Is it possible... [ancient astronauts]

I’ve always been fond of this possibility, given how short the lifetime of human civilization has been, and the lack of geologic durability even our greatest inventions and creations have when we’re talking tens of millions of years worth of the elements scouring clean the surface of the Earth.

Alas, the one thing that I can’t ever seem to get past was raised above: resource exhaustion. Any sufficiently advanced species would have exhausted / processed a tremendous amount of resources. All signs instead point to humanity being the first advanced species here.

Dusts off Devil’s Advocate hat

In the short term, yes. But the Earth’s crust isn’t static. Over a billion years, what was the surface would be turned under or even submerged and land that was underwater would be hundreds or thousands of feet above sea level.

While caving/hiking in Missouri I’ve found pieces of fossilized sediment with all sorts of imbedded shells in streambeds that are now a thousand feet above sea level.

There are only a few locations where we’ve gotten over a mile into the ground. Drag a few glaciers across those sites and no one will ever know we were there.

A great many people post questions here rather than just googling it because the ensuing discussion is more enjoyable than the eventual answer (yes, no or maybe in this situation).

That’s what GQ is for.

But there are also some places where we have surface rocks that are billions of years old. Just to the northeast of me in Minnesota they have some exposed rock that is dated to 3.8 bn years.

I think this is the bottom line. Any event sufficiently catastrophic to have completely wiped out all trace of a global technological civilization would also presumably have left a very clear geological signature, and there’s nothing like that in the past couple billion years. Before that time, we have no evidence of any life at all except for the most primitive sort. Thus it seems highly unlikely that Earth has harbored any other species that achieved a widespread civilization with a technology comparable to our own. Now, an intelligent but nontechnological species is a different kettle of fish, or dolphins, or whatever.

It’s an interesting thought experiment to ponder what the remains of our civilization would look like following a K-T event.

I went to the California State Fair yesterday and they had a Dino exhibit. One of the Dinos, I forgets the Species had the largest brain to body ratio. The plaque said it was probably the smartest dinosaur and said it was on par with modern dolphins. It than speculated if they Dinos were not taken out by the K2 event than this species might have evolved to be a reptilian hominid, and the dominate species.

Remember intelligence does not equal technology. Dolphins are smart as shit but why are they not the top species? Well they do not have fingers. It would be hard to make tools, the fire thing might be a drag too.

But it did make me think of this very question…What if another intelligent species did exist. Neanderthals were not THAT stupid FWIR, they just happened to die out for some reason. What if they took over instead of humans?

Or even better what if we co-existed well enough that earth had two sentient species? My guess is we would probably use them as slaves early on and they would always be considered 2nd class because of their sub intelligence

Probably nil but we have crap on the moon, unless both were taken out. But we have crap on mars to. What if our rover ran into another one that no other country sent up…holy crap someone recommend me some books on this theory!

Worked flint or other stone would have survived. And for anything we recognize as intelligence to have developed around the dinosaurs some sort of stone tool would be found somewhere in the fossil record with them. For 100% of it to have been on land now underwater (as some propose) stretches things quite a bit. The thought of sapient beings and dinosaurs together is cool but its so close to impossible that you can get away with calling it so most times.

The best chance would for something to have developed and then be destroyed in a planet-wide extinction of ALL life that resulted in the start of what we currently recognize as “recognized time”.

Its not a K-T event but the series “Life After People” is interesting. And not a bad place to start pondering the question you propose.

But have they been *on the surface *throughout this period? Maybe they were deep underground until softer rocks above them were eroded away. So 3.8 billion years old, but only on the surface for a few million years.

Or they would have used us as slaves and considered us 2nd class because of our lower intelligence. There’s not actually any evidence that we’re smarter than Neanderthals. All we know is that we managed to outcompete them, but that could just as easily mean that we were more aggressive, or prettier, or just plain lucky.

Really I thought we could tell by skull sizes that we were the smart ones and they were the strong ones

Technically - Richard Nixon, Buzz Aldrin and Niel Armstrong - the only identifable human names… oh, and Kurt Waldheim on one of the Voyagers. Great men until the end of time…

Neandertals had larger brain cases than modern humans. So while we have evidence that modern humans are more inventive–the Neandertal toolkit was stable for a hundred thousand years–it’s likely that Neandertals were as smart as we are, just in different ways. For example, we have larger frontal lobes, they had larger occipital lobes. What that would have meant psychologically is unclear.

Harry Turtledove wrote a collection of stories title “A Different Flesh”, which postulated that Homo erectus survived in the Americas, and so European discoverers found tribes of subhumans rather than Indians. Interesting book.

Next, it is untrue that any dinosaur species had a brain the size of a dolphin’s. A bottlenose dolphin has a brain larger than a human’s. Yes, there were small theropods with relatively large brains. But that’s relatively large for a dinosaur, not compared to mammals.

Lastly, glass and ceramic artifacts can last for billions of years. When far-future archeologists dig up our civilization, they’ll find middens of empty coke bottles and layers of shattered window glass long after metals have oxidized away.

I wasn’t stating the brain was as big as a dolphins but the claim was made that this Dino was as intelligent as a dolphin

How spread out did Neanderthals get? If they were as widespread as humans I cannot think of how they could have died out other than a virus. I simply do not see lack of resources as a reason they died. The planet had to been flourishing with all kinds of plant and animal life back than compared to now.

We had better tools than they did.

We had better tools that fossilized well.

Last I checked, the current theory was that we intermarried with Neanderthals, and thus they didn’t really die out. But that would imply we, not they, had the stronger genes.

The evidence suggests there was some limited interbreeding but it wasn’t enough to “assimilate” Neanderthal. Listen to the 2nd half of Michio Kaku’s 7/6/10 Exploration Podcast. He had Carl Zimmer on to discuss this very topic.

Yeah, but our amount of crap put into in space divided by the volume of space it occupies is pretty good approximation of zero.

If some ancient earth civilization managed to send a few probes to the other planets and into space a few billion years before us, IMO our chances of running across it today are virtually zero. And even THAT assumes the probes dont degrade to something nearly unrecognizable or get destroyed (which I think they well could) in a few BILLION years.