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Author Topic: Is it possible that pre-human civilisations have existed in the past?  (Read 9391 times)

Offline bizerl

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I have recently heard about "the next supercontinent" where it was suggested there have been other supercontinents prior to Pangaea.

Firstly: How is this discovered? and

Secondly: If the continents have been so turbulent over the billions of years, is it possible that some sort of intelligent civilisation could have risen and fallen, and there be no evidence of them at all? and

Thirdly: If so, if the proverbial meteorite came and extincted (if it's not a word, it should be! :)) us tomorrow, how long would it be before there was absolutely no evidence that we ever existed?


 

Offline CliffordK

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Hopefully someone else will comment on the periodic formation of super-continents.

There was a TV series a couple of years ago called "Life After People".
http://www.history.com/shows/life-after-people
http://en.wikipedia.org/wiki/Life_After_People

And another one called Aftermath: Population Zero.
http://en.wikipedia.org/wiki/Aftermath:_Population_Zero

This was discussed here on TNS a few times.
http://www.thenakedscientists.com/forum/index.php?topic=39651.0
http://www.thenakedscientists.com/forum/index.php?topic=26634.0
http://www.thenakedscientists.com/forum/index.php?topic=23359.0
http://www.thenakedscientists.com/forum/index.php?topic=37787.0

The basic premise was that without maintenance, after a few hundred, or a few thousand years, much of what we have built would decay, and would be crumbled and gone.  Voyager, and some of our space probes might still be out there, somewhere, but essentially undetectable. 

One might find some odd concentrations of metals.  For example Fort Knox might show up with a very high concentration of gold bars.

"Graveyard Orbits" should also last a very long time in space, around Earth.

Egyptian Pyramids might get covered in sand dunes, but may endure for eons. 

I suppose, if you think of coal and oil deposits, some are around 100 million years old, and buried a mile or so beneath the surface of the earth.  So, over a few million years, one might expect everything humans made to become buried.  This might, however, also provide some benefits of preserving what we've made.

Now, we do have very long-term fossil evidence, I believe back into the period prior to the evolution of eukaryotes.  In particular, one can trace the origin of hominid species back about 5 to 10 million years.  And, with these early hominids, there is also a slow progression of parallel technology with tools, art, living quarters, and etc.  The evidence left by humans during the Eemian Interglacial is sparse, but there is no evidence of early humans having cars and airplanes.

Now, could dinosaurs have evolved technology?  I suppose it is possible, but then one would expect to see evidence of their advanced technology with them in the fossil records and tar pits.  But, no such evidence has been found.

An Atlantis oasis of technology that was completely lost?
Perhaps, but then again, why didn't the technology spread globally?
Humans have left evidence of our presence everywhere from the North Pole to the South Pole to deserts to the tropics, and even on the Moon and Mars (along with other long-lived space probes).  And, I believe that "Graveyard Orbits" are particularly stable orbits, so the stuff left up there might stay there for millions of years.
 

Offline damocles

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...(snip)...

Thirdly: If so, if the proverbial meteorite came and extincted (if it's not a word, it should be! :)) us tomorrow, how long would it be before there was absolutely no evidence that we ever existed?

There is such a word. It is extinguished.
 

Offline bizerl

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Hmmmm... "Extinguished"...

I like the way that sounds. I think I'll use it!
 

Offline imatfaal

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Thirdly: If so, if the proverbial meteorite came and extincted (if it's not a word, it should be! :)) us tomorrow, how long would it be before there was absolutely no evidence that we ever existed?
I like extincted (notwithstanding Damocles correct but mundane extinguished).  On the substantive question - even if we had another Theia sort impact then there would still be evidence of Humanity for many years to come.  Voyager is currently heading into the incredible emptiness of interstellar space at the speed of about 17km/s; now this might be fast in human terms - but in relation to distances in the void it is practically stationary.  The next star it will even be close to is in 40,000 years time - and that is only a fly by at 1.3 light years
 

Offline CliffordK

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The voyager probes still have radio signals.
The Pioneer probes are now quiet (I think).

Can we find them with the telescopes?
If we didn't know where to look, we would never see them.
And, if we detected them, would we notice they weren't asteroids?
I suppose the anomalous heat signature would be noticeable for a few centuries.  But, in 40,000 years, most of the 238Pu will have decayed away, and the probes will be running more or less at background temperatures.

So, while the deep space probes would be ultimate evidence that we were here.  They may remain unseen forever.
 

Offline Don_1

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Secondly: If the continents have been so turbulent over the billions of years, is it possible that some sort of intelligent civilisation could have risen and fallen, and there be no evidence of them at all? and



I think there would be some fossil evidence of any previous intelligent species. Fossil cells have been found in Australia which are around 3.4b years old. Though we may not have found the remains of every species that has ever inhabited the planet, I rather think that a previous intelligent civilisation would have left behind it some clue as to its existance.
 

Offline Gordian Knot

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Though there has never been any evidence for a technologically advanced civilization, I have been fascinated at how we continue to push back the proof of our own species' advancement.

As I understand it, traditionally the oldest "civilized" cultures were in the 3,000 to 5,000 BCE time frame. This being roughly defined as the growth of agricultural societies, the formation of the first cities, megalith building, etc.

The discovery of the megalithic center Göbekli Tepe comes as quite a shock then, as it is estimated to have been built about 10,000 BCE. It has been called the oldest religious center (though personally I find that comment absurd; there is no evidence whatsoever what this site was built for).

It is also different in that it was apparently built by a hunter/gatherer civilization. No farming, no permanent settlements required. Yet it is megalith building equal to some of the civilizations 5,000 years later.

Since that discovery there have been a few other sites found to have been much earlier than our standard model of the rise of civilization. If these sites push back our advancement so far, how much farther back might there be evidence waiting to be found?

It also would seem to make the concept of a truly ancient advanced society a little bit more feasible. Since we haven't apparently even figured out how "old" human advancement is.
 

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