Welcome, Guest

• Forgot your password?
• Apply for membership

1. •  
     CommentAuthorDr. Orphusi
   • CommentTimeApr 13th 2006

    permalink
   Ok, here’s my query… it’s a theoretical ‘what-if’
   
   If every human on the Earth, right now, on this day, vanished… how long would it take for all human structures; items, building, anything we’ve physically created (skyscrapers, homes, phones, televisions, all of it) – in how many years will it take for these things to crumble into dust? 1,000 years? 2,000? I figure nature will pull apart things fairly quickly, but a more scientific answer would be great.
   
   Thanks.
2. • CommentAuthorwhat?
   • CommentTimeApr 13th 2006

    permalink
   If we can identify fossilised proto-amphibians that are hundreds of millions of years old then i'd guess the same would apply to us.
3. •  
     CommentAuthorDanieru
   • CommentTimeApr 13th 2006 edited

    permalink
   Here are two answers, separated for simplicity's sake into a long and a short version:
   
   LONG ANSWER:
   
   2,000 years? That's bugger all, look at the pyramids, stone henge (as obvious examples). If you want to find the oldest evidence of human settlements you won't necessarily find buildings (mainly cos we didn't start making them until a couple of tens of thousand years ago), but fires based in caves, or even our earliest stone tool remnants are all still accessible some 40,000 years after they were discarded.
   
   I would presume (but have no way of knowing this for sure) that obvious signs of primitive human settlements will still be in existence for many tens of thousands of years from now, maybe millions. Virtually anything can becomes fossilised given the right conditions, this includes a camp fire or a flint.
   
   I suppose this shows that our mark is difficult to wipe out, and I haven't said anything about technology created since those first stone tools. Imagine how modern settlements will show up in the fossil record. We have plastics, some of which take thousands of years to biodegrade under even the harshest conditions. We have other processed materials (such as carbon fibre, bulletproof glass, titanium laptop computers) embedded into the structure of our lives that were designed to never degrade. Of course nature will get most of the fundamental, obvious structures of civilisation out of the way within a few hundred / thousands years, but remnants will survive for much longer than this.
   
   I would say the only way to completely wipe out evidence of a Civilisation would be to destroy the planet itself, in it's entirety. Maybe the only way to do this would be the engulfing body of a parent star as its life cycle takes it through the red giant phase and the planets in the inner ring of its system are swallowed up in its wake. Merely impacting a planet with countless asteroids or other such 'extinction' measures would still leave some signs of what previously existed in eras long since past....
   
   I have often contemplated how the items we leave are likely to say the most about us. Any future sentient beings that dug up our extinct asses would find us lying amongst the most unbelieveble crap ever conceived by conscious life-forms. They'd be able to fill their museums with plastic garden gnomes, kylie minogue records, hang-on-the-wall singing fish, life size star wars cut outs and waterproof shower radios...
   
   What a legacy has mankind!
   
   SHORT ANSWER:
   
   Countless eons...
4. • CommentAuthorwhat?
   • CommentTimeApr 13th 2006 edited

    permalink
   Dont forget Voyager and co. happily traversing the heliopause on the way away
5. • CommentAuthorsheggers
   • CommentTimeApr 13th 2006

    permalink
   On an aside to this, if you happened to be the only human left when everyone vanished, what would be the first thing you would do?
6. •  
     CommentAuthorDanieru
   • CommentTimeApr 13th 2006 edited

    permalink
   the only human?
   
   after crying for a considerable amount of time i'd probably go search for some chimps to hang around with, maybe a couple of baboons and an orangutan.
   
   beats being alone
7. •  
     CommentAuthorDr. Orphusi
   • CommentTimeApr 13th 2006 edited

    permalink
   Haha, OK. I guess I thought it wouldn't take that long because a lot of human building materials are a lot weaker (plaster, brick, etc) because they're not made from the same sort of stones the ancients used, stones of the earth that were forged by the earth, etc...
   
   but the little things will last, yeah.
   
