Long term evidence of civilization.

[xilman]

Originally Posted by ewmayer

If it was populated by creatures with bony skeletons which built habitable structures and/or stone monuments, no. Because we already find evidence of those things for lots of protohumans who lived in small scattered tribal bands, whose key technologies consisted of fire and stone-and-wood-based tools, going back millions of years. "Civilization" implies much larger aggregates of intelligent creatures with significant social organization, and thus, ability to shape and exploit their environment and engage in far-flung economic-trade relationships in ways which leave unmistakeable long-term traces.

We should be careful to draw distinctions between intelligence, civilization and high technology.

Taking just our own species for an example, we have been intelligent for many millennia and civilised (in the sense of building cities, efficient information systems, sophisticated economys, etc) for about 5000 years. We've had high technology for about 300 years. Biological, nuclear or nanotechnology warfare could wipe us out in short order. Our existence would be obvious for 10K years perhaps 100K. After 100M years it would take a great deal of effort by high-tech supported paleontologists to find suggestive clues of our existence and that evidence would be highly disputed. Extraordinary claims require extraordinary evidence.

For all I know, there could have been a civilization in existence 66.5M years ago but they didn't build their industrial base and planetary defence systems soon enough.

[xilman]

Originally Posted by Prime95

Am I the only one that finds this thread to be utterly depressing? No matter what accomplishments mankind achieves they will be obliterated in relatively short order.

In the long run, everything is dead.

If stars burning all their hydrogen doesn't get you, proton decay will.

Welcome to the real universe.

[retina]

Originally Posted by xilman

For all I know, there could have been a civilization in existence 66.5M years ago but they didn't build their industrial base and planetary defence systems soon enough.

I expect that would require a (much) larger brain case than we currently see in the fossil evidence.

[tServo]

Originally Posted by Prime95

Am I the only one that finds this thread to be utterly depressing? No matter what accomplishments mankind achieves they will be obliterated in relatively short order.

In "Annie Hall" Alvy Singer agrees with you:

https://www.youtube.com/watch?v=5U1-OmAICpU

[masser]

100M was a good choice. Humanity, if it survives in some form that long, will have seen a lot of cool stuff:

Timeline of the far future

[Till]

My best guess: Genetically engineered weeds.

"Unkraut vergeht nicht" (bad weeds grow tall)



Other ideas: Nano particles, human shaped diamonds, maybe some human made chemicals will never leave the athmosphere...


I also like the proposals made before of long lasting radioactive elements or things put onto the moon.

[xilman]

Originally Posted by retina

I expect that would require a (much) larger brain case than we currently see in the fossil evidence.

You may very well be right.

However, I point to the abilities of African Grey parrots as an example that it doesn't matter how big it is, it's how you use it that's important.

[rogue]

We are in the midst of the Holocene Extinction. I expect that in 100M years that will be obvious in the fossil record. The question is if the intelligent species roaming this planet in 100M years will be able to determine that another intelligent species caused it.

[kriesel]

Originally Posted by masser

100M was a good choice. Humanity, if it survives in some form that long, will have seen a lot of cool stuff:

Timeline of the far future

There are some discouraging or ominous entries there, especially after a half billion. The good news is the estimates for complete extinction of terrestrial life have substantially lengthened in the past few years. Earth eventually resembles current day Mars. The occupants of Titan if any would have little reason to look for signs of previous life on Earth.
On the scale of 4 billion years, I think none of Earth's surface avoids getting cycled through the mantle. https://www.sciencedirect.com/scienc...125?via%3Dihub

[xilman]

Originally Posted by rogue

We are in the midst of the Holocene Extinction. I expect that in 100M years that will be obvious in the fossil record. The question is if the intelligent species roaming this planet in 100M years will be able to determine that another intelligent species caused it.

Undoubtedly obvious. As obvious as the previous ones.

The question is the really interesting part.

[pinhodecarlos]

Paul, if you let me amend, your K is lower case. Take care.