Time is stupid big.

As per the article, that civilization would have to predate all of the vast history of evolution that we know of. Wouldn't some higher life forms from such an earlier civilization have been in the fossil record?

https://en.m.wikipedia.org/wiki/Columbian_exchange

You would see some species inexplicably take on a worldwide distribution, or see species suddenly turn up on far away landmasses with no good explanation.

https://en.m.wikipedia.org/wiki/Chorioactis

The link above is fascinating, but I do not think it is evidence of any past civilization. This probably happened naturally, but it does seem exceedingly rare. If there were a past industrial civilization there would probably be tens of thousands of examples like this one.

It could also be that introduced species are less likely to be found in the fossil record for whatever reason.

Then again, maybe we have found such a thing but haven't recognized it for what it is due to missing context.

I also assume that these species, often invasive, would outlast the civilizations that introduced them. So you could probably also infer some of this by looking at descendant populations.

If we lacked progenitors of those species in some places, we would just call it a temporary gap in the fossil record, of which we have many.

We're pretty good at inventing explanations. Eventually these gaps might start looking conspicuous, but I'm not sure if we're at that point yet.

Eventually there might be enough separate lines of evidence to refute these possibilities, but no one aside from those on the fringe would entertain the possibility that this was evidence of an advanced culture without overwhelming evidence.

Percentage of total biomass is more interesting. The more (and bigger) bodies, the higher the likelihood of being fossilized.

Why does an industrial civilization need to be global?

Our industrial civilization appeared extremely quickly, perhaps in the past 300 years, but it happened to appear within a preexisting global trade and travel network. An industrial civilization which existed for a few hundred years, outside the context of such a network, might not ever see the need for one.

Im reaching here, but: https://en.wikipedia.org/wiki/Cat_gap

We know there were civilizations in North America such as the Mississippi River valley mound builders - but our knowledge tops out at “they existed”. It would not surprise me if agrarian civilization rose and fell multiple times due to climate change.

We might find some old equipment from an elder spacefaring species. If we don't find anything, maybe we should leave some human monuments out there so the next civilization can know about us.

> The points L1, L2, and L3 are positions of unstable equilibrium. Any object orbiting at L1, L2, or L3 will tend to fall out of orbit; it is therefore rare to find natural objects there, and spacecraft inhabiting these areas must employ a small but critical amount of station keeping in order to maintain their position.

Casting iron(copper) is relativly easy and powerful.

Experiment with hot things in fire and you will discover it after a while.

"Why couldn’t they have use some natural form of biodegradable materials?"

Like bones for bows and spears? Humans did that, but metal is apparently more effective and useful.

Also, there's essentially nothing you can't do with stone given primitive tools, sand, and a shitload of talent/time. One thing about ancient people is that they had all of these in abundance. Making arguments from the position of "they couldn't have done this with the tools they had" is almost always wrong because it's coming from a modern perspective of how tedious and uneconomical it'd be to do it today.

Again, you can do this to shape virtually any rock. Stonemasons don't do this today because it's excessively annoying and slow. It's not a coincidence that khafre enthroned is a royal piece for a wealthy and powerful pharoah.

Most people will have some familiarity with emery cloth/sandpaper, which are basically the same principle. We don't even need to look at fancy egyptian statues. Carnelian beads were a common trade item across the Ancient near east and Egypt made this way. It's not magic.

I think we just don't comprehend, as mentioned above, how much time and effort could be allowed for back then. I'm sure 100 people could create a near perfect vase given 30 years to work on it (random example).

This idea that its just not feasible because it is hard ignores existing architecture that we can date in places like China and India, but cannot easily replicate in the US or other spaces because the generationally developed skill and method is not available.

This precision occurs in hard materials like stone, in massive scale as well as in soft materials like cottons and silks which weren't replicated in Europe in previous or current times.

https://www.bbastrodesigns.com/JoyOfMirrorMaking/Intro.html

How absurd! Skill and craftsmanship can get you far, but they will not allow you to craft with such precision that it's imperceivable to the human eye, how could they even verify their efforts? The video, while long, presents dozens of well structured arguments with strong evidence, your dismissal comes off as extremely arrogant and foolish in comparison.

It doesn't take advanced technology to do either of those things.

My favorite one was pi is there in the relationship between the pyramid base length and its height, and the Egyptians had no notion of pi. Again, space aliens! But if the Egyptians used a wheel 1 cubit in diameter to mark out the base, and the height was in cubits, then there's pi.

(What's a cubit?)

In fact most earthly rock is relatively young.

