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Would it be possible to detect an industrial civilization in geological record?

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Re: Would it be possible to detect an industrial civilization in geological record?

#101

Post by bufferoverflow »

Retric wrote: post #56
ncmncm wrote: post #53

Earlier quoted context omitted.

But not finding fossil fuels wouldn't tell you anything, because nobody knows how much there ought to be. If they discovered better sources of energy a little faster, they would stop pumping almost immediately. But for politics, the US might easily have started the switch to wind power forty years ago, and billions of barrels' worth would still be in the ground.

Oil is useful for a lot more than just burning it. Fertilizers, plastics, and asphalt are the most well known but a host of industrial processes use it as a feedstock. It’s only recently that oil has been hard to find, initially it was seeping up from the ground which still occurs on the sea floor in some areas making it hard to miss. So some other civilization could exist without using it, but they would look nothin…

Oil is overwhelmingly used by burning it and its products. Only 4% of it goes to plastic production.

Re: Would it be possible to detect an industrial civilization in geological record?

#102

Post by samatman »

tsomctl wrote: post #99
samatman wrote: post #98

Earlier quoted context omitted.

That, and the real smoking gun: landfillite. Some significant fraction of landfills are going to fossilize into a pretty distinctive sedimentary rock. I don't know what it would look like, but it would have, like, fossil Barbie dolls in it. I don't think we'd have missed all of them if they existed. We could postulate an industrial civilization which just didn't make landfills? But we've only got ours to go on, and w…

I don't think so. Landfills are a source of many important minerals and energy. I'm convinced that we'll be mining ours in the next couple of centuries.

Maybe, but if so, it will be because we have really substantially depleted primary mines.

A precursor civilization which needed to mine its landfills would therefore undoubtedly have left a visible scar in the fossil record. If they suffered some calamity before getting to that point, then we get landfillite. Either way, I think we'd see evidence of any civilization which sustained the equivalent of a 19th and 20th century.

Re: Would it be possible to detect an industrial civilization in geological record?

#103

Post by yongjik »

ncmncm wrote: post #12

Every time this pops up on HN, people post insisting that it won't all go away, that the skyscrapers will, somehow, still be there. No, they won't. Look at any place in the world where there are mesas. All of the land around the mesa used to be level with the top of the mesa. It has all eroded away, and in only a few million years. So, the metals will corrode, collapse, and wash away. The stone will erode away. The c…

Forget skyscrapers, instead consider this: footprints. You likely made millions of them in your life. How many of them still exist? Approximately zero. It's hard to think of something more ephemeral.

Yet dinosaur footprints have been fossilized. They're found all around the earth.

I'm sure our civilization has already created a gazillion things more permanent than them.

Re: Would it be possible to detect an industrial civilization in geological record?

#104

Post by rtsil »

yissp wrote: post #72
rbrbr wrote: post #57

Isn’t a much easier way to look around our planet and search for satellites of past civilizations? Or even on the moon where everything lasts much longer. Long after we and everything of us is gone from this planet moon vehicles and other devices which were left there will likely still be there unless a meteorite hit them.

I don't think satellites stay in orbit for very long - like a few decades at the very most.

Depends on the orbit. Elon's roadster on its heliocentric orbit has a predicted half-life of 15 million years (1)

The moon has been on orbit around the earth for billions of year and will probably remain on orbit forever (whatever "forever" means).

(1) https://www.mdpi.com/2226-4310/5/2/57

Re: Would it be possible to detect an industrial civilization in geological record?

#105

Post by mjevans »

ffhhj wrote: post #20

A highly responsible civilization that achieves space fairing tech could rebuild its environment, leaving a clean planet as a gift for future species to emerge, and move to the stars. Sort of artifical-creationism, but phycally achievable, it's a matter of civilization goals.

Related, I highly recommend the videogame Outer Wilds, which notably includes a 22 min timeloop, and, related to this I'll add a tiny spoiler; an extinct civilization that was responsible enough to not wreck the ecology of a world that could have intelligent life in their future.

Re: Would it be possible to detect an industrial civilization in geological record?

#106

Post by danbolt »

lopmotr wrote: post #52
TeMPOraL wrote: post #39

Earlier quoted context omitted.

