Traces of past non-human civilizations on Earth

[Michchamp]

Article you may or may not find interesting.

Our industrial society is only ~200 years old, but the article considers some of the indicators we might leave in the geologic record. The different makeup of CO2 isotopes by burning so much carbon, nitrogen layers (from our use of artificial fertilizers), and ground up, compressed and heated plastics (whatever that would look like in millions of years) from all the plastic trash we make and throw around.

But assuming we're killing ourselves off sooner than later, it's unlikely our civilization will leave much of a geologic trace for any future Earth civilization to discover. When we find traces of geologic events in the Earth's rocks now, they're usually around 100,000 years long.

even 1,000 years of human industrial civilization (if we make it to 2800) is only a blip in the timescale.

assuming our experience isn't unique, it's likely other previous industrial societies would kill themselves off quickly as well. so it would be very difficult, given our current methods of geological study, to detect any trace of them.

man! we're just not very significant when we take a long term view of things.

 

[Michchamp]

I realize now my thread title might have gotten UFOlogists, History-channel theorists, and other such nutjobs and idiots hope that someone dug up an "ancient alien" or something. For that, I apologize. my actual post was not nearly that exciting.

 

[Gulo Blue]

man! we're just not very significant when we take a long term view of things.

It's tough to appreciate the time scales. This chart does a nice job of showing how tough it is to think about a 20,000 year chart, and that's just a blip relative to the scales this article is considering.

https://xkcd.com/1732/

 

[tinselwolverine]

The bones in the picture look like regular old human bones to me.

 

[Michchamp]

The bones in the picture look like regular old human bones to me.

yeah, WTF? misleading too. a pic of rock strata in a cliff face would be more appropos, given that no one found anything, it's all theoretical

 

[Michchamp]

It's tough to appreciate the time scales. This chart does a nice job of showing how tough it is to think about a 20,000 year chart, and that's just a blip relative to the scales this article is considering.

https://xkcd.com/1732/

yeah, I've seen that before. It really hammers home how serious & extreme the temperature change is.

I just read an article today that current events in the Antarctic are proving another climate change hypothesis - can't link to it, but it was in the WaPo today.

basically the melting of ice caps will stall ocean currents, creating ANOTHER one of those "feedback loops" that leads to warmer waters remaining around the ice caps and glaciers, melting them even faster.