Were there previous industrial civilizations before humanity's?

[bilby]

It's amazing that we know as much as we do about the dinosaurs, and they were around in huge numbers for over a hundred million years. A civilisation that was only around for a few centuries, tens of millions of years ago, might well have vanished without a trace; Or the only evidence of it might be somewhere we haven't yet looked in any great detail. There's LOTS of geological structures about which our knowledge is scant at best; If there are some artifacts buried a few feet below the surface in the high Himalayas, or the deep Sahara, then we may never find them.

In a hundred million years, the surface of the Moon might be the best place to look for easily found signs that we were here (for a given value of 'easily').

In a hundred million years there would still be an awful lot of mined-out ore bodies. It would be very strange indeed that mining would be so much harder in any rock older than 100 million years. You don't need to find a single artifact to see this.

(Not to mention that it would be basically impossible for a civilization to arise 100 million years from now anyway--global warming will not be friendly to large slow-reproducing (and thus slow-evolving) species by then.)

Do you have any idea how little of the available ore we have mined? Mines occupy a minuscule fraction of the crust; The chances of randomly hitting an old mine 100my from now are tiny. The chances that some of the surviving strata from today that are still close to the surface in 100my willl also be part of the crust we have mined are pretty damn small.

And we are talking about hypothetical past civilizations. Taking the modern influences on the Earth and rolling forward 100my is just a way to gain some perspective, as people seem to have a hard time thinking backwards.

 

[bilby]

Disagree--while it won't be dangerous at a million years we would still find several isotopes that have no natural origin. That would show fission was going on and since they could figure the U-235/U-238 ratio at the time they could figure out it wasn't a natural reactor.

Furthermore, there's another product of modern civilization that can be detected by nuclear means even after it's form is long gone: depleted uranium. What are all these little areas of uranium that seriously does not match the overall planetary ratio?

You only need to explain these things if you find them. There is very little uranium and very few places where it is in use. You are seriously talking 'needle in a haystack'.

Sure, IF you find it, you can tell it came from an older civilization. But how did you find it? It's a BIG planet.

 

[bilby]

It's an interesting question. I think it's very improbable, though. In addition to some points already made in the thread, I would mention two pieces of evidence (in increasing order of strength):

1. Fossils:

bilby correctly points out that they're rare, but we keep finding the fossils of early hominids and australophitecines up to 3+ million years ago. Sure, that's much less than 50 or 100 million years, but then, the numbers of individuals of those species were far lower than the absurdly high numbers of humans on the planet - and on pretty much every corner of the surface of the planet, save for Antarctica, so that includes areas with favorable conditions for fossilization. We have not found any old skull compatible with anything smart enough to have an advanced civilization. This may not be decisive, but it does seem to provide considerable evidence, at least for much of the past.

What about a much smaller civilization?
Also bilby mentions one possibility. But what is the prior of that small civilization? That leads to the second (and I think stronger) point.

2. Our industrial civilization has only lasted for a very short period. In fact, it's been less than 300 years from the Industrial Revolution. If our civilization goes on for, say, 300 more years, its blueprints will almost certainly be far from Earth, in the form of:

a. Moon bases (also mentioned by bilby, but I'm talking about much larger facilities).
b. Martian bases.
c. Probably very large space stations - large enough to be recognizable even after tens of millions of years of micrometeors.

If our civilization goes on for 1000 more years (and I'm being conservative here), there will be sustainable colonies on Mars and probably other places, and after that, it's hard to see what might destroy it. Maybe massive interplanetary warfare, alien attack or crazy AI, but any of that is likely to leave either good evidence or the aliens/crazy AI themselves!

My point is that in geological or even evolutionary timescales, there is an extremely short window for an industrial civilization to exist without leaving a lot more evidence than ours - but ours has already left quite a bit, some mentioned by Loren Pechtel, plus the potential fossils (point 1).

So, one may ask: if there was a previous industrial civilization, what happened to them, and wouldn't that leave evidence?

