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- Hacker News
- Technical ceramics would have survived.by Robotbeat
- > 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?
by xg15 - 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.by MrDrMcCoy
- Reminds me of this comic: https://badspacecomics.com/scour-copy-copyby Qem
- 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...
by senshan - 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.by graemep
- 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"?
by throw310822 - > 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.
by fnord77 - 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.
- 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.
by gorgoiler - 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...
by dav_Oz - 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...)
by tonymillion - 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".
by inhumantsar - 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.by hliyan
- 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.by mda
- 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.by neaden
- >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
by engineer_22 - 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.
- 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?by markus_zhang
- > 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.
by kergonath - 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.
by jerf - 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...)by dash2
- > I can't speak to dinosaur people
Dash out of context
by rubylimetea - they could be distinctly different dna, wiped out and evolved again from scratch.
- I know, let’s modify our DNA so if we’re wiped out nobody will ever know we existed!by simonh
- 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?by graemep
- >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 ?
by jmclnx - 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.by delichon
- 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...
by GolfPopper - 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...
by xg15