From author and druid John Michael Greer's essay, "The Next Ten Billion Years"[1],
"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."
Funny, as I was reading the original article, I was thinking that anything left on the moon would survive being recycled by plate tectonics.
It seems like reaching the moon isn't such a stretch for any technological civilization, so the lack of preexisting artifacts counts as pretty definitive for me.
I can't speak to dinosaur people, but the population genetics of our own DNA reveals that there were never many humans on the planet till recently, so that rules out any very large human civilization. (Unless they genetically altered themselves to hide the evidence! Ahaaa...)
If whole populations were wiped out and the world was repopulated by a small remnant would that not account for it? Or if an extinct human species had an advanced civilisation?
The founder effect differs between small populations filtered from a large population vs a smaller parent population.
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.
Yes. We'd find mines, where the richest veins were mined out and what's left is spread in a pattern that clearly appears to be "a rich deposit but with the best stuff taken already". The mine itself would have long collapsed but would also leave interesting evidence, a pattern of mismatched geological layers that rather than looking like an earthquake or a tectonic upheaval would be something that is relatively clearly shaft-shaped and if followed into the mountain would open out into a pattern that indicates intelligent mining activity as the anomaly is further charted.
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.
The exception that proves the rule is a nuclear reactor from Gabon that dates to 1.7bn years ago... and which was clearly natural, a uranium-rich cave got flooded and went supercritical: https://en.wikipedia.org/wiki/Oklo
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.
People get way too excited about the word "reactor". They hear "reactor" and think "oh, a natural formation of uranium was evaporating water into steam and generating electricity". They don't consciously examine that, of course, but it's clear a lot of people are letting that in unexamined.
What really happened is that some uranium got concentrated, and then it did was uranium does.
Similarly, if you want to make a very, very basic atomic bomb, you can do it by picking up two subcritical bits of uranium of the right isotopes and slamming it together in your hands. Basically the demon core but even more pure. The yield will be pathetic by military standards but you won't be around to care.
Fission isn't a process that requires intelligence, and fission causing cascading fission doesn't either.
"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."
Yes, that's why I'm careful to qualify it with "technological", which is by implication the whole thing we do with metals and minerals and oil and all that stuff. A past intelligent society that lived like hippies and had all sorts of fascinating philosophical debates until they died out with no major footprint can't be completely excluded. But I am fairly confident they never went to space. Well... you know... real space, like the kind of orbit the ISS is in. What they may have gotten up to on the influence of drugs I have no comment about.
Part of the reason I couldn't exclude it is that it has basically happened. If hypothetically an asteroid blew away humanity two or three thousand years ago, that's basically what would have been left behind. They did mining then, but at a scale easy to believe could be erased by time. Quite a bit of that time period is already gone as it is, let alone across millions of years. It's really that modern industrial mining that we do today, the cumulative effect of many decades of that mining, and barring disaster, the cumulative effect of yet more decades/centuries of mining that would survive for millions of years.
The first part of your comment seems to be replying to a pure strawman, and missing the point of my argument. My point was even small natural reactors leave very obvious evidence, so it seems like a city's worth of metallurgy could be detected 200m years later, probably by a surprised geologist in the 1800s. The fact that we haven't seen anything is conclusive evidence that modern humans were the first metallurgists.
Yes, that's why I'm careful to qualify it with "technological", which is by implication the whole thing we do with metals and minerals and oil and all that stuff.
"And minerals" is doing a lot of work, and it is just wrong to exclude plant/animal domestication from technology. Likewise earthworks, irrigation, trading networks and currency, etc. You're being very dismissive and closed-minded about what technology is. ("lived like hippies")
In particular, there don't seem to have been any dinosaurs that had anything like primate hands, so they would have never built real tools or weapons, or manipulated fires. That doesn't close off the possibility of an "advanced civilization" unless you mean "uses tools as fancy as ours." We don't actually know what 200,000 years of natural domestication would look like.
Add our nuclear waste dumps to the list of things I mention in another reply that I can't guarantee wouldn't still leave legible evidence even millions of years later. Especially since we seek out geologically stable places to put them... not that we've actually put them there yet, but, you know, maybe over the next couple hundred years we'll get it together....
> 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
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?
I'm not to stuck on the complete, 100% impossibility of things to be found.
But one counterargument that can be made is that fossilization requires very specific circumstances, and the legacy of the dinosaurs is from millions of years of opportunities. A blip of a 500 year civilization might not leave much behind.
No, I wouldn't expect a big pile of iron to leave anything interesting behind. It would rust, and rust has no structurally integrity and probably wouldn't resist the general forces of time very well. On geological timeframes rust is soluable in water.
However, I couldn't tell you that about every last industrial artifact we have. Could the Hoover Dam still indicate some sort of obvious construction activity a few million years hence? Could some of the concrete end up preserved and some future civilization realize that it is too precisely formulated for an engineering purpose to be constructed? Could some titanium structure survive for extended periods of time even though everything else in the plane or whatever else is long gone? Could New Orleans end up sinking into muck and leave some sort of fossilization behind of things that are still clearly artifacts millions of years later? It's hard to prove that every last thing we create has absolutely no chance of being recognizable as an artifact even in millions of years.
Especially if we leave Earth and start including the moon. Just a few things here or there could be wiped out with an unlucky asteroid strike, but if something was really systematically up there for long periods of time doing intelligent things, even hundreds of millions of years ago, could still leave an obviously-intelligent footprint.
I think concrete is one of the biggest signs of humanity that will be detectable in millions of years. It's very durable and we make a lot of it in big concentrations, like the foundations of buildings in a big city. It's not an especially advanced technology either, compared to say titanium or plastic. The Romans already had it.
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.
I don't think we have to go that far back. Plate tectonics, submersion and weathering does a good enough job of wiping the slate clean off the surface of the Earth, that any evidence of earlier hominids developing pre-industrial, coastal civilizations say, a million years ago, would be now under the crust. What we consider civilization is about 5000 years old, so it's not inconceivable that the cycle might have occurred multiple times during geologic time spans. Perhaps this is the first time civilization was not interrupted and made its way through to a technological civilization.
I mean sure, if they somehow didn't have any trade goods that went in land, didn't work with metals enough to do any appreciable mining, and didn't breed any plants or animals enough to change their genetics. Any hypothetical hidden past civilization would have to have been weird in a number of ways to not leave any evidence.
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.
Are you sure? what about fossils and other remains? So far there is zero evidence that there was an advanced or non advanced civilization. Unfortunately this nonsense is the bread and butter ot pseudo archeologists.
