
Was there a civilization on Earth before humans? - limbicsystem
https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/?single_page=true
======
peatmoss
This is one of my all-time favorite “what if” questions. Some years ago a
friend of mine coily posed this same question to me: What does humankind make
that would survive 60 million years into the future, and if some other
advanced industrial civilization had existed 60 million years ago, how would
we know?

It turns out my friend had put a LOT of thought into this exact question.
Enough to do a masters in geology, his work ultimately making it into a high
profile journal with writeups in places like the NY Times.

He started talking to various geologists about what might survive as telltale
markers of our civilization. Buildings or structures of any sort? Ha! Statues
and monuments? Maybe we’d notice the odd deposit or two of minerals.

After going through a long list of candidates, he settled on carbon
cenospheres. These are little balls of carbon almost exclusively made in
internal combustion engines as the result of aerosolizing fossil fuels. Sixty
million years ago, our love of the ICE will show up in the fossil record as a
light dusting of cenospheres covering the earth—contemporaneous with massive
numbers of species going extinct due to mankind’s other influence.

And as my friend was telling me his story, this is where my hair stood on end.
Sixty million years ago we see a massive species extinction... and a light
dusting of carbon cenospheres covering the globe.

But we also see unnatural levels of iridium at the same point. And, while it’s
hypothetically possible some industrial civilization was mining iridium and
blanketing the globe with it, it’s more probable that the iridium was
delivered by an asteroid.

But how would you know? So my friend, as part of his research, went taking
samples of his cenospheres from around the globe. What he found was
interesting: namely, the further one gets from the Yucatan (where scientists
had already validated there was an asteroid strike), the cenospheres get
smaller. The big heavy ones precipitated out of the air closest to the Yucatan
asteroid strike. Hardly likely to be coincidence.

So much for ancient civilization this time around.

However, his work rewrote a critical understanding of the KT asteroid
extinction event. Namely, we previously thought most of the carbon at the KT
boundary was the result of giant forest fires ignited by the strike. However
we now know that the strike must have aerosolized massive oil fields under the
Yucatan at that time and set them ablaze.

Not a bad contribution to science starting from a sci-fi premise!

~~~
wklauss
> Not a bad contribution to science starting from a sci-fi premise!

1\. Ancient civilization enters industrial and post-industrial era.

2\. Carbon levels rise, so do global temperatures.

3\. In a desperate attempt to save themselves they try geo-engineering by
slamming a massive asteroid in the too hot and thus unpopulated area of
Yucatan.

4\. Goes wrong.

I can see it working as sci-fi novel

~~~
snowwrestler
Maybe the Earth-based technological civilization attracted the attention of a
space-faring civilization, who dropped an asteroid to wipe out the Earth
civilization (successfully, as it turns out).

Which means maybe we should be a bit more careful about bleating our existence
out into the universe these days...

~~~
rekado
People who had this thought have also liked "The Dark Forest" and "Death's
End" by Liu Cixin :) (These are part 2 and 3 in the "Three Body Problem"
series.)

~~~
KineticLensman
Also 'The Forge of God' [0] by Greg Bear [1987]:

"We've been sitting in our tree chirping like foolish birds for over a century
now, wondering why no other birds answered. The galactic skies are full of
hawks, that's why. Planetisms that don't know enough to keep quiet, get
eaten".

[0]
[https://en.wikipedia.org/wiki/The_Forge_of_God](https://en.wikipedia.org/wiki/The_Forge_of_God)

------
briga
Ants are a good candidate for a second civilization. They live on every
continent except Antarctica, they build complex structures, they invented
argriculture millions of years before humans did (!), and they live in
socially stratified societies. But I guess it ultimately comes down to your
definition of what is a civilization.

