I sometimes think about how vast the parameter space of our physical universe is, and if that vastness means we wouldn’t be able to recognize ancient advanced technology if it’s far enough outside of our current mode of progress.
My favorite example is handing an SD card with all of Wikipedia and the Gutenberg Project and maybe even the Wayback Machine on it to a Roman emperor. He’d look at it and might have a mild interest in the geometrical metal bits on an otherwise insignificant tiny flake of weird material. If the deliverer were to tell him that it contained millions of documents, he wouldn’t believe it.
An expert in the field of storage media could, if for some reason permitted, spend years trying to explain it to the scholars of the time. Even if the expert succeeded in convincing them, it would take an unimaginable effort lasting lifetimes to ever make use of the thing. It would not succeed. Not because those people were stupid, but because the specialization that’s needed to understand the artifact is so far away from from their cultural knowledge and capabilities as to be unreachable. Why should we expect our culture be any different?
The primary counter-argument to this is math and physics, and it’s a pretty strong one. It holds up quite well when dealing with past civilizations that are beneath or somewhere close to our current level of understanding. If you’ll permit another flight of fancy though, imagine an ancient society that figured out how to encode information in the irregularities of crystalline structures: every lame-ass quartz medallion we’ve unearthed could be the equivalent of a 10TB hard drive, and we’d never be the wiser.
I think this is pretty unlikely, but it’s good to be humble and interrogate your assumptions.
For your SD Card example though, I'll nitpick. Sure, just a card and explanation won't get you very far ... but I think something like an iPad (with a good power-supply) would produce enough evidence to convince them (depending upon the individual, I grant there might be some who just attributed it to supernatural forces even in the face evidence and explanation). I suspect humans in general are more willing to deal with "blackbox" technology that has practical application than most tinker types on HN would admit. Very little historical technology that was hard earned with trail-and-error has a theoretical basis known to even skilled practitioners. Even today, to most most people I know, the technology they use on a daily might as well be magic. Sure they know there some kind of "science" beyond it, but I'm also not sure they could convince me it wasn't just goblins if I demanded some theory of it worked.
There's nothing shocking or unreasonable or even old-fashioned about understanding what something does before we wonder why it does it. In fact, I'm pretty sure the origin of almost all human knowledge has been precisely in questions of exactly that sort.
Its from "Matter"
Hippense cleared his throat and said, "The type of progress you guys are used to doesn't scale into this sort of civilisational level; societies progress until they Sublime - god-like retirement, if you will - and then others start again, finding their own way up the tech-face. But it is a tech-face, not a tech-ladder; there are a variety of routes to the top and any two civs who've achieved the summit might well have discovered quite different abilities en route. Ways of keeping technology viable over indefinite periods of time are known to have existed aeons ago, and just because something's ancient doesn't mean its inferior."
and those things would be pretty outdated - ancient - technology by time we spotted them.
I might be wrong about the emperor’s belief. I chose an SD card particularly because it looks insignificant. Getting an emperor to say “this is a sacred relic” is still a long way off from getting an emperor to say “let us endeavor to unlock the secrets of this relic.”
But an industrial civilization makes a LOT of stuff, and much of that is quite durable and easily recognizable as artificial, and is likely to be scattered all over the planet.
Given that there are places that preserve tracks over 300 million years old, and fossils, well, up to 4 billion years old, I have a hard time imagining that a worldwide civilization that's producing and using aluminum and titanium and ceramics and all sorts of other stuff on a wide basis would not leave something recognizable in basically all the available fossilizing environments. We might not ever find fossils of the species, but are we really not going to find anything from the million refuse dumps and cities and industrial facilities and whatnot, or millions of miles of roads, or the multi-billions of accidental losses bound to be all over the world?
Not to mention objects in high orbit or on the lunar surface, which is a whole other thing.
You have to posit a really limited civilization before I believe it.
Most mountains in Europe have surfaced with the last 10-20 mill years, and they have turned earth around to the point that you routinetly find marine fossis in top of 2000m mountains.
If any civilization was around, it would have left a mark somewhere, and mountains would be a great place to spot them.