Plate tectonics was such a clever idea. So obvious now, I mean just look at a map of the world of course continents were once one, you can see where they join, like a jigsaw puzzle.

It astonished early western explorers finding seashells on mountains!

the main crux of these arguments always depends on how it's hard to prove something didn't happen without exact historical evidence for every single organism in every single recorded geologic period, which is a terminating thought to actually holding a rational conversation. OK, cool, then we also: live in a simulation, are observed by aliens or influenced by aliens, move to alternate realities every time we sleep, etc. wow, so "interesting"!!

0: https://www.scientificamerican.com/article/superworms-eat-an...

"Rinke and his colleagues are not suggesting that superworms should be released into landfills or polluted landscapes to munch through mountains of plastic"

Sounds like they invented the magic wand.

In general the statement "They couldn't have been civilized because they aren't exactly like us" limits what we look for and how we look for it.

The actual question the article posits is "Could an Industrial Civilization Have Predated Humankind?", and so it seems logical to take evidence of industry as a starting point to answer that question. A mere couple of hundred years of human industry has moved vast quantities of matter about, created many new types of molecule, demonstrably altered the climate and filled sediment beds with objects far more eyecatching and likely to be preserved than the dinosaur feathers and skin prints and footprints we've found fossils of. An industrial civilization need not regard combustion engines as the most useful power source, prefer wheels to gliders or think straight lines look cool, but it does need to be characterised by some sort of industry.

A hypothetical species of dinosaur that spent its life writing beautiful poetry, studiously avoiding dropping its organic tools anywhere they might be fossilised and generally being content enough with its life to not try to remake the planet for its convenience might even be more intelligent and cultured than us, but it wouldn't be an industrial civilization.

neurons, however, fossilize very poorly indeed; after death they typically liquefy within days, losing all of the structure that could betray how they functioned

the particular shape of our industrial civilization is based on mass production in centralized facilities of durable goods that are identical to high precision (deep submicron precision in the case of this cpu). clearly this is not the only possible way to produce massive abundance; the rain forest or even the corn field does not work this way, but produces much more detail than tsmc does

much of the durability and fossilizability of our conventional technology stems from its stupidity. to remain standing, a two-story house would once be made with meter-thick walls, while modern hollow brick with plaster and reinforced concrete reduces this to perhaps ten solid centimeters between indoors and outdoors. more frugal balloon-frame designs consist entirely of metastable materials like wood and steel, materials which will lose their structure if left exposed to air and water, either suddenly in a fire or gradually over decades. but even a balloon-frame house is wasteful and inefficient compared to a five-meter-tall stand of bamboo

remaking the planet for your convenience is much cheaper if you can avoid spending resources on durability and fossilizability which don't benefit you during your lifetime

could you get there without a transitional phase of making lots of thick, solid objects out of materials that are stable on geological timescales? probably, but maybe not if your uplift path starts with fire instead of math...

So, a very wide range of "industrial civilizations" would be expected to leave behind lots of basic natural materials in artificial forms. Their basic natural materials would be about the same as ours because they are found in nature and not very diverse (compared to high tech pharma chemicals or digital algos), so we ought to be finding lots of evidence of pre-human low(ish) tech, even if they were quite high tech.

Take plastic or metal. Their main draw is that they do not decompose or degrade. There are a billion problems that can be solved when you have a material that does not naturally degrade or decompose.

So even if this civilization did not use plastic or metal, I find it hard to believe they didn’t come across a problem that needed a stable non-self-destructing material, which would then have been left behind for us to discover now.

It’s not feasible to build anything advanced if all your materials naturally decay.

It’s true that there are fewer decomposing organisms the farther back you go, but you have to go way way back to a point where the chance of intelligent life existing is pretty low.

I just find it hard to believe there to be not a single trace of anything.

What is the word industrial? Metallurgy, mass production, interchangeable parts, and the steam engine. Materials, tools, efficiency techniques, and energy.

The other aspect of industrialization is the sheer scale of it.

Honestly the only thing that comes close IMO is a lot of the cellular mechanisms. It uses materials in novel ways, efficient protein devices, and ATP energy. But I don't think it would scale to macro levels.

Maybe you could squint and look at ant/insect colonies?

What’s that?

Well if you go back to the dawn of Homo Sapiens that's quite a ways back, but then you could rearrange that concept to say "they couldn't have been that uncivilized because they were exactly like us."

Oh, wait a minute . . .

