While scouring the SD archive I came across a question/answer that talked about why archeological finds are often covered by big ol’ bunches of dirt (http://www.straightdope.com/classics/a3_351b.html). Cecil spoke of how quickly some of the “shoddy” buildings of the past deteriorated. From this, the thought immediately came to mind, “How long before what humanity has built are just artifacts and ruins covered by layers of dirt?”
So…if humanity ended today, how long before all things human have deteriorated to the point that everything is under a layer of soil, sand or whatever. Ruins covered by plants are not allowed. Archeologists from the planet Zeta are going to have to dig for this stuff.
I live in suburban New Jersey, and within walking distance of my house there’s a completely wild, overgrown place for which the only evidence of inhabitation by white men as far as the eye can see is the still obvious remnant of a bower.
The pyramids will probabbly last for a good while yet. The only reason they look as shoddy as they do is that humans have been stealing rock from them to build other structures. And it’s not like they’re going to get overgrown by vines any time soon.
On another note, Pioneers 10 and 11 and Voyagers 1 and 2, having escaped the Solar System, can be expected to last many times the lifetime of the Sun, unless they’re intercepted by aliens first. But they’re very small needles in a very big haystack, and it’d probably be easier for alien archaeologists to find artifacts hidden underground than them.
I would think that skyscrapers will take a lot longer to degrade and get buried than mud huts.
Flint objects from the stone age could last a very long time, and so could golden objects…some transistors could remain as strange shaped lumps of silicon and germanium, actually lots of objects have the potential for being preserved under the right conditions…
most buildings would be gone in a few million years above ground, mainly because they are full of joints to allow freeze-thaw cracking to develop.
Underground tunnels, railways and mines could be preserved for a very long time.
Large modern buildings are very much like living organisms and require a huge amount of maintenance.
I ounce heard somewhere (I don’t remember were. So don’t quote me or ask for a cite) that with out human intervention a modern skyscrapers steel support structure will, due to corrosion weaken to the point of collapse in about ten to fifteen years.
Actually that was: once heard :smack: