
If we weren’t the first industrial civilization on Earth, would we ever know? - occamschainsaw
https://www.technologyreview.com/s/610886/if-we-werent-the-first-industrial-civilization-on-earth-would-we-ever-know/
======
tzs
The History Channel had a 20 episode series called _Life After People_ that
looked at what would happen if every human suddenly disappeared.

The National Geographic had a similar, but only one episode program looking at
that questions, called _Aftermath: Population Zero_.

I have a vague recollection of seeing something like this on one of
Discovery's channels, too, but I may be mixing that up with an article in
their magazine.

My recollection is that they all concluded that in the very long term (tens of
millions of years), if some other species evolved intelligence it would
probably not be able to tell we were here.

Some of the materials we used might survive, but things like glaciers in ice
ages would grind them to a powder. The next intelligent species might notice
these odd concentrations of unusual combinations of metal particles and
powdered long chain carbon compounds, but there would be nothing to tell them
it wasn't made by some unknown natural process.

~~~
airza
At least they'd be incredibly confused when they eventually went to the Moon
:)

~~~
jacobwilliamroy
I've always wondered if future people will believe that we put up the all our
artificial satellites, without help from aliens. If we can't even imagine
egyptians being able to stack rocks, who's gonna believe that we forged metal
ships and launched them into orbit?

~~~
C14L
Satellites would disappear pretty quickly without constant orbit adjustments.

~~~
wongarsu
I would expect geostationary satellites to last pretty long, after all their
orbit should have close to zero atmospheric drag and barely any tidal forces.

~~~
koheripbal
"pretty long", yes. Tens or hundreds of millions of year? No.

------
nealabq
Ceramics should last a very long time if they are buried. Ceramic toilets and
stoneware dishes are like stone. If buried in sand or silt that collected over
time they would be like other fossils. They might get crushed or broken, but I
don't think they'd dissolve or corrode.

~~~
JohnJamesRambo
Yes we have fossils of many of the most delicate creatures that have ever
lived, it seems impossible to believe that nothing of all the durable items we
have created would remain or be fossilized. It’s a cool thought experiment
wondering if we aren’t the first but it seems completely impossible. I’m
afraid our generation will be known as “The Plastic Generation” from our layer
in the sediment.

~~~
c048
"I'm afraid we'll be called the plastic generation", why are you afraid?

Plastics are a hallmark of an era, like clay, bronze, bones, etc... .

Social and regular media is currently making plastic out to be this big boogie
man, intentionally ignoring the good sides of plastic, to sell you
tweets/articles about the benefits of plastics (and will point out how you
should suddenly feel bad for not using them already) in a few years anyway.
They're not about a balanced discussion anymore.

~~~
kingkawn
Cause it’s gonna kill us, in spite of the good it’s done

~~~
wongarsu
How would plastic kill us? The only issues I'm aware of are

1) the pollution of oceans, which seems very fixable with much less effort
than replacing plastic (filtering water at river outlets and in coastal
waters, preventing ships from just dumping their stuff everywhere).

2) microplastics. In marine environments that seems solvable by solving point
1, and while a cause for concern I don't think any negative effects outside
marine environments or food chains containing marine animals have been shown?

Of course particulate matter is somewhat related, but wheels on asphalt will
cause tiny airborne particulates no matter what material we use to make tires,
so we might be better off just filtering our air in any case.

~~~
eljimmy
You're forgetting the most important issue: 3) Human apathy.

Our ecosystems will collapse well before we change our cancerous existence on
this planet.

------
klodolph
We are the first nuclear civilization.

We know the expected isotope ratios too well and test them too often. This is
how we discovered evidence of a natural nuclear reactor from 1.7 Gya. Any
other nuclear civilization would have changed the isotope ratios in detectable
ways in some part of the world.

~~~
Engineering-MD
Out of interest what was this natural nuclear reactor? And also how do we know
it was definitely natural? I don’t believe it wasn’t natural, but I wonder how
one would prove that.

~~~
japaget
Oklo in Gabon, Africa. See [https://www.iaea.org/newscenter/news/meet-oklo-
the-earths-tw...](https://www.iaea.org/newscenter/news/meet-oklo-the-earths-
two-billion-year-old-only-known-natural-nuclear-reactor)

------
duxup
It's an interesting way of thinking of the age of the earth and geological
changes that there could have been a civilization and we wouldn't know.

Or someone later wouldn't know about us.... outside say an abandoned car
floating through space...