That, and the fact that we've found one antiktythera mechanism and nothing like it before or since raises questions. It seems implausible for a culture to produce a singular advanced mechanical computer with no precursors and then stop and never make anything like it again.

This could lend itself to the idea that one person made it, and if nothing whatsoever like it had ever come before you have to figure it took an awfully long time for one person to create something this complicated single-handedly.

Could be a number of years between iterations in a continuous improvement process that adds up to something like a life's work.

Maybe also could be passed down to a subsequent individual like a very specialized craft, and build technology across generations.

While I don't think that the following implies that robots existed, to my above point recall that Talos of Greek Myth is a robot.

Which does imply that the concept of such tech was shared across the entire culture. Which, in turn, suggests that related tech is less likely to be the product of one mind.

Extrapolating automatons only requires having basic concepts of mechanical automation, which the Greeks very much had.

The idea of space flight predates powered flight by centuries.

A culture didn't create it. A person or team created it. The Antikythera mechanism was built before the ISO 9001 specification so its documentation may not have survived long past its creators lives. The high precision manufacturing required, in an era before high precision was all that precise, suggests the mechanism was likely a rare artifact. It was dumb luck it was found in the first place.

There's likely many complicated ancient devices lost to time because they weren't widely available or described in documents that have persisted. You literally run a search engine for marginalia that may not be popular or widely known. It wouldn't take much to knock a lot of that content off the web and be lost to history.

Well that's my point. Not that the greeks had some forgotten industrial revolution, but that archeological records are very limited, and we were a stroke of dumb luck away from never discovering the antikythera mechanism. It raises the question of if we almost missed this, what else did we miss. Not just in greece but elsewhere too.

Right now about 30 billion tons of concrete are used by our species every year. If there were industrial civilizations of that scale, you'd have a whole stratum of very obvious artificial origin between the rocks.

Not only that, they would have had to achieve complete perfection because we haven’t found a single trace.

Where are the high relief carvings that predate Gobekli Tepe, which served as the skill development toward it?

For example.

And we don't need to go nearly that far back to notice lack of ancient metal that had to exist, given what it accomplished.

Metal disintegrates fast. Megalithic evidence, at minimum and across history, implies a woefully incomplete archaeological record.

From what I recall, until iron/steel was invented, it was pretty much abrasion as bronze was not hard enough to chisel nearly every stone.

Perhaps, I suppose. I don't know enough about the physics and control of the abrasive techniques referenced. Though, I'm always in favor of emphasizing plausible variables that weaken a hypothesis.

What are the chances that abrasion work like that, hypothetically, was so specialized and unknown in 10,000 BC that Gobekli Tepe's high relief sculptures are the sole examples of that period and the earliest examples of such large and truly technical work? Nevermind the artistic skill that is reflected.

Cro Magnon was carving anthropomorphic stone statuettes in the region of modern Germany in 40,000 BC.

Food for thought: the Tell archaeological sites that dot the Fertile Crescent, which includes the Haran area (Gobekli Tepe), contain the most concentrated evidence of human technological firsts that seems to exist. Including evidence of earliest metalsmithing tech, if I remember correctly. See Yarim Tepe for a jumping off point.

So the situation is:

a. Stone carving predated Gobekli Tepe by at least 30,000 years b. The earliest known stone carvings were not in the region of Gobekli Tepe. Implying that stone carving culture and tech was known far outside of Mesopotamia, from an extremely early period. c. Gobekli Tepe's specific accomplishments are the first evidence that we have of such advanced sculpture and megalith construction skill. d. Metalsmithing arose in the immediate regions and cultures that included the area of Gobekli Tepe.

So on one hand we have widespread tech suggested to be responsible for highly technical stonework in one area, and on the other we have specific tech (metallurgy) arising out of that same area.

It could be a coincidence, but arguably it would be a large one.

[1] https://stonetoolsmuseum.com/technique/pecking/

Add time to that, so that your project can have a scope of generations, passing down knowledge gained from a lifetime of doing this particular thing, the results become unsurprising even.

Amazing, inspiring and ingenious but also unsurprising.

I guess industrialization has made lot of people oblivious to this fact.

Whatever metal objects from ancient civilizations we know, are either grave goods (swords of warriors etc.), or were found in shipwrecks etc., or were found in destroyed settlements, plus a few accidentally lost (fell into a well etc.). But most metal objects get recycled.

Mostly flint. It's a seven on the Mohs hardness scale which is harder than unhardened steel tools.

Archaic humans have been making flint tools for millions of years.

> Where are the high relief carvings that predate Gobekli Tepe, which served as the skill development toward it?

