What will last 20,000 years?
Jim
take your pick), and in a thousand years or so a mini-ice age started
lasting between 5 and 10 thousand years, what would be left for a
newly built civilization's archaeologists to find of our works?
The pyramids would likely be gone by wind erosion (or tropical rains),
concrete buildings would have turned to dust, even stainless steel
would have rusted away.
I know that specific sites like Cheyenne Mountain, if sealed at the
start of the catastrophe, would probably have significant relics (if
not gutted by the survivors and their progeny), but that's only about
1 square mile out of 60 million.
Would they have any way of knowing that we were here?
J.Michael
___________________________________________
I went to a reincarnationist -- I learned
that in a previous life I was immortal.
Erik Max Francis
> If our civilization collapsed (self-extermination, plague, meteor,
> take your pick), and in a thousand years or so a mini-ice age started
> lasting between 5 and 10 thousand years, what would be left for a
> newly built civilization's archaeologists to find of our works?
Uh, how about the major cities? Sure, they wouldn't be intact or
pretty, but they'd be there, and really obvious once something of them
was uncovered.
--
Erik Max Francis / email m...@alcyone.com / whois mf303 / icq 16063900
Alcyone Systems / irc maxxon (efnet) / finger m...@finger.alcyone.com
San Jose, CA / languages En, Eo / web http://www.alcyone.com/max/
USA / icbm 37 20 07 N 121 53 38 W / &tSftDotIotE
\
/ Courage is the fear of being thought a coward.
/ Horace Smith
Phillip McGregor
>If our civilization collapsed (self-extermination, plague, meteor,
>take your pick), and in a thousand years or so a mini-ice age started
>lasting between 5 and 10 thousand years, what would be left for a
>newly built civilization's archaeologists to find of our works?
>The pyramids would likely be gone by wind erosion (or tropical rains),
>concrete buildings would have turned to dust, even stainless steel
>would have rusted away.
No, the Pyramids will likely still be here. Unless, of course, destroyed by the
catastrophe itself. Worn and eroded, but still *very* large. Perhaps not
recognisable as man-made until the mound that (might) cover them is excavated.
Interstates would be a possibility. All that concrete. Not natural.
The biggie, of course, is glass. Plain old garden variety glass.
Artifacts of gold or platinum *might* do so, if protected somehow. Probably
ceramics, again, if protected (things like fired house bricks).
Items on the moon would almost certainly still be there (not to mention Mars)
assuming that our hypothetical successors ever get there.
Actually, I proposed a question almost identical to this around four years ago
on this group for background for a role playing game I was designing
("Armageddon" as per the .sig below ... now available from www.hyperbooks.com
for under $20 as a pdf download only ... finish plug). The only difference was
that I was proposing 25k years into the future ... but the general consensus was
pretty much as I have indicated above.
Phil
--------------------------------------------------------------------------------
Phillip McGregor | asp...@curie.dialix.oz.au | www.fandom.net/~PGD/index.htm
| mcgr...@locs.org (emergencies only!!)
--------------------------------------------------------------------------------
YES! StaRPlay:Armageddon and Dark Star are now available from www.hyperbooks.com
--------------------------------------------------------------------------------
Co-designer, Space Opera (FGU); Author, Rigger Black Book (FASA)
Phillip McGregor
>Jim wrote:
>
>> If our civilization collapsed (self-extermination, plague, meteor,
>> take your pick), and in a thousand years or so a mini-ice age started
>> lasting between 5 and 10 thousand years, what would be left for a
>> newly built civilization's archaeologists to find of our works?
>
>Uh, how about the major cities? Sure, they wouldn't be intact or
>pretty, but they'd be there, and really obvious once something of them
>was uncovered.
Hmm.
Think for a minute.
All the iron and steel will rust.
Plants will get into cracks in the concrete.
Entropy will have its way.
All that will likely be left will be mounds of rubble. Perhaps not even
recognizable as such.
Rivers change courses, and so much might be washed away as many major cities are
on rivers.
Coastlines change by natural action as well as because of rises and falls in the
average sea level. So coastal cities may be inundated and swept away.
Glaciers, if we assume an ice age, will simply grind the cities in their path(s)
into nonexistence.
Some things will last ... all that glass. Ceramics (especially hard fired bricks
in protected places). Gold and Platinum items in protected places.
But not much.
Joseph Hertzlinger
writes:
>If our civilization collapsed (self-extermination, plague, meteor,
>take your pick), and in a thousand years or so a mini-ice age started
>lasting between 5 and 10 thousand years, what would be left for a
>newly built civilization's archaeologists to find of our works?
Nuclear waste (even after it has become non-radioactive the isotope
signatures will be recognizable for billions of years).
Fort Knox.
Cut diamonds.
A mysterious lack of valuable elements where they would be expected.
A mysterious presence of valuable elements where they aren't expected
(aka garbage dumps).
Satellites in high orbits.
Anything left on the Moon or Mars.
A mass extinction in the fossil record.
rcg...@esl.tamu.edu
>If our civilization collapsed (self-extermination, plague, meteor,
>take your pick), and in a thousand years or so a mini-ice age started
>lasting between 5 and 10 thousand years, what would be left for a
>newly built civilization's archaeologists to find of our works?
>
>The pyramids would likely be gone by wind erosion (or tropical rains),
>concrete buildings would have turned to dust, even stainless steel
>would have rusted away.
>
>I know that specific sites like Cheyenne Mountain, if sealed at the
>start of the catastrophe, would probably have significant relics (if
>not gutted by the survivors and their progeny), but that's only about
>1 square mile out of 60 million.
>
>Would they have any way of knowing that we were here?
Toilet bowls and Twinkies.
Jim
wrote:
>Jim wrote:
>
>> If our civilization collapsed (self-extermination, plague, meteor,
>> take your pick), and in a thousand years or so a mini-ice age started
>> lasting between 5 and 10 thousand years, what would be left for a
>> newly built civilization's archaeologists to find of our works?
>
>Uh, how about the major cities? Sure, they wouldn't be intact or
>pretty, but they'd be there, and really obvious once something of them
>was uncovered.
But they're such a small area, in respect to the overall land mass.
And a majority of them are coastal, which means they may or may not be
above water.
And there'll be some disintegration and amalgamation with the
environment, especially along the fringes.
My feeling is that if the pyramids will be gone, glass office
buildings don't have a prayer.
Erik Max Francis
> Think for a minute.
>
> All the iron and steel will rust.
>
> Plants will get into cracks in the concrete.
>
> Entropy will have its way.
>
> All that will likely be left will be mounds of rubble.
Huge, monstrous mounds of very distinct rubble.
--
Erik Max Francis / email m...@alcyone.com / whois mf303 / icq 16063900
Alcyone Systems / irc maxxon (efnet) / finger m...@finger.alcyone.com
San Jose, CA / languages En, Eo / web http://www.alcyone.com/max/
USA / icbm 37 20 07 N 121 53 38 W / &tSftDotIotE
\
/ Custom reconciles us to everything.
/ Edmund Burke
Peter Johnston
>On Fri, 01 Jan 1999 06:45:39 GMT, capu...@mcmsys.com (Jim) wrote:
>
>>If our civilization collapsed (self-extermination, plague, meteor,
>>take your pick), and in a thousand years or so a mini-ice age started
>>lasting between 5 and 10 thousand years, what would be left for a
>>newly built civilization's archaeologists to find of our works?
>>
How about evidence of an industrial civilisation's atmosphere trapped in air
bubbles in ice cores?
Or layers of plastic shopping bags buried in land fills?
In general, I'd opt for pollutants and possibly evidence of mass extinctions as
our most enduring legacy.
Peter Johnston
Natural Born Sluagh
Canberra Australia
Remove the obvious
John Thompson
>On Fri, 01 Jan 1999 02:33:25 -0800, Erik Max Francis <m...@alcyone.com>
>wrote:
>
>>
>>> If our civilization collapsed (self-extermination, plague, meteor,
>>> take your pick), and in a thousand years or so a mini-ice age started
>>> lasting between 5 and 10 thousand years, what would be left for a
>>> newly built civilization's archaeologists to find of our works?
>>
>>pretty, but they'd be there, and really obvious once something of them
>>was uncovered.
>
>But they're such a small area, in respect to the overall land mass.
>And a majority of them are coastal, which means they may or may not be
>above water.
>And there'll be some disintegration and amalgamation with the
>environment, especially along the fringes.
>
>My feeling is that if the pyramids will be gone, glass office
>buildings don't have a prayer.
>
>
>J.Michael
>___________________________________________
>
>I went to a reincarnationist -- I learned
>that in a previous life I was immortal.
If there's a mini-ice age, as water becomes locked in the polar caps and
glaciers, the sea level will FALL, at least for a few thousand years.
No one seems to have mentioned that in the past couple of hundred years, we
have literally covered the land surface with artifacts. Some, like glass and
ceramics are very durable, especially if buried. (Isn't there an old story
where future, maybe alien archeologists try to figure out the use of the most
common surviving artifact: commodes?) I think the sheer volume of material
would ensure that a great deal would survive.
John
Nyrath the nearly wise
John Thompson wrote:
> No one seems to have mentioned that in the past couple of hundred years, we
> have literally covered the land surface with artifacts. Some, like glass and
> ceramics are very durable, especially if buried. (Isn't there an old story
> where future, maybe alien archeologists try to figure out the use of the most
> common surviving artifact: commodes?)
I think you are thinking about the book MOTEL OF THE MYSTERIES.
The future archeologists conclude that the toilet is some sort
of ritual altar.
It is a truism that whenever an archeologist says that an
artifact is a ritual object, what they really mean is
that they have no idea what the hell it is.
Dan Goodman
The story is "No Connection" by Randall Garrett.
--
Dan Goodman
dsg...@visi.com
http://www.visi.com/~dsgood/index.html
Whatever you wish for me, may you have twice as much.
Steve Hix
slu...@SPAMMENOTdynamite.com.au (Peter Johnston) wrote:
> On Fri, 01 Jan 1999 18:43:14 GMT, rcg...@esl.tamu.edu wrote:
>
> >On Fri, 01 Jan 1999 06:45:39 GMT, capu...@mcmsys.com (Jim) wrote:
> >
> >>If our civilization collapsed (self-extermination, plague, meteor,
> >>take your pick), and in a thousand years or so a mini-ice age started
> >>lasting between 5 and 10 thousand years, what would be left for a
> >>newly built civilization's archaeologists to find of our works?
> >>
>
> How about evidence of an industrial civilisation's atmosphere trapped in air
> bubbles in ice cores?
>
> Or layers of plastic shopping bags buried in land fills?
>
> In general, I'd opt for pollutants and possibly evidence of mass
extinctions as
> our most enduring legacy.
Toilets and commodes. (Not my idea, unfortunately.)
Keith Morrison
> Other posters on this thread have pointed out that certain regions
> would exhibit anomalous materials abundances (or absences). But if
> those "anomalies" are as ubiquitous as today's cities, garbage and
> radioactive dumps and mines are, would they been seen as anomalous or
> perfectly normal? Without original ore beds to serve as a comparison?
Not a problem.
There is a huge number of mineral deposits that are not worked
because they are not economical, thus they maintain a record
of natural mineral formation.
And it doesn't take much to demonstrate that something isn't
kosher about a mineral anomaly. The Oklo reactors in Gabon
were discovered because the U-238 ratio was a few percent off
from what it should have been (not to mention that there was
plutonium there, which simply shouldn't have been). Anyone
with access to basic geological theory will quickly figure out
that there is something damn odd, especially for something like
plastic with no natural method of formation.
