If we weren’t the first industrial civilization on Earth, would we ever know?
technologyreview.com
technologyreview.com
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.
Does this assume every continent will have been under a glacier within a few tens of millions of years?
The glacial maximum with the current distribution of continents leaves most of Earth's land uncovered by glaciers: https://en.wikipedia.org/wiki/Last_Glacial_Maximum#/media/Fi...
> although we are likely triggering the next ice age a little early with our environmental impact
Wasn't it supposed to suppress it? https://www.pik-potsdam.de/news/press-releases/human-made-cl...
https://www.newscientist.com/article/2187838-when-humans-are...
So our fossil fuels could be the remnants of some long gone civilization?
Humanity has covered effectively the entire planet with items, human bones, and structures that will fossilize and make it pretty clear that an intelligent species was present.
The SURFACE of the Earth might not show it, but the fossil of the human femur with a knee replacement, or the plastic GI JOE that fossilized in mud, or the fossilized remains of any number of concrete structures around the world would clearly be visible with a little digging.
Many continents will undergo subduction, others will be flooded, or covered in glaciers, but there will be some areas that endure without much disruption.
I suppose that's not terribly useful when looking at mars though :P
Imagine that biologic creatures evolve over time long enough to develop, birth, and disperse AI out into the greater universe - and collapses after doing so. it takes a very long time for another civilization to evolve to the point that it spawns another AI form into the universe, and all remnants of the prior are gone.
Gah - I just mean I enjoyed the thought experiment of his statement.
If you are not aware, Elon said this on his appearance on Joe Rogan.
[0] https://www.mit.edu/people/dpolicar/writing/prose/text/think...
Maybe that's where we're getting all that oil from, prehistoric Silurian landfills.
https://www.sciencedirect.com/science/article/pii/S0025326X1...
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.
Do you realize what it would mean if we'd stop using all the things that can be harmful when used in certain ways?
It's a nice headline, though.
It is true, it will require a significant recalibration of our current methods. But engineering challenges are fun, interesting, and beneficial. The chance to improve our survival and give ourselves the chance to thrive.
Why turn down this opportunity for the sake of empty pedantry?
Despite that threat, the benefits of stepping out of bed are unquestionably worth it. When done properly.
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.
Our ecosystems will collapse well before we change our cancerous existence on this planet.
It's also worth nothing that several billion years from now, the Sun will turn into red giant and the Earth's atmosphere and surface will be vaporized and left as a sterile rock over tens of billions of years. That is, unless we manage its supply of H/He by managing its fuel from burning up too quickly, which could extend the life of the Sun by several to ten billion years. Star fuel management is a difficult but necessary problem for advanced species to solve.
I imagine that's not necessarily true. It may be that advanced civilizations harvest energy from stars, but live in interstellar space ships (which would also explain why we can't spot evidence of them).
It's not like we can miracle up another Earth or go to another solar system anytime soon. Our best bets are to preserve what we have and have a look at the moon, Mars, etc.
1: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
Actually, it might be. One solution to Fermi's Paradox is the idea that we can't see other alien species because they're hiding from potential predatory alien species. Hiding in the vastness of interstellar space would in that scenario be a very good move.
...or just move to Mars.
...or just move to a swarm of space stations.
...or just transcend to and merge with the AI.
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.
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.
I guess the most pressing evidence is that nobody used the fossil fuels before us (at least in large quantities), and a lot of it is from the time that plants first colonized the dry soil.
If somebody got it before us, they must have got very little of it.
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.
Maybe just the geo-sync ones, but I imagine anything closer will decay in “relatively short order”.
https://space.stackexchange.com/questions/5583/can-an-artifi...
Low-Earth orbits will decay over periods ranging from years to millennia, based on residual air resistance.
Those effects are minimal in geosynchronous orbit, though there's still some residual atmospheric drag which might be significant over millions to billions of years. The period under concern is roughly 5 billion years, at which point the Sun will have ballooned to a red giant, enveloping the Earth. (Increased solar radiance, as well as various cycles and changes on Earth will likely have long made it uninhabitable by life within the next 800 million years or so.)
Other effects include solar wind, possible interactions with the Earth's magnetic field, precessional effects caused by the Earth's axial tilt and irregular geometry (to use that word in its literal sense), as well as gravitational perturbation from the Moon and possibly other bodies within the solar system.
There's a slight possibility of impacts, though those would be highly unlikely -- space is big, as Doug said, and satellites tiny. Even the Earth only gets wallopped every few tens of millions of years. Though any such impacts might create a sufficient debries field within the orbital zone to affect other satellites. The Geostationary band itself is quite narrow, and preferential placement is above the equator, which would focus placement for potential interaction.
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
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://www.livescience.com/3542-oldest-surface-earth-discov...
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.
During the Precambrian era, the Earth's day was ~21 hours long, and a geostationary orbit would have been about 32,265 km rather than 35,787 km today.
So the satellites might not be precisely where we're putting them, but:
1. We'd all but certainly spot them.
2. The elevation / orbital period itself would give a very strong indication as to when the civilisation had existed.
https://blogs.scientificamerican.com/guest-blog/natures-nucl...
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)
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.
Interesting idea and covered many times before on HN including at the time:
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.
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.
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.
What about fossils from that era
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.
Any chance such books already exist?
and many others :)
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.
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...
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.
Also the Silurians from Doctor Who (and the 'Sea Devils', also from Doctor Who because of an IP licensing dispute)
https://en.m.wikipedia.org/wiki/The_Ice_People_(Barjavel_nov...