That would be an interesting story. We travel into space to find things out
there only to find things that seem to have come from... home.

~~~
hoorayimhelping
> _Or someone later wouldn 't know about us.... outside say an abandoned car
> floating through space..._

The cars we left on the moon will still be there. The satellites and trash in
orbit would still be there. The satellites orbiting Mars would still be there.

We can see clear evidence that life has altered the climate in the past [1].
Anyone looking like we are would notice our mark on the environment.

1)
[https://en.wikipedia.org/wiki/Great_Oxidation_Event](https://en.wikipedia.org/wiki/Great_Oxidation_Event)

~~~
zaroth
Are satellite orbits really stable over millennia?

Maybe just the geo-sync ones, but I imagine anything closer will decay in
“relatively short order”.

~~~
zamadatix
Depends what you consider "closer". Geosynchronous orbit is 35,786 km above
the surface and while at 500 km you get significant decay (order of years to
re-entry) while satellites at 1,000 km are estimated to take centuries to re-
enter. Extrapolating that anything above the start of medium earth orbit
(2,000 km) and out should last a hell of a long time.

------
gdm85
If another civilization had reached space-faring technology then one day they
might come back and discover that the (perhaps inhospitable) home
planet...harbors again life. Probably too far-fetched and better suited as
material for a scifi story, but the idea is interesting.

~~~
adventured
> Probably too far-fetched and better suited as material for a scifi story,
> but the idea is interesting

M. Night Shyamalan directed a terrible movie from 2013 that is a version of
that premise. After Earth, starring Will and Jaden Smith. Solid idea for a
sci-fi movie, they botched it unfortunately.

"In the future, an environmental cataclysm forces the human race to abandon
Earth in search of a new habitable planet, eventually settling on the planet
Nova Prime" ... "A crash landing leaves Kitai Raige and his father Cypher
stranded on Earth, a millennium after events forced humanity's escape. With
Cypher injured, Kitai must embark on a perilous journey to signal for help."

[https://en.wikipedia.org/wiki/After_Earth](https://en.wikipedia.org/wiki/After_Earth)

[https://www.imdb.com/title/tt1815862/](https://www.imdb.com/title/tt1815862/)

------
kanzenryu2
Increased carbon levels are found in ice deposits from the period of the Roman
Empire. There's nothing prior to that.

~~~
empath75
There’s no ice that goes back a hundred million years.

~~~
zaroth
I think 2 million years is about as far as we can go...

[https://www.nature.com/articles/s41586-019-1692-3](https://www.nature.com/articles/s41586-019-1692-3)

------
irrational
How long does it take for tectonic action to "recycle" the plates? Could a
civilization have existed as extensive as our own in the extreme past, but we
can't see any evidence because it is all hundreds of miles under the surface
of the earth being melted down slowly?

~~~
adrianN
The oldest rocks are about four billion years old:
[https://en.wikipedia.org/wiki/Oldest_dated_rocks](https://en.wikipedia.org/wiki/Oldest_dated_rocks)

~~~
dotancohen
But the oldest surface material is less than 2 million years old (Israel), and
the second oldest surface is about half a million year old (Nevada).

[https://www.livescience.com/3542-oldest-surface-earth-
discov...](https://www.livescience.com/3542-oldest-surface-earth-
discovered.html)

------
gmuslera
Oil was a good push for the development of our civilization, and should have
been for any past technological civilization too. If we have oil today (in the
amount we are getting it, at least) then the previous civilizations didn't
reached our oil dependent civilization stage, or existed before the actual oil
reserves formed.

It doesn't imply that there wasn't any civilization before, but or it happened
hundreds of millions of years ago, or never became as advanced or global as
our actual one. Unless there could had been back then an abundant energy
source different from oil but with similar efficiency, and it got globally
depleted by that previous civilization.

~~~
koheripbal
The same argument can be made for rich surface deposits of Iron, Aluminum,
Tin, etc... If there were civilizations in the past - even a hundred million
years ago - they likely would have mined those.

------
ThrustVectoring
If a previous industrial civilization put satellites into geo-stationary
orbit, they'd still be up there. If there are unknown objects in geo-
stationary orbit, would be be able to find them? If we could find them, and we
haven't, doesn't that put an upper limit to the technological sophistication
of possible previous industrial civilizations?

~~~
droithomme
Not all industrial civilizations launch geo-stationary satellites.

~~~
hermitdev
Only the ones we know of.

~~~
droithomme
Not necessarily. It is true that the industrial civilizations we know of,
considered on a consolidated planetary short-recent-history level, have
launched satellites in geostationary orbits. But we can not logically infer
from this that only the ones we know of have launched satellites in
geostationary orbits. There may be ones that have launched geostationary
satellites which we do not know of.

------
ColanR
Isn't there some level of radiation that is ubiquitously present ever since we
started nuclear testing? Seems like we could figure out if there ever was a
nuclear-capable society in the past just by looking at radiation decay.

~~~
marcosdumay
On the millions of years scale, that signature disappears.