Going back to minerals, they don't just happen. There is
always an explanation as to how that particular concentration
should be at that point (assuming purely natural processes).
If, 20,000 years from now a moderately-intelligent geologist
finds a concentration of radioactive material located in a
discrete horizon with nothing above or below it to indicate
where the hell it came from, and it is in a confined area
for no particular geological reason, that raises a red flag.
Also, 20,000 years is virtually an eyeblink in geological
terms. The stuff will still be close to the surface in most
parts of the world.
--
Keith Morrison
kei...@polarnet.ca
Brett Evill
Of course, the first question to ask is what has lasted from 20,000 years
ago. As bone and shaped stones have lasted since then, bone and various
ceramics are likely to do it again, not to mention worked stone of various
sorts: finished surfaces on granite, basalt, and quartzite, gemstones,
building blocks in various large civil works. Concrete won't last in the
weather, nor in acidic conditions, but buried in basic soil it should last
as long as limestone: and there are some very old limestones. Even if the
mortar and reinforcing rods are weathered away, the deposits of
uniformly-sized gravel and basalt screenings could be diagnostic. And the
major threat to buried statuary and ceramics from antiquity is recovery:
nothing much seems to be happening to it in situ. Figure on shards of
glass and crockery lasting a very long time.
Then again, there may be some works too large to die. The Pyramids are
still pyramidal after four thousand years, mostly unmaintained. They look
to me as though they will last another five times as long, 'bloodied but
unbowed'. Twenty thousand years' erosion will wear down most cuttings and
embankments: if they are in areas where erosion is to be expected. But
other embankments and cuttings will be buried in, and protected by,
sediment.
Speaking of sediment, some of our larger dams will accumulate huge
deposits of sediment behind them, and when the rivers are allowed to run
free they will (in some cases) cut through these meadows rather than
sweeping them away. This will leave a characteristic landform.
Remember: at Laetoli *footprints* survive from about 3.6 million years
ago. At other places dinosaurs' footprints survive from over 65 million
years. As this can happen surely some large-scale engineering works will
last a mere 20,000 years. Our vast road-cuttings and embankments. Some
tunnels and quarries. Deep basements cut and blasted forty metres into
bedrock.
Then there are metals. Worked gold has been recovered three thousand years
old, and it is still as bright as when it was lost. Some jewelry will
last, some dental bridgework. And time will do, basically, nothing to the
millions of gold bricks we have horded in such places as Fort Knox and the
Fed vaults in New York. I have seen bronze and steel artifacts that have
been recovered after a millenium or two under water. A steel sword is a
battered wreck after that time. I cannot suppose that it would be
recognisable after ten to twenty times as long. But some stainless steels
have more than twenty times the corrosion resistance of iron and mild
steel. They should leave recognisable wreckage. And some items (such as
tank hulls, sections of 15" armour plate, and even some vault doors) have
more than twenty times the bulk of a sword. In dry and/or anoxic
conditions they should still be recognisable as artifacts after 20,000
years.
--
Brett Evill
To reply by e-mail, remove 'spamblocker.' from <b.e...@spamblocker.tyndale.apana.org.au>
Creator/editor, 'Flat Black' SF comic <http://www.dreamriders.com/FlatBlack.html>
Phillip Thorne
>If our civilization collapsed (self-extermination, plague, meteor,
>take your pick), and in a thousand years or so a mini-ice age started
>lasting between 5 and 10 thousand years, what would be left for a
>newly built civilization's archaeologists to find of our works?
It depends partially on what search techniques they can apply, and how
widely. E.g., who knows how many human and dinosaur fossil beds
today's archeologiests and paleontologists have missed!
Other posters on this thread have pointed out that certain regions
would exhibit anomalous materials abundances (or absences). But if
those "anomalies" are as ubiquitous as today's cities, garbage and
radioactive dumps and mines are, would they been seen as anomalous or
perfectly normal? Without original ore beds to serve as a comparison?
(Vernor Vinge's _Marooned in Realtime_ takes place 50My from now, by
which era *new* ore beds have formed.)
What about the *foundations* of skyscrapers, down against/in the
bedrock? The skyline above might be eroded, but Manhattan's (or
Chicago's, or Tokyo's) basements (subways, plumbing) wouldn't be
exposed to nearly the same destructive force of wind, grit, water,
vegetation and corrosive animal droppings (except maybe rats).
Undersea cables and the lower end of oil-drilling platforms? The
near-freezing benthic depths are good to preserve wooden shipwrecks
for a few centuries, at least.
What would be visible with aerial or satellite remote sensing? That's
been a successful technique for detecting archeological remnants that
aren't visible from the ground, but the cases I recall were all in
arid regions of the near and middle east.
Have there been any recent equivalents to Pompeii -- cities buried
quickly in volcanic ash?
Artificial coastlines and harbors with suspiciously rectilinear
shapes? I can't say how much silting-up would occur. Perhaps it would
better if it *did* -- the silt would "fossilize" concrete embankments.
How about the levees along the Mississippi River -- with its periodic
floodings, it's a *good* candidate to get buried.
When you say "our works" do you mean those we have *right now*, or any
(possibly far more durable) works we may erect in the next few
centuries? Possibly using large quantities of diamond-based structural
materials -- durable, and not something you'd expect to find in
nature.
Arthur C. Clarke's _The Ghost from the Grand Banks_ posits that an
alien probe discovers the wreck of the _Titanic_ some millions of
years from now (after it was buried in an undersea mudslide).
.-- Phillip Thorne, RPI CSCI '98 ----------------------------------.
| peth...@earthlink.net It's the boundary |
| home.earthlink.net/~pethorne/ conditions that get you |
\__ RHI Consulting/SB PharmR&D Bioinformatics _____________________/
Christopher Michael Jones
in solar or planetary) orbits would be around for far
longer than 20,000 years. However, there are a lot of
manmade things that are made out of plastic, concrete,
aluminum, stainless steel, and other long lasting
materials. These things will show the traces of human
occupation (and technology) for many millenia. Also,
one of the halmarks of the modern age, a ceramic
encased silicon "chip", would most likely survive
for much longer than 20,000 years. There's certainly
enough of those lying around to demonstrate our
technological sophistication to archaeologists of
the future (be they human or alien).
Also, there's quite a lot of crud at the bottom of
the oceans and seas of Earth. Everything from roman
galleys, the Titanic, a space capsule, the USS Yorktown,
and a balloon that 3 people tried to fly around the
world is down there, and they will be preserved for
an insanely long period of time (for some of these
objects, only burial or subduction will hide or
destroy them).
Currently, our level of technology is enough to find
very old and very small artifacts that are as much as
millions of years (rock tools). Comparatively, it
would be easy for a child to locate artifacts of
our present civilization tens of thousands (or more)
years into the future. Just think about the mountains
of plastic and non-biodegradable waste) that we
have created. These will not be gone in a long time.
And think about the impact we have had on the
environment, we have razed mountains, we have
subverted the sea, we have dug down into the bowels
of the Earth and extracted minerals, oil, diamonds,
Uranium, coal, and so many other materials, we have
created many strange and unnatural materials that
are not easily mistaken for natural materials, even
after thousands or millions of years of wear. The
strange material in Chornobyl's reactor (corium,
I believe it is called) will bear witness to the
hands of a technological civilization for billions
of years (as will large quantities of Uranium
tailings and spent fuel rods).
20,000 years might do much to wear down the corners
and erode the polish of civilization, but it will
do essentially nothing to erase the signal of
civilization.
Jim (capu...@mcmsys.com) wrote:
> If our civilization collapsed (self-extermination, plague, meteor,
> take your pick), and in a thousand years or so a mini-ice age started
> lasting between 5 and 10 thousand years, what would be left for a
> newly built civilization's archaeologists to find of our works?
> The pyramids would likely be gone by wind erosion (or tropical rains),
> concrete buildings would have turned to dust, even stainless steel
> would have rusted away.
> I know that specific sites like Cheyenne Mountain, if sealed at the
> start of the catastrophe, would probably have significant relics (if
> not gutted by the survivors and their progeny), but that's only about
> 1 square mile out of 60 million.
> Would they have any way of knowing that we were here?
> J.Michael
--
------------------------------------------------------------
Chris Jones
My Web Page - "http://www.cs.uoregon.edu/~cjones/web/"
Jim
wrote:
>In article <368d3916...@news.mcmsys.com>, capu...@mail.mcmsys.com wrote:
>>On Fri, 01 Jan 1999 02:33:25 -0800, Erik Max Francis <m...@alcyone.com>
>>wrote:
>>>> If our civilization collapsed (self-extermination, plague, meteor,
>>>> take your pick), and in a thousand years or so a mini-ice age started
>>>> lasting between 5 and 10 thousand years, what would be left for a
>>>> newly built civilization's archaeologists to find of our works?
>>>pretty, but they'd be there, and really obvious once something of them
>>>was uncovered.
>>But they're such a small area, in respect to the overall land mass.
>>And a majority of them are coastal, which means they may or may not be
>>above water.
>>And there'll be some disintegration and amalgamation with the
>>environment, especially along the fringes.
>glaciers, the sea level will FALL, at least for a few thousand years.
be higher than it is now. (The original post ((above)) says a thousand
years, 5-10 thou for a mini-ice-age, and then enough after that to
equal 20,000).
Also, since most civilizations have the majority of construction
(digging foundations, etc.) near the shoreline, there's slim chance
they'll be exactly over the location of our present cities.
>No one seems to have mentioned that in the past couple of hundred years, we
>have literally covered the land surface with artifacts. Some, like glass and
>ceramics are very durable, especially if buried.
I take it you're a city boy. Not only have we not covered the land
surface with artifacts, there is still a large percentage of the globe
that's unexplored. What we have is basically large concentrations with
some scattering.
Glass and ceramics: yes, okay, that's sort of what I was asking about.
I can see at least a few shreds of those eventually being found. (If
buried, though, what's the chance they'd ever be unearthed? I read
somewhere that we've dug up less than 1/100,000 of 1% of the earth.)
J.Michael
________________________________________________
Do you ever get the feeling that Rod Serling
is standing around the corner talking about you?
Anthony Buckland
> ... Concrete won't last in the
> weather, nor in acidic conditions, but buried in basic soil it should last
> as long as limestone: and there are some very old limestones. Even if the
> mortar and reinforcing rods are weathered away, the deposits of
... [much good stuff clipped] ...
A parking area of several stories under a major office
building, constructed of massive reinforced concrete,
jammed (depending on the civilization-ending event)
with vehicles containing large quantities of metals
disinclined to corrode, is going to leave a _very_
untypical entry in the geological record, even after
much more than 20k years.
Anthony Buckland
> ...
> What would be visible with aerial or satellite remote sensing? ...
First off, it might tell you something that you have to place
your satellites carefully because of all the dead satellites
out in geostationary orbit.
Anthony Buckland
> ... The
> strange material in Chornobyl's reactor (corium,
> I believe it is called) will bear witness to the
> hands of a technological civilization for billions
In fact you only have to get close to Chernobyl
(I hope, for your health, that you do it with
radiation detector in hand) to know that something
happened there. It may be a ghastly mess
esthetically, but all the concrete dumped on it to
try to contain the radiation is going to make a
_very_ long-lived memorial (of a sort we might
prefer not to leave).
Jim
<nyr...@clark.net> wrote:
> It is a truism that whenever an archeologist says that an
> artifact is a ritual object, what they really mean is
> that they have no idea what the hell it is.
Some years ago (early 70s?) I watched a short film done by a social
researcher -- he laid a dozen objects in front of test subjects (some
of whom were archeology students) and asked them to explain the
function.