This article is a weird mash-up of an actually very interesting paper [0] with random personal slop like i've asked my rabbi, consulted my kabbalah-initiated friends and for the fun mixed it up with some fashionable ancient text (Mahabharatha)
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.
I think there is no evidence for it, but I think the point of the Silurain hypothesis (which the article does not convey well) is that if there were such civilisations we would not know as its unlikely we would find any evidence.
Its not, which is why it should not be treated as a theory. It is a speculation.
On the other hand, a claim that we are the first species on the planet to reach a particular point of development of civilisation (agriculture, cities, various levels of technology) is a falsifiable statement.
It is falsifiable, in the sense that we have ample evidence of the many forms of life that have existed on earth... including fossil evidence, genetic evidence, preserved tissue samples and a long litany of other pieces of data broadly consilient with our understanding the biological timeline.
On the other hand, we have zero evidence of Silurians or whatever.
Those two observations are inconsistent and require explanation.
Sure, one can hedge and qualify and excuse or whatever, and on pain of irrationality we have to allow that it's possible we're missing evidence of one of a bajillion possible competing hypotheses about intelligent life... but the theory most consistent with the evidence we have is that there wasn't any.
That's falsifiable enough for me?
The criterion of falsifiability pushed by positivists is kind of crappy anyway, it doesn't speak well to how we build models of the world while doing actual empirical work (and is itself non-falsifiable), but in practical terms idk, I don't see much to recommend the Silurian Hypothesis over the null hypothesis, so to speak.
There's a seam of volcanic mountains that runs down the center of the Atlantic, but nothing that resembles a supervolcano. The supervolcano complex under the Pacific is one of the largest known in the solar system, however.
No the seam at the center of the Atlantic is a mid-oceanic ridge, and it’s very much like a volcano since magma comes out. Icelandic volcanology comes from it being on the ridge.
There are ridges off of the US coast (Explorer, Juan de Fuca, Gorda) but the ring of fire which surrounds the pacific is mostly subduction areas.
Sorry, you're right of course (and yeah, the Pacific rim can obviously not be in the Atlantic, typed too fast there...)
With "opposite" I meant the role in plate tectonics, in that classical volcanoes seem to mostly appear near subduction zones or hotspot but not on the ridges from what I know. (Iceland being the exception, but even there it's because of a hotspot that happens to be located right on the ridge)
But I think the ridge system usually does not have volcanoes in the sense that there are magma chambers that fill up or cause eruptions. So the usual scenario of the "asleep supervolcano" does not apply.
> The supervolcano complex under the Pacific is one of the largest known in the solar system, however.
That sounds interesting. Do you have some links about that?
I wrote a sci-fi short story on this idea once. It took place in the present, and left the truth of the hypothesis open. Submitted it to Analog, but it was rejected. I suppose there are now places one can self-publish sci-fi stuff, but I'm not sure I can even find my original.
Edit: Did a Linux find, and...it did find the story. Unfortunately, it didn't find me a place to publish it.
I think the article greatly underestimates our archaeological capabilities. We can identify five mass extinctions in the last 500 million years, so why should such a civilization simply be overlooked? Of course, we wouldn't find abandoned ruins, but the idea that an industrial civilization wouldn't leave behind any detectable artifacts is practically impossible. Perhaps there were a few primate species before that could make fire and hunt with bows and arrows, but certainly nothing industrial and hardly any extensive agricultural culture.
> I think the article greatly underestimates our archaeological capabilities.
"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]
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.
"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..."
Yeah, the author is contradicting himself here: On the one hand, that civilization must have ended several million years ago, so erosion and plate tectonics had time to erase all traces - but on the other hand, humans were still having lively exchanges with those guys and viewing them as a normal part of their world in 10.000 BC...
I have a toy hypothesis that once civilization level intelligent life emerges it never disappears barring the planet it inhabits being vaporized by some unfortunately directed GRB or some similar catastrophe.
Our knowledge is becoming holographic such that to prevent the reemergence of civilization one would have to wipe out all of us at once.
depends how you define civilization level life.if you mean we cant be bumped back to hunter gatherers without wiping out almost all of us, you are probably correct. If you mean we will always have computers and the ability to split the atom, i dont agree. Knowledge and industry is way more fragile and we have loat working knowledge of simpler processes in favor of more advanced ones so it wont be that easy rebuilding through the lower rungs of the tech tree.
Surprised so few are pushing back against some of the claims in this article.
Eg that the entire surface of the earth gets replaced in a million years by tectonics.
Many of the large plates are more than 1000km across, they’d need to be moving meters per year for that to happen. In reality it’s cm per year. Also typically it’s oceanic plates that get subducted and take material under the crust, not continental plates. If it were true, then how do we see dinosaur fossils, and creatures even older than that; how do we find rocks that are over a billion years old.
This doesnt reject the possibility that there was a civilization tens of millions of years ago, but it makes the article hard to take seriously. If you’re gonna spend time writing an article on this you might as well try to research it a bit more. Someone is gonna read this and repeat this nonsense like it’s some fun trivia.
We’ve already got fossils of dolphins. Not exactly the species we know today but close enough. We have enough fossils to trace their evolution since their ancestors walked on land. So yes, we definitely would have evidence that dolphins were here.
right, so how can one easily say this hypothesis is false? "advanced civilization" seems to be strangely characterized. would something a few steps above beavers be advanced enough?
When people speculate about "advanced" ancient civilizations they usually mean said civilizations had technology at least as advanced as our own if not more so like nuclear weapons, antigravity, modern manufacturing and engineering, etc. A hypothesis that millions of years ago humans or some progenitor could build rough shelters out of sticks isn't particularly interesting.
>The oldest place on the earth’s surface—a stretch of Israel’s Negev Desert
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:
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 ?
The claim isn't about the age of rock, but that the surface has churned almost everywhere. Israel does contain the oldest measured continuous surface at about 1.8M yo, but nobody claims to have looked everywhere.
How churned is "churned"? Does this mean particular pebbles have have been found to have lain in their current arrangement for 1.8 million years, or just that not much has happened? I expect any arid region far from the poles or mountains and lacking dune fields will have similar patches of inert land. Much of Australia would fit this bill.
This is a good thought experiment to show how time is as vast as space.
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.
How can a galaxy spanning civilisation fail. If life can spread to other worlds, unless you get FTL, how could you end all life in a galaxy
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.
1.) It's definitely a giant leap from current technology to interstellar colonization.
2.) Other civilizations even in the nearest solar system would basically be impossible to detect. Even in our own solar system, there could be millions of undetected spacecraft right now. They're simply too small to see.
To be detectable, they'd either have to be massive and massively disruptive, like Dyson spheres, which are and most likely will forever remain pure fiction, or they'd have to happen to use radio for communication.