~~~
zaphirplane
What about fossils, surely children in that ancient vibrant civilization
dropped their shoes, phone, remote and it got fossilized

~~~
marcosdumay
The article explains that one. If we were gone today, we would probably not
leave any fossil.

------
dontbenebby
>The current area of urbanization is less than 1% of the Earth’s surface

But doesn't this assume cities are distributed uniformly and randomly? Cities
seem to be build at ports (ex: Port of NY, Oakland) and waypoints with natural
resources or barriers (Salt Lake City, Denver on either side of the mountains
for example)

~~~
gshdg
The locations of rivers, good natural harbors and resources would have been
completely different tens of millions of years ago.

~~~
dredmorbius
Different, yes. Unknowable, no.

We know the general distribution of continents dating to 550 million years ago
(Gondwanaland), and to some extent prior, though that largely predates the
Cambrian explosion of complex life on Earth.

Ancient coastlines, estuaries, and riverbeds leave quite distinctive
geological traces and would be detectable. We'd be looking for ancient
civilisations on or near such features.

------
mellosouls
2018.

Interesting idea and covered many times before on HN including at the time:

[https://news.ycombinator.com/item?id=16837120](https://news.ycombinator.com/item?id=16837120)

------
ropiwqefjnpoa
It also assumes industrialization similar to our own. A past civilization
would most likely have developed entirely different technologies that we may
not know what to look for.

~~~
adrianN
Some technologies seem too universal to assume an industrial civilization
would miss them. Things like ceramics for example are easy to make, very
useful and would likely survive in the geological record.

~~~
koheripbal
Fossil fuels are the same. It burns. It's obvious it burns. The internal
combustion engine was inevitable.

------
leetcrew
sorry for the total aside, but this article reminded me of one of my deepest
typo curiosities: why is the misspelling ratio -> ration so common? there are
lots of words that can have a character erroneously appended and still be a
correctly spelled (different) word. for example: most verbs in english (ride
-> rides, bake -> baked, etc.). but for some reason, I see ratio -> ration all
the time. 'n' isn't even that close to 'o' on the keyboard! it really jumps
out when you subvocalize; the 'n' changes the pronunciation a lot.

~~~
pacbard
I wonder if it has to do with the suffix -tion. Maybe muscle memory is
triggered when the letters “tio” are typed at the end of the word and “n” is
automatically added to the end of the word.

~~~
caymanjim
I'm fairly sure this is why I do it. I'm an average typist and above-average
speller, but -ion spills out whenever I type it. There are almost no words
ending in -io, and there are a lot ending in -ion. For some quick numbers, the
OSPD database I have here has 1432 -ion words and only 47 -io words.

~~~
shalmanese
I always type ratio as ration but never type radio as radion.

------
xenadu02
We would know it. We probably wouldn't know much about that civilization;
almost all of their culture or art would not survive. But we would find bits
of glass or pottery fossilized in rocks at the very least. We haven't found
anything like that so it seems extremely unlikely.

------
resheku
this youtube channel i like "Curious Droid" made not long ago a video on the
subject

[https://www.youtube.com/watch?v=8xDK2LgSeyk](https://www.youtube.com/watch?v=8xDK2LgSeyk)

What Fossils Will We Leave Behind in 65 Million Years?

65 million years ago the dinosaurs died out, we only know of their existence
because of the few fossil remains found. So what if a similar fate were to
happen to us humans tomorrow, in 65 million years time what would remain of
everything we had created and would there be anything be left for any future
intelligent species to find.

------
Zenbit_UX
They glaced over nuclear war a little too quickly. While I'm not an expert,
I've heard many times that a significant nuclear exchange between countries
would likely result in so much debris being thrown into the atmosphere it
would cause a nuclear winter. This could lead to a full blown ice age, mass
extinctions, etc...