The responses fell into two categories: either they knew what it was,
or they were way off base. Only 8% (if memory serves) even hit on
whether it might be a kitchen utensil or a machinist's tool, etc. and
the arch students weren't better than anyone else at guessing.
The only one I remember was a guy picking up a potato peeler and
saying that it was what women use to shave their legs.
Beth and Richard Treitel
>If our civilization collapsed (self-extermination, plague, meteor,
>take your pick), and in a thousand years or so a mini-ice age started
>lasting between 5 and 10 thousand years, what would be left for a
>newly built civilization's archaeologists to find of our works?
>
>The pyramids would likely be gone by wind erosion (or tropical rains),
>concrete buildings would have turned to dust, even stainless steel
>would have rusted away.
Given how well the Pyramids have held up over the past few thousand
years, I expect they'll last quite a lot more millennia. Likewise
Stonehenge-like monuments, though Stonehenge itself is probably far
enough north to be demolished by an ice age. On the North American
continent, Mount Rushmore.
If the new civ has Geiger counters, it'll notice a few places that are
"hotter" than they should be.
Quite possibly some of the tunnels that were dug through solid stone
mountains by railway engineers will still exist to be discovered.
And, eventually, our TV satellites will be rather hard to miss -- their
orbits may drift, but will still be suspiciously close to geosynch.
-- Richard
------
I don't read Usenet as regularly as I used to. Please be patient.
See also http://www.sirius.com/~treitel/Mark/index.html
John Thompson
>>No one seems to have mentioned that in the past couple of hundred years, we
>>have literally covered the land surface with artifacts. Some, like glass and
>>ceramics are very durable, especially if buried.
>I take it you're a city boy. Not only have we not covered the land
>surface with artifacts, there is still a large percentage of the globe
>that's unexplored. What we have is basically large concentrations with
>some scattering.
>J.Michael
I live in rural SC; from my house I can see some type of artifact in every
direction. Roads, brick houses, highways cut into hillsides: these are pretty
durable. Compare this to the state of affairs just 1000 years ago, here in
the US. My point is we have produced so many artifacts, of so many types,
that the situation really isn't the equivalent searching for signs of Troy or
ancient Egypt.
The Beaker People were traders in the Mediteranian, so named because they
traded beakers, perhaps so they could also sell beer. Compare then number of
beakers they produced to the number glasses, jars, and coffee mugs in use
today.... If we can still find evidence of them 5000 years later, surely
20,000 is no stretch.
Hmmm... Compare the total mass of glass, asphalt, and ceramic material today
to the total mass of dinosaur bone.... now think that ceramics are much more
durable than bone, able to stand up to far more weather, plus no animal is
going to try to eat them. Also consider that our junk only has to last 20,000
years, not millions...
If we found dinosaur bones, it would be easy to find signs of our
civilization.
sim...@msi-uk.com
ster...@scsn.net (John Thompson) wrote:
>
> If there's a mini-ice age, as water becomes locked in the polar caps and
> glaciers, the sea level will FALL, at least for a few thousand years.
>
> have literally covered the land surface with artifacts. Some, like glass and
> where future, maybe alien archeologists try to figure out the use of the most
> would ensure that a great deal would survive.
That's true. There are cities and towns on earth in paces that have been
geologicaly stable for millions of years. Arizona, Colorado and neighbouring
states are good examples. Many of the settlements there would simply be
covered with sand and survive largely intact. All across the globe many
plastic artefacts would degrade away, but others would survive especialy if
they were preserved in favourable conditions. The world is criss crossed with
an incredibly fine lattice of roads and railways. The physical evidence of
their existence would survive for hundreds of millions of years in the form
of layered and banked deposits of rubble, shale, tar and artificial concrete.
Buried railway sleepers would vitrify in dry conditions, still displaying
bolt holes, staple marks and carved initials. Bricks would be found
everywhere, complete with manufacturers markings. Artefacts made from inert
metals such as gold and tungsten would also survive indefinitely. Artefacts
made from glass and ceramics would also last as long as natural equivalents.
The globe is littered with evidence of our existance.
Simon Hibbs
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Anthony Buckland
> ...
> Hmmm... Compare the total mass of glass, asphalt, and ceramic material today
> to the total mass of dinosaur bone.... now think that ceramics are much more
> durable than bone, able to stand up to far more weather, plus no animal is
> going to try to eat them. Also consider that our junk only has to last 20,000
> years, not millions...
death if not before, the target of other, hungry
dinosaurs. While our civilization functions, _something_
of the same thing can be said about our artifacts. For
instance, most city walls have been torn down and their
materials used to construct something else. But if our
civilization suddenly ends, a lot of that stuff is going
to face nothing in the way of organized destruction.
Just (after the initial trauma, if it's physical) random
weather effects and, in a mere 20k years, extremely
limited geological effects. Certainly, after a winter
or two almost all roads would lose their functionality;
but you only need 50m of a 500km highway to conclude
that something with a lot of tools was at work here once.
You only need a few of those sets of non-rusting cooking
pots that the US has something approaching a hundred
million of. You need only one (detected) of those
top-of-the-line caskets containing an artificial heart
valve, even if the remainder of the contents finally
turned into unpleasant liquid millenia before.
Phillip McGregor
>
>>>No one seems to have mentioned that in the past couple of hundred years, we
>>>have literally covered the land surface with artifacts. Some, like glass and
>>>ceramics are very durable, especially if buried.
>
>>I take it you're a city boy. Not only have we not covered the land
>>surface with artifacts, there is still a large percentage of the globe
>>that's unexplored. What we have is basically large concentrations with
>>some scattering.
>>J.Michael
>
>I live in rural SC; from my house I can see some type of artifact in every
>direction. Roads, brick houses, highways cut into hillsides: these are pretty
>durable. Compare this to the state of affairs just 1000 years ago, here in
>the US. My point is we have produced so many artifacts, of so many types,
>that the situation really isn't the equivalent searching for signs of Troy or
>ancient Egypt.
Roads.
Of ashphalt/tarmacadam? That are easily broken up by the action of plant growth
and which, in 20000 (probably in 200) years will be a collection of blackish
gravel? Which future archaeologists will probably interpret as being "ritual
objects" if they recognise it at all.
Brick Houses.
OK, the bricks will probably survive, assuming the glaciers don't get 'em (we're
evidently at least half way through an interglacial ... probably no more than
8000 years to go, possibly much much less -- OK, SC may not be affected, but the
further north you go, the less likely anything is to survive), but only as a
mound of probably unrecognisable debris. The wooden framework of the house will
rot, or be consumed in random forest fires, and plant and environmental factors
will conspire to pulling down the walls and scattering the bricks.
Highways cut into hillsides.
Well, assuming the highways are tarmacadam/ashphalt, the roads themselves are
gone very quickly. The *cutting* will be erased or so softened by erosion that
it may not be possible to even recognise that it was man-made. There are many
"natural" features around the world that have been mistakenly thought to be
man-made, so I would suspect the future archaeologists and geologists would not
necessarily know.
Concrete might survive, but chances are that natural and vegetational forces
will break it up into rubble and leave it unrecognisable at such spots.
Interstate highways with their huge systems of overpasses may be more
recognisable, although it is unlikely in the extreme that any will remain
intact.
>The Beaker People were traders in the Mediteranian, so named because they
>traded beakers, perhaps so they could also sell beer. Compare then number of
>beakers they produced to the number glasses, jars, and coffee mugs in use
>today.... If we can still find evidence of them 5000 years later, surely
>20,000 is no stretch.
Glass is one of the few sure things to survive.
>Hmmm... Compare the total mass of glass, asphalt, and ceramic material today
Ashphalt is unlikely to survive. It will be broken up by frost and plant action
and, being flammable, will probably be consumed in random natural forest fires.
>to the total mass of dinosaur bone.... now think that ceramics are much more
>durable than bone, able to stand up to far more weather, plus no animal is
Depends on the ceramics. Generally, yes.
>going to try to eat them. Also consider that our junk only has to last 20,000
>years, not millions...
>
>If we found dinosaur bones, it would be easy to find signs of our
>civilization.
"Easy" is, perhaps, overdoing it somewhat.
Hume
whether it was slow or quick, and whether people had warning.
A meteor impact similar to the one that created our moon would destroy
everything, pretty much (and may even do a lot of damage to the stuff in
orbit). One like the impact avoided in the movie Armageddon would also likely
leave no visible signs of a previous civilization.
At the same time, a plaque, meteor impact, or the like might give people enough
time to prepare something that will survive for that long, and an opportunity
to put it in someplace obvious. Perhaps a probe that returns in 20,000 years
(or in 100 years, but is programmed to find a conspicuous place to set down).
Artefacts in orbit or on the moon would require a fairly sophisticated level of
technology to discover. With the naked eye, some satellites may appear as very
faint moons - and would be assumed to be such (not manufactured objects). You
would have to actually visit the moon to find what was left there.
Yet, particularly for those craft that landed on the Lunar mare, they would be
easy to spot from lunar orbit. So, as soon as the civilization had space travel
they would know that there was something on the moon worth investigating.
One thing they might find is a Millennial Archive such as the Applied Space
Resources (http://www.appliedspace.com) hopes to send to the moon.
Anthony Buckland
>
> What will survive will, of course, depend on how civilization collapsed,
> whether it was slow or quick, and whether people had warning.
>
> A meteor impact similar to the one that created our moon would destroy
> everything, pretty much (and may even do a lot of damage to the stuff in
> orbit). One like the impact avoided in the movie Armageddon would also likely
> leave no visible signs of a previous civilization.
and the ejecta might wipe out all but a few geostationary
satellites. But you's still have maybe a few of those, and
at least some traces on the Moon. However, a visitor might
assume these had all been left by _other_ visitors
investigating this obviously deadly planet. Meanwhile, the
Voyager spacecraft, each carrying a copy of the record,
plough slowly on into interstellar space ...
Leonard Erickson
> If our civilization collapsed (self-extermination, plague, meteor,
> take your pick), and in a thousand years or so a mini-ice age started
> lasting between 5 and 10 thousand years, what would be left for a
> newly built civilization's archaeologists to find of our works?
There are a lot of *big* quarries and open pit mines. Big enough that
it'd take a *major* ice age to erase them. Ditto for a lot of railroad
and highway cuts in mountain areas. Unless a glacier forms in the same
valley, they aren't likely to get erased.
> The pyramids would likely be gone by wind erosion (or tropical rains),
> concrete buildings would have turned to dust, even stainless steel
> would have rusted away.
Concrete foundations and highways are going to lead to a *lot* of
anomalous "conglomerate" rock with embedded chunks of steel. That's
going to be pretty obvious.
> Would they have any way of knowing that we were here?
Mine shafts, especailly "hard rock" mines. The *lack* of certain types
of mineral deposits above a very small size. And all that *plastic*.
--
Leonard Erickson (aka Shadow)
sha...@krypton.rain.com <--preferred
leo...@qiclab.scn.rain.com <--last resort
Leonard Erickson
> Right, but when it recedes there's a 50-50 chance the water level will
> be higher than it is now. (The original post ((above)) says a thousand
> years, 5-10 thou for a mini-ice-age, and then enough after that to
> equal 20,000).
> Also, since most civilizations have the majority of construction
> (digging foundations, etc.) near the shoreline, there's slim chance
> they'll be exactly over the location of our present cities.
Most large *coastal* cities are either at river mouths or good harbors.
Both are things that are apt to be in the same general area over a mere
20,000 years.
>
>>No one seems to have mentioned that in the past couple of hundred years, we
>>have literally covered the land surface with artifacts. Some, like glass
> and
>>ceramics are very durable, especially if buried.
