the upper to the under, from the cosmos to our own earth. Why look for alien life there when we might find it here, removed not by miles but years. There was indeed a mysterious jump in surface heat; 55 million years ago, global temperatures rose from 9 to 14 degrees Fahrenheit. Called the Paleocene–Eocene Thermal Maximum, it left the same sort of geological evidence that will be left by our current carbon binge. There may have been other jumps, but we wouldn’t know it, as the geologic record only goes back so far. (We live in a compactor, where all things are crushed, recycled, and returned as new.) A meteor could’ve caused the Thermal Maximum, or it could’ve been the eruption of a monster volcano, the sort that presently smolders beneath the Atlantic. Or it could have been caused by the awakening of an ancient civilization, which rose like we rose, then fell as we will. That could be the fate of all advanced species, a rise and fall that flows as naturally as the change of seasons. Such a universe is ironic, continually creating characters whose technology brings on the very end they’re trying to avoid.
When Schmidt and Frank searched, they found a single forerunner to their idea of deep time. It came not from science, but from science fiction. At this level of conjecture, there’s little difference. It was an episode of Dr. Who, in which the time traveler visits an ancient species of advanced, long-extinct lizard people who’d achieved technological mastery 450 million years before modern man. The lizards were called Silurians, hence the Silurian Hypotheses.
It’s not really a new idea. Ancient mystical texts hint at earlier creation, the life that preceded the Garden, prequels to Genesis. These incarnations are not reported in the Bible because they are none of your goddamn business, but the evidence is everywhere. Some students of conspiracy believe there was a time when lizard people shared the earth with modern men, the older race dying as the younger emerged from the forest. The last of the lizards were worshipped as gods; these were the deities of ancient India and Greece. The technology—weapons and machines—created miracles. You can see the lizard kings in carvings from Mesopotamia, the oldest historical records, where humans bow before reptile men. You find them again in the Torah, where they appear as Nephilim, the so-called watchers—“The Nephilim were on the earth in those days and also afterward when the sons of God went to the daughters of humans and had children by them,” according to Genesis, “they were the heroes of old, men of renown”—which no priest, minister, or rabbi can properly explain. Just ask a clergyman and see for yourself. (I asked my rabbi.) There is some weird shit in the Bible.
According to a kabbalah-besotted friend, this world is God’s seventh creation, which explains dinosaur bones and other fossils. “The evidence is everywhere,” he told me one night. “They can say a meteor wiped out the past, but what is a meteor? God.” Some believe there are still Silurians walking the earth, holdovers who share their technology with a hidden elite—possibly Freemasons, possibly Jews. Some pseudoscientists speak of an atomic blast that took place in India 10,000 years ago. It might’ve been a natural phenomenon, or might’ve been the war that wiped out the Silurians or drove them off the earth. A website called Vedic Knowledge reported evidence “of an atomic blast dating back thousands of years. It destroyed most of the buildings and probably a half-million people in Rajasthan, India. One researcher estimates that the bomb used was about the size of the ones dropped on Japan in 1945.”
This ancient catastrophe, which some take as evidence of an ancient nuclear war, shows up in the Mahabharata, a Sanskrit epic, with the appearance of “a single projectile charged with all the power in the Universe … An incandescent column of smoke and flame as bright as 10,000 suns, rose in all its splendor … it was an unknown weapon, an iron thunderbolt, a gigantic messenger of death which reduced to ashes an entire race.”
It’s heartbreaking—the fact that, as we face the nightmare of climate change, some of us have read our own perilous present back into the geological past and have come to see even our apocalypse as unremarkable, something that’s been experienced before and was inevitable from the start. It’s thrilling, too, the idea of a pre-human industrial civilization. It means we don’t know anything: who we are, or where, or even the history of our own home.
Read more of Rich Cohen’s Conspiracy column here.
Rich Cohen is the author of The Last Pirate of New York: A Ghost Ship, a Killer, and the Birth of a Gangster Nation_._
but again, would someone a million in the future be able to tell that today's bananas, corn, watermelons, cattle, dogs etc. were the result of selective breeding by an intelligent species? (with no human records for reference)
They might be able to, based on when these disappeared, by comparing them to something more durable that is easier to date definitevely.
All those organic things bred to fulfill the purpose of being useful to our civilization would very quickly disappear and become outcompeted by the undomesticated species. This sudden disappearance (along with the disappearance of more durable artefacts, like steel/plastics) might hint to someone that these species "are not like the others".
Also by tying them to the cutoff in human remains (this is assuming humans disappear along with advanced civilization)