And, as predicted by the argument, the fossils don't abound, and to find them you have to start digging.

I wonder if that's always been the case. Maybe humans quickly cleaned up all the easily accessible fossils before realizing what they were. Ancient Greeks thought they'd found a giant's bone and other cultures seem to have used dinosaur fossils as inspiration for myths of dragons. Even western researchers a few hundred years ago thought dinosaur bones were just recent animal bones. Imagine how careless every previous…

> Even the 1000s of years old Chinese civilization never invented science and had to wait for it to be imported.

This line didn't pass the sniff test for me, so I did a quick Wikipedia check on the history of science in China. [1] Given the fact that Chinese Society has a large population and long written history, it seemed a bit strange to think that science and technology might have been imported from elsewhere 1000 years ago.

It was actually quite cool! Turns out gunpowder and crossbows were invented there for gaining an advantage in war. [3][4] In AD 132, Zhang Heng created the first seismometer to study or detect earthquakes. [2] Looks like China's had science longer than the United Kingdom's been united.

EDIT: added newlines to break up the Wikipedia hyperlinks

[1] https://en.wikipedia.org/wiki/History_of_science_and_technol...

[2] https://en.wikipedia.org/wiki/Seismometer#Ancient_era

[3] https://en.wikipedia.org/wiki/Crossbow#East_Asia

[4] https://en.wikipedia.org/wiki/Gunpowder

Re: Would it be possible to detect an industrial civilization in geological record?

#107

Post by nradov »

treis wrote: post #76
yissp wrote: post #72

Earlier quoted context omitted.

I don't think satellites stay in orbit for very long - like a few decades at the very most.

Depends on their orbit. LEO will see drag from the atmosphere and will fall from orbit relatively quickly. Geostationary satellites will orbit basically forever.

Some of the Lagrange points allow for more stable orbits so would presumably be better places to look.

Re: Would it be possible to detect an industrial civilization in geological record?

#108

Post by jlawson »

yongjik wrote: post #103
ncmncm wrote: post #12

Every time this pops up on HN, people post insisting that it won't all go away, that the skyscrapers will, somehow, still be there. No, they won't. Look at any place in the world where there are mesas. All of the land around the mesa used to be level with the top of the mesa. It has all eroded away, and in only a few million years. So, the metals will corrode, collapse, and wash away. The stone will erode away. The c…

Forget skyscrapers, instead consider this: footprints. You likely made millions of them in your life. How many of them still exist? Approximately zero. It's hard to think of something more ephemeral. Yet dinosaur footprints have been fossilized. They're found all around the earth. I'm sure our civilization has already created a gazillion things more permanent than them.

Yeah, but consider the base rate. Even if the things we create are more permanent that footprints, there are just so many footprints that some of them, by unbelievable triple-corner case coincidences, end up here for us. Even if the chance per footprint is really low, there are so many of them made over the course of hundreds of millions of years that it doesn't matter. Our 100 year industrial history is nothing compared to that.

Re: Would it be possible to detect an industrial civilization in geological record?

#109

Post by jlawson »

pmiller2 wrote: post #22
ncmncm wrote: post #12

Every time this pops up on HN, people post insisting that it won't all go away, that the skyscrapers will, somehow, still be there. No, they won't. Look at any place in the world where there are mesas. All of the land around the mesa used to be level with the top of the mesa. It has all eroded away, and in only a few million years. So, the metals will corrode, collapse, and wash away. The stone will erode away. The c…

Those people need to watch a few episodes of the TV series Life After People . Watching it, and realizing that everything around us would literally start to fail in a matter of days without us as its caretakers, really brought home the impermanence of everything. Skyscrapers are certainly not going to outlast ancient cave dwellings. In a matter of a couple hundred years, I would be surprised if a single skyscraper wa…

I wonder how long the Egyptian pyramids would last.

Re: Would it be possible to detect an industrial civilization in geological record?

#110

Post by markwkw »

Some tongue-in-cheek ideas: Stockpile of synthetic diamonds

A few cemeteries could make for curious fossils

Mines - some caves survived for 200+ million years. Conceivably a part of a mine somewhere could survive, with concrete structural reinforcements and parts of non-corroding tools intact

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