Asteroids, comets, or things like that, are extremely improbable to wipe them out. The reason: those events are extremely rare, so what are the odds that an industrial civilization gets wiped out by one of them before it colonizes the Moon and Mars (and gets the tech to divert them, by the way) is very low. Something similar goes for things like gamma-ray bursts. Crazy AI is extremely improbable, because where is the AI? (okay, crazy suicidal AI, or something, but it does seem pretty improbable).

Perhaps the most likely scenario is war. But what sort of war would really kill us off? It's hard to say. Even global nuclear war does not guarantee extinction, and if there are humans left and widely distributed, chances are they will build eventually an industrial civilization. Maybe a nuclear war with even more advanced nukes? But then we're close to the "interplanetary war" scenario. Even a massive enough nuclear war seems to leave traces for a very long time.

Of course, global warming or things like that aren't going to do it.

In short, these sorts of civilizations seem to be very hard to kill without means massive enough to leave plenty of long-lasting evidence.

Now, granted, nonhumans may have different minds and interests, but if they already developed an industrial civilization, it seems likely they'll want to just stop at Earth.

I guess it depends on what qualifies as an industrial civilization. The Roman empire was around for a few centuries, and did some impressive stuff, including developing some impressive hydraulic engineering on a large scale - But nothing on the scale of the post-Industrial Revolution society. The modern industrial civilization is also global; Rome at its height was quite small relative to the size of the global land area.

Rome left very little that will be obvious in as little as a few million years. And the end of that civilization left no lasting mark on the planet - it wasn't wiped out by a meteor, a nuclear war, or even an extinction event, it just faded into the Dark Ages.

I agree that it is very improbable that there was any earlier, pre-human, civilization; And even less probable that there was any such civilization that equaled our post-Industrial stature. But I don't think either is sufficiently improbable as to be completely dismissed. We could stumble across the evidence tomorrow. (Though we probably won't).

 

[Angra Mainyu]

I guess it depends on what qualifies as an industrial civilization. The Roman empire was around for a few centuries, and did some impressive stuff, including developing some impressive hydraulic engineering on a large scale - But nothing on the scale of the post-Industrial Revolution society. The modern industrial civilization is also global; Rome at its height was quite small relative to the size of the global land area.

Rome left very little that will be obvious in as little as a few million years. And the end of that civilization left no lasting mark on the planet - it wasn't wiped out by a meteor, a nuclear war, or even an extinction event, it just faded into the Dark Ages.

If we include something as advanced as Rome as already an industrial civilization, it does takes longer for a civilization to leave Earth and colonize the solar system.

But that aside, I don't think Rome is a civilization in the sense we're talking about. It was a society, country, etc., but in this context, Rome was a part of a much larger civilization - human civilization on Earth. Granted, one can separate it in different parts, study Rome in particular, and in some contexts call Rome a "civilization". That's fine, and useful for some purposes, so it's a matter of terminology. But I think a crucial factor is that even if Rome had been completely destroyed (supervolcano or whatever), that would only have slowed down human civilization for a very short time, in evolutionary terms, let alone geological ones. For example, China would have continued as it did without Rome, and even without any exchanges from Rome, it would have moved forward, even if more slowly. The same goes for India, and a few other countries, and even other, less advanced countries would have moved forward, even if more slowly.

More generally, we can ask the question: what could have ended human civilization 2000 years ago, preventing it from reaching other planets eventually?

A supervolcano is probably not enough. Maybe something like a massive asteroid, or a comet, or gamma ray burst. But that's extremely improbable given the short time scale.

Granted, it could be more likely for a species limited to a small geographical region. But when some social group has reached the level of sophistication of Rome (or even considerably less than that), chances are the species is already widely distributed. What could stop them? Climate is not so big a factor against technology. We are tropical African apes, but clothes and other technologies (even technologies much more primitive than those available to Rome) allowed our ancestors to reach and live in places like the British Isles, North America, Siberia, Australia, etc.

Maybe some species are less inclined to spread, but that's very improbable for a species curious enough that some groups have reached the technological level of Rome. I grant that estimating the probability (i.e., how improbable it is) is somewhat difficult, though.