Where to begin? Abri Castanet 35 kYa [1]. Venus of Laussel 25 kYa [2]. Roc de Sers cave 17 kYa [3]. There are countless other examples - most of them don't event have wikipedia pages.

Oldest known engravings by an Erectus are about 500,000 years old so it's been in the family for hundreds of thousands of years.

[1] https://www.archaeology.org/issues/63-features/top-10/270-to...

[2] https://en.wikipedia.org/wiki/Venus_of_Laussel

[3] http://www.visual-arts-cork.com/prehistoric/roc-de-sers.htm

There is so much cosmic space that exists between any two historical artifacts. There's definitely room for a multitude of completely unpreserved civilizations.

On-the-nose reading that comes to mind, Of Ants and Dinosaurs by Liu Cixin... very anomalous book / quick entertaining read...

For example, when you are debugging code, you usually have an idea of where the error might be. So the process looks like: print at line 43, is everything as expected? yes, so print at line 48 and try inspecting values at the suspected code path in search of errors.

The same detective-like work (which he calls question and answer) is used by historians and archaeologists to reconstruct historical narratives. If you don't have specific questions in your head and a way to falsify them while trying to answer a question, you likely aren't going to learn as much.

https://en.wikipedia.org/wiki/List_of_human_evolution_fossil...

The authors of the Silurian hypothesis paper believe it's unlikely that there was an ancient non-human industrialized civilization. But they think if there was we wouldn't find its fossils. We might need to look for other markers like climate variances, radioactive materials or artifacts on the moon. Maybe some civilization arose, got stuck in the bronze age or early industrial tech for a thousand years, didn't generate those signatures, then died out. If our fossil record isn't thorough enough to find them then that possibility seems hard to disprove.

Wikipedia has a bit more detail on the Silurian hypothesis: https://en.wikipedia.org/wiki/Silurian_hypothesis

And the actual paper is here: https://www.cambridge.org/core/journals/international-journa...

In otherwords this is a supernatural, not natural hypothesis.

In other words, that’s more of a religious rather than scientific hypothesis.

It’s cool to have inspiration from where-ever, the whole point of religion and art is that they don’t need to be scientific.

But one really shouldn’t confuse non-scientific inspiration with actual science. Confusing the two leads to arguments like earth is 6000 years old and god just faked all the fossil evidence etc.

I get what you're getting at, but I don't think it's so clear cut. Religion is more about organizational beliefs than just beliefs. Many parts of science are pretty far fetched in terms of us only knowing a bit with a very tightly constrained perspective (humans sitting on Earth with limited technology in the Solar System in the Milky Way) but making leaping conjectures. So in fact, science and religion have some shared analogues. (C.f. Paul Feyerabend.)

Certainly, the hypothesis you replied to is incredibly far fetched. But I don't think it's religious. It's more fantasy.

You'd need a civilization that did not produce long-lived technological signatures (e.g. glass panes), that did not have a large number of individuals (i.e. produce remains), that did not substantially alter their environment (i.e. leave geographic markers), AND that did not consume easily available resources (e.g. oil/gas or metal ore).

Which is to say... possible, but not very likely.

[0] https://en.m.wikipedia.org/wiki/Drake_equation#Equation

This is the topic of the paper, I think the authors settled on climate markers and radiation from elements like plutonium-239 as among the very few pieces of evidence that might still be around on that time scale. They also observe that there has likely been enough exploitable energy in the form of oil, natural gas etc. to support an industrial civilization since about 250 million years ago.

It's chemically inert like aluminum (after oxidizing, e.g. foil), so the processes acting on it are mechanical and subject to probability.

Some amount is going to be abraded, buried, etc, but you only need a few pieces to remain. Given their ubiquity in our culture, there'd be some somewhere.

Yet we can barely imagine a society without wheels, but some human cultures in South America didn't get that idea.

Assuming that every civilization invented glass is very tenuous.

Dinosaurs presumably fossilize very badly compared to many artificial artifacts, like buildings made out of machined stone.

They wouldn’t fossilise. That’s specific to the porosity of organic tissue. They might be preserved, but the Cambridge paper explains why it’s unlikely they would last for a hundred millennia or more.

Why? The Cambridge paper gives a scientist’s reasons for that not being the case being supposition.

Pompeii looked remarkably fresh when dug out.

The point stands, most things don’t survive all that long (in the grand scheme of things). Occasionally, the conditions are exactly right to preserve something, but there is a limit.

However, that happened very early in the history of the solar system, likely before life had a chance to start.

Those things also are all in the probability.

The answer was "not much", aside from discrepancies in metals distribution, with intriguing concentrations of iron oxyde, nuclear waste, or gold.

I am aware it certainly isn’t the most scientific or authoritative of sources, but they made interesting points.

[0]: https://worldbuilding.stackexchange.com/questions/117267/hum...

Welcome to the Anthropocene, Earth's new chapter (phys.org)

https://phys.org/news/2023-07-anthropocene-earth-chapter.htm...

    Since 2009, a cloistered band of hard-rock geologists and other scientists have toiled on a mission of great consequence.

    On Tuesday they will deliver the last of their findings—the location of ground-zero for the Anthropocene, the proposed geological epoch borne of humanity's outsized impact on the planet.

https://phys.org/news/2023-07-weight-world-fell-geologist-sh...

    Zalasiewicz pointed to an "embarrassment of riches" of evidence locked in ice cores, sediment and coral skeletons: microplastics, forever chemicals, traces of invasive species, greenhouse gases, and the fallout from nuclear bombs.

https://phys.org/news/2023-07-proof-humans-reshaped-world-ch...

    When aliens or our distant progeny sift through layers of sediment 500,000 years from now to decode the Earth's past, they will find unusual evidence of the abrupt change that upended life half-a-million years earlier: chicken bones.

Much more than we are finding. The earth would be a mess with plenty of really puzzling events.

Wild tomatoes with narcissus and flounder genes for example.

Sudden extinction of entire groups of animals and plants

Radioactivity holes and missile holes fosilized with metals in the bottom

A collection of grey granite from Canada carved in lames of uniform thick. Plates polished for no reason and accumulated in specific locations. At 20 meters another set of lames of black granite and 30 meters far away a lot of yellow marble only known from Italy. All wrapped in asphalt, gravel, glass and concrete. Cities and cemeteries in particular would be a geological nightmare waiting for an explanation. Dumpsters would also be very strange

Gems also. Diamonds carved in impossible shapes all ending in a more or less conical tail. Strange collections of elements with unique properties of the periodic table found always together: Mixed minerals found near, gold, silver and platinum, at tens thousands of Km far away from its known mines. As they are often saved in fireproof boxes, would had survived miraculously in burnt areas.

Implants. Titanium fossils shaped like the femur of an animal and always the same animal would be enough to show a civilization.

Here are a few examples: * https://en.wikipedia.org/wiki/London_Hammer * https://en.wikipedia.org/wiki/Coso_artifact * https://en.wikipedia.org/wiki/Nazca_Lines * https://en.wikipedia.org/wiki/Yonaguni_Monument * Parts of the Egyptian Pyramids seem to have been cut with circular saws. * Places in the ancient world seem to have been nuked, including the ancient city of Sodom. * Some ancient maps are amazingly accurate, when they should not have know the shapes of land masses.

I'm NOT saying any of this proves the Silurian Hypothesis. I looked into some of these claims, and realized how hard it is to be an archaeologist. The amount of stuff left behind is small, and you can never be sure who did what to it over the centuries.

Artifacts are not stored in hermetically sealed containers until archaeologists dig them up. Instead, artifacts mix with their environments for centuries. This mixes up the carbon and makes carbon dating iffy at best.

I classify archaeology as a pseudo-science.

If my hypothesis is that pottery will look like this after being buried for 2,000 years, how do I test that? I don't have 2,000 years before I need to publish.

So anyway, since fungi and bacteria are more evolved today, it's unlikely that such massive buildup of organic matter would occur again. Any given burial event would trap less organic material, so the resulting fossil fuel deposits would be smaller and it would take much longer for a given amount of carbon to be buried.

Of course this is just one theory and there are many other factors in fossil fuel formation as well.

https://en.m.wikipedia.org/wiki/Carboniferous

Wood was important in the US for industrialization. Unlike Europe, the US had lots of forests. Those might be enough for start.

Also, we know how to make electricity from solar, wind, and hydro. They need electricity and good design so may not work in beginning but for later stages.

As a cynical young adult I always giggled at the 'coke express' train cars that flew by on the railroad tracks but nowadays I know what that means what it's used for and how we get it.

I.e. so many of our modern industrial processes still depend on coal, and the alternatives often require huge energy inputs themselves.

https://www.hou.usra.edu/meetings/lpsc2015/eposter/2660.pdf

If that slide was a joke, they should have made it obvious for those looking at the slides without context of a presentation.

John E.Brandenburg

https://www.tsijournals.com/abstract/evidence-of-massive-the...

