Posted by andsoitis 6 hours ago
"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...
Though I'm kind of disappointed the last section did not end with fusion power, stellar migration and artificial intelligence...
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.
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).
Jokes aside, what is the evidence, beyond "Ancient mystical texts"?
[0] http://www.myths.com/pub/fiction/science-fiction/Asimov/Nigh...
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...
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.
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.
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?
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.
Nah, you way off on that, coastlines have remained relatively same last million years, def not subducted into an ocean trench
We have plenty of fossil evidence from, from your example, a million year old hominids. Far more than we would need to expect to see evidence of civilization.
Subduction makes up for a tiny tiny proportion of where coastal land "goes" in any age.
You'd need an enormous set of coincidences for a past civilization of hominids to go unnoticed.
I know about Yellowstone, Campi Flegrei, etc, but I haven't heard about a supervolcano below the Atlantic. What's that referring to?
Yeah, that's the pacific rim, which in some sense is the opposite of a volcano.
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.
"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]