According to most scientists, the oldest mountain range on Earth is called the Barberton Greenstone Belt and is found in South Africa. It's estimated that the range is at least 3.2 billion (yes, billion!) years old.
Archaeologists can read worked surfaces with amazing skill. E.g. a bed of pebbles could be a lake bed, a road surface, a floor inside a building, a foundation, and there's ways to distinguish them.
Unless the soil was erased/reformed completely there would be a record of almost any activity, from digging a post hole or trench, to building a wall then removing it again then dumping construction waste into the hole then plowing it under. All are different from 'native' soils deposited by random processes.
Geologic time is not enough to erase evidence of worked soils. Not unless it gets scrubbed to the bedrock and redeposited. And even if that happened some places, it wouldn't happen every place. And its fair to say today, that our civilization has been pretty much every place.
As for rebar, if any water were to get in there repeatedly it would all just rust away.
The specifics of the environment play huge here. Anything in a freeze-thaw cycle would get obliterated. Dry and cool areas would do better, but then only for so long. Maybe if things were intentionally buried in anoxic environments, like many fossils, you'd have a chance at retrieval.
I'm not saying it's impossible, but it would take a lot of luck.
And those million/billion years tracts of land that archaeologists see are like 0.0000001% (guess) of the total. Odds seem good that surviving rocks came from very boring, very pointless places.
It's not what such civilizations would have left, but what they would have taken.
Our early civilizations found easily accessible deposits or tin, copper, gold, etc that would have been depleted if another advanced civilization had existed in the past 10 million years or so.
Some of that would be theoretically be recoverable with a lot of effort and energy, but some of it will basically be gone. No one is going to get back small bits of metal fallen off ships into the deep ocean.
Perhaps they also found remains of other advanced civilizations and axploited those?
10 million years is nothing in geological terms.
We haven't looked deep enough very much. Many of the 10-25,000 year sites are buried dozens of feet underground. If there are any previous ruins, they're probably a hundred-or-more feet down. Seaside ruins from 10k+ years ago are now under 400 feet of water and 10k+ years of sediment. We've just started to notice evidence of major changes only 13k years back ... with more on the way.
Over 100,000 years, water has scoured (and deeply buried) much of the surface. Consider the number of glaciations in the past 2M years ... each one of which has scoured the surface in northern regions repeatedly. Much farther back than that, and most geo- and bio-records are erased.
The planet's dynamics would have scrubbed almost anything before 10 million years ago. There've been 400 of those; 5 major extinctions left some traces. The scale of upheavals has been massive. How long ago did the Andes arise? It was first noticed in the 1700s that Whole sections of the Earth's surface have gone missing. https://en.wikipedia.org/wiki/Hutton%27s_Unconformity
as earth / plate tectonic move around, underneath earth is constantly surfaced... from dinosaur fragments, to Cambrian era mollusks found in top of mountains (due to earth's crust movement).
If there was a previous 'intelligent' civilization previous to us, they would have altered their environment to be detectable to us even today.
We -believed- the Clovis story. Until some people -looked harder-. Plate tectonics ... laughed at. Until some people -looked harder-. Absence of evidence is not evidence of absence.
Conversely, a concentration of rusted metal is not likely to occur naturally.
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 we really like burying trash. If our hypothetical forbearers were anything like us, we'd know about them.
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.
Even modern waste incineration comming quite close with iron & even alluminium collected from the slag & the mostly inert reminder reused in consturction. The local waste incineration plant already covers all district heat requirements of the 400k people city in the summer and is poised to cover 50% of the inter load once their new nr. 3 furnace is installed.
That's not a bad idea, but finding synthetic isotopes with extremely long half-lifes (e.g., Tellurium-128) would clinch the deal.
> The Anthropocene layer in ocean sediment will be abrupt and multi-variate, consisting of seemingly concurrent specific peaks in multiple geochemical proxies, biomarkers, elemental composition, and mineralogy. It will likely demarcate a clear transition of faunal taxa prior to the event compared to afterwards. Most of the individual markers will not be unique in the context of Earth history, but the combination of tracers may be. However, we speculate that some specific tracers that would be unique, specifically persistent synthetic molecules, plastics, and (potentially) very long-lived radioactive fallout in the event of nuclear catastrophe.
