Humans have established various animal and plant populations in locations far from home. If enough of them survive, it would be a clue that there was a technological civilization on Earth.
I forget if it was an article or a documentary, but I do recall that there are major problems with yearly freezing and thawing widening cracks in the monument. They periodically have crews go to fill new ones with epoxy to keep the cracks from growing. While the rock itself may take a long time to erode completely, there are still forces that could shatter it in the meantime, albeit slowly. Water’s a tenacious little bastard.
It might actually have been on CNN; I’ll check on it after work.
Among other geological features, Long Island is, as stated in the article:
On a smaller scale, the mountains in Glacier National Park, Montana were carved out of a miles-thick ovethrust of rock by glaciers as well.
An ice age will indeed erase everything its glaciers cover and grind it to sand. The Great Wall may be a remarkable piece of engineering, but I’d be willing to bet that, by virtue of being made of stone blocks or bricks with convenient gaps between them, glaciers would make short work of it.
I once had the privilege of visiting the SES uplink site in Betzdorf, Luxembourg. It controls the Astra satellite which transmits satellite TV to the UK. They had to adjust its position every two weeks by firing its onboard rockets. Some geostationary satellites have already run out of fuel and are drifting out of orbit. I doubt if any of them will still be in place in a million years.
Did glaciation make it that far south last time?
That assumes a constant process. Over a million years, gigantic catastrophes are likely to alter that rate.
Case in point: Do we know and would a reliable geologist even be willing to guess what the shape of Stone Mountain was one million years ago? I doubt the answer would be yes.
Assuming no catastrophic events take place. You know like the ones our ancestors talk about that we like to shrug off as the imaginations of stupid, crazy, primitive humans.
Twinkies.
Glass objects could last for hundreds of millions of years. However, they are likely to survive only if they are buried, and the OP specified no archeological digs.
I would guess any large earthmoving operations could be detectable without digging as long as you could survey from the air.
We’ve done this before.
Short answer is that in a million years time there is pretty much no chance of anything being visible via casual inspection.
To repost what I said in that thread the big thing to remember in this kind of speculation is that the Earth isn’t stable. It really isn’t. Get a geo survey map and try to find some surface rocks that are 100 million years old. It’s extremely rare and where they do exist it’s because they have eroded back to that date, not because the same surface rocks exist in the same place undisturbed.
And that’s the real reason why remains will be uncommon. In that time the very rocks the cities stand on will have eroded away into the oceans, or been lifted up and turned sideways by earthquakes, or capped with hundreds of metres of mud, or covered in flowing lava. It might seem stable to us but the surface of the Earth isn’t stable and it doesn’t sit still for millions of years like that. It’s a big difference talking about neolithic postholes 50, 0000 years old and rocks tens of millions of years old.
Even million year old surfaces are rare. To have any chance of finding anything after a million years you would need to have some extraordinary coincidences:
Start with an area that is geologically stable. North Africa and the Mediterranean are out, they’re too close to plate boundaries. The pyramids have stood up fairly well for a few thousand years, but hundreds of thousands of years of earthquakes will reduce them to rubble.
Then you need to select an areas below the ice line in the next ice age, so anything North of New York can be ruled out.
Then you need to select areas that will be outside the range of watercourses for the next million years. Rivers and streams all gradually change course so in most places simply being within 20 miles of a river will guarantee destruction. That alone will eliminate most populated regions. But you also need to factor in what will happen as climates change and new rivers form.
You also need regions that will be arid for the next million years. Rain and snow are killers on structures, undermining them, causing the foundations to shift.
Next you need to look at solid structures built on rock. The chances of anything that isn’t basically solid rock surviving more than a few hundred years unattended is remote. A modern city would be fortunate to be recognisable without excavation after 500 years.
So we need to be looking at huge, solid stone structures in desert regions, far from watercourses in geologically stable regions in the tropics or warm temperate regions. And I can’t think of anything that qualifies. The Great Wall in arid regions tends to be geologically unstable. The pyramids will one day be undermined when the Nile shifts its course.
My bet would be that within 100, 000 years nothing would be visible to suggest human occupation.
It’s hard to see how. Within a few centuries holes will become filled with eroded material, mounds will become covered in vegetation, earthquakes and erosion will round out the edges comepletely within a few hundred thousand years.
Ceramic objects - spark plugs, cups and bowls, toilets - will last a long time, especially if buried. I expect that alien archaeologists coming to earth millions of years from now will be able to find many unambigiously aritificial pieces of ceramic if they dig in the right place.
From the OP
Sorry. My bad. Didn’t read the OP well enough. Carry on.
I don’t car if Blake said it before. The evidence shows that structures like Mount Rushmore and the Pyramids would look anomalous even after 100,000-1,000,000 years. Not to mention statues elsewhere carved into cliffs (like those at Bamiyan destroyed by the Taliban in Afghanistan), where they are protected smewhat from th weathr. The ones in Afghanistan are gone, but others remain in Japan and elsewhere. Or carved stuctures such as the Temple at Petra (the one featured in Sinbad and the Eye of the Tiger and Indiana Jones and the Last Crusade, and the Rock Churches of Ethiopia ( http://www.gisdevelopment.net/application/archaeology/general/archg0012.htm ) (not to mention the Sphinx). Not t mention thoe protected, partially-completed statues i the quarries o Easter Island. And all those suspiciously regular holes and tunnels dug into he gneiss and granite of Manhattn Island that will still be there after the structures decay, and which don’t line up with the natural graining.
