11
$\begingroup$

Let's say there was a society of lizard people that were highly intelligent, about 50 million years ago. They built permanent structures and developed up to an industrial tech level; they had iron bridges and skyscrapers. They used electricity, had massive telephone lines underground, and had landed on the moon. Then an asteroid hit and wiped them out.

Would there be any traces of this lost civilization that humans with medieval tech could identify? Is it possible for them to even know they had existed?

$\endgroup$
15
  • 11
    $\begingroup$ Medival humans had no idea how old the human civilization was... $\endgroup$
    – AlexP
    Apr 16 at 11:49
  • 2
    $\begingroup$ Even obvious fossilized plants that were found even centuries after what we consider medieval were explained away. Ex fossilized ferns were thought to have grown in the rock, not just by joe pesant, but scholars. They may be aware of the artifacts if they survive, but what they would surmise what they were would be as random as anything you could imagine. $\endgroup$
    – Gillgamesh
    Apr 16 at 12:38
  • 5
    $\begingroup$ You don't really say what the peak population was of these people. nor how long these people lived. population of 10 M over 100 k years won't leave as much footprint as 1 G pop over 500 k years.That is you need to decide what is the population curve over time. The fossil footprint is proportional to integration of that population curve. Compare with dinosaurs that had millions of pop over many tens of millions of years. $\endgroup$ Apr 16 at 20:05
  • 2
    $\begingroup$ A civilization capable of landing in the moon can't be wiped out by a meteorite, unless it is an almost complete destruction of the planet. A meteorite such as the one that's credited with the extinction of dinosaurs would cause mass casualties, but we'd survive. Even if cultivating plants with articifially iluminated crops and hydroponia could only sustain a few hundred million humans on the planet, rather than billions, we would carry on and rebuild. There are very few natural disasters that could wipe us completeley, and most of them would also erase any material remains as well. $\endgroup$
    – Rekesoft
    Apr 17 at 9:37
  • 3
    $\begingroup$ Zuckerberg left the chat $\endgroup$
    – Alastor
    Apr 17 at 12:19

7 Answers 7

16
$\begingroup$

No

To put things in perspective, 50 million years ago the continents were not even in their current positions. India was halfway between Asia and the linked Australia-Antarctica. (South America was still cozy with Antarctica too, but broke it off a bit earlier than Australia.) Mountains, rivers and other major terrain features form, disappear or change completely over that sort of time scale.

Let's be really conservative (by an order of magnitude or so) and assume that everything is really calm and peaceful and only 1 mm of erosion (from chemical interactions or friction) and/or burying in blown debris occurs every 10 years. Over 50 million years, it means that everything has been eroded down by 5 km and/or buried by 5 km of debris - given that we don't have structures that are 5 km thick or high, there's nothing left. No 21st-century-equivalent civilisation's artefacts can survive the erosion or be expected to be visible if buried. (In addition to being really conservative, this also ignores tectonic events that may change whether things are on land, kilometres underwater or encased in lava.)

To cover a point from another answer, any underground structures will have collapsed and been ground to powder by normal, slow movement of the earth. Even if, somehow, some artefacts survived deep underground, medieval people were not equipped for deep underground expeditions. Without machinery for ventilation and sources of illumination that would not consume the oxygen they needed to breathe, they were limited to very shallow explorations underground (and still had horrendous fatality rates when mining). There is effectively zero chance of subterranean medieval activities locating any recognisably intact artefacts from 50 million years earlier.

$\endgroup$
3
  • $\begingroup$ As a sidenote, the Roman Gadara Aqueduct has one section, 66 miles long, under a mountain. But this doesn't change the fact that the odds of them finding an artifact are almost nil, and even if they did, they'd probably just explain it away with a Biblical explanation. $\endgroup$ Apr 18 at 4:40
  • 1
    $\begingroup$ @MooingDuck: How old is that mountain? I don't know about Syria, but in Europe the landscape was very drastically remodelled during the last 50 million years, with huge mountain chains rising, entire seas drying up, hundreds of meters of sediment being deposited (and quite often folded afterwards) and so on. $\endgroup$
    – AlexP
    Apr 18 at 9:10
  • 2
    $\begingroup$ far less than 50m years My point was rather that ancient peoples were surprisingly good diggers. But that doesn't change the fact they wouldn't find or recognize artifacts. $\endgroup$ Apr 18 at 17:19
10
$\begingroup$

Most likely NO.