One that they didn't mention was our artifacts on the moon which will last 100 million years or so. Geostationary and HEO satellites will stay for a while but I'm not exactly sure how long.
However if you wait 50 million years or so, most of the stuff on earth won't be obvious and you would need to check very carefully.
Erosion due to micrometeorites erodes the surface of the moon at 1mm per 1e6 years . I wonder whether erosion of human-made moon artifacts will commence at a comparable rate.
Note that the hull thickness of the apollo lander is just 0.3 mm . Part of the propulsion system, tanks etc. would be the components to last longest, butt 100 million years may be quite a stretch.
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 concrete will erode away. The radioactives will decay. It will all end up as a millimeter-thick layer on the sea bottom, one of thousands of millimeter-thick layers with nothing to call attention to itself. Microplastics will abound, but somebody needs to be looking for them in exactly that layer, the way we found iridium at the K-T boundary layer, after specifically looking. There is a huge overabundance of platinum (parts-per-billion) in layers only 12900 years old, just discovered in the past decade, and only because we are really interested in that layer. (It was the start of the 1300-year Younger Dryas cold spell whose end is the start of the Holocene Epoch.)
Will anything last? Big mining and quarry pits will fill in, but recognizably. Big mine tunnels will fill in or collapse, but recognizably. A rectangular mine shaft dug down through a thousand meters of sedimentary rock will have no other explanation.
Some structures will be buried, instead of eroding away. Those will be deep underground, and then might be exposed again through subsequent erosion or uplift. Again, a brick chimney found buried will have no other explanation, though people will try.
Strictly speaking, one is all you need, but some people ("people"?) need more convincing.
Ouch... that's an enormous red flag. That irrecoverably tarnishes the entire article.
Another point that I don’t see made, is that if there was advanced tech, the “artifacts” were likely used until they ceased to exist and/or their purpose was lost.
Just think about our own society. If our entire power grid was lost, we would probably lose the ability to repair/rebuild them within a few generations. There may be pockets where electricity still runs, and some people will remember, but there will be no way to build new computers or phones, so they will invariably be brought to wherever electricity still exists, but even then, the ability to recreate them will cease to exist.
This man is trying to build a clock to last 10k years.
St. Louis has a lot of cool abandoned architecture, although you might want to be careful wandering around East of the river.
I wonder how many cities have abandoned towers that became historical places thanks to longstanding traditions of not being able to afford a demolition.
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.
I've been working on a paper comparing the effects of the Anthropocene to mega catastrophes in the geologically recent past. In addition to the Younger Dryas Impact (12kya), there's the Oruani (26kya) and Mt Toba (77kya) eruptions. From my calculations, it seems the climate change from each of these dwarfs any actions humans are currently capable of, namely petrocarbon burning and also total nuclear war.
I'm also critical of the account given to these events in the IPCC reports.
It seems unbelievable to me that the climate change debate isn't considering these more, so I'm still debugging the numbers and research. But happy to take comments from anyone who's interested!
The erupted mass was, at the very least, 12 times greater than that of the largest volcanic eruption in recent history, the 1815 eruption of Mount Tambora in Indonesia, which caused the 1816 "Year Without a Summer" in the Northern Hemisphere. Toba's erupted mass deposited an ash layer of about 15 centimetres (5.9 in) thick over the whole of South Asia. A blanket of volcanic ash was also deposited over the Indian Ocean, the Arabian Sea, and the South China Sea. Deep-sea cores retrieved from the South China Sea have extended the known reach of the eruption, suggesting that the 2,800 km³ calculation of the erupted mass is a minimum value or even an underestimate. Based on new methods (crystal concentration and exponential), the Lake Toba Caldera possibly erupted as much as 3,200 km³ of ignimbrite and co-ignimbrite.
I think its more likely your cursory dismissal which is failing to appreciate the magnitude of this event, than that the person who is actually crunching the numbers is getting it wrong. But what do I know?