Surely those "side effects" of the bombs would be measurable far longer than
the radiation. We know of past super volcanic eruptions and the dinosaurs'
extinction because of similar circumstances.

~~~
simonh
It’s not just radioactive material that would betray a past nuclear war. Some
of the stable decay products are extremely rare in nature, and their presence
in the ratios we know atomic weapons produce would be a dead giveaway.

------
jammygit
Its not industrial, but I recommend At the Mountains of Madness by lovecraft
for an example of this sort of question being asked in fiction

------
geuis
Just thinking off the cuff and channeling a bit of Isaac Arthur here.

Coming from the angle of a non-native intelligence colonizing Earth in the
super distant past, there may not be many or any terrestrial remains over such
a long span of time.

It’s reasonable to think “aliens” would not burn coal and oil for energy. If
they crossed the gulf of space, they likely used fusion or some other power
source. A ground side civilization could sift helium3 from the oceans for
thousands of years without a noticeable depreciation. If they used power
satellites, those would likely have fallen from orbit or been knocked out of
the Earth-Moon system within hundreds to thousands of years.

Within human history, many of the same geographical areas of the world have
been good places to live for thousands of years. But when you extend that to
hundreds of thousands to millions of years, those places generally change
drastically and disappear. One could assume, for the sake of argument, that
aliens colonizing Earth might have similar biological needs as we do and would
live in similar areas of the distant past. We might not easily find those
places now given environmental changes over geological ages.

We also are still very early in exploring the solar system. It’s plausible
there could be remnants of mining and manufacturing in places we haven’t
looked. It’s important to remember that if your civilization is colonizing a
new system, you’re already a space based society. It’s then reasonable to
expect little on the ground industrialization since most of your
infrastructure will be in space.

There’s a new study talking about solar electrostatic effects on the Moon and
how it causes lunar dust to rise and drift around despite no atmosphere. Given
long enough spans of time this might even conceal evidence of prior space-
based industrialization.

One big red flag to me that this hasn’t happened in Earth’s history is the
biological record. We have a fairly good overall map of biology over large
areas of the world. Everything alive here seems to come from here. There’s
nothing alive that doesn’t appear to use the same general base chemistry and
biology as everything else.

If some aliens showed up a hundred million years ago, we might expect to see
some distantly evolved branches of life that are somewhat different in at
least DNA or other chemistry. We might find something like this but it’s
unlikely.

The follow-on to that might be an argument that all current life is descended
from some ancient aliens. That could be true but it would be nearly impossible
to tell at this point. All life seems to have a common descent with no
aberration, so following up on this line of thought is extremely difficult to
test for. We would need to find examples of life outside of Earth before we
could make comparisons to investigate that hypothesis.

~~~
zaphirplane
I suppose it’s possible an ET civilization had an outpost on earth and that
outpost is now in the middle of the ocean. I think the discussion is an earth
based civilization, then the chances of all their cities, discarded equipment,
lost items haven’t left a single mark is very unlikely.

What about fossils from that era

~~~
geuis
Right but I think in terms of interstellar colonization there can’t really be
a concept of an outpost how we think of say bases in Antarctica or the ISS. If
you’re sending people to another star system, it has to be a minimum viable
colony or nothing.

In regards to fossils, excellent point. The problem is that despite all of the
fossils we’ve found, overall it accounts for less than 1% of all species that
have ever existed on Earth. The odds of finding even a single fossil from an
animal from a non-terrestrial colony are exceptionally low. Not zero, but so
low as to be extremely unlikely.

------
adaisadais
This sounds like an incredible science fiction series that needs to be
written.

Any chance such books already exist?

~~~
brownbat
In some ways, Howard's Hyborian Age stories featuring Conan were a response to
scientific revelations of his day indicating the plausibility of a vanished
age prior to recorded history.

Aschulean hand axes have been dated to 1.76 million years ago, Oldowan tools
were made up to 2.6 Mya. Just really smart apes, sure, but who would know if
they had a breakaway 5,000 years of brilliance reflected mainly through an
extensive oral tradition and crafts with exceptionally disposable materials.

Not known in Howard's day, but Göbekli Tepe is an extensive temple complex in
Turkey that predates when we thought sophisticated organized societies
emerged, and seems like something his Hyboreans might have built.

If you want to get way out on a limb, our theory about how monkeys got to the
new world is pretty suspicious. Currently, we theorize that a breeding
population managed to accidentally raft across the Atlantic exactly one time
in all of history, but this is so rare it didn't happen for other animals, and
never took them to the much closer North America from there.

Might as well guess some ancient extinct navigators brought some monkeys along
as pets, then died out and left the monkeys as the only evidence. Crazy and
unsupported conjecture, but why not, par for current theories.

~~~
filoeleven
“Just really smart apes” basically describes us, too!

There’s that 40k-year-old bracelet that was made with a “relatively high
speed” drill, something we didn’t think the denisovans could do:
[http://siberiantimes.com/science/casestudy/features/f0100-st...](http://siberiantimes.com/science/casestudy/features/f0100-stone-
bracelet-is-oldest-ever-found-in-the-world/)

I’m also reminded how in the past 15 years or so, using LIDAR, we are learning
that there are way more Mayan or Aztec ruins than previously thought; they
were just covered up by the jungle.

There’s a lot of mystery still buried in the earth.

------
sfblah
What about artifacts on the moon?

------
dmead
star trek voyager had an episode about this

~~~
dylan604
Isn't it the premise of the Stargate universe as well?

------
arthurcolle
This idea has come up a few times on conspiracy subreddits, but it seems like
a pretty big stretch. Look at all our landfills full of old obsolete
electronics. The fact that we don't find similar things make these "hidden
civilization" theories pretty unlikely in my opinion.

~~~
duxup
I think article accounts for that.