The Silurian hypothesis argues that even with modern tools it would be extremely hard to detect traces of a relatively short-lived (~thousands of years) technological civilization millions of years ago.

Fossils are unlikely to survive in any noticeable number, because conditions for fossilization are rare - even after extensive mining and fossil searches, we typically observe just a single or a small handful of fossils of any species, despite most species existing for millions of years.

Only good sources of evidence of such a long-gone civilization would be in things like climate record, isotope compositions and possible artifacts in space or on other celestial bodies. All completely out of reach of medieval tech.

Things would probably be slightly more optimistics if the civilization kept running for tens of millions of years. This could maybe be enough to leave non-trivial fossil record scattered over a range of geological strata.

There's a nice video by PBS on the topic: https://www.pbs.org/video/what-if-humans-are-not-earths-first-civilization-wju7l3/

$\endgroup$
9
$\begingroup$

Yes, because mines and underground buildings would leave fossils.

Fifty million years is enough time to break down most things. Some plastics would survive, but fifty million years of weathering would break them down into microplastics. The main obvious evidence would be mines and other underground things. Sediments would wash down and fossilize the people and machines of the time, and miners would discover old and strange creatures down below.

They'd pass into legend and myth as dinosaurs and dragons and monsters, strange giant creatures that dwelled below the earth used to scare children to sleep.

$\endgroup$
3
  • 8
    $\begingroup$ The question is about medieval humans. Fossils were considered ludi naturae. There was no knowledge of geology, so that whatever they found would be, shrug, stuff you find in a mine. $\endgroup$
    – AlexP
    Apr 16 at 12:21
  • 4
    $\begingroup$ @AlexP Only when science could not be resolved with the Bible. In most cases, they would believe whatever explanation lines up with and supports the Biblical narrative. So, if they found evidence of a very different and old civilization, they might assume it is evidence of the Nephilim from before the great flood. $\endgroup$
    – Nosajimiki
    Apr 16 at 14:24
  • 7
    $\begingroup$ Claims that microplastics last forever are false. They only last about 100 to 1,000 years before they break down into metabolizable hydrocarbons like methane and ethylene. While this is a long time at the scope of human lifespans, plastics are very short lived at geological timescales. $\endgroup$
    – Nosajimiki
    Apr 17 at 13:20
5
$\begingroup$

Satellites

I'm aware that this theory has more holes than merit, but I just like this idea, maybe it will spark some more answers

If the ancient lizard did land on the moon, they likely have the technology to launch satellites into the orbit. Geosynchronous orbit is far enough to not experience atmospheric drag and not very difficult to reach (we launched first GSO satellites three years after sending first satellite ever). 50 million years is a very long time, even for cosmic scale, but let's assume at least one satellite did manage to stay in orbit without getting knocked off by random meteor passing by.

While some satellites are big enough to be noticed with naked eye, we need to see them in detail to tell that they are not natural. First telescope we know was made in 1608, but optics and lenses were known since ancient times, so it's not unlikely to say that someone discovered the idea a bit earlier.

Now, for the holes in this theory: I don't know how stable satellites can be, but 50 million years seems highly unlikely. Also, simple telescope might not be powerful enough to tell that this object was man- (or lizard-) made. And even of both of these happen, it would be impossible to deduce that it was lizards who put the satellites in orbit - at best, you could suppose it's an ancient human civilisation or aliens. And even then, you would struggle to explain that idea to other people - a non-natural object floating in the sky? Utter madness.

But maybe, just maybe, it would spark the idea and myths of ancient lizardmen who travelled the skies would be told to children as bedtime stories...

