I'm a geologist and have worked as such academically and professionally. Yes, there would be ample evidence to work out an industrial society jad once been present. The research and discovery would take time, but given what we have done to date there would have been time enough to find evidence of a society like ours.
Wouldn’t all of our oil & gas and mineral extraction leave huge evidence in the geologic record? Even if some aliens scooped up all traces of civilization from the surface, you’d still have all those emptied wells, water-filled wells, evidence from fracking, open pit mining, and all the rest.
If you entertain the notion that 55M years ago the PETM was caused by the Silurian civilization then geologically you have to realize that it was only 40M years ago that the Indian plate slammed into the Eurasian plate and caused the uplift of the Himalayas. Mt Everest just didn't exist at all back then. And shield glaciers have carved the continents on a 100k year cycle for at least the past 1M years which would have destroyed all of the surface mining evidence at northern latitudes. A lot changes geologically over those kinds of time periods.
Of course most of our oil reserves come from the Mesozoic age (66-252 million years ago) so either the Silurians quickly transitioned away from fossil fuels, or blew themselves up and went extinct before they could extract all of it.
Over the timescales we’re talking about, most all of the evidence would be shredded, compacted, oxidized/metamorphized then the above, filled with sediment then the above, etc.
One example of those - Intact fossils are very rare, and life has been ever present on the surface of the planet a billion+ years, near as we can tell.
That said, unless they weren’t around for long or didn’t have much success/impact, some difficult to dismiss evidence would likely to be present somewhere we ran across already - like fossils. Even if 99.99999% of all our evidence gets subducted, anyone doing as much digging 50 million years from now as we’ve done recently would have a hard time missing all of traces we’ve left.
A really weird set of isotopes and geological features
(like in Oklo, but not explainable naturally) from something like the National Test Site, or a layer of something like lead or mercury or radioisotopes in the sediment record not explainable by other means (like we’ve left), or a landfill full of plastic+stainless steel+carbon since metamorphized, or weird geological features like road fragments with no plausible natural explanation.
So unlikely, but not impossible. We are talking lengths of time 1000x (approx.) the furthest back of our own artifacts we’ve found.
The comment presents no arguments aside from a fallacious one (argument from authority).
>but given what we have done to date there would have been time enough to find evidence of a society like ours
Geology is a relatively young science. Today's widely accepted facts were laughed at only a few decades ago. Take Wegener's plate tectonics theory: He was ridiculed for it and it only started to become mainstream accepted opinion among geologists after his death, around the 1960s. Your grandparents may still have been taught the land bride idea¹ when they were kids, which nowadays is seen as extremely ridiculous. Yet many today, who may not consciously be aware of these developments, assume that science™ has always known this and that we basically understand earth. We've barely started scratching the surface, in the literal sense.
As for hypothetical civilizations lost millions of years ago, there is no way one can rationally claim to know for certain, it depends on so many factors. The Silurian is merely an example, since this is a thought experiment. It could have been much longer ago, it's speculation. But let's assume Silurian it is, and let's say plastics would stay detectable that long (we don't know this for sure). All you have to have is a civilization that didn't invent them, or didn't widely use them. And no nuclear bombs either - hardly inconceivable. Though as an aside, the half-life of Plutonium-239 is only around 24k years! So good luck detecting that.
“Laughed at” and “ridiculed” seem to be common aspects of a dysfunctional science culture. In that, I always maintain heavy skepticism of loud, and especially media-echoed, claims scientific consensus. I say that generally.
What if it wasn't at our scale but more like late 1800s europe and limited to regions like phoenicia, mesopotamia or the mediterranean coast.
Places like alexandria have a ton of history under the city that can't be explored because people live there now but what if what people were building on top of 2-3k years ago was on top of a ruins that existed millenia before their time?
When you find roman ruins for example you would stop digging right?
I like the origin of “Silurian”, especially the caveat in the second sentence.
> We name the hypothesis after a 1970 episode of the British science fiction TV series Doctor Who where a long-buried race of intelligent reptiles ‘Silurians’ are awakened by an experimental nuclear reactor.
> We are not however suggesting that intelligent reptiles actually existed in the Silurian age, nor that experimental nuclear physics is liable to wake them from hibernation.
I'm somewhat surprised he didn't talk about evidence of space-faring ancient civilizations. If humans perish and a new intelligent species comes around in millions of years, they would be able to find stuff we've left on the moon, provided we pepper it all over its surface so as to survive any future meteor impacts.
I see people think about what evidence for what we've built might exist after millions of years but I wonder if evidence of what we've destroyed might be more lasting? Just out of curiosity I wonder if in the future we will be able to rule out "natural" causes (such as volcanic activity/meteorites/gamma ray bursts etc) and find otherwise unexplainable mass extinctions.