3.) There are good reasons for them not to be using radio for communication. They might have discovered a different physical phenomenon that allows them to communicate in ways we can't detect. Or they might not be as reckless as humans and don't want to broadcast their presence and activity to completely unknown and potentially hostile other species.
Though there is likely life throughout the galaxy, it's probably difficult for one sentient spacefaring race to find another habitable planet they'd be comfortable on, i.e., one with a similar atmosphere and mass. If it's a long way from your planet to another you'd care to set foot on, you're left with lots of space stations. But who wants to live in that precarity?
I’d also say that we do not know for certain that no dinosaurs, such as raptors perhaps, were intelligent enough for language and culture.
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.
So we have microbial fossils from 3.5 billion years ago, fossilised 300 million year old skin, bones from almost 200 my ago, even actually soft tissue inside a fossilised bone from 70 my ago. Ah, footprints too, the most unsubstantial matter of all: pure shape. That's in addition to all the million other fossils that are so common we hardly care: shells, small bones, etc.
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"?
The counter argument: dinosaurs were around for a staggering amount of time, no pun intended. 165 million years is reasonably long enough to ensure they left behind some nests, bones, and a feather or two. Modern humans have been around for more like 0.02 million years.
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.
Yea, but if humans went extinct tomorrow, very little human artifacts would remain after millions of years. Indeed, most would be gone well before that. How much stuff from the 18th century still remains, in percentage terms?
Unless it was burned, melted, decomposed or crushed to dust, it's all out there or in a landfill somewhere.
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?
There would still be many signs. Dug up mines, metal alloys that don't exist in nature along with refined metals in quantities they don't exist, animal and plant species we bred along with all the ones we made extinct.
Very few things would in fact remain, you’re correct. But we’ve also created radioactive elements with half lives of many millions of years.
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.
Indeed. Did a rapid check on T-rex, just as an example.
Was around for max 3.6 million years. Max population at any one time must have been around 20k individuals. We have about 150 skeletons.
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.
> How long to dissolve carved stone sculptures (in sizes ranging from 1cm to 100m?)
A quick search on "rock weathering depth per century" suggests a "typical range" of 0.05 mm to 6 mm, depending on rock type and environmental factors. At 0.05 mm, a stone object with radius 0.5 cm would crumble in 10000 years. With radius 50 m, it would take 100 million years.
I would expect them to be unrecognizable long before that though.
> And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
What do those findings tell you about the cognitive abilities and social organization of the creatures who left them behind?
> A quick search on "rock weathering depth per century"
That's a great illustration of what I meant. Of course an exposed rock consumes away in the space of a few millennia- this is exactly where the "Silurian theory" comes from. Yet it's also obvious that we have plenty of perfectly conserved rocks that are intact after hundreds of millions of years- i.e. fossils. Any small sculpture buried in clay can survive for an eternity.
> What do those findings tell you about the cognitive abilities and social organization
Skin? Like, with clothes on, or the shape of clothes? And shoes and hiking gear? Footprints with the shape of boots? Drawings "I LOVE YOU" in the sand? The shape of a coca-cola bottle buried in solidified clay? Come on...
> Any small sculpture buried in clay can survive for an eternity.
If it's made of granite, maybe. But how many granite sculptures have you seen? Sculptors tend to prefer prettier and more easily shaped materials, like marble and limestone. Those happen to be mostly calcium carbonate, just like bones and teeth, so section 1.2 in [1] (chemical dissolution in acidic environments) applies, along with section 1.3 and [2] (mechanical fracturing and dispersion during wetting-drying cycles).
Even if your sculpture was buried in a maximally favorable environment, it would not have stayed that way over tens of millions of years. 50 million years ago, the Himalayas were just starting to rise as India crashed into Eurasia, Australia was waving goodbye to a forest-covered Antarctica while the Americas, North and South, had yet to link up. At a rate of one ice age every 100k years, 500 ice ages separate us from those days. One is enough to raze half a continent and turn a muddy seabed into granite.
> Skin? Like, with clothes on, or the shape of clothes? And shoes and hiking gear? Footprints with the shape of boots?
This is extremely anthropocentric. A hypothetical "Silurian" civilization would obviously not have been human, and may have had no need for such things. Would bears endowed with human-level intelligence want to wear clothes and boots?
> Drawings "I LOVE YOU" in the sand?
Have any such preserved drawings in the sand been found from the ~200k years humans have been around?
> The shape of a coca-cola bottle buried in solidified clay?
See section 1.3 in [1], and remember that the time scale discussed in that kind of paper is a few thousand years, not tens of millions.
We use enormous amounts of it in construction, cut to precise shapes.
> just like bones and teeth
Of which we have ample amounts of fossils. Even included in marble, which is itself hundreds of millions of years old.
> it would not have stayed that way over tens of millions of years.
So we don't have fossils from hundreds of millions of years ago?
> Would bears endowed with human-level intelligence want to wear clothes and boots?
Absolutely if they had a civilisation capable of producing climate change. We're talking about at least a billion individuals living in all environments on Earth, from the tropics to the arctic, and doing all things an advanced civilization does: farming, mining, building, transporting, exploring etc. At least elements of technical clothing are needed in many of these activities.
> See section 1.3 in [1]
You keep repeating an argument that disproves the possibility of all fossils. Really you can't understand that it's contradicted by facts?
> We use enormous amounts of it in construction, cut to precise shapes.
The question, which you did not answer, was about granite sculptures.
We use enormous amounts of granite in construction, crushed and mixed with cement, sand, and water to make concrete. Larger irregular pieces are also used for roads (under the asphalt and mixed with it) and railways. Some regularly shaped objects made of granite are used in construction, which is not generally undertaken on the kind of waterlogged terrain needed for clay to sink in, and will be subject to weathering at the previously discussed rates, to the extent that they are not broken or recycled when buildings are torn down.
>> just like bones and teeth
> Of which we have ample amounts of fossils.
A few million, counting all fossils of all species which have existed over the past three billion years or so.
Humans are one out of the billion or so species which have lived on Earth [1], the ~200k years we've been around are less than a millionth of that time span, the vast majority of humans never make sculptures, and the vast majority of sculptures are destroyed within a few centuries. But here you are, complaining that we have no sculptures from tens of millions of years ago.
>> Would bears endowed with human-level intelligence want to wear clothes and boots?
> Absolutely if they had a civilisation capable of producing climate change.
Ah yes, I can totally see a bear going "OMG it's getting so hot, I totally need to wear some artificial fur over my own!"
> You keep repeating an argument that disproves the possibility of all fossils.
No. You keep ignoring the time scale, the dynamics and the odds.
Actually correct. We have very very few fossils compared to the millions of species that have evolved and gone extinct over 4 billion years.
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.
> It’s more showing you the limits of scientific inquiry into the deep history of Earth.
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.
> 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?
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.
> If humanity vanished today, in 1 million years almost all of our artifacts would be gone or burned under miles of subduction.
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 really enjoyed this article. It was a very pleasant read. The author should write a book and or movie script. The original Doctor Who Silurian episodes were fun to watch. Makes sense to connect dinosaurs or the remnants of Silurian civilization to dragons and deities. Star Trek Strange New Worlds S04E01 deals with the dinosaurs and Mars @ 65 million years ago. The story is rather intriguing and fun to watch as well. Invincible S04E04 deals with the various ages that planet Earth has gone through and has a different take on the meaning of Hell and Satan and why they exist. Last episode of the Season 4 is rather interesting, as well as it relates to the possible next phase or not, of human evolution.
Time Machine movie reboot did this in opposite direction into future decently well
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
To recognize the possibility, one has to grapple with incredible scale and deep time: In roughly 300 million years (1/10th of the time life has been around), the Appalachians split off from the Atlas; the Atlantic Ocean first started splitting open; uplifts underneath North America pushing the West up from the seabed and caused the rivers to carve millions of acres of sandstone landscape down, leaving towering plateaus, cliffs, and eventually river chasms. Over the 3 billion years before that, what was carried away like so much sediment? What was subsumed by subduction boundaries?
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.
Interesting topic, but (to immediately veer off of it) I really wish he would find another word and stop misusing "conspiracy." The word has already been through hell.
That was my first reaction as well. The author seems very confused about it.
He starts off defining it as something that is unknown or secret, and more specifically, he goes on to say, a secret "kept by a nefarious elite". I suppose secrets are usually associated with conspiracies, but a secret is not a conspiracy and conspirators don't have to be an elite.
And then he says that in this case, it's the Earth itself that's conspiring alone. This contradicts all the dictionaries I consulted, which define it to involve multiple parties, which makes sense considering the etymology.
The fact there is still coal(and oil) in the ground pretty much rules out any "advanced" industrialized civilization that came before us.
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 thing I enjoyed about The Children of Time by Adrian Tchaikovsky: the spiders learned to build "computers" out of ant colonies by hijacking the ants ability to generate and respond to chemical stimuli.
not that it makes me believe in the silurian hypothesis, but i'm always reminded of that whenever i start to think "well it couldn't possibly be done any other way".
Petroleum could be the byproduct of a previous civilization.
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.
> Petroleum could be the byproduct of a previous civilization.
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?
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)
If they’re a bit observant they will see that a humongous number of animals of the same species shows up suddenly, and localised in big numbers. Besides, there are a lot of signs of human activities. We changed the atmosphere in ways that are likely to show up in sediments. We mined all the minerals we could find to turn them into widgets that are not going to disappear. Our plastic items will end up in sediments all over the place, with wrong isotopic signatures. We find them in all places where we can look, down to the bottom of the Mariana Trench. They are carried to the seas by the same rivers that leave the silt that turns into rocks. Beyond that, we are leaving entire strata of plastics and metals in landfills. A lot of the satellites we put up there will fall back to Earth, but not all of them will. Some have orbits that won’t decay in millions years. There is not a single aspect of the planet that we haven’t touched.
> 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?
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)
Silurian Hypothesis, SETI, a widely help motivation for space exploration, much of sci-fi: all posit a high-ish rate of life (or intelligent life) invention, because the alternative is terrifying. I/we need/enjoy this, but it's fiction. When humans reason about the rate, they're extremely biased by what they want to be true.
+1 in general that anthropic bias is strong, but it cuts both ways, even in relatively hard nosed statistical models (@see Drake equation vs Rare Earth hypothesis). Truth is, there are a ton of factors we just can't observe (yet?) that play a big part. For example, since the rare earth hypothesis was published, we know a lot more about exoplanets, and earth-range size in the habitable zone of a stable star and galaxy appears much more common than we thought. But we don't know if plate tectonics are really required, or gas giant "vacuum cleaner" planets int he same system, or even oxygen. But we do know that the minimum value for intelligent species is at least 1, because we exist.
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.
From author and druid John Michael Greer's essay, "The Next Ten Billion Years"[1],
"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...
Funny, as I was reading the original article, I was thinking that anything left on the moon would survive being recycled by plate tectonics.
It seems like reaching the moon isn't such a stretch for any technological civilization, so the lack of preexisting artifacts counts as pretty definitive for me.
What an amazing read! (and only slightly depressing)
Though I'm kind of disappointed the last section did not end with fusion power, stellar migration and artificial intelligence...
I can't speak to dinosaur people, but the population genetics of our own DNA reveals that there were never many humans on the planet till recently, so that rules out any very large human civilization. (Unless they genetically altered themselves to hide the evidence! Ahaaa...)
If whole populations were wiped out and the world was repopulated by a small remnant would that not account for it? Or if an extinct human species had an advanced civilisation?
The founder effect differs between small populations filtered from a large population vs a smaller parent population.
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.
“Basically, a hypothetical precursor society . . . has to materialize out of nowhere like alien colonists, or they didn't exist.”
Proof aliens exist—thermodynamics, no materialization out of nowhere.
There are layers ;)
There’s always the hollow earth!
My thoughts:
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).
The proper Silurian period had no pollen, so that wouldn't make any sense.
Or it stayed concentrated for a long time until local conditions forced a scattering.
No. That’s exactly how we know.
> I can't speak to dinosaur people
Dash out of context
I know, let’s modify our DNA so if we’re wiped out nobody will ever know we existed!
However, since we do have plenty of fossils from Silurian, it is hard to believe that none of the advanced technologies never left any hint. Any idea?
Yes. We'd find mines, where the richest veins were mined out and what's left is spread in a pattern that clearly appears to be "a rich deposit but with the best stuff taken already". The mine itself would have long collapsed but would also leave interesting evidence, a pattern of mismatched geological layers that rather than looking like an earthquake or a tectonic upheaval would be something that is relatively clearly shaft-shaped and if followed into the mountain would open out into a pattern that indicates intelligent mining activity as the anomaly is further charted.
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.
The exception that proves the rule is a nuclear reactor from Gabon that dates to 1.7bn years ago... and which was clearly natural, a uranium-rich cave got flooded and went supercritical: https://en.wikipedia.org/wiki/Oklo
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.
People get way too excited about the word "reactor". They hear "reactor" and think "oh, a natural formation of uranium was evaporating water into steam and generating electricity". They don't consciously examine that, of course, but it's clear a lot of people are letting that in unexamined.