In this case, that's some industrial grade bullshit !

https://www.youtube.com/watch?v=0xOGeZt71sg

https://youtu.be/0Y8v3X6Oft4

I'd be really interested in generating on the fly numerical apophenia like those. In fact I dabbled into doing exactly that using GPT to code a python script. I ran L-BFGS-B on a unit pyramid to optimize its basic dimensions (height, base-length, set to 1 initially) so that it matches the pyramid equations [1]. As a result I get the pyramid's actual dimensions. My synthetic pyramid is slightly better than the actual pyramid when it comes to matching the "pyramid equations". I know this is tautological, yet when I observe the actual pyramid dimensions and where it fits on the gradient magnitude graph my script[2] provides, it falls right when the gradient becomes almost flat. That made me want to explore further, and I attempted to come up with my own crackpot equations using symbolic regression/genetic programming[3]. The ultimate goal: a VR app, let's call it the "conspiracy lens".

[1]https://tobeornottobe.org/the-great-pyramid-intro/math-const...

[2]https://pastebin.com/TsUtcWAa

[3]https://pastebin.com/9CEU76K6

There's a field studying this kind of stuff: https://en.wikipedia.org/wiki/Relevance_theory

And look what I found: https://journals.openedition.org/tipa/3068 – Louis de Saussure & Tim Wharton, 2019

Seems like the de Saussure family still has a very robust scientific tradition. The most famous of the de Saussure, Ferdinand, founder of synchronic linguistics, got trapped into an apophenia trap with his theory of "hypograms" underlying saturnian verses. More at https://www.degruyter.com/document/doi/10.1515/sem-2016-0158...

https://rationalwiki.org/wiki/John_Brandenburg

It's pretty funny.

“The best [counter-argument] is probably the issue of deep mining,” Schmidt said. “We are mining very old deposits for metals and ore, and if these had been depleted by a prior civilization, it might have been noticed. These place limits on the scope of a prior civilization, but don’t eliminate the possibility.”

This has interested me before, and I think it's good evidence to the contrary.

I am not a geologist, but from what I know, "Very old" means the precambrian shield in Canada, for example, which is among, if not the, oldest rock on earth (~3.6Gy). Oldest, because before that time, the planet was molten on its surface. We're mining that today, and the geology can be fit to geological models: afaik, the geology being encountered in the very old rock is what people expect to see from naturally-occurring processes.

I do still wonder, though, what rock would look like after ~billions of years, if parts of it had been mined out, and whether that mining would be detectable. The rock is hard rock; would you see a corridor of rubble in solid rock, from a collapsed tunnel? Or are there still enough geological forces acting on the rock to turn the rubble from a collapsed tunnel into something resembling metamorphic placer (river-borne) rock, for example?

Interesting question, either way.

https://en.wikipedia.org/wiki/Silurian_hypothesis

The Silurian hypothesis is a thought experiment which assesses modern science's ability to detect evidence of a prior advanced civilization, perhaps several million years ago. The most probable cues for such a civilization could be carbon, radioactive elements or temperature variation. The name "Silurian" derives from the eponymous sapient species from the BBC science fiction series Doctor Who, who in the series established an advanced civilization prior to humanity.

Plates shift and subduct. Huge sections of land suddenly (geologically speaking) find themselves under the ocean. Just read about "Doggerland", or "Beringia", and you realize that the history we have is only the history of things that remain on the surface of the earth.

Seeing as there are only a few logical options:

* We stop being able to advance computing power

* We somehow make it impossible or undesirable to create a realistic simulation

* We destroy ourselves

* We advance to the point where can and do create realistic simulations

Then there is a very good chance that we are in fact, living in a simulation.

We're as close in orders of magnitude to the size galaxy 10^20 as we are to the nucleus 10^-18. Or put it another way, there is the same amount of units of proton radius in 10 meters as there are 10 meters in the entire Galaxy.

Another way to look at it, is that the most plausible assumption about self- simulation is that it is maxed out at some constant efficiency, say you need a system that is 10 times bigger. Then the entire babushka of simulations are merely a geometric series, and in fact you're most likely to exist in the outermost babushka except the most efficient of all simulations.

If you assume the world is a simulation, it must be an imperfect simulation that shortcuts away several orders of magnitude compared to whatever it is meant to mimic.

I don't assume we are in a simulation, but I do agree with the bullet points I stated. Do you?