If we were to find evidence of an industrial civilization before humans we
might not even recognize it as evidence, given how different it might be from
ours.

~~~
mabbo
> they live in socially stratified societies

This is gross anthropomorphism. Ants don't have societies any more than the
cells in our body have societies.

An ant colony is an organism. Each individual ant has just enough neurons to
do the one task that ant does. The overall organism is quite capable, true,
but it's not intelligent. It doesn't learn novel things, it doesn't purposely
invent, it doesn't 'know' anything.

Ants may take over the world some day, but they won't know it.

~~~
3131s
Ants pass the mirror test, which is something very few animals are capable of.

~~~
aalleavitch
Wait really? Do you have a source for this, I'd love to learn more.

~~~
ahakki
No source, but iirc the scientists applied a colored dot on the ants head.
When they saw themselves in the mirror the started trying to remove it from
their heads.

~~~
dogma1138
There are parasitic mites that attach themselves to ants and they look like a
colored dot (usually red). I think the ant “thinking” that the dot was a mite
is a much more plausible explanation than the that the ant is some how
conscious with its cluster of like 3 and a half neurons

~~~
yaks_hairbrush
So the ant (allegedly -- I'm eagerly awaiting that source!) saw a dot on the
ant in the mirror, and tried to remove the dot on its own forehead. The key
point: that looks an awful lot like the identification of the self with the
reflected image.

The issue you brought up about the mite is a bit orthogonal to this point. I
can give you that the ant was concerned about the possibility of having a
mite, and the point still remains that the ant thought it was on its own head
only on basis of a reflected image of itself. (Compare to the alternative
behavior: the ant tries to get the mite off the reflected image, never making
any attempt to remove it from itself.)

~~~
ahakki
it was on hn a while back. the link is dead now.
[https://news.ycombinator.com/item?id=14146776](https://news.ycombinator.com/item?id=14146776)

it’s on wikipedia, with the same dead source
[https://en.wikipedia.org/wiki/Mirror_test?wprov=sfti1](https://en.wikipedia.org/wiki/Mirror_test?wprov=sfti1)

EDIT: Working link to the paper (in some journal of science):
[https://www.udocz.com/read/are-ants-capable-of-self-
recognit...](https://www.udocz.com/read/are-ants-capable-of-self-recognition-
pdf)

[http://difusion.ulb.ac.be/vufind/Record/ULB-
DIPOT:oai:dipot....](http://difusion.ulb.ac.be/vufind/Record/ULB-
DIPOT:oai:dipot.ulb.ac.be:2013/219269/Details)

------
BurningFrog
One strong argument against a civilization in the last 100 million years or so
is that our separate continents have clearly been completely isolated, and
gone separate evolutionary paths.

If there was a planetary civilization 20 million years ago, there are tons of
"invasive species" that would have spread across all continents then rather
than in the 1800s. Think rats, sparrows, cockroaches, etc x 1000.

I don't think I have an argument against one back in Pangean times though.

~~~
aalleavitch
What if it were a civilization of ocean-dwelling creatures?

That would make the whole premise more plausible for a number of reasons.

------
Tossrock
Arthur C. Clarke and Stephen Baxter briefly touched on this idea in The Light
of Other Days.

(Spoiler) The book is primarily concerned with the development of a
miniaturized wormhole technology which allows remote viewing anywhere on
Earth, and the effects this has on privacy, etc. They discover it can also be
used to view backwards in time, and at the end of the book they trace the tree
of life backwards towards the universal common ancestor, and discover that it
was a microbe seeded deep in a geothermal vent by a civilization of
intelligent trilobyte/arthropod like creatures, which knew its own extinction
was imminent at the hand of a massive asteroid.

~~~
rapnie
Thank you!! I have been looking for this book in my own sci-fi bookcase a
number of times having forgotten both author + title. Got it now :)

This is a great book!

------
hapnin
"It’s not often that you write a paper proposing a hypothesis that you don’t
support."

We should all do this at least once. What a great practice.

------
asmithmd1
The fact that we found pressurized oil reservoirs ("gusher" oil wells) means
that nothing had tapped these cheap and easy sources of energy before.