What really happened is that some uranium got concentrated, and then it did was uranium does.
Similarly, if you want to make a very, very basic atomic bomb, you can do it by picking up two subcritical bits of uranium of the right isotopes and slamming it together in your hands. Basically the demon core but even more pure. The yield will be pathetic by military standards but you won't be around to care.
Fission isn't a process that requires intelligence, and fission causing cascading fission doesn't either.
"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."
Yes, that's why I'm careful to qualify it with "technological", which is by implication the whole thing we do with metals and minerals and oil and all that stuff. A past intelligent society that lived like hippies and had all sorts of fascinating philosophical debates until they died out with no major footprint can't be completely excluded. But I am fairly confident they never went to space. Well... you know... real space, like the kind of orbit the ISS is in. What they may have gotten up to on the influence of drugs I have no comment about.
Part of the reason I couldn't exclude it is that it has basically happened. If hypothetically an asteroid blew away humanity two or three thousand years ago, that's basically what would have been left behind. They did mining then, but at a scale easy to believe could be erased by time. Quite a bit of that time period is already gone as it is, let alone across millions of years. It's really that modern industrial mining that we do today, the cumulative effect of many decades of that mining, and barring disaster, the cumulative effect of yet more decades/centuries of mining that would survive for millions of years.
"talking dinosaurs": I don't know about that, but the Farside had a picture of cigarette-smoking dinosaurs, which requires at least some intelligence: https://i.pinimg.com/736x/6a/87/1a/6a871af3a7754a3ac7f1b2c11...
The first part of your comment seems to be replying to a pure strawman, and missing the point of my argument. My point was even small natural reactors leave very obvious evidence, so it seems like a city's worth of metallurgy could be detected 200m years later, probably by a surprised geologist in the 1800s. The fact that we haven't seen anything is conclusive evidence that modern humans were the first metallurgists.
"And minerals" is doing a lot of work, and it is just wrong to exclude plant/animal domestication from technology. Likewise earthworks, irrigation, trading networks and currency, etc. You're being very dismissive and closed-minded about what technology is. ("lived like hippies")In particular, there don't seem to have been any dinosaurs that had anything like primate hands, so they would have never built real tools or weapons, or manipulated fires. That doesn't close off the possibility of an "advanced civilization" unless you mean "uses tools as fancy as ours." We don't actually know what 200,000 years of natural domestication would look like.
Ah, sorry, I did misinterpret. My apologies.
Add our nuclear waste dumps to the list of things I mention in another reply that I can't guarantee wouldn't still leave legible evidence even millions of years later. Especially since we seek out geologically stable places to put them... not that we've actually put them there yet, but, you know, maybe over the next couple hundred years we'll get it together....
> 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
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?
I'm not to stuck on the complete, 100% impossibility of things to be found.
But one counterargument that can be made is that fossilization requires very specific circumstances, and the legacy of the dinosaurs is from millions of years of opportunities. A blip of a 500 year civilization might not leave much behind.
No, I wouldn't expect a big pile of iron to leave anything interesting behind. It would rust, and rust has no structurally integrity and probably wouldn't resist the general forces of time very well. On geological timeframes rust is soluable in water.
However, I couldn't tell you that about every last industrial artifact we have. Could the Hoover Dam still indicate some sort of obvious construction activity a few million years hence? Could some of the concrete end up preserved and some future civilization realize that it is too precisely formulated for an engineering purpose to be constructed? Could some titanium structure survive for extended periods of time even though everything else in the plane or whatever else is long gone? Could New Orleans end up sinking into muck and leave some sort of fossilization behind of things that are still clearly artifacts millions of years later? It's hard to prove that every last thing we create has absolutely no chance of being recognizable as an artifact even in millions of years.
Especially if we leave Earth and start including the moon. Just a few things here or there could be wiped out with an unlucky asteroid strike, but if something was really systematically up there for long periods of time doing intelligent things, even hundreds of millions of years ago, could still leave an obviously-intelligent footprint.
I think concrete is one of the biggest signs of humanity that will be detectable in millions of years. It's very durable and we make a lot of it in big concentrations, like the foundations of buildings in a big city. It's not an especially advanced technology either, compared to say titanium or plastic. The Romans already had it.
> Any idea?
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.
I don't think we have to go that far back. Plate tectonics, submersion and weathering does a good enough job of wiping the slate clean off the surface of the Earth, that any evidence of earlier hominids developing pre-industrial, coastal civilizations say, a million years ago, would be now under the crust. What we consider civilization is about 5000 years old, so it's not inconceivable that the cycle might have occurred multiple times during geologic time spans. Perhaps this is the first time civilization was not interrupted and made its way through to a technological civilization.
I mean sure, if they somehow didn't have any trade goods that went in land, didn't work with metals enough to do any appreciable mining, and didn't breed any plants or animals enough to change their genetics. Any hypothetical hidden past civilization would have to have been weird in a number of ways to not leave any evidence.
>coastal civilizations say, a million years ago, would be now under the crust.
Nah, you way off on that, coastlines have remained relatively same last million years, def not subducted into an ocean trench
Huh?
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.
Are you sure? what about fossils and other remains? So far there is zero evidence that there was an advanced or non advanced civilization. Unfortunately this nonsense is the bread and butter ot pseudo archeologists.
This article is a weird mash-up of an actually very interesting paper [0] with random personal slop like i've asked my rabbi, consulted my kabbalah-initiated friends and for the fun mixed it up with some fashionable ancient text (Mahabharatha)
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...
Isaac Asimov's Nightfall [0], but on a longer cycle?
Jokes aside, what is the evidence, beyond "Ancient mystical texts"?
[0] http://www.myths.com/pub/fiction/science-fiction/Asimov/Nigh...
I think there is no evidence for it, but I think the point of the Silurain hypothesis (which the article does not convey well) is that if there were such civilisations we would not know as its unlikely we would find any evidence.
So it not a falsifiable statement from the onset?
https://en.wikipedia.org/wiki/Falsifiability
Its not, which is why it should not be treated as a theory. It is a speculation.
On the other hand, a claim that we are the first species on the planet to reach a particular point of development of civilisation (agriculture, cities, various levels of technology) is a falsifiable statement.
I don’t think it’s necessary to falsify a statement that has absolutely no evidence for it being true.
It is falsifiable, in the sense that we have ample evidence of the many forms of life that have existed on earth... including fossil evidence, genetic evidence, preserved tissue samples and a long litany of other pieces of data broadly consilient with our understanding the biological timeline.
On the other hand, we have zero evidence of Silurians or whatever.