> I take it you're a city boy. Not only have we not covered the land
> surface with artifacts, there is still a large percentage of the globe
> that's unexplored. What we have is basically large concentrations with
> some scattering.
>
> Glass and ceramics: yes, okay, that's sort of what I was asking about.
> I can see at least a few shreds of those eventually being found. (If
> buried, though, what's the chance they'd ever be unearthed? I read
> somewhere that we've dug up less than 1/100,000 of 1% of the earth.)
> J.Michael
> ________________________________________________
> Do you ever get the feeling that Rod Serling
> is standing around the corner talking about you?
Joe
McGregor) wrote:
>On Mon, 04 Jan 1999 05:50:03 GMT, ster...@scsn.net (John Thompson) wrote:
>
>>
>>>>No one seems to have mentioned that in the past couple of hundred years, we
>>>>have literally covered the land surface with artifacts. Some, like glass and
>>>>ceramics are very durable, especially if buried.
>>
>>>I take it you're a city boy. Not only have we not covered the land
>>>surface with artifacts, there is still a large percentage of the globe
>>>that's unexplored. What we have is basically large concentrations with
>>>some scattering.
>>>J.Michael
>>
>>I live in rural SC; from my house I can see some type of artifact in every
>>direction. Roads, brick houses, highways cut into hillsides: these are pretty
>>durable. Compare this to the state of affairs just 1000 years ago, here in
>>the US. My point is we have produced so many artifacts, of so many types,
>>that the situation really isn't the equivalent searching for signs of Troy or
>>ancient Egypt.
>
>Roads.
>
>Of ashphalt/tarmacadam? That are easily broken up by the action of plant growth
>and which, in 20000 (probably in 200) years will be a collection of blackish
>gravel? Which future archaeologists will probably interpret as being "ritual
>objects" if they recognise it at all.
>
Yes but there will be several feet to several meters of stratified
gravel winding along the countryside in a pattern that could not be
laid by water with the odd extra bit for flyovers and underpasses and
what not and it will connect to some very impressive mounds of rubble
and ceramics and plastics and stuff like that. It would take a rather
determined effort to conjure a 'natural' explaination for that.
Remember under the right circumstances almost anything can be
preserved, footprints, bacterial cells, the inner structure of soft
bodied animals. Given the sheer numbers of roads, cities and
artifacts in general we have a lot will still be findable in 20k
years.
>Brick Houses.
>
>OK, the bricks will probably survive, assuming the glaciers don't get 'em (we're
>evidently at least half way through an interglacial ... probably no more than
>8000 years to go, possibly much much less -- OK, SC may not be affected, but the
>further north you go, the less likely anything is to survive), but only as a
>mound of probably unrecognisable debris. The wooden framework of the house will
>rot, or be consumed in random forest fires, and plant and environmental factors
>will conspire to pulling down the walls and scattering the bricks.
>
Well I dunno about Europe in general but in Ireland almost all houses
are made from bricks, stone or cement blocks. I would reckon that the
same is true in Europe. At least in France and Britian any buildingd I
have seen in vilages/small towns tended to be of those materials. I
suspect that wood was scare for too long in Europe and any the
ravaging army will burn wood, with stone the thatch will burn but the
walls can be easily rebuilt.
Most farms nowadays have outbuildings of steel and mass concrete and
slurry containment and silage yards of steel reinforced concrete. Say
on average 1/4 acre of concrete flooring (yard and floors combined)
and say 130,000 farms in Ireland. For the rest of Europe I would
reckon similar averages in cattle regions but lower density of farm
yard.
>Highways cut into hillsides.
>
>Well, assuming the highways are tarmacadam/ashphalt, the roads themselves are
>gone very quickly.
But not the material
>The *cutting* will be erased or so softened by erosion that
>it may not be possible to even recognise that it was man-made. There are many
>"natural" features around the world that have been mistakenly thought to be
>man-made, so I would suspect the future archaeologists and geologists would not
>necessarily know.
>
>Concrete might survive, but chances are that natural and vegetational forces
>will break it up into rubble and leave it unrecognisable at such spots.
>
>Interstate highways with their huge systems of overpasses may be more
>recognisable, although it is unlikely in the extreme that any will remain
>intact.
Any thing buried under silt or dust will survive
snip
regads
Joe
--
***********************************************************************
Since my earlier anti spam measure did not work]
Hitting the reply button will not work. My email address is jdineen at
iol dot ie
Christopher Michael Jones
> Mine shafts, especailly "hard rock" mines. The *lack* of certain types
> of mineral deposits above a very small size. And all that *plastic*.
I would think that the huge piles of non-biodegradable materials
that we bury in landfills would stay round for quite a while.
And, it would be hard for future generations to miss not
just mine shafts, but huges holes in the Earth and mountains
that have been not just cut through and cut up but _razed_.
There are places in "coal country USA" where the tops of
large mountains have been cut off and the material
rearranged. And if mining operations weren't enough,
you would think the strange geology of the Netherlands
would be a tipoff to future generations. And then
there's all those old plastic cigarette holders and
tear-off aluminum can tops.
And, as I mentioned previously, small bits of silicon
embedded in ceramic packages are very resistant to
corrosion and wear. They (all kinds of microchips)
will leave nothing less than a big flashing sign
saying "We were here and we had sophisticated
technology!" for many millenia (well over 20) from
now.
Phillip McGregor
Yes. But where are most of these sorts of roads? In basically advanced G7
countries.
And where are they?
In the areas most likely to be covered by glaciers *if* there is an ice age
(likely, depending on who you believe, we're either 8000 or so years off one, or
its "just around the corner")!
So, the scouring action of the glacial flows will break up pretty much all (or a
hell of a lot) of this stuff.
That's if there's an ice age, of course.
>>Brick Houses.
>>
>>OK, the bricks will probably survive, assuming the glaciers don't get 'em (we're
>>evidently at least half way through an interglacial ... probably no more than
>>8000 years to go, possibly much much less -- OK, SC may not be affected, but the
>>further north you go, the less likely anything is to survive), but only as a
>>mound of probably unrecognisable debris. The wooden framework of the house will
>>rot, or be consumed in random forest fires, and plant and environmental factors
>>will conspire to pulling down the walls and scattering the bricks.
>>
>
>Well I dunno about Europe in general but in Ireland almost all houses
>are made from bricks, stone or cement blocks. I would reckon that the
But the *framework* is often of wood. The roof trusses, for example. The doors
and window frames (often).
And, of course, the glaciers will grind and displace.
>>Highways cut into hillsides.
>>
>>Well, assuming the highways are tarmacadam/ashphalt, the roads themselves are
>>gone very quickly.
>
>But not the material
Unless there is glacial activity, then it probably is. Or it may actually be
protected in such a cutting, depending on placement compared to glacial flow.
>Any thing buried under silt or dust will survive
Depends. Metals that can oxidise will probably still do so even under silt ...
we're talking 20000 years, not 200 or 2000.
Phillip McGregor
wrote:
>Leonard Erickson (sha...@krypton.rain.com) wrote:
>
>> Mine shafts, especailly "hard rock" mines. The *lack* of certain types
>> of mineral deposits above a very small size. And all that *plastic*.
>
>I would think that the huge piles of non-biodegradable materials
>that we bury in landfills would stay round for quite a while.
OK. What is the "lifespan" of plastics, for example? Is it 20,000 years?
Thousands of years, yes, but how many?
>And, it would be hard for future generations to miss not
>just mine shafts, but huges holes in the Earth and mountains
Mine shafts ... after 20,000 years of no maintenance!
They will be collapsed! They simply will not exist any more.
>that have been not just cut through and cut up but _razed_.
>There are places in "coal country USA" where the tops of
>large mountains have been cut off and the material
>rearranged. And if mining operations weren't enough,
And after 20,000 years of erosion, and possibly glaciation, will this look
"unnatural" still, or will the whole damn thing look so worn that it may be
missed.
>you would think the strange geology of the Netherlands
>would be a tipoff to future generations. And then
The Netherlands will mostly be under the North Sea (or whatever they call it).
>there's all those old plastic cigarette holders and
>tear-off aluminum can tops.
>
>And, as I mentioned previously, small bits of silicon
>embedded in ceramic packages are very resistant to
>corrosion and wear. They (all kinds of microchips)
>will leave nothing less than a big flashing sign
>saying "We were here and we had sophisticated
>technology!" for many millenia (well over 20) from
>now.
Just as a for example.
There are a number of Old Persian inscriptions on sheltered cliff faces in the
Middle East (Persia, IIRC, modern day Iran) which were first noted by westerners
around the middle of last century and recorded by interested
artists/antiquarians. These are no longer legible due to weathering and erosion
and only the original drawings are decipherable.
Now, these rock inscriptions were around 2000 years old when first sighted by
the western travellers, but were eroded into illegibility within a century and a
half after that.
Sure, the rock was evidently soft. But 20000 years is a *long* time.
Anthony Buckland
>
> On Wed, 06 Jan 1999 22:59:16 GMT, this_will_not_work@not_here.com (Joe) wrote:
>
> >On Mon, 04 Jan 1999 23:18:07 GMT, asp...@curie.dialix.oz.au (Phillip
> >McGregor) wrote:
> >
> >>On Mon, 04 Jan 1999 05:50:03 GMT, ster...@scsn.net (John Thompson) wrote:
> >>Roads.
> >>
> >>Of ashphalt/tarmacadam? That are easily broken up by the action of plant growth
> >>and which, in 20000 (probably in 200) years will be a collection of blackish
> >>gravel? Which future archaeologists will probably interpret as being "ritual
> >>objects" if they recognise it at all.
> >>
> >
> >Yes but there will be several feet to several meters of stratified
> >gravel winding along the countryside in a pattern that could not be
>
> Yes. But where are most of these sorts of roads? In basically advanced G7
> countries.
every third-world country where the boss-for-life left his
people to starve while he built a freeway from his palace to
nowhere.
Keith Morrison
> > >Yes but there will be several feet to several meters of stratified
> > >gravel winding along the countryside in a pattern that could not be
> >
> > Yes. But where are most of these sorts of roads? In basically advanced G7
> > countries.
>
> Ahem. Brazil. Indonesia. Singapore. Australia. Not to mention
> every third-world country where the boss-for-life left his
> people to starve while he built a freeway from his palace to
> nowhere.
Most of the US (the glaciers, at maximum extant, didn't get much
beyond the northern border states). Southern Europe. The Middle
East. Lots of roads in lots of areas that will be safe from
glaciation for the next few million years.
--
Keith Morrison
kei...@polarnet.ca
Keith Morrison
> Mine shafts ... after 20,000 years of no maintenance!
>
> They will be collapsed! They simply will not exist any more.
Ahem. Just how old do you think some natural caves are?
--
Keith Morrison
kei...@polarnet.ca
Christopher Michael Jones
> On 6 Jan 1999 23:26:03 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael Jones)
> wrote:
> >I would think that the huge piles of non-biodegradable materials
> >that we bury in landfills would stay round for quite a while.
> OK. What is the "lifespan" of plastics, for example? Is it 20,000 years?
> Thousands of years, yes, but how many?
Some types of plastics can last a _long_ time, and plastics sealed
inside a huge mound and protected from the effects of nature
will certainly last 20,000 years.
> >And, it would be hard for future generations to miss not
> >just mine shafts, but huges holes in the Earth and mountains
> Mine shafts ... after 20,000 years of no maintenance!
> They will be collapsed! They simply will not exist any more.
Oh yeah, sure, and every cave in the entire world is
less than 20,000 years old. Here's a quarter, go
buy yourself some logic.