~~~
soneil
Not just oil, we probably wouldn't have an an iron age without access to
unmolested surface deposits.

Iron, tin, copper. If there was a pre-human civilization, they couldn't have
gone beyond the stone age, else they'd have consumed the resources our iron
age depended on.

~~~
BurningFrog
Unless they shipped the metals off planet, that's not really an argument. If
anything, an iron using civilization would have made iron more concentrated
and easier to find.

~~~
scottie_m
Aluminum sure, but iron rusts. In tens of millions of years you could have
oxides of iron from a civilization, but no workable steel or iron. Aluminum
might survive, gold and platinum would be fine, but not iron. It doesn’t
matter though, we’d have gone through many cycles of subduction and renewal in
such a long time, so we’d have new surface deposits. Coal and oil would even
have started to form over such a long time scale.

~~~
PeterisP
What do you mean by "workable steel or iron" ? We're not mining for steel, and
it's not like iron age started with finding some magic store of "workable
iron" instead of iron oxides - the surface iron and mined iron deposits e.g.
hematite, magnetite, etc _are_ oxides of iron. The fully oxidized remains of a
scrapyard would form pretty much perfect iron ore.

Our iron (and other metal) mining is not "using iron up", it's just bringing
the iron closer to the surface and transforming it in ways that will be undone
by millions of years. Fossil fuels are a different case, though.

~~~
scottie_m
The majority is hematite, but iron exposed to air will not form hematite, or
even magnetite, but _hydrated_ oxides. That iron will also be spread out over
large areas in low concentrations, not richly concentrated ores of oxides. It
would be economically and energetically unfeasible to gather hydrated oxides
from rusted metal and then try to make workable iron from it. It’s certainly
possible, but it would be a kind of insane process with low yields.

The other problem is that you need to use coke as a reducing agent, so we’re
back to fossile fuels.

~~~
FreeFull
Charcoal also work as a reducing agent. The problem with using charcoal is
that you're going to be using up a lot of wood to make it.

------
isthatart
An older period: Carboniferous [0]

Lots of plastic non biodegradable (at the moment): lignin. That's why we have
coal, which fueled our Industrial Revolution :)

Ended with the Carboniferous rainforest collapse, caused by climate change.

[0]
[https://en.wikipedia.org/wiki/Carboniferous](https://en.wikipedia.org/wiki/Carboniferous)

------
spullara
Me: "It would be amazing to go out to the asteroid belt and return a rare-
earth metal rich asteroid to solve that problem once and for all."

Other: "That's what the dinosaurs thought."

------
dustfinger
As the article points out, an ancient industrial civilization would need to
mine resources. I think it is fair to say that they would mine a lot of gold
and silver for use in electronics. If such a civilization existed then one
would think that most of the earth's natural veins of gold and silver would
have been mined making large easy to find naturally occurring veins rare. It
seems though that our civilization has found plenty of easy to find large
scale veins of gold and silver.

Does that not make it unlikely that any ancient industrial civilization
lasting centuries could have existed before us? Or over tens of millions of
years would more naturally occurring easy to find veins of gold and silver
rise to the surface of the Earth's crust?

~~~
leetcrew
> Or over tens of millions of years would more naturally occurring easy to
> find veins of gold and silver rise to the surface of the Earth's crust?