Those two observations are inconsistent and require explanation.
Sure, one can hedge and qualify and excuse or whatever, and on pain of irrationality we have to allow that it's possible we're missing evidence of one of a bajillion possible competing hypotheses about intelligent life... but the theory most consistent with the evidence we have is that there wasn't any.
That's falsifiable enough for me?
The criterion of falsifiability pushed by positivists is kind of crappy anyway, it doesn't speak well to how we build models of the world while doing actual empirical work (and is itself non-falsifiable), but in practical terms idk, I don't see much to recommend the Silurian Hypothesis over the null hypothesis, so to speak.
> or it could’ve been the eruption of a monster volcano, the sort that presently smolders beneath the Atlantic.
I know about Yellowstone, Campi Flegrei, etc, but I haven't heard about a supervolcano below the Atlantic. What's that referring to?
There's a seam of volcanic mountains that runs down the center of the Atlantic, but nothing that resembles a supervolcano. The supervolcano complex under the Pacific is one of the largest known in the solar system, however.
> There's a seam of volcanic mountains that runs down the center of the Atlantic
Yeah, that's the pacific rim, which in some sense is the opposite of a volcano.
No the seam at the center of the Atlantic is a mid-oceanic ridge, and it’s very much like a volcano since magma comes out. Icelandic volcanology comes from it being on the ridge.
There are ridges off of the US coast (Explorer, Juan de Fuca, Gorda) but the ring of fire which surrounds the pacific is mostly subduction areas.
Sorry, you're right of course (and yeah, the Pacific rim can obviously not be in the Atlantic, typed too fast there...)
With "opposite" I meant the role in plate tectonics, in that classical volcanoes seem to mostly appear near subduction zones or hotspot but not on the ridges from what I know. (Iceland being the exception, but even there it's because of a hotspot that happens to be located right on the ridge)
But I think the ridge system usually does not have volcanoes in the sense that there are magma chambers that fill up or cause eruptions. So the usual scenario of the "asleep supervolcano" does not apply.
> The supervolcano complex under the Pacific is one of the largest known in the solar system, however.
That sounds interesting. Do you have some links about that?
Reminds me of this comic: https://badspacecomics.com/scour-copy-copy
Technical ceramics would have survived.
I wrote a sci-fi short story on this idea once. It took place in the present, and left the truth of the hypothesis open. Submitted it to Analog, but it was rejected. I suppose there are now places one can self-publish sci-fi stuff, but I'm not sure I can even find my original.
Edit: Did a Linux find, and...it did find the story. Unfortunately, it didn't find me a place to publish it.
I think the article greatly underestimates our archaeological capabilities. We can identify five mass extinctions in the last 500 million years, so why should such a civilization simply be overlooked? Of course, we wouldn't find abandoned ruins, but the idea that an industrial civilization wouldn't leave behind any detectable artifacts is practically impossible. Perhaps there were a few primate species before that could make fire and hunt with bows and arrows, but certainly nothing industrial and hardly any extensive agricultural culture.
> I think the article greatly underestimates our archaeological capabilities.
"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]
[0] https://en.wikipedia.org/wiki/Serpent_Men
The timelines don't really add up for me.
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.
No. The idea is they could have lived and thrived for a few thousand years a few million years ago, then gone extinct.
That's not what the articles says though:
"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..."
That’s not the Silurian hypothesis the astrophysicists put out. That’s the author extending it to fit those myths.
Yeah, the author is contradicting himself here: On the one hand, that civilization must have ended several million years ago, so erosion and plate tectonics had time to erase all traces - but on the other hand, humans were still having lively exchanges with those guys and viewing them as a normal part of their world in 10.000 BC...
Yeah sorry if I haven't made myself clearer, I was referring to the article.
I have a toy hypothesis that once civilization level intelligent life emerges it never disappears barring the planet it inhabits being vaporized by some unfortunately directed GRB or some similar catastrophe.
Our knowledge is becoming holographic such that to prevent the reemergence of civilization one would have to wipe out all of us at once.
depends how you define civilization level life.if you mean we cant be bumped back to hunter gatherers without wiping out almost all of us, you are probably correct. If you mean we will always have computers and the ability to split the atom, i dont agree. Knowledge and industry is way more fragile and we have loat working knowledge of simpler processes in favor of more advanced ones so it wont be that easy rebuilding through the lower rungs of the tech tree.
Surprised so few are pushing back against some of the claims in this article.
Eg that the entire surface of the earth gets replaced in a million years by tectonics.
Many of the large plates are more than 1000km across, they’d need to be moving meters per year for that to happen. In reality it’s cm per year. Also typically it’s oceanic plates that get subducted and take material under the crust, not continental plates. If it were true, then how do we see dinosaur fossils, and creatures even older than that; how do we find rocks that are over a billion years old.
This doesnt reject the possibility that there was a civilization tens of millions of years ago, but it makes the article hard to take seriously. If you’re gonna spend time writing an article on this you might as well try to research it a bit more. Someone is gonna read this and repeat this nonsense like it’s some fun trivia.
> Many of the large plates are more than 1000km across, they’d need to be moving meters per year for that to happen. In reality it’s cm per year.
A plate moving one centimeter per year would move over 10,000 km (6000 miles) over a million year, isn't?
It's two times the distance from New-York to San Francisco, one fourth of the Earth circumference!
And the Cretaceous–Paleogene extinction event was approximately 66 mya.
if all dolphins were wiped out could we know that they were ever here from physical evidence?
We’ve already got fossils of dolphins. Not exactly the species we know today but close enough. We have enough fossils to trace their evolution since their ancestors walked on land. So yes, we definitely would have evidence that dolphins were here.
We’ll never know of the existence of most species that ever existed. Fossilization is rare.
right, so how can one easily say this hypothesis is false? "advanced civilization" seems to be strangely characterized. would something a few steps above beavers be advanced enough?
How can anyone say the hypothesis is true? There is absolutely no evidence for it. It’s just a thought experiment.
Typically the ones proposing a hypothesis have the burden of proof. Still waiting on any evidence in favor of the hypothesis.
I won’t hold my breath.
When people speculate about "advanced" ancient civilizations they usually mean said civilizations had technology at least as advanced as our own if not more so like nuclear weapons, antigravity, modern manufacturing and engineering, etc. A hypothesis that millions of years ago humans or some progenitor could build rough shelters out of sticks isn't particularly interesting.
>The oldest place on the earth’s surface—a stretch of Israel’s Negev Desert
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 ?
https://en.wikipedia.org/wiki/Carboniferous
The claim isn't about the age of rock, but that the surface has churned almost everywhere. Israel does contain the oldest measured continuous surface at about 1.8M yo, but nobody claims to have looked everywhere.