> >that have been not just cut through and cut up but _razed_.
> >There are places in "coal country USA" where the tops of
> >large mountains have been cut off and the material
> >rearranged. And if mining operations weren't enough,
> And after 20,000 years of erosion, and possibly glaciation, will this look
> "unnatural" still, or will the whole damn thing look so worn that it may be
> missed.
There is a mountain in the Atacama desert that has had its
top completely sheared off. It's flat. There is very
little erosion in the Atacama desert, it is one of the
driest places in the world. Considering how short a time
20,000 years is in geological terms, I would think that
not only would Cerro Paranal be noticeably strange, but
the telescopes on top would probably not be piles of
ruble yet.
> >you would think the strange geology of the Netherlands
> >would be a tipoff to future generations. And then
> The Netherlands will mostly be under the North Sea (or whatever they call it).
And nobody can look under the water? Besides, this depends
on the sea level (which would undoubtably change if there
was a period of glaciation).
> >there's all those old plastic cigarette holders and
> >tear-off aluminum can tops.
> >
> >And, as I mentioned previously, small bits of silicon
> >embedded in ceramic packages are very resistant to
> >corrosion and wear. They (all kinds of microchips)
> >will leave nothing less than a big flashing sign
> >saying "We were here and we had sophisticated
> >technology!" for many millenia (well over 20) from
> >now.
> Just as a for example.
> There are a number of Old Persian inscriptions on sheltered cliff faces in the
> Middle East (Persia, IIRC, modern day Iran) which were first noted by westerners
> around the middle of last century and recorded by interested
> artists/antiquarians. These are no longer legible due to weathering and erosion
> and only the original drawings are decipherable.
> Now, these rock inscriptions were around 2000 years old when first sighted by
> the western travellers, but were eroded into illegibility within a century and a
> half after that.
> Sure, the rock was evidently soft. But 20000 years is a *long* time.
You clearly have no clue how well little bits of silicon
inside modern ceramics can hold up to wear. Poor
quality ceramics have lasted thousands of years despite
conditions not suited to conservation. Soft rock
inscriptions are not ceramics and do not ever hold
up to much wear (as opposed to ceramic). Do not
confuse rocks and ceramics, they are different beasts.
Modern ceramics (like say Silicon Carbide) are practically
indestructible compared to ancient ceramics. And
the variety of ceramics (and plastics) used to
encase microchips are for the most part much more
rugged than any ceramic from the ancient world.
I have no doubt that erasing the evidence of
microchips would require no less than a global
catastrophe that would almost assuredly kill
most of the life on Earth.
20,000 years is a very *short* time, even in terms
of humans living on Earth (there are human made
tools that are more than 500,000 years old).
It is but a blink of an eye in geological history.
Phillip McGregor
>Phillip McGregor wrote:
>
>> Mine shafts ... after 20,000 years of no maintenance!
>>
>> They will be collapsed! They simply will not exist any more.
>
>Ahem. Just how old do you think some natural caves are?
Some are *very* old. But Mines are not the same. Caves have been created
naturally, in areas (one presumes) of low stress in the earth's crust. If not,
they would also tend to collapse over time.
Coming from a mining family only one generation removed (my grandad and a lot of
my uncles and cousins are still in, or retired from, the industry) I know that
(coal mines anyway) are in need of constant maintenance to ensure the tunnels do
not collapse, and even then there are cave ins that occur, basically, for no
discernible reason.
After a few *hundred* years of no maintenance, let alone 20000, I think its fair
to say that they will no longer exist.
Phillip McGregor
wrote:
>Phillip McGregor (asp...@curie.dialix.oz.au) wrote:
>> On 6 Jan 1999 23:26:03 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael Jones)
>> wrote:
>
>> >I would think that the huge piles of non-biodegradable materials
>> >that we bury in landfills would stay round for quite a while.
>
>> OK. What is the "lifespan" of plastics, for example? Is it 20,000 years?
>> Thousands of years, yes, but how many?
>
>Some types of plastics can last a _long_ time, and plastics sealed
>inside a huge mound and protected from the effects of nature
>will certainly last 20,000 years.
>
>> >And, it would be hard for future generations to miss not
>> >just mine shafts, but huges holes in the Earth and mountains
>
>> Mine shafts ... after 20,000 years of no maintenance!
>
>> They will be collapsed! They simply will not exist any more.
>
>Oh yeah, sure, and every cave in the entire world is
>less than 20,000 years old. Here's a quarter, go
>buy yourself some logic.
Caves are, presumably, natural. They have been formed in areas of the crust
where the natural situation favours their formation and survival. Mines are no
natural. They take a lot of maintenance to keep those tunnels intact ... and
even then there are perennial cave ins.
With no maintenance for a few hundred or a few thousand years it is unlikely
that they will survive.
The key is *no maintenance*.
And, of course, glacial action and weight (assuming an intervening ice age,
which is reasonably likely) will collapse a lot as well, and even a lot of
caves, I guess.
>> >that have been not just cut through and cut up but _razed_.
>> >There are places in "coal country USA" where the tops of
>> >large mountains have been cut off and the material
>> >rearranged. And if mining operations weren't enough,
>
>> And after 20,000 years of erosion, and possibly glaciation, will this look
>> "unnatural" still, or will the whole damn thing look so worn that it may be
>> missed.
>
>There is a mountain in the Atacama desert that has had its
>top completely sheared off. It's flat. There is very
>little erosion in the Atacama desert, it is one of the
>driest places in the world. Considering how short a time
>20,000 years is in geological terms, I would think that
>not only would Cerro Paranal be noticeably strange, but
>the telescopes on top would probably not be piles of
>ruble yet.
I think that you are a tad optimistic.
Ice ages tend to change weather patterns pretty drastically. Whether this will
mean the Atacama desert will remain dry (or even become drier) or, perhaps,
become a wetter place, is debatable.
However, on balance, it is not certain.
Certainly, unless fairly heroic measures are taken with the telescopes, they
will be severely affected by the passage of time at the very least, dry weather
remaining the case.
>> >you would think the strange geology of the Netherlands
>> >would be a tipoff to future generations. And then
>
>> The Netherlands will mostly be under the North Sea (or whatever they call it).
>
>And nobody can look under the water? Besides, this depends
>on the sea level (which would undoubtably change if there
>was a period of glaciation).
Yes. True. But there's not only the sea level to consider, there's a lot of silt
laid down, and the damage that may/will have been done as the Netherlands were
inundated. It may be there, but not so easy to detect.
>> >there's all those old plastic cigarette holders and
>> >tear-off aluminum can tops.
>> >
>> >And, as I mentioned previously, small bits of silicon
>> >embedded in ceramic packages are very resistant to
>> >corrosion and wear. They (all kinds of microchips)
>> >will leave nothing less than a big flashing sign
>> >saying "We were here and we had sophisticated
>> >technology!" for many millenia (well over 20) from
>> >now.
>
>> Just as a for example.
>
>> There are a number of Old Persian inscriptions on sheltered cliff faces in the
>> Middle East (Persia, IIRC, modern day Iran) which were first noted by westerners
>> around the middle of last century and recorded by interested
>> artists/antiquarians. These are no longer legible due to weathering and erosion
>> and only the original drawings are decipherable.
>
>> Now, these rock inscriptions were around 2000 years old when first sighted by
>> the western travellers, but were eroded into illegibility within a century and a
>> half after that.
>
>> Sure, the rock was evidently soft. But 20000 years is a *long* time.
>
>You clearly have no clue how well little bits of silicon
>inside modern ceramics can hold up to wear. Poor
Sorry, you misunderstand. I was not referring to silicon chips with the last
comments, I was referring to how fragile even seeming "eternal" things can be.
Glass, as I said in a much earlier post, and some ceramics, will be the biggest
finds.
Phillip McGregor
>Phillip McGregor wrote:
>>
>> On Wed, 06 Jan 1999 22:59:16 GMT, this_will_not_work@not_here.com (Joe) wrote:
>>
>> >On Mon, 04 Jan 1999 23:18:07 GMT, asp...@curie.dialix.oz.au (Phillip
>> >McGregor) wrote:
>> >
>> >>On Mon, 04 Jan 1999 05:50:03 GMT, ster...@scsn.net (John Thompson) wrote:
> ...
>> >>Roads.
>> >>
>> >>Of ashphalt/tarmacadam? That are easily broken up by the action of plant growth
>> >>and which, in 20000 (probably in 200) years will be a collection of blackish
>> >>gravel? Which future archaeologists will probably interpret as being "ritual
>> >>objects" if they recognise it at all.
>> >>
>> >
>> >Yes but there will be several feet to several meters of stratified
>> >gravel winding along the countryside in a pattern that could not be
>>
>> Yes. But where are most of these sorts of roads? In basically advanced G7
>> countries.
>
> Ahem. Brazil. Indonesia. Singapore. Australia. Not to mention
> every third-world country where the boss-for-life left his
> people to starve while he built a freeway from his palace to
> nowhere.
Well, we don't have american style superhighways here in Oz. Even our best roads
are basically tar and are high maintenance.
As for the other three, well tropical plant growth will do wonders I expect.
So, even if they figure something out, they will (mistakenly) assume that
whatever was going on 20k years before was much more limited than it in fact
was, and they will get a completely skewed distribution of finds that will
further falsify the picture.
Leonard Erickson
> On 6 Jan 1999 23:26:03 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael
> Jones)
> wrote:
>
>>Leonard Erickson (sha...@krypton.rain.com) wrote:
>>
>>> Mine shafts, especailly "hard rock" mines. The *lack* of certain types
>>> of mineral deposits above a very small size. And all that *plastic*.
>>
>>I would think that the huge piles of non-biodegradable materials
>>that we bury in landfills would stay round for quite a while.
>
> OK. What is the "lifespan" of plastics, for example? Is it 20,000 years?
> Thousands of years, yes, but how many?
Teflon will last until it is subjected to temperatures in the range of
molten aluminum. In other words, until it gets subducted. "bulk"
polyethylene and polypropylene (as opposed to "films") are likely to
last almost as long. There are quite literally *no* organisms that can
eat the stuff. Nor are there any likely chemical processes other than
extreme heat, that will degrade them. On the *surface* UV light
degrades them somewhat over time. But buried, they'll last essentially
forever.
>>And, it would be hard for future generations to miss not
>>just mine shafts, but huges holes in the Earth and mountains
>
> Mine shafts ... after 20,000 years of no maintenance!
There are caves that are older than that. Barring major earthquakes, a
*lot* of tunnels and the like will survive. And open-pit mines resemble
*nothing* natural. Once you dig thru any dirt/sand/etc that's blown in
or washed in, and note that you've hit a halfway decent ore body, you
are going to *know* that it's the remains of a mine. And the sheer
*size* will rule out pre-industrial revolution societies.
> They will be collapsed! They simply will not exist any more.
Not necessarily!
>>that have been not just cut through and cut up but _razed_.
>>There are places in "coal country USA" where the tops of
>>large mountains have been cut off and the material
>>rearranged. And if mining operations weren't enough,
> And after 20,000 years of erosion, and possibly glaciation, will this look
> "unnatural" still, or will the whole damn thing look so worn that it may be
> missed.
20k years is *not* all that long geologically. And many of these things
are placed where glaciation isn't all *that* likely to do anything to
them.
>>there's all those old plastic cigarette holders and
>>tear-off aluminum can tops.
>>
>>And, as I mentioned previously, small bits of silicon
>>embedded in ceramic packages are very resistant to
>>corrosion and wear. They (all kinds of microchips)
>>will leave nothing less than a big flashing sign
>>saying "We were here and we had sophisticated
>>technology!" for many millenia (well over 20) from
>>now.
>
> Just as a for example.
>
> There are a number of Old Persian inscriptions on sheltered cliff
> faces in the Middle East (Persia, IIRC, modern day Iran) which were
> first noted by westerners around the middle of last century and
> recorded by interested artists/antiquarians. These are no longer
> legible due to weathering and erosion and only the original drawings
> are decipherable.
> Now, these rock inscriptions were around 2000 years old when first sighted by
> the western travellers, but were eroded into illegibility within a century
> and a half after that.
> Sure, the rock was evidently soft. But 20000 years is a *long* time.
Don't forget that there's evidence that the Sphinx dates back more than
9000 years, and was exposed to *rain* erosion for a good chunk of them
(the distinctive rain weathering is *how* they've determined that it
has to be at least that old, as that's how long ago there was
substantial rain in the area).
And again, 20,000 years is a long time *culturally*. It's pretty short
by geological standards.
There's a big difference between weathering away some inscriptions, and
weathering away a quarry or or major road cut. For the latter, you'd
have to erode the rocks by tens of yards. Which doesn't happen in a
measly 20k years. Not in hard rocks like granite or basalt.
Brett Evill
asp...@curie.dialix.oz.au (Phillip McGregor) wrote:
>Well, we don't have american style superhighways here in Oz. Even our
best roads
>are basically tar and are high maintenance.
That's funny. I seem to have been driving on a lot of concrete highways
lately. Such as the Federal Highway--Hume Highway--Pacific Highway route
from Canberra to Kempsey and back. There was some blacktop, but an awful
lot of concrete too. I must have left the country without realising.
And when I examined the new highway construction along Lake George the
supervising engineer told me it was a metre and a half of concrete on top
of a formation three and a half metres deep made of crushed rock, earth,
and lime, with stone retaining walls. I even examined the quarries and the
lime-kilns. Now that you have enlightened by I shall rush into the office
of the Minister of Transport and tell him that the Department has been
ripped off to the tune of $118 million dollars.
--
Brett Evill
To reply by e-mail, remove 'spamblocker.' from <b.e...@spamblocker.tyndale.apana.org.au>
Creator/editor, 'Flat Black' SF comic <http://www.dreamriders.com/FlatBlack.html>
Brett Evill
asp...@curie.dialix.oz.au (Phillip McGregor) wrote:
>The Netherlands will mostly be under the North Sea (or whatever they call it).
Surely not. My rheologist friend tells me that Northern Europe is
rebounding, and that the land levels are rising. Further, you have to
figure that the Rhine will drop silt.
Justin Fang
Phillip McGregor <asp...@curie.dialix.oz.au> wrote:
>On 7 Jan 1999 20:58:29 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael Jones)
>wrote:
>>not only would Cerro Paranal be noticeably strange, but
>>the telescopes on top would probably not be piles of
>>ruble yet.
>Certainly, unless fairly heroic measures are taken with the telescopes,
>they will be severely affected by the passage of time at the very least,
>dry weather remaining the case.
[...snip...]
>Glass, as I said in a much earlier post, and some ceramics, will be the
>biggest finds.
Like, say, telescope mirrors? Even if they fall and break when the
superstructure rusts away/collapses, there's still going to be some pretty
large chunks of glass (surrounded by bits of aluminum, etc.) on top of a
number of mountains.
--
Justin Fang (jus...@ugcs.caltech.edu)
This space intentionally left blank.
Anthony Buckland
>
> In article <36968377...@news.curie.dialix.com.au>,
> asp...@curie.dialix.oz.au (Phillip McGregor) wrote:
>
> >The Netherlands will mostly be under the North Sea (or whatever they call it).
>
> Surely not. My rheologist friend tells me that Northern Europe is
> rebounding, and that the land levels are rising. Further, you have to
> figure that the Rhine will drop silt.
part of the Netherlands will be a shallow arm of the sea.
The Rhine may silt, if it isn't under a glacier, but the
silt will fall into salt water. An interesting question
though is whether in 20k years there would still be some
remnant as barrier islands of the dikes.
Christopher Michael Jones
>
> But once the dikes, unmaintained, breach, the reclaimed
> part of the Netherlands will be a shallow arm of the sea.
Not all of the land in the Netherlands is kept dry
by dikes. Some of it has been built up above sea
level.
> The Rhine may silt, if it isn't under a glacier, but the
> silt will fall into salt water. An interesting question
> though is whether in 20k years there would still be some
> remnant as barrier islands of the dikes.
--
Phillip McGregor
>In article <36973e18...@news.curie.dialix.com.au>,
>Phillip McGregor <asp...@curie.dialix.oz.au> wrote:
>>On 7 Jan 1999 20:58:29 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael Jones)
>>wrote:
>
>>>not only would Cerro Paranal be noticeably strange, but
>>>the telescopes on top would probably not be piles of
>>>ruble yet.
>
>>Certainly, unless fairly heroic measures are taken with the telescopes,
>>they will be severely affected by the passage of time at the very least,
>>dry weather remaining the case.
>
>[...snip...]
>
>>Glass, as I said in a much earlier post, and some ceramics, will be the
>>biggest finds.
>
>Like, say, telescope mirrors? Even if they fall and break when the
>superstructure rusts away/collapses, there's still going to be some pretty
>large chunks of glass (surrounded by bits of aluminum, etc.) on top of a
>number of mountains.
Yes. Sure. But that assumes that the 20k year future locals are as interested in
climbimg mountains as we are. And that they'll be able to interpret what these
strange misshapen hunks of glass are!
Phillip McGregor
wrote:
>>>And, it would be hard for future generations to miss not
>>>just mine shafts, but huges holes in the Earth and mountains
>>
>> Mine shafts ... after 20,000 years of no maintenance!
>
>There are caves that are older than that. Barring major earthquakes, a
>*lot* of tunnels and the like will survive. And open-pit mines resemble
>*nothing* natural. Once you dig thru any dirt/sand/etc that's blown in
>or washed in, and note that you've hit a halfway decent ore body, you
>are going to *know* that it's the remains of a mine. And the sheer
>*size* will rule out pre-industrial revolution societies.
Some of them (all of them?) will be filled with water and, from the surface,
will probably look like "normal" lakes.
And, of course, if they're in regions of glaciation, the outlines have been
scoured so thoroughly that there probably *aren't* any "outlines" any more.
Sure, this doesn't apply to regions which have not been glaciated.
>> They will be collapsed! They simply will not exist any more.
>
>Not necessarily!
But more than likely. For coal mines, at least, according to what my relatives
seem to think.
>>>that have been not just cut through and cut up but _razed_.
>>>There are places in "coal country USA" where the tops of
>>>large mountains have been cut off and the material
>>>rearranged. And if mining operations weren't enough,
>
>> And after 20,000 years of erosion, and possibly glaciation, will this look
>> "unnatural" still, or will the whole damn thing look so worn that it may be
>> missed.
>
>20k years is *not* all that long geologically. And many of these things
>are placed where glaciation isn't all *that* likely to do anything to
>them.
Yes, true. But it may, as I suggested, make our successors have an entirely
false picture of the range and relative importance of sites as a result.
>> Now, these rock inscriptions were around 2000 years old when first sighted by
>> the western travellers, but were eroded into illegibility within a century
>> and a half after that.
>
>> Sure, the rock was evidently soft. But 20000 years is a *long* time.
>
>Don't forget that there's evidence that the Sphinx dates back more than
>9000 years, and was exposed to *rain* erosion for a good chunk of them
>(the distinctive rain weathering is *how* they've determined that it
>has to be at least that old, as that's how long ago there was
>substantial rain in the area).
Well, yes and no. There is some evidence recently raised that may point to the
Sphinx being 9000 years old. However, and I do not claim to have kept up with
this in any real way, what I have seen of this "evidence" seems to indicate that
it is not universally accepted as being correct, with (evidently) good reason
(there simply is no other evidence for the existence of a civilisation capable
of doing such work in 7000 BC that anyone seems to be aware of *other* than the
Sphinx) and there seems to be a consensus amongst the opposition that there are
probably factors that are being misinterpreted by the champions of the idea to
give such a date.
Then there is the fact that, of course, there is evidence that the Sphinx has
been given an entirely new face *at least* once.
>And again, 20,000 years is a long time *culturally*. It's pretty short
>by geological standards.
And the Sphinx is pretty soft rock, isn't it?
>There's a big difference between weathering away some inscriptions, and
>weathering away a quarry or or major road cut. For the latter, you'd
>have to erode the rocks by tens of yards. Which doesn't happen in a
>measly 20k years. Not in hard rocks like granite or basalt.
Sure. But not all cuts are through such hard rocks.
I'm not saying there would be no evidence at all, but that it wouldn't
necessarily be as widespread as some seem to think ... or as obvious and easy to
interpret.
Phillip McGregor
Evill) wrote:
>In article <36968377...@news.curie.dialix.com.au>,
>asp...@curie.dialix.oz.au (Phillip McGregor) wrote:
>
>>The Netherlands will mostly be under the North Sea (or whatever they call it).
>
>Surely not. My rheologist friend tells me that Northern Europe is
>rebounding, and that the land levels are rising. Further, you have to
>figure that the Rhine will drop silt.
Well, if there is a period of glaciation, this will (I forget the technical
term) basically push down the whole area again.
Phillip McGregor
Evill) wrote:
>In article <36984008...@news.curie.dialix.com.au>,
>asp...@curie.dialix.oz.au (Phillip McGregor) wrote:
>
>
>>Well, we don't have american style superhighways here in Oz. Even our
>best roads
>>are basically tar and are high maintenance.
>
>That's funny. I seem to have been driving on a lot of concrete highways
>lately. Such as the Federal Highway--Hume Highway--Pacific Highway route
>from Canberra to Kempsey and back. There was some blacktop, but an awful
>lot of concrete too. I must have left the country without realising.
OOOPS!
Ah, er, yes. Well, I'd forgotten about the Federal Highway. And I'd seen the
damn thing under construction when I went down to Canberra for Xmas 97.
I stand completely corrected!
<grovel> <tug forelock> <whine>
Keith Morrison
> >> Mine shafts ... after 20,000 years of no maintenance!
> >>
> >> They will be collapsed! They simply will not exist any more.
> >
> >Ahem. Just how old do you think some natural caves are?
>
> Some are *very* old. But Mines are not the same. Caves have been created
> naturally, in areas (one presumes) of low stress in the earth's crust. If not,
> they would also tend to collapse over time.
>
> Coming from a mining family only one generation removed (my grandad and a lot of
> my uncles and cousins are still in, or retired from, the industry) I know that
> (coal mines anyway) are in need of constant maintenance to ensure the tunnels do
> not collapse, and even then there are cave ins that occur, basically, for no
> discernible reason.
>
> After a few *hundred* years of no maintenance, let alone 20000, I think its fair
> to say that they will no longer exist.
As a former mine geologist, that's not a fair statement. Yes,
most mines need some form of support, but not all. The large
open areas will probably collapse but small, narrow access drifts
and shafts may not, especially if near surface.
The mine I used to work at was in sediments that would probably
collapse but one section was drilled into solid granite and
that section was made into a lunchroom/refuge station specifically
because it would not be prone to collapse.
An additional factor is water. Mines generally flood if
not pumped out (in temperate climates, anyway) so the passages
aren't empty: they are filled with a rather incompressible
liquid which will help support the back and walls.
Even more obvious are mines being abandoned now. Most are
plugged with concrete, which will be blatantly obvious (not
to mention all the other crap they leave in there).