i am not a geologist but, as i understand it, plate tectonics cause a lot of
"churn" in the crust. so i think it is certainly conceivable that a
civilization could mine all the accessible veins to exhaustion but have many
more veins brought up near the surface in the following 60 million years.

~~~
dustfinger
Yah, as I wrote my comment I realized that it made sense that there would be
churn. I am not a geologist though. It is a fascinating notion. It makes me
think of Mote Cook's Numenera [http://numenera.com](http://numenera.com)

------
aurizon
The nuclear war between the Dinosaurs and the Martian Kangaroos laid waste to
both their planets 65 million years ago. The final phase occurred when the
Martian forward base on the moon, from where they bombarded the earth, was
wiped out by asteroidal bombardment by the dinosaurs. Then the Venusians moved
in and finished the job, eliminated all the remaining dinosaurs and the
Martian kangaroo people and retreated behind their cloud cover. A few 'roos
survived, but retroevolved to a pastoral state. We had better tread with care
- lest we anger Venus...

------
ajmurmann
I wish this article had also gone into how long indicators might survive
outside of Earth. Could satellites survive? Things on moon or Mars? Might we
go to Mars and find some old Mars Rover or underground base or that we left
Mars for Earth after we made it uninhabitable?

Edit: typo has -> had

~~~
mr_toad
Anything on the surface will be eroded by micometeorites over millions of
years. The lunar surface is a layer of dust several meters thick that is the
product of that erosion.

Underground artefacts might survive longer, since there is no plate tectonics
and little other geological activity, but finding them would be difficult.

------
givan
We don't even know about previous human civilizations.

Recently discovered Göbekli
Tepe[https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe](https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe),
the oldest megalith structure, confirmed by radiocarbon tests to be more than
12.000 years old with massive stone pillars and 3d relief stone sculptures
mostly still buried is still a mystery to science and some "scientists" still
think hunter-gatherers built it with stone chisels.

The interesting thing is that a study based on the drawings on the structure
correlated with Younger Dryas period might explain why nothing was found about
the ancient civilization that built it.

[https://phys.org/news/2017-04-ancient-stone-pillars-clues-
co...](https://phys.org/news/2017-04-ancient-stone-pillars-clues-comet.html)

[https://www.newscientist.com/article/2128512-ancient-
carving...](https://www.newscientist.com/article/2128512-ancient-carvings-
show-comet-hit-earth-and-triggered-mini-ice-age/)

So after all the Atlantis and the flood myth found in most cultures from
around the world might be real.

~~~
thaumaturgy
> _...and some "scientists" still think hunter-gatherers built it with stone
> chisels._

Well yes, that's how actual scientists work: on evidence. Until there's
evidence to the contrary, the most likely hypothesis is that the structures
were built with the tools and labor that we think humans possessed at the
time.

I didn't find anything in your links that mentioned the myth of Atlantis.

~~~
Alex3917
> I didn't find anything in your links that mentioned the myth of Atlantis.

Do a YouTube search for Younger Dryas.

~~~
thaumaturgy
You're kidding, right? I'm getting Joe Rogan podcasts, channels like "Atlantis
in the Java Sea", "Joe Rogan University" (...). I'm not watching any of that
shit. I feel dumber just for knowing that "Joe Rogan University" exists.

Point me towards something that _isn 't_ part of the Kook Productions Network
please.

~~~
Alex3917
> I'm not watching any of that shit.

Even if the best academic papers on the topic are likely to have less
obviously incorrect information, you'd probably still learn a lot more by just
sitting down and watching all the videos. I haven't seen the Joe Rogan thing
that comes up, but I doubt that watching it would magically make you dumber or
whatever.

~~~
thaumaturgy
I have to politely disagree. Sure, one video isn't a big deal -- it's just
five or ten minutes. But, if I followed up every silly idea presented online
with five or ten minutes of watching kooky videos, then yeah, I'd end up less
knowledgeable than if I stuck to the stuff that tends to come from better
sources.

Also, I've met enough smart people infected by silly ideas to know that nobody
is immune to misinformation. Maybe I'm bored and one of those videos leads me
down some YouTube rabbit hole that gets me stuck on some nonsense. I'd
probably never see it coming; the people who listened to a little too much
Coast to Coast surely didn't.

So while I'm excited by new ideas on just about every subject, I also have
something of an immune response to them, a conscious decision that I'd rather
be uninformed -- and maybe spend that time reading a book or doing something
fun outside -- than misinformed. Since I'm not smart enough to know what's
right and what's not when I don't know anything about the subject, I rely on
the source as a strong signal of trustworthiness.

HN's just about the only guilty pleasure I've got left, but the S:N here is
still better than a lot of other places.

------
babalulu
This reminds me of Lovecraft. His mythos was based on the premise that Earth
has been inhabited by a series of alien and native civilizations, mostly
malign, over the past billion years. Occasionally an artifact or part of a
city is thrust to the surface by geologic forces. According to Lovecraft,
after humanity falls a race of intelligent beetles will arise.

