Can We Be Sure We're the First Industrial Civilization on Earth?
In a new paper, Gavin Schmidt of the NASA Goddard Institute for Space Studies and Adam Frank from the University of Rochester ask a provocative question [open, DOI: 10.1017/S1473550418000095] [DX]: Could there have been an industrial civilization on Earth millions of years ago? And if so, what evidence of it would we be able to find today?
The authors first considered what signs of industrial civilization would be expected to survive in the geological record. In our own time, these include plastics, synthetic pollutants, increased metal concentrations, and evidence of large-scale energy use, such as carbon-based fossil fuels. Taken together, they mark what some scientists call the Anthropocene era, in which humans are having a significant and measurable impact on our planet.
The authors conclude, however, that it would be very difficult after tens of millions of years to distinguish these industrial byproducts from the natural background. Even plastic, which was previously thought to be quite resistant, can be degraded by enzymes relatively quickly. Only radiation from nuclear power plants—or from a nuclear war—would be discernible in the geological rock record after such a long time.
Anonymous Coward says "I told you so!" and starts babbling about megaliths.
Related: Homo Sapiens Began Advanced Toolmaking, Pigment Use, and Trade Earlier Than Previously Thought
(Score: 2) by frojack on Thursday April 19 2018, @08:46PM (7 children)
But fragile dinosaur eggs do! ???
Rectilinear metal rich veins inside rectilinear carbonate rock structures sealed inside of eroding lava flows are going to be pretty easy to detect. Especially when people start mining those rich metallic ore bodies and notice the appear lattice shaped.
No, you are mistaken. I've always had this sig.
(Score: 2) by urza9814 on Friday April 20 2018, @12:02AM (6 children)
How many dinosaurs ever lived? Probably billions. How many eggs did they lay? Many, many billions certainly. How many of those have we found? Very few.
It takes a very specific set of circumstances for something like that to be fossilized. Tar pits are a common example, as something can fall into the tar and be buried and free from oxygen, scavengers, and bacteria. You think technological societies are building their structures on these tar pits? Probably not. They're going to look for stable, fertile land, which also happens to be places where decomposition tends to occur pretty quick.
Preservation can occasionally happen by accident...we've got human remains mummified by deserts, or frozen in ice, or embalmed by bogs...but it's pretty rare, and it generally occurs in the kinds of places that a technological creature would try to avoid...
(Score: 1) by khallow on Friday April 20 2018, @12:19AM (4 children)
(Score: 2) by urza9814 on Friday April 20 2018, @03:01AM (1 child)
The point of my post was that they wouldn't.
(Score: 1) by khallow on Friday April 20 2018, @04:28AM
Another example is our habit of placing cities in river deltas and estuaries. These are great places for burying artifacts and trash that falls into the river. The continental shelf which these rivers flow out to will be around for tens of millions of years.
Finally, on that same subject, every city we have ever created buries stuff. A lot of it is merely tearing down what was there and building on top of the old. And these layers can get rather thick. There are a number of standard burying processes associated with civilization. It seems reasonable to expect those to hold for any pre-human industrial civilization as well.
(Score: 2) by TheRaven on Friday April 20 2018, @10:34AM (1 child)
We have been a technological civilisation for, at most, a thousand years or so. If we were to leave artefacts around at the same rate as the Dinosaurs, there would be so few in the world that a civilisation that arose a few million years after us would likely miss them all.
Most of what we have found are not dinosaur eggs or bones, they are fossils. These form only in a few very specific circumstances. In particular, they require that the thing that is being fossilised be quickly covered in rock so that its shape is preserved. Again, most of the time that something like this happens to humans (or valuable human creations), we try to excavate it and don't leave fossil records behind. If our civilisation were to collapse, the majority of what we'd leave behind would be things that were standing at the end. Anything exposed to the weather would be unlikely to survive, so that limits you to things that are already buried in geologically stable places.
sudo mod me up
(Score: 1) by khallow on Friday April 20 2018, @02:00PM
We also have only scratched the surface in more than one sense. There's orders of magnitude more stuff down there that what we've found.
(Score: 0) by Anonymous Coward on Friday April 20 2018, @03:28PM
You *almost* got it here, but then missed it completely...
We're talking about a possible *industrial* civilization. How many structures would they have built? How many screwdrivers would they have had? Screws? Arrowheads?
How many of those have we found? Zero.
Sure, anything can be destroyed by millions of years of erosion. But, not *everything*.