No, quite a few mines will be quite recognizable.
--
Keith Morrison
kei...@polarnet.ca
Phillip McGregor
<interesting facts snipped>
>No, quite a few mines will be quite recognizable.
Or, perhaps more accurately, *parts* of mines will still be there?
Urban Fredriksson
Phillip McGregor <asp...@curie.dialix.oz.au> wrote:
>Mine shafts ... after 20,000 years of no maintenance!
>They will be collapsed! They simply will not exist any more.
I don't think that goes for shafts through solid bedrock,
there are simply too many 100s of km of shafts in a mine
to not be noticable. And if you take a mine like the one
in Kiruna, there's a 4 km long cut through the mountain
where they take the ore from below and let everything
above it collapse, down a kilometer or more, so there you
have a deep cut filled with rubble and not even an ice age
will remove the traces of that.
--
Urban Fredriksson gri...@canit.se SF- och serie-recensioner
http://www.canit.se/%7Egriffon/diverse/recensioner/recensioner.html
Joe
McGregor) wrote:
>On Wed, 06 Jan 1999 22:59:16 GMT, this_will_not_work@not_here.com (Joe) wrote:
>
>>On Mon, 04 Jan 1999 23:18:07 GMT, asp...@curie.dialix.oz.au (Phillip
>>McGregor) wrote:
>>
>>>On Mon, 04 Jan 1999 05:50:03 GMT, ster...@scsn.net (John Thompson) wrote:
snip
>>Well I dunno about Europe in general but in Ireland almost all houses
>>are made from bricks, stone or cement blocks. I would reckon that the
>
>But the *framework* is often of wood. The roof trusses, for example. The doors
>and window frames (often).
>
No it is not, not around here at any rate. Only the roof supports are
wood. Door and windows often but recently most windows tend to be
aluminiun or PVC wood just rots to fast around here.
>And, of course, the glaciers will grind and displace.
>
As for glaciers that depends, on whether there is an ice age and the
severity of the ice age. Some ice ages have seen all of Europe covered
and some have not. In the last ice age the southwestern tip of Ireland
was not under permanent ice AFIK. There were local glaciers in the
mountains in kerry but this did not get everywhere as far as I know
>>>Highways cut into hillsides.
>>>
>>>Well, assuming the highways are tarmacadam/ashphalt, the roads themselves are
>>>gone very quickly.
>>
>>But not the material
>
>Unless there is glacial activity, then it probably is. Or it may actually be
>protected in such a cutting, depending on placement compared to glacial flow.
>
>>Any thing buried under silt or dust will survive
>
>Depends. Metals that can oxidise will probably still do so even under silt ...
>we're talking 20000 years, not 200 or 2000.
>
Some do some will not and in either case they will leave an artifact
shaped fosil
Joe
McGregor) wrote:
>On 6 Jan 1999 23:26:03 GMT, cjo...@ix.cs.uoregon.edu (Christopher Michael Jones)
>wrote:
>
>>Leonard Erickson (sha...@krypton.rain.com) wrote:
>>
>>> Mine shafts, especailly "hard rock" mines. The *lack* of certain types
>>> of mineral deposits above a very small size. And all that *plastic*.
>>
Some bits will have fallen in some bits will not. Depends on how much
water gets in as well as the local geology. It would not surpirse me
if some bits ok.
>>I would think that the huge piles of non-biodegradable materials
>>that we bury in landfills would stay round for quite a while.
>
>OK. What is the "lifespan" of plastics, for example? Is it 20,000 years?
>Thousands of years, yes, but how many?
>
Look, we have dinosaur footprints from 65 million years old. We have
trilobite (That is what they were called) from way back further than
that. We bits of humans and their ancestors from a couple of million
to 5 or 6 millions years back not to mention some of their artifacts.
>>And, it would be hard for future generations to miss not
>>just mine shafts, but huges holes in the Earth and mountains
>
>Mine shafts ... after 20,000 years of no maintenance!
>
>They will be collapsed! They simply will not exist any more.
Even collpased they will leave unusual patterns of material in the
remains. Fossilised roof supports for instance.
Nothing like a fosilisted RSJ or tramline tracks to give a future
paleontholigist (sp??) pause for thought.
>
>>that have been not just cut through and cut up but _razed_.
>>There are places in "coal country USA" where the tops of
>>large mountains have been cut off and the material
>>rearranged. And if mining operations weren't enough,
>
>And after 20,000 years of erosion, and possibly glaciation, will this look
>"unnatural" still, or will the whole damn thing look so worn that it may be
>missed.
Considering what our geologists are starting to notice, someone will
get suspicous.
>
>>you would think the strange geology of the Netherlands
>>would be a tipoff to future generations. And then
>
>The Netherlands will mostly be under the North Sea (or whatever they call it).
>
That will not stop it from being strange. Especially as the silt fron
the rhine will preserve alot of the structures built there. Just needs
some to start serious reclamation or undersea dredging to bring up odd
stuff that will set minds thinking
>>there's all those old plastic cigarette holders and
>>tear-off aluminum can tops.
>>
>>And, as I mentioned previously, small bits of silicon
>>embedded in ceramic packages are very resistant to
>>corrosion and wear. They (all kinds of microchips)
>>will leave nothing less than a big flashing sign
>>saying "We were here and we had sophisticated
>>technology!" for many millenia (well over 20) from
>>now.
>
>Just as a for example.
>
>There are a number of Old Persian inscriptions on sheltered cliff faces in the
>Middle East (Persia, IIRC, modern day Iran) which were first noted by westerners
>around the middle of last century and recorded by interested
>artists/antiquarians. These are no longer legible due to weathering and erosion
>and only the original drawings are decipherable.
>
Stuff in the air will weather but if some one buryid them properly in
hte 19th century and ther were not disturbed for 20K years they would
be still readable
Also consider the following tourist resorts.
The Azores, The Canary Islands, the Schyelles, Hawaii, The entire
Mediterranian coast heavily developed and unlikely to suffer from
glaciation. How far souht in the USA have Glaciers ever reached? I
doubt if they ever made it all the way to the Gulf coast.
regards
Leonard Erickson
> On Fri, 8 Jan 1999 06:29:07 PST, sha...@krypton.rain.com (Leonard Erickson)
> wrote:
>
>>>>And, it would be hard for future generations to miss not
>>>>just mine shafts, but huges holes in the Earth and mountains
>>>
>>> Mine shafts ... after 20,000 years of no maintenance!
>>
>>There are caves that are older than that. Barring major earthquakes, a
>>*lot* of tunnels and the like will survive. And open-pit mines resemble
>>*nothing* natural. Once you dig thru any dirt/sand/etc that's blown in
>>or washed in, and note that you've hit a halfway decent ore body, you
>>are going to *know* that it's the remains of a mine. And the sheer
>>*size* will rule out pre-industrial revolution societies.
>
> Some of them (all of them?) will be filled with water and, from the surface,
> will probably look like "normal" lakes.
Many of them *won't* fill with water. Most don't require pumping *now*,
they either have an exit for the water, don't get that much rain, or
both.
> And, of course, if they're in regions of glaciation, the outlines have been
> scoured so thoroughly that there probably *aren't* any "outlines" any more.
>
> Sure, this doesn't apply to regions which have not been glaciated.
Which turns out to be much of the US.
>>> They will be collapsed! They simply will not exist any more.
>>
>>Not necessarily!
>
> But more than likely. For coal mines, at least, according to what my
> relatives seem to think.
Sure. But "hard rock" mines are a rather different situation.
>>20k years is *not* all that long geologically. And many of these things
>>are placed where glaciation isn't all *that* likely to do anything to
>>them.
>
> Yes, true. But it may, as I suggested, make our successors have an entirely
> false picture of the range and relative importance of sites as a result.
Well, for example, I know of a thousand foot tall basalt cliff that has
a railroad line running along a several *miles* of shelf cut into the
face of the cliff. And not only is the shelf not natural, it runs at a
constant grade for all those miles. That's *not* going to erode away
significantly in a measly 20k years.
In case you've never dealt with the stuff, basalt is incredibly tough
stuff. We made the mistake of grabbing a chunk of it to use in the
"classic" erosion experiment where you heat rock with a propane torch
or a bunsen burner, then plunge it into icewater. Repeat several times
and watch as pieces flake off. With basalt, nothing much happens.
>>Don't forget that there's evidence that the Sphinx dates back more than
>>9000 years, and was exposed to *rain* erosion for a good chunk of them
>>(the distinctive rain weathering is *how* they've determined that it
>>has to be at least that old, as that's how long ago there was
>>substantial rain in the area).
>
> Well, yes and no. There is some evidence recently raised that may
> point to the Sphinx being 9000 years old. However, and I do not claim
> to have kept up with this in any real way, what I have seen of this
> "evidence" seems to indicate that it is not universally accepted as
> being correct, with (evidently) good reason (there simply is no other
> evidence for the existence of a civilisation capable of doing such
> work in 7000 BC that anyone seems to be aware of *other* than the
> Sphinx) and there seems to be a consensus amongst the opposition that
> there are probably factors that are being misinterpreted by the
> champions of the idea to give such a date.
Funny thing. The "pro" camp has all the geologists. The "anti" group
arguments seem a bit weak. They argue about the lack of traces of such
a culture, and offer *no* explanation for the geological evidence.
> Then there is the fact that, of course, there is evidence that the Sphinx has
> been given an entirely new face *at least* once.
Which demolishes the argument I heard on on the "young sphinx"
advocates give about the facial features, hairstyles etc being evidence
that the Egyptians had to have been the original carvers.
>>And again, 20,000 years is a long time *culturally*. It's pretty short
>>by geological standards.
>
> And the Sphinx is pretty soft rock, isn't it?
Not *that* soft. And compare the erosion on the Sphinx with that on
other monuments that are allegedly of the same age.
> I'm not saying there would be no evidence at all, but that it wouldn't
> necessarily be as widespread as some seem to think ... or as obvious and
> easy to interpret.
Perhaps. Then again, I was kinda suprised to find out just *how* old
some early neolithic artifacts are. Like 25-35k years.
Leonard Erickson
> On Mon, 04 Jan 1999 23:18:07 GMT, asp...@curie.dialix.oz.au (Phillip
> McGregor) wrote:
>
>>On Mon, 04 Jan 1999 05:50:03 GMT, ster...@scsn.net (John Thompson) wrote:
>>
>>>
>>>>>No one seems to have mentioned that in the past couple of hundred years,
> we
>>>>>have literally covered the land surface with artifacts. Some, like
> glass and
>>>>>ceramics are very durable, especially if buried.
>>>
>>>>I take it you're a city boy. Not only have we not covered the land
>>>>surface with artifacts, there is still a large percentage of the globe
>>>>that's unexplored. What we have is basically large concentrations with
>>>>some scattering.
>>>>J.Michael
>>>
>>>I live in rural SC; from my house I can see some type of artifact in every
>>>direction. Roads, brick houses, highways cut into hillsides: these are
> pretty
>>>durable. Compare this to the state of affairs just 1000 years ago, here
> in
>>>the US. My point is we have produced so many artifacts, of so many types,
>>>that the situation really isn't the equivalent searching for signs of Troy
> or
>>>ancient Egypt.
>>
>>Roads.
>>
>>Of ashphalt/tarmacadam? That are easily broken up by the action of plant
> growth
>>and which, in 20000 (probably in 200) years will be a collection of blackish
>>gravel? Which future archaeologists will probably interpret as being "ritual
>>objects" if they recognise it at all.