Mt. Toba 74kya, VEI 8/M8.8 eruption energy: 1e21-1e22 Joules
Global Warming: 7.88e21 Joules/year
A hurricane: 1e21 J
Hiawatha Crater impact energy: 3e21 J
Human energy production 2013: 5.7e20 J/year
Mt. Tambora 1815, VEI 7 eruption energy: 1.3e20 J
Largest earthquakes 2: 1e19 J
Mt. Pinatubo 1991, Krakatoa 1883; VEI 6 eruption energy: 8.3e17 J
Mt. St. Helens 1980, VEI 4 eruption energy: 1e17 J
World nuclear weapon stockpile yield (estimate 2, extrapolated from USA): ~1e16 J
United States nuclear weapon stockpile yield 2020: 1.37e15 J
M8 Volcanoes once every million years, but M7 yield > 10x more energy over time:
“Analysis of this dataset indicates that eruptions of size M8 and larger have occurred with minimum frequency of 1.4 events/Ma… While the effect of any individual M8 or larger eruption is considerable, the time-averaged impact (i.e., erupted mass*frequency) of the very largest eruptions is small, due to their rarity. The long-term, time-averaged erupted mass flux from magnitude 8 and 9 eruptions is ~10–100 times less than for M7 eruptions; the time-averaged mass eruption rate from M7 eruptions is 9,500 kg s1, whereas for M8 and M9 eruptions it is ~70– 1,000 kg s1. Comparison of the energy release by volcanic eruptions with that due to asteroid impacts suggests that on timescales of <100,000 years, explosive volcanic eruptions are considerably more frequent than impacts of similar energy yield. This has important implications for understanding the risk of extreme events.” - Mason et al2
The question is how many more years do you want to give it until we do. These are huge slow systems we are looking at, at the point there is clear evidence around us that disaster is on the horizon, it is already several decades too late to do anything about it.
The US is supposed to switch from HFCs to something else around 2024. A lot of companies are switching to propane refrigerant ahead of time because it's cheaper, and worry about it igniting has dissipated, vs. looming ecological catastrophe.
BTW, to my knowledge the Greenland structure has not been reliably dated, nor even confirmed to be a bolide crater (although it seems like one). YD bolide impact seems pretty secure, though.
Temperature change might be a relatively minor effect of the CO2 concentration peak. Ocean acidification causing a collapse at the base of the food web, as marine animals become unable to fix calcium to make shells, might be more important.
I'm looking at the wiki articles, and then at the related chem articles about HFC types and synthesis. I'm not a chemist, but a quick look around makes me think the known CFC, fluorocarbon and halomethanes in volcanic gases would suggest the same or similar compounds as in our engineering uses.
On Hiawatha, agreed it's not yet dated, though it is recent: "The age of the crater is presently unknown, but an impact sometime during the Pleistocene is consistent with presently available geological and geophysical data." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/
They also raise the possibility that some of the radar returns indicate it's still hot in the center of the impact area(!). If so, it's probably one of the YDB impactors.
Btw, there's been another one discovered near it: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL07.... They say they don't think it's related, though it does still have large features that should have been eroded away if it were really old. We'll see!
If we wipe ourselves out the following civilization will have a much tougher time getting through their equivalent of the industrial age, especially if they're dealing with the aftereffects of climate change.
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.
So some other civilization could exist without using it, but they would look nothing like ours.
They would still have started with easily extracted sources not offshore oil or ultra deep oil. The world had very easily extracted oil when we started. Further, there is no missing oil based on geology.
I wonder where the term "dry well" came from.
However, most of what I've read about prehistoric advanced civilizations discussed them using crystals (quartz) and deriving energy from the earth. Some form of piezoelectricity. There are theories today connecting earth quakes, quartz deposits, and ball lightning, which could be hinting at an energy source we haven't explored yet.