Funny enough there are actually one or two Ancient Alients episodes on this topic. One asks the same question and draws the same conclusion (i.e., it's hard to say, but certainly not impossible). The other is about odd out of the ordinary artifacts. One of the more intriguing ones was a hammer type object found in sandstone (?), and evidently such rock requires millions of years to form.

```

However, there are plenty of documented, though not widely known, reasons why the methods used to date ancient earth materials are faulty.4 In fact, when "300 million year old" coal is examined for carbon, it routinely returns measurable radioactive carbon-14, which would have disappeared by radioactive decay in under 90,000 years.5

Also, the Bible's historical information documents a world that is only thousands of years old. In this context, deeply buried coal deposits were produced by the historical Flood of Noah.6 The people who were alive back then could have provided coal-embedded artifacts.

```

Oh, are we doing a fun thought experiment? Entertaining the idea that the coal was formed merely thousands of years ago? Like, in the time of the Ancient Egyptians? It's coal made of mammoths? I guess it's possible, but... :D

Yeah, nope, not bothering to read that. It is ridiculous the lengths to which people will go to justify the balderdash in an old cracked book written two thousand years ago.

But that assumes every intelligence operates like our own. Heck you even see that with the difference in worldview that Westerners and indigenous people have. That's why I can imagine a species that chose to focus its energies on other things than resource extraction and industrialization. It's not a bad path for us to consider.

It is an interesting thought exercise though.

The probability is so low that we are the first true industrial civilization to have been on this planet’s 4.5 billion years, yet here we are.

Anyway, I would bet that the 'terrestrial great filter' is evolutionary selection for large brains. Big brain costs a lot of energy and makes birth difficult to the point that humans have to be born prematurely and are as newborns utterly incompetent compared to other animals. And marginally better brain gives very little advantage to gene spreading.

This means there can't have been a civilization that routinely traveled between the continents during that time.

When one digs into the history of Socotra going back about 8 million years iirc, I believe that there is logical evidence of homo sea travel millions of years ago. Going on the timelines of Socotra's emergence as an island, of homo species, and of the evidence of who resided on Socotra.

We need to survey the areas of the ocean less than about 200 foot deep (and the seabed below them) to see what mankind was doing before the sea level rose to the current levels.

https://www.cbsnews.com/news/human-dna-tied-mostly-to-single...

A species with human-level technology could survive even the Chicxulub asteroid that killed off non-avian dinosaurs, given the huge population and vast range that industrial civilization enables that species to attain, as well as the diverse array of energy sources, and robust habitats that become accessible to such a species.

Getting rid of every member of species that is adapted to wide range of environments and globally spread might be impossible. And likely they would at least leave some evidence somewhere. It is not like every surface of planet has gone through ice ages or other events grinding away the top soil.

That humans could be reduced back to scattered pre-industrial tribes, many people would call an "existential" crisis. Even if a species of animal called Homo Sapiens would still survive.

I think a lot of people would disagree that this is a good outcome, even if some humans are still alive and wondering around.

Hindus, 1/6th of the world population usually cremate their dead.

The bodies are gone.

And the bones are washed away into ganges.

I would guess Hindus in USA or Europe would do the same.

An archeological study of skeletons in 4000 AD would drastically undercount groups that cremate their dead. Or won't it?

Cataclysms have rewritten the surface geography many times, and combined with erosion and more gradual plate and water changes, the Earth has buried, eroded and eaten most of the evidence.

What little there has been, has been covered up and sequestered away for the same reasons the alien UAP info has been: because the rulers of men are terrified their subjects will see something else besides humans, more advanced, because they fear it will erode their authority and influence.

It’s never been because “we can’t take it, therefore suppressed for ‘our own good’” — that’s just how we’ve been gaslit — it’s always been because our rulers are terrified. We’re an ape species and therefore tribal and hierarchical. A new alpha is a serious destabilizing threat to those who see themselves as the existing alpha.

As a species, our collective mind has grown up with blinders on, shaped, in a test tube, so to speak, of artificial ideas. I hope a big explosion is coming, to blow away all our ignorance and put us in touch with who we are and who everyone else is.

But I don’t think I could just list some sources where you could go in and sort of in computational fashion go and deduce this conclusion.

And I understand that, so for the most part for many people, this conclusion will remain out of reach, because there are it appears no easy set of sources that could satisfy them that they couldn’t say “well that source could be discredited because of this, or clearly, it was written by this person who we can discredit, or by saying they’re sure it was written at a time where people didn’t understand, or that there was political pressure to write such and such a thing or it was done for entertainment or whatever it is,” I mean there’s always arguments you can make against any source.