 

[Sarpedon]

Before industry, there must be agriculture. I defy you to start a farm with diplodocuses wandering around.

No matter how intelligent a pure predator might be, it will never build a civilization, because for such a beast, there's no incentive to stay in one place. Quite the opposite. Nor would such a species require tools.

I'll betcha only an omnivore or perhaps a pure vegetarian species can build a civilization. Using tools to move from getting meat from scavenging to hunting is a logical step. Why would a pure predator do that?

 

[lpetrich]

Before industry, there must be agriculture. I defy you to start a farm with diplodocuses wandering around.

They would have been no worse than elephants, I'm sure.

No matter how intelligent a pure predator might be, it will never build a civilization, because for such a beast, there's no incentive to stay in one place. Quite the opposite. Nor would such a species require tools.

However, many past human societies have been nomadic. Furthermore, intelligent carnivores could invent herding.

I'll betcha only an omnivore or perhaps a pure vegetarian species can build a civilization. Using tools to move from getting meat from scavenging to hunting is a logical step. Why would a pure predator do that?

Predators often scavenge. Why turn down good meat?

Omnivores typically prefer to eat high-quality plant parts, like roots, fruits, nuts, seeds, and even sprouts. Species like us. Such parts have the problem of relatively low density, but humanity's agriculture has successfully gotten around that problem.

Some herbivores can subsist on low-quality plant parts like leaves. They often have stomach or intestinal fermentation to improve their nutrition, but that often has rather limited efficiency. So despite the abundance of such parts, the animals' population will be limited by their digestive efficiency.

Humanity's food animals have been at least partially herbivorous, thus eating relatively low on the food chain. This includes eaters of low-quality plant parts (cows, sheep, goats, camels, horses, ...), and eaters of high-quality plant parts (pigs, chickens, ...) Eaters of dog meat have often fed their dogs high-quality plant parts cooked for easier digestion, thus making them like pigs and chickens.

 

[Sarpedon]

They would have been no worse than elephants, I'm sure.

Really? Are you so sure? I doubt it. I really do. You can make barriers to deter an elephant. The amount of labor needed to deter dinosaurs would be much greater. And need I point out that the range of elephants has been sharply reduced, largely because of agriculture. I don't think there's any doubt that they would already be exitinct if not for conservation efforts.

Also, may I point out that the cretaceous era was before flowering plants.

And so what if they invented herding? That still wouldn't give them an incentive to settle down and make tools. Herding is dependent on moving the animals about. Humans who herd centering on permanent housing do it because they like having a permanent house, not because this is necessarily efficient. Anyway, I'm unconvinced that it would occur to a predator to invent herding. The baby steps from hunting and gathering to agriculture seem to be much more logical. A gathering/scavenging omnivore by definition needs to be flexible and willing to experiment. Does a predator? Not really, the predator's diet is much more limited, and whatever it is hunting, it uses largely the same skill set.

 

[Angra Mainyu]

Using tools to move from getting meat from scavenging to hunting is a logical step. Why would a pure predator do that?

One motivation would be to access food sources otherwise unavailable. For example, there are animals protected by hard shells. The same goes for eggs. Some predators might be able to break them, but others cannot.
Similarly, some predators cannot access the bone marrow in their prey. Sometimes, tools can also be useful for reaching insects and other small animals hiding in crevices and the like.

Additionally, tools can be useful for nest-making.

Not really, the predator's diet is much more limited, and whatever it is hunting, it uses largely the same skill set.

A predator specialized on one or some prey animals, yes. But there are more flexible predators. For example, the Egyptian vulture feeds on carrion and also small live animals. But it uses different strategies, including some tools. They also use tools for nests.

http://digital.csic.es/bitstream/10261/65850/1/JRR-09-20.pdf

ETA: Then again, it seems you're ruling out scavengers, so that leaves out vultures. But there are also predators that don't have the stomach for carrion so they're pure predators, and could still use tools (e.g., dolphins https://www.theatlantic.com/technol...lphins-are-using-sea-sponges-as-tools/361168/ ). It's rudimentary, but then, so is tool usage by most species.