Read the paper. The fossil record is very incomplete, only a handful of species are known from it compared to the abundance of variations that have ever existed. We have evidence of mass extinctions far greater than that caused by humans but there were many smaller scale ones among the background noise of normal extinction.
Right.. but that's why I said "in the future". I know there's little evidence and I commented elsewhere that this paper comes to the same conclusion as the Kurzgesagt vid. What I'm suggesting is with future tech we might get a better mapping of these extinctions and the identifiable causes if known. I'm not suggesting we will find fossils that just don't exist.. but maybe getting a better holistic view of each layer around the earth.
Shouldn't atomic testing have produced a layer of light platinum group elements (predominant in fission products) that are not associated with heavy platinum group elements (rare in fission products)? Anomalies in the concentration of PGEs have been seen as indicators of meteorite impacts before:
Perhaps we should create stone tablets akin to the voyager records that we scatter all over. Ideally they give a set of precise dates and times where we plan to be “listening” — just in case we can test whether we can receive messages from the future.
The Dark Forest idea was pretty convincing to me. I'm not sure we should throw around information about our existence, not until we learn more about other space civilizations.
Readit News
Of course most of our oil reserves come from the Mesozoic age (66-252 million years ago) so either the Silurians quickly transitioned away from fossil fuels, or blew themselves up and went extinct before they could extract all of it.
One example of those - Intact fossils are very rare, and life has been ever present on the surface of the planet a billion+ years, near as we can tell.
That said, unless they weren’t around for long or didn’t have much success/impact, some difficult to dismiss evidence would likely to be present somewhere we ran across already - like fossils. Even if 99.99999% of all our evidence gets subducted, anyone doing as much digging 50 million years from now as we’ve done recently would have a hard time missing all of traces we’ve left.
A really weird set of isotopes and geological features (like in Oklo, but not explainable naturally) from something like the National Test Site, or a layer of something like lead or mercury or radioisotopes in the sediment record not explainable by other means (like we’ve left), or a landfill full of plastic+stainless steel+carbon since metamorphized, or weird geological features like road fragments with no plausible natural explanation.
So unlikely, but not impossible. We are talking lengths of time 1000x (approx.) the furthest back of our own artifacts we’ve found.
>but given what we have done to date there would have been time enough to find evidence of a society like ours
Geology is a relatively young science. Today's widely accepted facts were laughed at only a few decades ago. Take Wegener's plate tectonics theory: He was ridiculed for it and it only started to become mainstream accepted opinion among geologists after his death, around the 1960s. Your grandparents may still have been taught the land bride idea¹ when they were kids, which nowadays is seen as extremely ridiculous. Yet many today, who may not consciously be aware of these developments, assume that science™ has always known this and that we basically understand earth. We've barely started scratching the surface, in the literal sense.
As for hypothetical civilizations lost millions of years ago, there is no way one can rationally claim to know for certain, it depends on so many factors. The Silurian is merely an example, since this is a thought experiment. It could have been much longer ago, it's speculation. But let's assume Silurian it is, and let's say plastics would stay detectable that long (we don't know this for sure). All you have to have is a civilization that didn't invent them, or didn't widely use them. And no nuclear bombs either - hardly inconceivable. Though as an aside, the half-life of Plutonium-239 is only around 24k years! So good luck detecting that.
¹ https://people.wku.edu/charles.smith/biogeog/pics/sim1940e.j...
Places like alexandria have a ton of history under the city that can't be explored because people live there now but what if what people were building on top of 2-3k years ago was on top of a ruins that existed millenia before their time?
When you find roman ruins for example you would stop digging right?
Would it be possible to detect an industrial civilization in geological record? - https://news.ycombinator.com/item?id=24601375 - Sept 2020 (178 comments)
The Silurian Hypothesis - https://news.ycombinator.com/item?id=21840320 - Dec 2019 (52 comments)
Deleted Comment
> We name the hypothesis after a 1970 episode of the British science fiction TV series Doctor Who where a long-buried race of intelligent reptiles ‘Silurians’ are awakened by an experimental nuclear reactor.
> We are not however suggesting that intelligent reptiles actually existed in the Silurian age, nor that experimental nuclear physics is liable to wake them from hibernation.
And just like the paper, it acknowledges the challenges in detecting such evidence due to the limited and complex nature of the geological record.
https://www.un.org/sustainabledevelopment/blog/2019/05/natur...
A refreshing conclusion to an academic paper, and beats the hell out of "further study is needed."
https://en.wikipedia.org/wiki/Iridium_anomaly
The article mentions 244Pu and 247Cm, but ruthenium is produced in larger quantities and is stable.