And so I understand and I think it’s perfectly fine for those people that These types of ideas will remain out of reach for them for now until such a day as there is some sort of official confirmation from some important authority figures of these ideas and at that point those ideas will then have a wider audience of acceptance, because there is certainly some people that require not discovery, but authoritative confirmation, I suppose.

Yet, if you were the discovering type than what I have said, combined with your innate abilities, surely you already have enough to go put the picture together for yourself to your own satisfaction. If so, my friend, good luck! Bon voyage :)

Cold is a straightforward problem to solve - make a fire, throw a fur or a blanket on you. Even the most primitive emerging civilizations ca thrive in cold climates.

Heat on the other hand is a lot more complex to solve. You need fully industrial civilization to have air conditioning, and we still don't have anything portable enough. Even today's solution to 40C+ is "drink a lot of water and stay inside".

So if you want a large scale industrial civilization that got to Mars but didn't leave large traces, a possibility is that they evolved at a time when Antarctica was friendly (for them), and the rest of the world was above their threshold temperature. GPT was full of disclaimers, but suggested a typical heat wave in Late Cretaceous might exceed 50°C (122°F), while parts of Antarctica would be a very comfortable 20°C (68°F). One could easily imagine an intelligent species with poor thermal control that was very well adapted to Antarctica, but could never settle the rest of the world if once every 5-10 summers a heat wave would wipe them out. That was the time of Velociraptors btw, so not a bad stock to evolve intelligence from.

Are you arguing that the chances of a large-scale Antarctic industrial civilization that reached Mars is higher than one that reached South America, Southern Africa, or Australia?

I think they have a point on heat management, too much heat can easily make a place totally uninhabitable while cold can practically always be managed.

Only if you don’t believe the Chinese’s plans to colonize the Moon & Mars, as well as Musk’s plan to form a colony on Mars, which is informed by the energy and time requirements it would take to get to planets orbiting other stars.

If they can't bear positive temperatures then all other continents are totally out of bounds for them, while Mars isn't. That's different from the reverse, in that even if we can't naturally live in negative temperatures we can easily enough wear warm clothes and heat up the spaces we live in.

Same reason we find nearby Venus uninhabitable but faraway Europa seems almost colonisable.

Of course there wasn't actually an Antarctic industrial civilisation, but that's not really the point.

Also, any evidence would be found either under 2000 meters of ice or at the bottom of the Antarctic ocean, so we wouldn't know about it yet.

Also, we're discussing prehuman civilisations so dismissing an hypothesis as being an "extraordinary claim" within this context is a bit weird.

So yeah, it's certainly possible they've sent a couple of dinosaurs on Mars, but didn't leave a lot of concrete buildings anywhere else.

Now, it is conceivable (and kinda scary) to contemplate that earlier versions of humans developed a sustainability consciousness much earlier, before actually engaging industrial level terraforming.

The result would have been very limited tangible environmental impact, possibly hard to identify today.

https://www.youtube.com/watch?v=WAyQQRNoQaE

That doesn't explain what happened to the tools, but that might be attributable to rust, death of small numbers of experts by war/famine/cataclysm/disease, and widespread recycling of rare metals and objects. OOP artifact-finders have traditionally been mocked into silence. It was 50 years before Antikythera got serious study, 50 more before it got close attention.

The ultimate explanation might not be as wild as non-human civilizations, advanced "prehistoric" humans, or aliens. But it does seem that there are some mysteries of construction over the eons that have been lost.

We currently equate “advanced civilization” with “large scale”. But what if there was a small-scale advanced civilization? Small enough to evade detection using the crude geological tools at our disposal.

Imagine a species that was both intelligent (like humans) and immortal (like jellyfish). With unbounded lifespans, they could do work that would take millions of humans - just over a much longer period of time. With no urgent need to reproduce, their population could stay small. Perhaps with long life comes enough accumulated wisdom to exercise restraint. They might even marvel at how a mortal species could ever achieve civilization when knowledge has to be re-learned by every generation.

Over millions of years of slow civilization they might have achieved great sophistication and advanced technology, concentrated in one small region that we either haven’t found yet, or which has been subsumed beneath ocean or tectonic plate.

Perhaps a changing climate forced them to leave Earth, or to hibernate somewhere, peeking out every few million years to see if the conditions are right for their return.

A much more plausible speculation is that stone civilizations rose and fell that we don't know about. Cultivating crops among wild forest and domesticating animals that subsequently go feral is so much more likely to have happened in the time that Sapiens was physiologically modern.