How churned is "churned"? Does this mean particular pebbles have have been found to have lain in their current arrangement for 1.8 million years, or just that not much has happened? I expect any arid region far from the poles or mountains and lacking dune fields will have similar patches of inert land. Much of Australia would fit this bill.
Dr Who and the Silurians had this covered: https://tardis.fandom.com/wiki/Silurian
That is explicitly referenced in the article.
This is a good thought experiment to show how time is as vast as space.
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.
How can a galaxy spanning civilisation fail. If life can spread to other worlds, unless you get FTL, how could you end all life in a galaxy
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.
1.) It's definitely a giant leap from current technology to interstellar colonization.
2.) Other civilizations even in the nearest solar system would basically be impossible to detect. Even in our own solar system, there could be millions of undetected spacecraft right now. They're simply too small to see. To be detectable, they'd either have to be massive and massively disruptive, like Dyson spheres, which are and most likely will forever remain pure fiction, or they'd have to happen to use radio for communication.
3.) There are good reasons for them not to be using radio for communication. They might have discovered a different physical phenomenon that allows them to communicate in ways we can't detect. Or they might not be as reckless as humans and don't want to broadcast their presence and activity to completely unknown and potentially hostile other species.
Not compared to the leap from something as advanced as pyramid building to today, let alone the advancement in the last 100,000 years
Any life form will expand to use all resources. We know that nothing is consuming all resources in our solar system.
Though there is likely life throughout the galaxy, it's probably difficult for one sentient spacefaring race to find another habitable planet they'd be comfortable on, i.e., one with a similar atmosphere and mass. If it's a long way from your planet to another you'd care to set foot on, you're left with lots of space stations. But who wants to live in that precarity?
The main requirement is energy. From stars. Our system has a star, and thus is a resource to be tapped.
Without FTL you don’t get a single civilisation, so even if one civilisation doesn’t rant to expand evolution will mean the ones that do will do so.
So you’re left with “they haven’t tapped our star yet” or “nothing can reach us”
> time is as vast as space.
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.
I’d also say that we do not know for certain that no dinosaurs, such as raptors perhaps, were intelligent enough for language and culture.
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.
So we have microbial fossils from 3.5 billion years ago, fossilised 300 million year old skin, bones from almost 200 my ago, even actually soft tissue inside a fossilised bone from 70 my ago. Ah, footprints too, the most unsubstantial matter of all: pure shape. That's in addition to all the million other fossils that are so common we hardly care: shells, small bones, etc.
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"?
The counter argument: dinosaurs were around for a staggering amount of time, no pun intended. 165 million years is reasonably long enough to ensure they left behind some nests, bones, and a feather or two. Modern humans have been around for more like 0.02 million years.
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.
Yea, but if humans went extinct tomorrow, very little human artifacts would remain after millions of years. Indeed, most would be gone well before that. How much stuff from the 18th century still remains, in percentage terms?
Unless it was burned, melted, decomposed or crushed to dust, it's all out there or in a landfill somewhere.
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?
There would still be many signs. Dug up mines, metal alloys that don't exist in nature along with refined metals in quantities they don't exist, animal and plant species we bred along with all the ones we made extinct.
Very few things would in fact remain, you’re correct. But we’ve also created radioactive elements with half lives of many millions of years.
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.
Indeed. Did a rapid check on T-rex, just as an example. Was around for max 3.6 million years. Max population at any one time must have been around 20k individuals. We have about 150 skeletons.
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.
>We also produce an absolutely staggering amount of artifacts of all kinds, from plastic straws to giant tunnels and artificial caves.
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").
How long to dissolve carved stone sculptures (in sizes ranging from 1cm to 100m?)
And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
> How long to dissolve carved stone sculptures (in sizes ranging from 1cm to 100m?)
A quick search on "rock weathering depth per century" suggests a "typical range" of 0.05 mm to 6 mm, depending on rock type and environmental factors. At 0.05 mm, a stone object with radius 0.5 cm would crumble in 10000 years. With radius 50 m, it would take 100 million years.
I would expect them to be unrecognizable long before that though.
> And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
What do those findings tell you about the cognitive abilities and social organization of the creatures who left them behind?
> A quick search on "rock weathering depth per century"
That's a great illustration of what I meant. Of course an exposed rock consumes away in the space of a few millennia- this is exactly where the "Silurian theory" comes from. Yet it's also obvious that we have plenty of perfectly conserved rocks that are intact after hundreds of millions of years- i.e. fossils. Any small sculpture buried in clay can survive for an eternity.
> What do those findings tell you about the cognitive abilities and social organization
Skin? Like, with clothes on, or the shape of clothes? And shoes and hiking gear? Footprints with the shape of boots? Drawings "I LOVE YOU" in the sand? The shape of a coca-cola bottle buried in solidified clay? Come on...
> Any small sculpture buried in clay can survive for an eternity.
If it's made of granite, maybe. But how many granite sculptures have you seen? Sculptors tend to prefer prettier and more easily shaped materials, like marble and limestone. Those happen to be mostly calcium carbonate, just like bones and teeth, so section 1.2 in [1] (chemical dissolution in acidic environments) applies, along with section 1.3 and [2] (mechanical fracturing and dispersion during wetting-drying cycles).
Even if your sculpture was buried in a maximally favorable environment, it would not have stayed that way over tens of millions of years. 50 million years ago, the Himalayas were just starting to rise as India crashed into Eurasia, Australia was waving goodbye to a forest-covered Antarctica while the Americas, North and South, had yet to link up. At a rate of one ice age every 100k years, 500 ice ages separate us from those days. One is enough to raze half a continent and turn a muddy seabed into granite.
> Skin? Like, with clothes on, or the shape of clothes? And shoes and hiking gear? Footprints with the shape of boots?
This is extremely anthropocentric. A hypothetical "Silurian" civilization would obviously not have been human, and may have had no need for such things. Would bears endowed with human-level intelligence want to wear clothes and boots?
> Drawings "I LOVE YOU" in the sand?
Have any such preserved drawings in the sand been found from the ~200k years humans have been around?
> The shape of a coca-cola bottle buried in solidified clay?
See section 1.3 in [1], and remember that the time scale discussed in that kind of paper is a few thousand years, not tens of millions.
[1] https://www.sciencedirect.com/science/article/pii/S004896971...
[2] https://www.tandfonline.com/doi/abs/10.1179/0197136978063731...
> how many granite sculptures have you seen?
We use enormous amounts of it in construction, cut to precise shapes.