How about London Bridge at Lake Havasu, Arizona, out in the desert, a solid stone structure? or Hole in the Rock house in Moab Utah, which looks awfully suspicious for a natura cave(Its entrance is on the surface, well above ground, so it doesn’t require excavation and probably won’t get silted up)?
If Global warming spares Florida, what about Leedskalnin’s Coral Castle?
Cement and asphalt and mortared construction will deteriorate, but there will still be plenty of at least partially-organized stone structures in esert or regions of sparse growth to indicate intelligent maipulation.
The whole question is somewhat arbitrary and artificial – you’re really asking what human structures will remain out in the open, where they’re subjected to the worst of weathering. Onl the least curious of aliens, having gone to all the trouble of travelling here, will be satisfied with a superficial look. Any determined archaeological dig would concentrate on the likely locations for cities, and couldn’t help but find the many structures and artifacts buried away from that grindin erosion. Our stainless steel and plastic and ceramic goods will last for an extremely long time. Even the passage of many years won’t disguide foundation holes, tunnels for pipes, subway tunnels, mines, and quarries.
I don’t car if Blake said it before. The evidence shows that structures like Mount Rushmore and the Pyramids would look anomalous even after 100,000-1,000,000 years. Not to mention statues elsewhere carved into cliffs (like those at Bamiyan destroyed by the Taliban in Afghanistan), where they are protected smewhat from th weathr. The ones in Afghanistan are gone, but others remain in Japan and elsewhere. Or carved stuctures such as the Temple at Petra (the one featured in Sinbad and the Eye of the Tiger and Indiana Jones and the Last Crusade, and the Rock Churches of Ethiopia ( http://www.gisdevelopment.net/application/archaeology/general/archg0012.htm ) (not to mention the Sphinx). Not t mention thoe protected, partially-completed statues i the quarries o Easter Island. And all those suspiciously regular holes and tunnels dug into he gneiss and granite of Manhattn Island that will still be there after the structures decay, and which don’t line up with the natural graining.
How about London Bridge at Lake Havasu, Arizona, out in the desert, a solid stone structure? or Hole in the Rock house in Moab Utah, which looks awfully suspicious for a natura cave(Its entrance is on the surface, well above ground, so it doesn’t require excavation and probably won’t get silted up)?
If Global warming spares Florida, what about Leedskalnin’s Coral Castle?
Cement and asphalt and mortared construction will deteriorate, but there will still be plenty of at least partially-organized stone structures in esert or regions of sparse growth to indicate intelligent maipulation.
The whole question is somewhat arbitrary and artificial – you’re really asking what human structures will remain out in the open, where they’re subjected to the worst of weathering. Onl the least curious of aliens, having gone to all the trouble of travelling here, will be satisfied with a superficial look. Any determined archaeological dig would concentrate on the likely locations for cities, and couldn’t help but find the many structures and artifacts buried away from that grindin erosion. Our stainless steel and plastic and ceramic goods will last for an extremely long time. Even the passage of many years won’t disguide foundation holes, tunnels for pipes, subway tunnels, mines, and quarries.
Well, had a whole long post on this subject but unfortunately it just got eaten (something thats pretty rare now a days around here IMHO…I don’t usually even bother saving before submitting anymore).
Anyway, to summarize, how about cities in desert environments? I know that wooden artifacts from the great migrations west in the 19th centure are still to be found out in the desert…and still pretty much intact. You can see cars and such from the early 20th century also pretty much intact (though the seats and such are often eaten by desert animals). In addition I imagine that cities like Phoenix would be covered in sand…further perserving them from the elements. Even if eventually they completely collapsed (which I don’t see…how long does glass and stainless steel last in a desert environment?), the mounds would most likely still be visible from the air…and would show definite signs of SOME kind of intelligence, even if these non-curious aliens didn’t want to bother digging anything up to prove it.
And how about cities in arctic areas (Alaska, or some of the more northern cities in Canada, Europe, Russia/Siberia)? How about the settlements in antartica for instance? Perhaps they would be covered in snow or ice, but perhaps from time to time the glaciers would also spit out some rather interesting artifacts (assuming that they don’t all melt of course…but if humans got wacked tomorrow, say, I assume there is a good chance that if the Global Warming crowd is right and it IS all humans fault, and if they are further right that we can do something about it, that removing all the humans would have a benificial effect on rebalancing the environment in fairly short order :)).
-XT
I’m getting the impression that people don’t really appreciate just how long 1, 000, 000 years is.
Less than a thousand years of sandblasting has already damaged Petra and the pyramids extensively, and we are talking about a thousand times that amount of damage. If they have been etched a mm in the last thousands years they will have holes a metres deep gouged in them by wind in a million years time. And that is just one force.