~~~
krapp
I think Lovecraft's aliens were more indifferent to humans than malign, or at
best slightly annoyed, the way a human might be by a small anthill in their
yard. As far as I know, Lovecraft hated the theistic ideal of humanity being
the "center of God's creation" and wanted to portray a universe where humans
were utterly insignificant and incapable of dealing with the scale of horrors
that awaited beyond the safety of the anthill.

------
ownedthx
My all time favorite theory: [http://pbfcomics.com/comics/dinosaur-
meteors/](http://pbfcomics.com/comics/dinosaur-meteors/)

------
zw123456
We left some evidence of our existence on the moon so the next civilization
will be able to find that even millions of years from now, perhaps.

~~~
koboll
Does LIDAR penetrate dust? I wonder what we might find if we scanned the
entire Moon...

~~~
c22
We have LIDAR scans of most of the moon.

[https://www.nasa.gov/multimedia/imagegallery/image_feature_2...](https://www.nasa.gov/multimedia/imagegallery/image_feature_2110.html)

[https://nssdc.gsfc.nasa.gov/planetary/clementine.html](https://nssdc.gsfc.nasa.gov/planetary/clementine.html)

[https://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1994...](https://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1994-004A-04)

[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201200...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120012916.pdf)

------
amriksohata
On a side, Hindus believe in 4 Yuga's or phases that go around and round in
circles, we are in the fourth one at the moment. Humans exist in all Yuga's
and there is then a mahayuga after which there is destruction

~~~
dahidahi1
After that destruction, the cycle starts all over again. It is the closest
thing to evolution formulated by the Indian rishis (scientists of their time).
It begins with (on a high level) the water based living beings (fish),
amphibians (turtle), mammal (boar), neanderthal (Parashuram), the perfect
humans (Ram & Krishna) and so on. It is quite interesting.

Another name for Hinduism is Sanatana Dharma - or the Eternal Way of Life.

~~~
yantrams
> scientists of their time

Please don't masquerade mythologocal saints/yogis as scientists. You are doing
a disservice to the accomplishments of real historical figures like Panini,
Brahmagupta etc by making statements like this. You don't have to resort to
mythological characters to feel good about the supposed glorious past.

I can understand how the tales of Dasavataras can possibly have some
allegorical references to evolution but claiming the rishis to be scientists
only serves to further ridiculous beliefs like Quantum Mechanics and
Relativity originated from Vedas, Rishi scientists developed nuclear weapons
in 10000 BC etc.

The main purpose they(Puranas (post-vedic Hindu mythology)) served was to
legitimize the Vishnu cult, get rid of the pantheon of older Vedic gods (Indra
etc.) and to counter the rise of Buddhism. Most of these stories were made up
ad hoc to suit the purposes of their times. I find them quite clever to be
honest and fascinating from literary and sociological perspectives.

Take Buddha for example. Once Buddhism and its crusade against animal
slaughter / rituals became a hit with the masses and started competing with
Brahmanism/Sanatan Dharma/Hinduism, Buddha was made an incarnation of Vishnu
and added to the Purana bloatware, while simultaneously obliterating Buddhist
monasteries and driving it out of the subcontinent.

~~~
fooker
>Please don't masquerade mythologocal saints/yogis as scientists.

What is a scientist?

Does Newton qualify as one in your worldview? He spent about half his life on
alchemy.

Will any of our scientists qualify as scientists after a thousand more years
of science?

~~~
ralfd
Newton was a mathematician, but he was not a scientist. John Maynard Keynes
opined "Newton was not the first of the age of reason, he was the last of the
magicians."

"Scientist" is a modern term and I would grant historic figures only that
label, if they (disregarding if their conclusions were right or wrong) tried
to reason about the world in a systematic fashion and according to empiricism
and logic.

~~~
aalleavitch
The modern idea of a scientist is almost purely an enlightenment-era concept,
and only represents one revision towards a better understanding of the world
out of many throughout human history.

I think your distinction is pretty arbitrary; in what way does a mathematician
not attempt to reason about the world in a systematic fashion and according to
empiricism and logic? The only real difference over time has been in our
ability to determine valid logic, our rigor in what empirical evidence we'll
accept, and our sophistication in how we systematically go about this process.
Early philosophers were attempting each of these things to various degrees,
they just weren't as good as we are now at them. Really defining the "first
scientist" is like defining the "first mammal"; the category is fuzzy and
doesn't really mean anything at that level of granularity.

------
alcover
"Ski boots are the worst. Solid plastic. They'll be around till the sun goes
supernova."

\- Douglas Coupland, Generation X

------
bitL
What if past civilizations exhausted their naturally reachable energy
deposits, like we now do with oil, so we can't even guess what did they use as
we won't find it on Earth anymore?

------
djsumdog
Would our roads would survive? Never before has humanity so dramatically
changed the planet in such a fundamental way. Roads from older civilizations
like the Romans and the Sumerians would probably erode, but our modern asphalt
is pretty insane when you think about it.

If left on the surface for millions of years, yes they would fade to nothing.
But in many locations, they'd get buried in layers of swamp and sediment. Even
if they shifted around via plate tectonics, many of our modern highway
junctions are quite massive. With 7 billion people and the insane amount of
infrastructure on our planet, surely some of that would survive if a future
civilization started digging a few hundred meters through bedrock.

How long before roads churned under the pressure of the earth into
indistinguishable small pieces of rock? Would they be gone in less than a
million years?

As a side note, this makes me think about all the world that goes into nuclear
waste burial sites, and how we're currently trying to create warnings that may
need to outlast our civilization by millions of years.

~~~
greedo
Anything made of concrete would probably be gone in less than 1K years. Even
granite slabs don't last very long...

~~~
credit_guy
What about the Colosseum? The Pyramids are also in quite good condition. And
the ruins of Gobekli Tepe are more than 10k years old.

~~~
Udik
It seems to me that commenters in this thread keep taking the durability of
materials under average conditions as a measure of what traces would be left
after millions of years. By the same standards, we shouldn't have a single
bone or trace that anything that lived more than a few hundred years ago.
However, when there is a very large amounts of specimens, some happen to be
preserved in exceptional conditions or undergo transformations which let them
survive or leave traces, direct or indirect, for tens or even hundreds of
millions of years.

------
Joeri
There’s a book series by julian may that deals with a time travel device being
invented to 6 million years ago where to everyone’s surprise an alien
civilization is ruling the planet.

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

------
brandonmenc
An underrated sci-fi book based on this premise is _Toolmaker Koan_ by John C.
McLoughlin.

~~~
Wildgoose
Author of "The Helix and the Sword"? Just ordered a copy.

------
mattnewport
Could something like Fort Knox survive as an unusually concentrated deposit of
gold?

On a larger scale, would a city like New York leave an area with an anomalous
distribution of elements of a similar nature to what we see where there has
been an ancient meteorite impact?

~~~
jlg23
If you look at it in just the right scale: definitely.

The problem is to find the exact spot to look at. Even today, geo-exploration
is mostly a joke: drill where experience tells us to. New hotness: Have AI do
inference from formalized experience.

There could be a thousand former fort knoxes or NYCs and we, with our methods,
only have a snowball's chance in hell to find any.

------
erikb
There are so many open questions out there. For instance, how do we know that
the bacteria don't form an intelligent species, too? What if there's something
else out there, that just is not intelligence but just like intelligence
enables a life form to advance as far as we have and beyond?

Even our understanding of the beginning of the universe is just a model, an
idea. It's not like we have proof.

From time to time it's quite important to remember how vast the knowledge is
that we don't possess in contrast to the one we do.

------
spraak
A very interesting and difficult part of these kinds of questions is that what
we look for has to be very carefully considered. If we look for just what we
know now, we might not find the evidence, even if it's there. One of my
favorite examples of this is radio waves. Try telling someone in the 1600s
about them; it seems unlikely they'd believe you--but yet they've existed
forever (?) and e.g. lightning and other natural forces can generate them.

------
mixmastamyk
Theres a cool ST Voyager episode about this, the species gets labeled the
Saurians. They are extremely powerful and dogmatic, due to living in space for
millions of years.

------
hudathun
The Mediocrity Principle applied to civilisations would suggest we're not the
'special' first one here. We thought we were special in lots of ways that
we've since had to abandon

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

------
ganzuul
Would be fun to find artifacts on the moon.

~~~
alxlaz
I've read about such events and I am a little concerned about their unfolding
along with the quickened pace of development in the AI field.

If any artifacts are discovered on the moon, I sure as hell ain't boarding
anything called Discovery One, ever.

------
interfixus
Surely, we'll leave a few satellites in high orbit, and presumably the raptors
would have done as well.

Also, their sitcoms would by now have penetrated a decent bit of intergalactic
space, and attracted some attention. Because if it happened twice on this
planet, the universe at large would be teeming hi-tech societies.

~~~
palunon
Or not.

Maybe the apparition of multicellular life is super rare, but once it has
happened hi-tech societies are common.

------
Robotbeat
I imagine we’d find a LOT of stone tools before the civilization developed
higher tools and then collapsed. Africa is littered with them deep in some
areas (due to a million years of humans), and they’re on all continents but
Antarctica.

------
mdekkers
_It’s not often that you write a paper proposing a hypothesis that you don’t
support._

Come work in corporate IT, we do this all the time :)

------
ohiovr
Long lasting nuclear waste products could survive for a few million years that
may have no natural occurrences.

~~~
candiodari
But there would only be, say 2000 sites of them. Each 10x10 meters in size,
buried deep underground. Good luck finding them.

------
shams93
There's no real evidence for this in archeology. We would find little statues
of these non humans. we have highly intelligent non humans like dolphins and
octopi but they don't have the ability to make fire despite being extremely
intelligent, flippers and tentacles are quite limiting.

~~~
api
Read the other posts in this thread. None of that would remain after tens to
hundreds of millions of years.

------
21
The article asks about detecting an industrial level civilization.

But what about a former civilization which only rose to the level of the Roman
Empire lets say? Could we detect that?

~~~
newsbinator
There may be a goldilocks period for detecting civilizations:

Too early and they never industrialized at scale, so there's little to detect.

Too late and they became a stage n civilisation and are now the substrate of
our universe, so there's nothing to detect.

~~~
aalleavitch
They Sublimed, Culture-universe style.

------
jngreenlee
The lizards...and some say they still are with us! /s
[https://en.wikipedia.org/wiki/Triune_brain](https://en.wikipedia.org/wiki/Triune_brain)

------
antonvs
Betteridge's Law says no. But it's fun to think about.

~~~
ajross
Heh, this is a rare situation where this doesn't apply. The point to the
leading question in the title is clearly not to refute it, it's to point out
the idea that we _can 't refute it as well as everyone expects._

The point is more "Yeah, there's no evidence for this. But if there was, it
would be very easy to miss."

~~~
antonvs
> Heh, this is a rare situation where this doesn't apply.

The law states, "Any headline that ends in a question mark can be answered by
the word no."

Presumably you're a believer in the lizardmen.