$\endgroup$
5
  • 2
    $\begingroup$ Orbital decay will likely be measured in a few hundred to a few thousand years. Disposing of a geosynchronous satellite by moving it slightly outward into a graveyard orbit does significantly increase that but I don't think it increases it by the orders of magnitude needed to last 50 million years. $\endgroup$ Apr 17 at 15:33
  • 2
    $\begingroup$ @MichaelRichardson I think it's at least not _im_possible, it just requires doing so intentionally. LAGEOS-1, for example, has a projected orbital stability of ~8.4 million years, and it was specifically designed for that purpose, with a Voyager-type engraving on it portraying (among other things) the current continental layout and the projected continental layout by that point. I could at least theoretically imagine a similar satellite with an orbital lifespan in the 50 million year range, maybe even something constructed intentionally like LAGEOS-1. $\endgroup$
    – Idran
    Apr 17 at 21:41
  • 4
    $\begingroup$ @Idran, for an object in geostationary orbit, the decay time is so high we can't predict it -- it's probably in the high hundreds of millions of years, and things like gravitational perturbations from Jupiter become important. $\endgroup$
    – Mark
    Apr 18 at 2:47
  • 1
    $\begingroup$ Relevant physics analysis: space.stackexchange.com/a/37597/894 $\endgroup$
    – Zags
    Apr 18 at 15:01
  • $\begingroup$ Fascinating, especially the fact that geostationary sattelites are so very high up they might last for billions of years - but "identify"ing them as such, for a medieval society? They might be able to spot them as fast-moving dots of light, but I think "that's one of the angels watching over us" would be a more likely conclusion than "oh, there was an advanced civilization of lizardpeople here before us", I think $\endgroup$
    – Syndic
    Apr 19 at 5:42
2
$\begingroup$

Well consider that we consider "Ancient Egyptians" well, Ancient, and they're about... 6000 years old?

As others have said, with extreme amounts of time it's practically impossible, but just because it's "ancient" doesn't mean it has to be millions of years old. If you make them such that their remnants are very distinct from the current civilization, and it's just long enough for it to be buried, but still shallow enough that mining could allow you to find them, then probably yes

$\endgroup$
2
  • $\begingroup$ Finding half a skyscraper could be very impressive, and point towards an older civilization. I expect however that, most people living in those times to start pointing at the sky an declare that some god (whom they might invent on the spot) did it. $\endgroup$
    – vinzzz001
    Apr 18 at 10:02
  • 1
    $\begingroup$ Well ancient beliefs posit that "gods" have, basically, a civilization of their own with their own bureaucratic apparatus and such. In a way, it's not completely wrong $\endgroup$
    – Raestloz
    Apr 19 at 2:38
0
$\begingroup$

No. There would be technological fossils, but they would not be interpreted as such, or they would be assumed to be much younger than their actual age and created by their ancestors at a remove of historical not geological time.

I am, of course, assuming that scientific geology arrives at the same point in technological development as here in the real world. The point at which technological fossils here would have been found, scrutinized, and identified as evidence of a civilisation tens of millions of yours ago, corresponds to the early Victorian era. (Post industrial revolution, steam engines widely used, research into electromagnetism under way but not yet applied to technology).

You might be able to hand-wave a different order for scientific advancement which brought scientific geology forwards into the medieval era. Unlike many other sciences, geology needs only simple tools and the scientific method. Here, geologists had worked out that the Earth must be at least a billion years old, while physicists insisted that the sun could not have been "burning" for more than fifty million years. Unusually, the physicists were wrong! Both, of course, were bitterly opposed by biblical literalists in the churches (who in earlier times, would probably have burned the "heretic" geologists at the stake).

Technological fossils would mostly be either ceramic artifacts (artificial metamorphic rocks), or metal artifacts that created voids in rock when they dissolved, later filled with some sort of mineralization by groundwater. Eventually they might even find a piece of once lost gold jewellery (gold alone of the metals, would not dissolve away, and diamonds really are pretty much forever).

$\endgroup$
0
$\begingroup$

The oldest dinosaur fossils are five times older (Eoraptor, Herrerasaurus, and Staurikosaurus), so fossils of this ancient civilized race should be possible to find (I cannot believe there were as many large dinosaurs ever as there are now humans on the Earth). The size of skull, etc would have show these beings were likely sentient.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .