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Old 02-14-2017, 04:04 PM
 
1,217 posts, read 378,740 times
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Let's say the human race ends today, so all humans bye bye, but our bodies, buildings, etc all are untouched. How long would it take for all evidence to be gone?

I am talking about if aliens came to Earth in the future and dug around but found no evidence.

Also are there any theories, books, movies about this happening or it happened?
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Old 02-14-2017, 04:29 PM
 
Location: San Antonio/Houston
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If the human race were to become extinct tomorrow then our buildings and roads would gradually decay and possibly within a hundred or hundreds of years many buildings would start to collapse. Very sturdy structures will stand longest - think Greek Temples and Egyptian pyramids.
Reinforced concrete, plastics etc. these would certainly survive for millions of years. Plastic most likely will never biodegrade.
Sea levels will rise again and continents will be flooded, and then all of our cities will become deeply buried by marine sediments.
Over geological time, over millions of years they'll be preserved in a rock stratum in just the same way that dinosaurs are preserved in rock strata from 65 million years ago.
Organisms that live in the sea are much more likely to be fossilised than organisms like humans that live on land - those will be rather scarce.
To answer your question, OP, when the human race does eventually become extinct, as it certainly will, although evidence of our existence will disappear from the Earth's surface relatively quickly – say within a few millennia – evidence of our existence will survive buried at depth probably for as long as the planet survives.
Aliens will find plenty of evidence.

In 2013, in Ethiopia, paleoanthropologists have discovered a 2.8-million-year-old jawbone, making it the oldest fossil in the human ancestral line ever found.
http://www.history.com/news/discover...olutionary-gap
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Last edited by elnina; 02-14-2017 at 04:46 PM..
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Old 02-14-2017, 06:22 PM
 
Location: Somewhere in northern Alabama
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I doubt that evidence would ever be completely gone, and even if it was obliterated on Earth, there is the moon, Mars, and space where we have left traces. Hoover dam is a massive monolith of concrete that would survive even nuclear bombs. There are metal alloys we make and use that don't occur in nature. The chances of glacial scouring seem to grow less as we know more about the solar constant and climatology. Our quarries, especially granite quarries, will continue to exist even if the surface becomes hotter than Venus.
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Old 02-14-2017, 06:29 PM
 
Location: 10110001010110100
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I believe, things last a whole a lot shorter with people are around, and a whole a lot longer if they were gone.
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Old 02-14-2017, 06:31 PM
 
Location: Lake Grove
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There was a fascinating TV show called Life After People. The computer imagery was great.

https://en.wikipedia.org/wiki/Life_After_People
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Old 02-15-2017, 03:59 PM
 
Location: New England
1,001 posts, read 271,035 times
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Quote:
Originally Posted by peequi View Post

Also are there any theories, books, movies about this happening or it happened?
Planet of the Apes, any Zombie apocalypse movie, Dr. Who, take your pick.
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Old 02-20-2017, 12:52 PM
 
7,016 posts, read 7,238,422 times
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Quote:
Originally Posted by peequi View Post
Let's say the human race ends today, so all humans bye bye, but our bodies, buildings, etc all are untouched. How long would it take for all evidence to be gone?
I suppose the easiest way to answer that question is to look at the oldest objects we have know. Irrefutably, we have a handful of objects that are 40,000 years old, and a few objects that look like tools that could be much older.

The Toba catastrophe theory is that human beings went through a population bottleneck about 70,000 years ago, and were reduced to a few tens of thousands of human beings. The Toba catastrophe may have wiped out competing species with a handful of exceptions like Neanderthals. Since homo sapiens sapiens are though to have had modern cranial capacity for over 100,000 years the Toba catastrophe theory does leave open the possibility that a civilization had evolved that was completely wiped out with all traces eliminated.

Oldest objects
Intact European Book 11300 years
Coins between 660 and 600 B.C.
Still-Standing Wooden Building Construction began in A.D. 587 in Japan
The Venus of Hohle Fels is the world’s oldest figurine to depict the human form 40,000-year-old statuette
Musical Instruments bone flutes,39,000–40,000 years ago
Cave Paintings a new discovery on the Indonesian island of Sulawesi, east of Borneo, could be over 40,000 years old.

Abstract Design
In 2007, archaeologists studying mollusk shells gathered from the island of Java in Indonesia discovered one that appeared to have etchings on its surface. Others had characteristic holes near where the shells joined together, indicating that someone had used tools on them.In 2014, a team of researchers confirmed that the shell was probably a tool of some sort. The etchings were the work of humans, probably Homo erectus, who had been thought only capable of using stone tools. Even more astonishing, the zigzag pattern of the etchings indicated the oldest known example of abstract representation in hominids to date. The team, led by Josephine Joordens of Leiden University in the Netherlands, dated the shell to be about 500,000 years old.

The oldest tools ever found were discovered in Gona, Ethiopia and are 2.5–2.6 million years old. Not only does this make them the oldest tools, they are the oldest human artifacts in the world to date.

======================
But that leaves open the question that modern civilization and technology and over 7 billion people and trillions of artifacts would leave a longer lasting mark than mankind of 40,000 years ago which were though to number far less than a million people.

The general consensus is that modern day artifacts would not survive much longer with a few exceptions like the gold ingots in Fort Knox and in New York city. Gold ingots are though to survive much longer than 40,000 years. But the aliens might have trouble finding them if there are no trace of cities or buildings.
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Old 02-20-2017, 06:54 PM
 
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It has been suggested that human artifacts made of plastics will survive for 50,000,000 years.
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Old 02-20-2017, 08:33 PM
 
Location: Somewhere in northern Alabama
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Originally Posted by PacoMartin View Post
It has been suggested that human artifacts made of plastics will survive for 50,000,000 years.
Riggghhhttt. Sounds like coprolite to me.
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Old 02-22-2017, 12:26 PM
 
Location: NW NJ & SE Oahu
3,907 posts, read 4,488,736 times
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Quote:
Originally Posted by Zen88 View Post
There was a fascinating TV show called Life After People. The computer imagery was great.

https://en.wikipedia.org/wiki/Life_After_People
Interesting...

I love George Carlin's 'save the earth' routine:

https://youtu.be/xjfiIow-eW0?t=300
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