   and if I was the last human I'd find a lot of drugs and befriend a lot of cool animals.
8. • CommentAuthorsheggers
   • CommentTimeApr 13th 2006

    permalink
   Do you think there is any chance of reproducing if you, ahem, got friendly with one of our closer genetic relatives?
9. •  
     CommentAuthorDanieru
   • CommentTimeApr 13th 2006

    permalink
   no more human vaginas anywhere?
   
   damn right i'd be doing some loving with the chimps
10. •  
      CommentAuthormike2050
    • CommentTimeMay 2nd 2006

     permalink

    The now-defunct magazine Whole Earth Review (which was originally titled "Co-Evolution Quarterly" when it sprung from the loins of the old Whole Earth Catalogue) once ran an article that addressed exaclty this question: How long would human-built structures last without ongoing maintenance and replacement?
    

    Unfortunately, a cursory net search did not turn up the article. It's probably buried in the magazine's archives in Sausalito, CA (last known address). Anyway, as best I recall the skyscrapers were predicted to topple after a century or so, and the dams silt up (but without cracking) only after many centuries.
    

    But I could be wrong about that, since my memory is known to be less reliable than those structures in terms of its ability to retain accurate recollections over many years without the refreshment of paper or electronic reminders!
    

    Regards,
    

    Mike

11. • CommentAuthorEndymion
    • CommentTimeMay 5th 2006

     permalink
    The question posits the simultaneous disappearance of every human being on earth. What would be the consequences of that?
    
    Unmanned control-rooms in nuclear power-stations, plus submarines and aircraft carriers at sea - and 200,000 ton oil-tankers left ploughing through the oceans unpiloted. Unmanned oil-rigs in the world's seas with their pumps still running, ditto oil pipe-lines crossing continents. Nuclear missiles in their silos left to their computers. "What's the matter, Dave? Dave? Are you still there, Dave?"
    
    Would the Earth even survive it? Fifty years ago I'd have said yes, but now....
12. • CommentAuthorwhat?
    • CommentTimeMay 6th 2006

     permalink
    Did I leave the gas on?
13. •  
      CommentAuthorTman
    • CommentTimeMay 6th 2006

     permalink
    "On an aside to this, if you happened to be the only human left when everyone vanished, what would be the first thing you would do?"
    
    I could read books for all enternity, then unfortunutly suffer a twilight zone cliche
    
    Seriously though, I'd make sure there were no Zombies first, then get drunk. SERIOUSLY drunk
14. • CommentAuthorEndymion
    • CommentTimeMay 6th 2006

     permalink
    "On an aside to this, if you happened to be the only human left when everyone vanished, what would be the first thing you would do?"
    
    Turn the gas off.
    
    Then I'd go to the Vatican's secret archives, and know for sure!
15. •  
      CommentAuthorDanieru
    • CommentTimeMay 7th 2006 edited

     permalink
    I'd spend 10 years gathering light reflecting material and solar panel technology which I would arrange into an enormous circle surrounding an appropriately located mountain. The circle would be so large, given 10 years of constant 1 man labour (perhaps I could rope in some monkeys to help me) that I would assume it was visible from space. I would strap the solar panels to a generator and let them start creating juice.
    
    I would then head off and track down a cryogenic lab on my continent (let's hope I was in the US, there's 100 crazy, rich cryo-dudes there for every 1 in Europe)
    
    I would finally drag an empty cryo tank to the centre of the enormous circle (i.e. the top of the appropriately located mountain), hook the thing up and spend a few more years training Orangutaans to work it. When I was sure I could trust their cryo skills I would turn on the power for my homemade cryo lab and strap myself in.
    
    Hopefully a passing spaceship would spot my circle-mountain-cyrotank within the next thousand years or so. Whether I could trust the Orangutaans to look after my frozen body for that long is the only element of luck I'll allow in my devilish plan to be the last physically accessible human cadavar in the entire universe.
    
    Let's hope the apes don't evolve into a superior species before I get rescued.