If you could grow pure crystals more easily (thinking Diamon Age), why not have giant plates serving as a piezo generator or ambient electromagnetic waveguide harvesters?
| -> --->--- -> |
+- -> -/ \- -> -+
-> / \ ->
/ -> / /II\ \ | -+
+----+ -> | |IIII| | | +- IN SHADOW
| \ -> \ \II/ / | -+
| -> \ / ->
| +- -> -\ /- -> -+
| | -> ---<--- -> |
RADIAL | |
(also raise apo) |
((I think...)) RETROGRADE
I'm not sure how long such a process would take for a satellite not designed to exploit solar radiation for propulsion, nor whether it wouldn't be dwarfed by other orbit-disturbing influences such as the Moon and other planets.
Also: aerobraking a highly elliptical orbit isn't going to leave you much of a satellite to find.
(Note: I studied orbital mechanics in university on Kerbin, under Jebediah Kerman, so I might be wrong here.)
Usually people blame the moon, and three-body dynamics, for disrupting other Earth orbits.
Whatever space junk we leave behind will be gone 100 years from now. https://www.nasa.gov/news/debris_faq.html
Geosynchronous satellites 35,786 km (22,236 mi) are going to be up there for a very long time.
PS: If you’re interested https://aiaa.kavi.com/apps/group_public/download.php/3172/IS...'
BTW, it's a bit mind boggling how big and empty even just interplanetary space is - there could be wrecks of an unlucky discovery fleet paying a visit couple milion years ago and we might never find them unless they come really close to Earth or other sensor rich human inhabitted place or possibly still produce some active emissions (outgassing, sporadic radio signals, abnormal heat absorption/radiation, weird albedo variations, etc.).
Which reminds me of some decsriptions of Indian Vimanas, or rather the parts about their engines, which allegedly were made of some crystals.
E: To be pedantic, it only disproves most fossils.
Maybe the biggest obstacle to archeology is having people around who are interested in explaining what they're seeing. Science is a very rare thing for human cultures to spontaneously do. Even the 1000s of years old Chinese civilization never invented science and had to wait for it to be imported. I tend to think that human societies naturally actively discourage science because they'd quickly think up and memetically spread myths for any unexplained phenomena then anyone challenging the popular myths would have to be a misfit and that would come with punishment because misfits were generally harmful to society in the short term.
This line didn't pass the sniff test for me, so I did a quick Wikipedia check on the history of science in China.  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.  In AD 132, Zhang Heng created the first seismometer to study or detect earthquakes.  Looks like China's had science longer than the United Kingdom's been united.
EDIT: added newlines to break up the Wikipedia hyperlinks
For clarity, I'm not counting engineering and technology as science. You can develop techniques for building ships that float without understanding anything about buoyancy or mechanics of materials but just though gradual evolution of ideas and passing knowledge down through generations of craftsmen.
Medicine was a complete shit-show until modern science because people didn't even understand how to test if it caused patients to live or die! Even today in modern China, doctors still prescribe useless herbs based on superstition. They've stripped away the obvious nonsense about stars and planets that it used originally but still explain it using a mythical description of how the body works and how traditional medicines interact with it.
So building war implements, like weapons and armor, and techniques, like how to target a canon, but also non-military disciplines, like the construction of buildings and bridges, the manufacture of commercial goods, etc.
While a stretch as a motivation, the Uplift saga by David Brin has this as a core point: ecology and biodiversity is important for all the species in these books; planets are leased and used for a while, and then lain fallow to let them regrow and potentially spawn more sentient beings that could then (be helped to) join the galactic community.
The moon has been on orbit around the earth for billions of year and will probably remain on orbit forever (whatever "forever" means).
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
I mean, Manhattan may be under water in 100 million years (or, much sooner), but all those gigantic steel, concrete, plastic and glass structures aren't just going to dissolve.
From the Atlantic article by one of the authors:  
When it comes to direct evidence of an industrial civilization—things like cities, factories, and roads—the geologic record doesn’t go back past what’s called the Quaternary period 2.6 million years ago. For example, the oldest large-scale stretch of ancient surface lies in the Negev Desert. It’s “just” 1.8 million years old—older surfaces are mostly visible in cross section via something like a cliff face or rock cuts. Go back much further than the Quaternary, and everything has been turned over and crushed to dust.
We know, that before industry took off we had huge amount of natural resources almost lying on the ground. Now many of crucial resources have to be dug from huge depths or recovered from dilute sources.
I can't imagine a previous industrial civilization leaving huge amount of resources available on the surface. Almost by definition, industry is about scaling and efficiency and it always look to get to the results as quickly as possible.
Over shorter time scales this argument mostly holds, though one can imagine an intelligence with technology but with less expansionary drive and conspicuous consumption than humans. This intelligence may use resources more slowly.
I'm not sure about that number, but the ancient the bronze swords are better conserved than the steel ones.
Plastic will get washed away, and glass may get crunched and be difficult to find.
The rest of the concrete has a longer lifetime.
Cities disappear completely. Concrete and glass becomes rock (again), steel is oxidized and is just layer of iron ore. Plastics degradate and breaks into nanoparticles.
As the article speculates, most evidence would be likely something like synthetic biomarkers in deep sea sediments. Traces of industrial chemicals not produced naturally. Wrong chirality in some organic chemicals. Transuranic elements.
Evidence of civilization could be just below the surface.
That said, the answer to TFA's question is "almost certainly yes, unless they deliberately tried to conceal geological evidence of their existence, and probably even then".
0: nor vice versa, technically, though the logistics of using pre-industrial steel as building material would be prohibitive. see https://news.ycombinator.com/item?id=24591216
Note to self. Don't speculate on HN. Got it. :-)
So it seems unequivocal to me that human impact on the planet will be preserved for millions of years via the same mechanisms that have preserved snapshots of what was going on millions of years ago.
Iron (and steel) is stable outside the presence of oxygen and water. It doesn't just dissolve. And certainly if it were part of the steel reinforcement inside concrete in a building where special measures had been taken to insure that neither oxygen nor water would come in contact with it (as modern skyscrapers do) would persist for an exceptionally long time.
But I'm just guessing ;-)
Note how rounded all the stones are. And the stones that are there are generally speaking a LOT more resilient than any variant of limestone will ever be (including concrete).
"The Younger Dryas was a period of rapid cooling in the late Pleistocene 12,800 to 11,500 calendar years ago. It followed closely on the heels of a dramatically abrupt warming that brought the last Ice Age to a close (17,500 calendar years ago), lasted for about 1,300 years, then ended as abruptly as it started. The cause of these remarkably sudden climate changes has puzzled geologists and climatologists for decades and despite much effort to find the answer, can still only be considered enigmatic."
Edit: From my quick perusal, the warming for the Younger Dryas period is not mysterious at all. The main theory is that there was a sudden cooling due to the failure of the Atlantic meridional overturning circulation around 12,900 BC. This cooling was then rapidly reversed back to the median warming trend about 11,700BC.
Evidence for a bolide strike producing a huge meltwater pulse, to start the process, is accumulating, coinciding with extinction of 30+ genera and the sudden end of the Clovis culture. Another strike at the Holocene boundary is less well supported; but we do need a cause.
These people have clearly never been to the beach--any beach. The oceans are absolutely chock full of our garbage and it is being deposited not only on the ocean floor, but on every shoreline the world over, where much is ground up and still more silted over. Plastic trash wafts the world over. Everything from beer cans to glass bottles to cars to aircraft are strewn through the entire industrialized world, in forests, creeks, and backyards. We have landfills the size of small towns. There are thousands of shipwrecks all over the oceans. Bazillions of items will be fossilized and preserved, and the odds of stumbling over something just digging anywhere will be very high.
This article is completely full of shit. Humans have left their mark and our junk is going to be here, fossilized, for eternity. If we've discovered hundreds or thousands of fossilized dinosaurs from over 100 million years ago, when there might be only a few thousand such skeletons even to be found, there's a damn good bet that someone is going to find one of the tens of billions of beer cans or beer bottles that are lying around, even if only a tiny fraction survive the aeons.
Fossilization isn't a universal process, there's no such thing as a fossilized beer can.
For sufficiently short values of forever.