Generally speaking, hunting animals that don't move much but are protected by hard shells is not that different from gathering similarly protected nuts and other non-animal food sources. The motivation in the predator case here could be very similar to that of the non-predatory gatherer.

 

[Peez]

They would have been no worse than elephants, I'm sure.

Really? Are you so sure? I doubt it. I really do. You can make barriers to deter an elephant. The amount of labor needed to deter dinosaurs would be much greater.

A pet peeve of mine is that people often exaggerate the sizes of dinosaurs. We tend to focus on the very biggest ones, but Diplodocus was a genus that included some species with a mass about the same as the mass of a very large African elephant. I can imagine someone who had never heard of an animal any larger than a cow might think it impossible to farm where there are animals as big as elephants, but there is no clear reason why farming could not be accomplished in an ecosystem that includes much larger dinosaurs. If the farmers were as big as, say, giant ground sloths (up to 4 tons), it might have been even easier.

In any event Sauropods generally lived between about 210 million years ago (MYA) and 66 MYA, being relatively widespread between about 150 MYA and 70 MYA, but presumably were not found everywhere even at that time. Thus even if farming would have been problematic with such creatures about, it could easily have occurred in another time or place.

And need I point out that the range of elephants has been sharply reduced, largely because of agriculture.

Perhaps the range of some sauropods was similarly reduced.

Peez

 

[Politesse]

So now we're positing... Silurians?

And I thought this thread started in the somewhat-crazy zone!

 

[Peez]

So now we're positing... Silurians?

And I thought this thread started in the somewhat-crazy zone!

Silurians were mentioned in the article linked from the OP.



Peez

 

[Tharmas]

On this topic, here is a website devoted to the subject, at least in terms of how long some of our major artifacts - skyscrapers and the like - would last without humans around. Ironically it's some of the more primitive structures such as the Great Wall or the pyramids that might last the longest (but only into the tens of thousands of years), because they are just big piles of rock.

 

[Politesse]

What's so "primitive" about them, if they are obviously superior to our stuff?

 

[lpetrich]

Because they require much less advanced technology to make. They also have much simpler structure, though cutting and transporting several million stone blocks was a big achievement for Bronze Age technology, especially cutting the blocks so that they will fit each other.

 

[Politesse]

So to you, difficulty of construction trumps practicality of construction? One is more "advanced" if one invests more to get less return?

 

[Sarpedon]

There is also economy. Why on earth would anyone choose 'durability' as the sole criterion for quality of construction?

 

[Angra Mainyu]

What's so "primitive" about them, if they are obviously superior to our stuff?

Why do you think they're "superior" to our stuff?
A stone knife is very likely to last much more than a cell phone. But is it superior? How do you estimate superiority of things made for very different purposes?

 

[Juma]

What's so "primitive" about them, if they are obviously superior to our stuff?

In what way are they superior?

 

[bilby]

There is also economy. Why on earth would anyone choose 'durability' as the sole criterion for quality of construction?

Yup, over-engineering is not a feature; It's a bug. Something that lasts a few times its designed lifespan is well made; Something that lasts thousands of times longer is over-engineered, and could presumably have been made more cheaply, while still meeting the design intent.

The pyramids are a bit of an exception, as presumably their designers wanted them to last until the end of the world, (which they will fail to achieve by some considerable amount). But most artifacts are not required or intended to outlast their makers, and amongst those few which are - buildings, bridges, viaducts, tunnels, and the like - their design lifespans are typically only hundreds of years.

One classic example of superb engineering is the Ness Viaduct, at Inverness, Scotland. Built in 1862, the design brief called for a 125 year lifespan, which was difficult to achieve, given the large floods that are characteristic of that part of the river, and the unstable nature of the riverbed. The viaduct collapsed (due scouring of the riverbed by a major flood) in 1989, 127 years after it was completed.

 

[Politesse]

How do you estimate the superiority of things made for very different purposes and in different contexts? It seems absurd to me, this ranking business.