> just like bones and teeth
Of which we have ample amounts of fossils. Even included in marble, which is itself hundreds of millions of years old.
> it would not have stayed that way over tens of millions of years.
So we don't have fossils from hundreds of millions of years ago?
> Would bears endowed with human-level intelligence want to wear clothes and boots?
Absolutely if they had a civilisation capable of producing climate change. We're talking about at least a billion individuals living in all environments on Earth, from the tropics to the arctic, and doing all things an advanced civilization does: farming, mining, building, transporting, exploring etc. At least elements of technical clothing are needed in many of these activities.
> See section 1.3 in [1]
You keep repeating an argument that disproves the possibility of all fossils. Really you can't understand that it's contradicted by facts?
> We use enormous amounts of it in construction, cut to precise shapes.
The question, which you did not answer, was about granite sculptures.
We use enormous amounts of granite in construction, crushed and mixed with cement, sand, and water to make concrete. Larger irregular pieces are also used for roads (under the asphalt and mixed with it) and railways. Some regularly shaped objects made of granite are used in construction, which is not generally undertaken on the kind of waterlogged terrain needed for clay to sink in, and will be subject to weathering at the previously discussed rates, to the extent that they are not broken or recycled when buildings are torn down.
>> just like bones and teeth
> Of which we have ample amounts of fossils.
A few million, counting all fossils of all species which have existed over the past three billion years or so.
Humans are one out of the billion or so species which have lived on Earth [1], the ~200k years we've been around are less than a millionth of that time span, the vast majority of humans never make sculptures, and the vast majority of sculptures are destroyed within a few centuries. But here you are, complaining that we have no sculptures from tens of millions of years ago.
>> Would bears endowed with human-level intelligence want to wear clothes and boots?
> Absolutely if they had a civilisation capable of producing climate change.
Ah yes, I can totally see a bear going "OMG it's getting so hot, I totally need to wear some artificial fur over my own!"
> You keep repeating an argument that disproves the possibility of all fossils.
No. You keep ignoring the time scale, the dynamics and the odds.
[1] https://www.livescience.com/animals/how-many-animals-have-ev...
Actually correct. We have very very few fossils compared to the millions of species that have evolved and gone extinct over 4 billion years.
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.
> It’s more showing you the limits of scientific inquiry into the deep history of Earth.
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.
> 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?
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.
> If humanity vanished today, in 1 million years almost all of our artifacts would be gone or burned under miles of subduction.
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.
Bollocks. We find fossils millions of years old right on the surface.
> under miles 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 really enjoyed this article. It was a very pleasant read. The author should write a book and or movie script. The original Doctor Who Silurian episodes were fun to watch. Makes sense to connect dinosaurs or the remnants of Silurian civilization to dragons and deities. Star Trek Strange New Worlds S04E01 deals with the dinosaurs and Mars @ 65 million years ago. The story is rather intriguing and fun to watch as well. Invincible S04E04 deals with the various ages that planet Earth has gone through and has a different take on the meaning of Hell and Satan and why they exist. Last episode of the Season 4 is rather interesting, as well as it relates to the possible next phase or not, of human evolution.
Time Machine movie reboot did this in opposite direction into future decently well
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
To recognize the possibility, one has to grapple with incredible scale and deep time: In roughly 300 million years (1/10th of the time life has been around), the Appalachians split off from the Atlas; the Atlantic Ocean first started splitting open; uplifts underneath North America pushing the West up from the seabed and caused the rivers to carve millions of acres of sandstone landscape down, leaving towering plateaus, cliffs, and eventually river chasms. Over the 3 billion years before that, what was carried away like so much sediment? What was subsumed by subduction boundaries?
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.
Interesting topic, but (to immediately veer off of it) I really wish he would find another word and stop misusing "conspiracy." The word has already been through hell.
That was my first reaction as well. The author seems very confused about it.
He starts off defining it as something that is unknown or secret, and more specifically, he goes on to say, a secret "kept by a nefarious elite". I suppose secrets are usually associated with conspiracies, but a secret is not a conspiracy and conspirators don't have to be an elite.
And then he says that in this case, it's the Earth itself that's conspiring alone. This contradicts all the dictionaries I consulted, which define it to involve multiple parties, which makes sense considering the etymology.
The fact there is still coal(and oil) in the ground pretty much rules out any "advanced" industrialized civilization that came before us.
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 thing I enjoyed about The Children of Time by Adrian Tchaikovsky: the spiders learned to build "computers" out of ant colonies by hijacking the ants ability to generate and respond to chemical stimuli.
not that it makes me believe in the silurian hypothesis, but i'm always reminded of that whenever i start to think "well it couldn't possibly be done any other way".
Petroleum could be the byproduct of a previous civilization.
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.
> Petroleum could be the byproduct of a previous civilization.
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?
Just fun to think about and base fiction on
I mean, would an ant walking on a highway be able to tell that it's artificial?
Probably not, but an ant cannot do any kind of isotope analysis.
hah
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)
If they’re a bit observant they will see that a humongous number of animals of the same species shows up suddenly, and localised in big numbers. Besides, there are a lot of signs of human activities. We changed the atmosphere in ways that are likely to show up in sediments. We mined all the minerals we could find to turn them into widgets that are not going to disappear. Our plastic items will end up in sediments all over the place, with wrong isotopic signatures. We find them in all places where we can look, down to the bottom of the Mariana Trench. They are carried to the seas by the same rivers that leave the silt that turns into rocks. Beyond that, we are leaving entire strata of plastics and metals in landfills. A lot of the satellites we put up there will fall back to Earth, but not all of them will. Some have orbits that won’t decay in millions years. There is not a single aspect of the planet that we haven’t touched.
> 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?
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)
I'm butt hurt that I'm five paragraphs in and still have no idea what the hypothesis is.
Joe Rogan tier pseudoscience.
Silurian Hypothesis, SETI, a widely help motivation for space exploration, much of sci-fi: all posit a high-ish rate of life (or intelligent life) invention, because the alternative is terrifying. I/we need/enjoy this, but it's fiction. When humans reason about the rate, they're extremely biased by what they want to be true.
+1 in general that anthropic bias is strong, but it cuts both ways, even in relatively hard nosed statistical models (@see Drake equation vs Rare Earth hypothesis). Truth is, there are a ton of factors we just can't observe (yet?) that play a big part. For example, since the rare earth hypothesis was published, we know a lot more about exoplanets, and earth-range size in the habitable zone of a stable star and galaxy appears much more common than we thought. But we don't know if plate tectonics are really required, or gas giant "vacuum cleaner" planets int he same system, or even oxygen. But we do know that the minimum value for intelligent species is at least 1, because we exist.
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.