>>
>
> Yes but there will be several feet to several meters of stratified
> gravel winding along the countryside in a pattern that could not be
> laid by water with the odd extra bit for flyovers and underpasses and
> what not and it will connect to some very impressive mounds of rubble
> and ceramics and plastics and stuff like that. It would take a rather
> determined effort to conjure a 'natural' explaination for that.
> Remember under the right circumstances almost anything can be
> preserved, footprints, bacterial cells, the inner structure of soft
> bodied animals. Given the sheer numbers of roads, cities and
> artifacts in general we have a lot will still be findable in 20k
> years.
As I noted in another post, a lot more will survive 20k years than I
thought. We've got crude poterry, carved bone, and even some *wooden*
items that are older than that which archeologists have dug up.
>>Brick Houses.
>>
>>OK, the bricks will probably survive, assuming the glaciers don't get 'em
> (we're
>>evidently at least half way through an interglacial ... probably no more
> than
>>8000 years to go, possibly much much less -- OK, SC may not be affected,
> but the
>>further north you go, the less likely anything is to survive), but only as a
>>mound of probably unrecognisable debris. The wooden framework of the house
> will
>>rot, or be consumed in random forest fires, and plant and environmental
> factors
>>will conspire to pulling down the walls and scattering the bricks.
Please note that they've found "huts" made of mammoth bones from
*before* the last glaciation. Mortared brick and stone will last a lot
longer.
>>Well, assuming the highways are tarmacadam/ashphalt, the roads themselves
> are
>>gone very quickly.
>
> But not the material
Amen. Asphalt/macadam is *not* terribly biodegradable.
Leonard Erickson
> On Fri, 08 Jan 1999 16:27:12 -0700, Keith Morrison <kei...@polarnet.ca>
> wrote:
>
> <interesting facts snipped>
>
>>No, quite a few mines will be quite recognizable.
>
> Or, perhaps more accurately, *parts* of mines will still be there?
And just those parts will be major anomalies.
Phillip McGregor
wrote:
>asp...@curie.dialix.oz.au (Phillip McGregor) writes:
>
>> On Fri, 08 Jan 1999 16:27:12 -0700, Keith Morrison <kei...@polarnet.ca>
>> wrote:
>>
>> <interesting facts snipped>
>>
>>>No, quite a few mines will be quite recognizable.
>>
>> Or, perhaps more accurately, *parts* of mines will still be there?
>
>And just those parts will be major anomalies.
Depends on where they are.
If all the *surface* parts and tunnels are gone, or substantially filled in by
debris (and probably grown over by vegetation) they won't generally be found
accidentally. And then you have to assume that the future locals dig down (or
use some sort of seismic imaging) to find the underground uncollapsed tunnels.
They may think that they're anomalies without actually realising what they are?
Or will it necessarily be so obvious that they couldn't miss it?
Phillip McGregor
wrote:
>> Some of them (all of them?) will be filled with water and, from the surface,
>> will probably look like "normal" lakes.
>
>Many of them *won't* fill with water. Most don't require pumping *now*,
>they either have an exit for the water, don't get that much rain, or
>both.
Yes. And, like the Great Salt Lake and Lake Agassiz, all things like that are
forever and permanent?
Seriously, climactic change and the filling up of what is, after all, a
non-natural watercourse where they may be no other way of draining, will account
for a lot.
And 20,000 years of erosion ... well, depending on the type of rock, the sides
will be pretty worn down, and they may look *on first examination* to be
"natural". After all, there are some pretty unnatural looking "natural"
geological formations around even now.
>> And, of course, if they're in regions of glaciation, the outlines have been
>> scoured so thoroughly that there probably *aren't* any "outlines" any more.
>>
>> Sure, this doesn't apply to regions which have not been glaciated.
>
>Which turns out to be much of the US.
Depends on the extent. But, yes, down to the northern states will be covered at
least (or seems to have been in the most recent ice ages), this leaves the
middle and southern states ice free.
However, the climate will not be the same!
>>>> They will be collapsed! They simply will not exist any more.
>>>
>>>Not necessarily!
>>
>> But more than likely. For coal mines, at least, according to what my
>> relatives seem to think.
>
>Sure. But "hard rock" mines are a rather different situation.
OK, granted. But I suspect that that means a *lot* of existing mines are coal
mines and will be gone.
And not all the "hard rock" mines will be *all* through hard rock. The surface
parts may not be, so will possibly collapse, and the subsurface workings will
not be obvious (unless seismological methods are employed). And, of course, if
there is a vertical shaft down, during 20k years this will tend to fill up with
debris and be, eventually, covered over with vegetation even in hard rock areas.
Mines driven horizontally first will probably not have as much of a problem ...
though, even there, the chance of the hillside sliding down to cover over the
entrance must be high over a 20k period of no maintenance.
After all, as I understand it, railway and road cuttings need constant
maintenance in most areas because they destabilise the area which will then try
to reach a new level of stability ... so the sides of the cutting tend to
collapse etc.
Of course, where possible, most such cuttings (as opposed to tunnels) tend to go
through relatively soft rock, I guess. But wouldn't it still apply even for hard
rock?
>>>20k years is *not* all that long geologically. And many of these things
>>>are placed where glaciation isn't all *that* likely to do anything to
>>>them.
>>
>> Yes, true. But it may, as I suggested, make our successors have an entirely
>> false picture of the range and relative importance of sites as a result.
>
>Well, for example, I know of a thousand foot tall basalt cliff that has
>a railroad line running along a several *miles* of shelf cut into the
>face of the cliff. And not only is the shelf not natural, it runs at a
>constant grade for all those miles. That's *not* going to erode away
>significantly in a measly 20k years.
Yes, but is it *stable*? As noted above, the collapse of the sides of cuttings
is a problem (see it all the time on selected local roads and highways ... its
not a daily event, but there's ongoing maintenance to *prevent* it from
*becoming* so).
>In case you've never dealt with the stuff, basalt is incredibly tough
>stuff. We made the mistake of grabbing a chunk of it to use in the
>"classic" erosion experiment where you heat rock with a propane torch
>or a bunsen burner, then plunge it into icewater. Repeat several times
>and watch as pieces flake off. With basalt, nothing much happens.
OK. My question above remains. Erosion won't get it, but will the track shelf be
*stable* over a 20k year period?
>>>Don't forget that there's evidence that the Sphinx dates back more than
>>>9000 years, and was exposed to *rain* erosion for a good chunk of them
>>>(the distinctive rain weathering is *how* they've determined that it
>>>has to be at least that old, as that's how long ago there was
>>>substantial rain in the area).
>>
>> Well, yes and no. There is some evidence recently raised that may
>> point to the Sphinx being 9000 years old. However, and I do not claim
>> to have kept up with this in any real way, what I have seen of this
>> "evidence" seems to indicate that it is not universally accepted as
>> being correct, with (evidently) good reason (there simply is no other
>> evidence for the existence of a civilisation capable of doing such
>> work in 7000 BC that anyone seems to be aware of *other* than the
>> Sphinx) and there seems to be a consensus amongst the opposition that
>> there are probably factors that are being misinterpreted by the
>> champions of the idea to give such a date.
>
>Funny thing. The "pro" camp has all the geologists. The "anti" group
>arguments seem a bit weak. They argue about the lack of traces of such
>a culture, and offer *no* explanation for the geological evidence.
Sure. But if the culture in question was capable of doing something as large as
the Sphinx (and the courtyard its in and some nearby temples, if I recall the
argument/evidence correctly), then surely it would have left some *other*
remains.
Of course, there are ways and means by which all this could have been missed,
but it is, on balance, a *little* unlikely. It *may* prove to be true, but, at
present, not being a geologist but a Historian, I *tend* to go for the "anti"
camp and think that the pro camp has missed something.
Undoubtedly there will be more research in the area and something more will come
of it, at the present, I really think its too early to tell anything for sure,
except that there *seems* to be an anomaly.
>> Then there is the fact that, of course, there is evidence that the Sphinx has
>> been given an entirely new face *at least* once.
>
>Which demolishes the argument I heard on on the "young sphinx"
What argument? Doesn't demolish anything, as far as I can see.
The Sphinx *is* pretty badly eroded, not all of which is due to modern
pollutants by any means.
>advocates give about the facial features, hairstyles etc being evidence
>that the Egyptians had to have been the original carvers.
That's only true if the *previous* face wasn't Egyptian as well. It wouldn't be
the first time heavily stylised Egyptian carvings were re-used for another
Pharoah by simply chiselling out one name and replacing it with another. As for
statues being representational of a "real" person, even Graeco-Roman ones
weren't ... they were idealised propaganda pieces for the most part.
>>>And again, 20,000 years is a long time *culturally*. It's pretty short
>>>by geological standards.
>>
>> And the Sphinx is pretty soft rock, isn't it?
>
>Not *that* soft. And compare the erosion on the Sphinx with that on
>other monuments that are allegedly of the same age.
There are other explanations that don't require it to be older. Maybe they seem
to be (maybe they are) silly or wrong, but I'd like to see some evidence of a
supporting civilisation before I believe the Sphinx is older than we have
heretofore thought.
It seems rather farfetched that the constructing civilisation can construct the
Sphinx, the courtyard around it (including walls) and at least one nearby temple
and yet leave no other remains. It seems unlikely that people capable of such
sophisticated work all (including the wealthy and powerful) lived in Reed Huts.
>> I'm not saying there would be no evidence at all, but that it wouldn't
>> necessarily be as widespread as some seem to think ... or as obvious and
>> easy to interpret.
>
>Perhaps. Then again, I was kinda suprised to find out just *how* old
>some early neolithic artifacts are. Like 25-35k years.
But how *many* of them are there in a single spot? And how widely separated are
those spots?
Larry Caldwell
sha...@krypton.rain.com writes:
> In case you've never dealt with the stuff, basalt is incredibly tough
> stuff. We made the mistake of grabbing a chunk of it to use in the
> "classic" erosion experiment where you heat rock with a propane torch
> or a bunsen burner, then plunge it into icewater. Repeat several times
> and watch as pieces flake off. With basalt, nothing much happens.
I happen to live in a region of the USA where most of the rock is basalt.
It is indeed quite solid stuff, but it decomposes readily through
oxidation. The top several feet of any basalt layer is normally pretty
rotten. An exposed basalt face may not break down as fast as granite or
limestone, but 20,000 years is a long time. The durability of a basalt
feature would depend a lot on the weather in that location. If it is in
a desert, it might last.
> Perhaps. Then again, I was kinda suprised to find out just *how* old
> some early neolithic artifacts are. Like 25-35k years.
That's a little early for neolithic, which is stone age agriculture,
animal husbandry and (later) ceramics. 20kya+ is mesolithic. Still
pretty fancy, and obvious high culture in places, but no farming.
-- Larry
Larry Caldwell
20,000 years, or even 10x that long.
1) The top of the heap - garbage dumps. We have generated some middens
of truly mythological proportions. Of course, subsequent civilizations
may destroy them by mining them for raw materials.
2) Radioactive waste. We already have decommissioned nuclear plants
dotting the landscape all over the planet. Chances are most of them will
never be cleaned up. Anybody with a gold leaf electroscope will be able
to tell something went on there.
3) Open pit mines. Forget the silly tunnel mines. We have leveled
entire mountain ranges in Central America mining bauxite, for instance.
Nobody will miss that in only 20,000 years. And of course, there is
always Anaconda's monument in Montana.
4) Space junk. The stuff in near earth orbit will decay out, but all
those comm satellites will be out there for millennia.
5) Desert cities, like Phoenix and Palm Springs. Of course they will be
the first cities abandoned by our civilization, but they will be
preserved by the climate.
-- Larry