After a few hundred years the quarries on Easter Island are already covered in shrubbery and grass. After a million years the island wil be recolonised by trees and have reverted to the sub-tropical jungle it was when people first arrived. No chance of finding a quarry.
A millions years of minor tremors and erosion and subway tunnels will collapse. A million years of water flowing into them will fill in the entrance to any subway tunnel.
And a bridge standing for a million years? Not a chance. No bridge has stood for more than a thousand years at the best of times. A million years of freeze fracturing, tremors and sandblasting and London bridge will be little more than sand itself. Aside from that the gorge itself will be many metres deeper and wider in a million years time. Unless the bridge somehow floats on air it will be sitting in pieces in the river.
And coral? As in calcium salts? The little acidity in rainfall alone will melt it completely within 100, 000 years. Just assuming normal rainfall it will be reduced to constituent atoms and washed out to sea in less than 1/10th of the time we have.
And speaking of structures remaining in desert regions as though somehow aridity will preserve them. How many desert regions do we think were desert a million years ago? Maybe a tiny, tiny part of in the core of the Sahara and a tiny part of southern Australia. That’s it. 99% of the Sahara and Australian deserts, all the Atatcama, Kalahari, Namib and Southwestern deserts were forests or swamps at sometime in the last million years. How well would a structure last in a jungle or swamp?
And even within desert environments, how long do glass and steel last? As long as any other surface rock. Actually much less because as soon as stainless steel is exposed to salts and water it dissolves itself via pit erosion. A few tens of thousands of years and their would be nothing but fine crystals left of glass. IOW sand. Hard to spot sand in a desert.
And Arctic areas? The odds of any Arctic are not being covered by a thousand feet of ice in the next million years are zero. It;s not case of being covered in snow and ice, it’s a case of being rolled under a river of ice for thousands of years. That will result in immediate burial aside from the pulverising effect of glacial action.
Seriously, the easiest way to sea how much chance their is of any structure being recogniable is to go out and try to find some surface rock that is 1, 000, 000 years old that hasn’t come from overlying layers eroding away and that is itself not eroded more than a few inches. It simply doesn’t exist. And is the rock the structure is built on has eroded several inches how can the structure itself still be standing?
Well, actually the damage to the pyramids is due to over 4500 years of sandblasting. So we’re only talking about 220 times the damage they’ve taken so far.
My Guiness Book says the oldest surviving dateable bridge is a single arch bridge over the River Meles in Smyrna, c. 850BC. That’s 2856 years and counting. There are numerous surviving Roman bridges at ages at or close to two millenia. I’m pretty sure there are Chinese bridges of similar ages.
I don’t disagree with your broader point, but you’re overstating your evidence and playing fast and loose with the facts here.
Are you suggesting that the sandblasting thatocured in the last 1000 years hasn’t caused any damage to the pyramids? If not then how does this contradict my point that less than 1000 years of sandblastinghas caused damage? Are you attempting to argue that the first 999 years caused no damage?
And it has been totaly unmaintained for that entire period has it? Not a single stone replaced, no mortar added?That a bridge or any other structure with constant mainatinence and repair can last forever seems self evident. It’s like my Grandfather’s axe. The point we are discussing here is structures that last for over a thousand years after being abandonded.
I can’t see that you have any broader point with the introduction of trivial irrelevancies.
Yep, a million years is a long ass time…to long to make anything but wild predictions about what the environment will or won’t do. And what artificial artifacts will and won’t do…or what improbable things may happen (such as, well, the improbability of bones fossilizing). Having seen for myself animals that walked around 10’s or even hundreds of MILLIONS of years ago sitting on the surface in the desert…well, probability is a strange beast.
Are you saying that an arid environment wouldn’t protect artifacts from corrosion and decay? Even if buried in sand?
Also, my understanding with the Global Warming arguement is that the deserts are growing, not shrinking…and will continue to do so for quite a long time even if man is out of the picture. Even if they grew for only 1/4 of the million years (which doesn’t seem unreasonable to me, though I’m WAGging all over the place here of course :)) and then went into retreat it seems reasonable that SOME desert cities would hit the probability jackpot and at least the outlines would remain buried in the sand.
And steel and glass buried under sand in an arid (and relatively geologically stable environment)? Will that be nothing but fine crystal also? We find Tells in the desert of civilizations that are thousands of years old all the time…and even in modern cities stone and terracotta are used (along with the concrete and structural steel). Certainly a million years is a long ass time…but not ONE such convergence of circumstance and luck in all the world? THAT seems improbable to me. YMMV.
I’ll give you this one…you are probably quite correct that anything in an artic or even semi-artic location today would be buried under thousands of feet of ice. I was thinking (again) of rolling 100 6’s in a row and hitting the probability jackpot…sort of like the ice man found in the alps type scenerio. How probable was that after all?
You ever been to the South West? 
You can see surface rock thats been erroded down to layers that were part of the environment millions of years ago…and even (sometimes, if you roll all the 6’s) the beasts (and their eggs) that roamed about during those times. Hell, there is a whole field of study where folks go out and hunt for these things. Can’t think of what its called, its a rather obscure branch of science after all…
-XT