Is it possible... [ancient astronauts]

[Peter_Morris]

I read somewhere that when the pyramids at Giza have eroded to nothing, Neil Armstrong’s footprints will still be on the Moon.

[billfish678]

@Peter_Morris

I read somewhere that when the pyramids at Giza have eroded to nothing, Neil Armstrong’s footprints will still be on the Moon.

Most very likely true. But what percentage of the moons surface do they cover?

And I imagine that time scale is on the order of millions of years and certainly not billions.

[peledre]

@Peter_Morris

I read somewhere that when the pyramids at Giza have eroded to nothing, Neil Armstrong’s footprints will still be on the Moon.

This is assuming a meteorite doesn’t strike at or near the site.

[BMalion]

@Chronos

… In other words, if you ever drop your keys in molten lava, forget about them, because man, they’re gone.

Shit.

[Peter_Morris]

Question - if there had been an intelligent dinosaur civilization, would they have had a fuel source available to them? We have oil and coal that was derived from animals and plants that lived millions of years ago. Would the hypothetical intelligent dinosaurs have fossil fuels laid down by even earlier life?

[AnalogSignal]

@Chronos

In other words, if you ever drop your keys in molten lava, forget about them, because man, they’re gone.

From now on, I will have my keys made of tungsten (melting point 3410 C) so they will be lava (700 to 1300 C) proof.

[Lemur866]

@Peter_Morris

Question - if there had been an intelligent dinosaur civilization, would they have had a fuel source available to them? We have oil and coal that was derived from animals and plants that lived millions of years ago. Would the hypothetical intelligent dinosaurs have fossil fuels laid down by even earlier life?

Most coal was laid down in the–wait for it–Carboniferous Era, which was long before the dinosaurs. One theory is that there were almost no land herbivores at the time, very few large animals could digest plants which meant lots and lots of biomass buildup.

Neadertals were restricted to Europe and the Middle East. There were other types of archaic Homo sapiens in Africa and Asia, but not Neandertals proper.

If someone made a claim that a particular species of dinosaur was as smart as a dolphin, they were wrong. This claim was also made in Jurassic Park III, but that was fictional. No dinosaur was as smart as a dolphin, or even a cat. They had very small brains compared to extant mammals, even the ones with relatively large brains compared to other dinosaurs had very small brains compared to modern mammals.

[Chronos]

Brain size isn’t everything, though: African grey parrots, for instance, are much smarter than you’d guess from the size of their brain.

[ChrisBooth12]

@BigT

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.

I was under the impression that we have Neanderthal genes and we have tested people and so far no known person has ever shown to have any Neanderthal genes in them.Not that I don’t think a rape or two happened but perhaps the offspring were always infertile?

[Sailboat]

@Projammer

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.

Right. The Permian-Triassic Extinction Event (the “Great Dying”) was the most profound extinction event we know of, and occurred “only” 251 million years ago (one tenth as long ago as the OP’s timeframe) and Wikipedia says this:

If impact is a major cause of the P–Tr extinction, it is likely that the crater would no longer exist. As 70% of the Earth’s surface is sea, an asteroid or comet fragment is more than twice as likely to hit ocean as it is to hit land. However, Earth has no ocean-floor crust more than 200 million years old, because the “conveyor belt” process of sea-floor spreading and subduction destroys it within that time. It has also been speculated that craters produced by very large impacts may be masked by extensive lava flooding from below after the crust is punctured or weakened.

So despite the fact that we have some rocks of 3-4 billion years in age, a lot of the earth’s crust has been recycled in that timeframe, enough to obliterate even giant impact craters, and there’s also weathering/erosion on the continental landmasses to consider.

Also, we don’t find many fossils of anything, compared to the populations we believe existed. Fossils are rare and hard to find. And what if that population we’re looking for was small? If a previous civilization did not expand uncontrollably into the billions like we have, but managed its numbers and stayed small, and minimized its impact on the environment intentionally, it’s conceivable we might find no trace of it today (assuming it was long enough ago).

But of course not finding such does not imply that such a civilization existed. Parsimony compels us to assume none did, unless we find evidence of some kind.

[Sailboat]

@Chronos

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.

Or more disease-infested.

[Triskadecamus]

You guys know that the civilizations of the Saurian Age ended with space bombardment by kinetic weapons? It’s obvious, really. Impact craters, lava flows, worldwide dust layers of iridium, rapid climate change. Of course all their cities were at ground zero of the many impact events, and their constant warfare had created a fortress mentality that made them highly urbanized.

Tris

[Chronos]

I was under the impression that we have Neanderthal genes and we have tested people and so far no known person has ever shown to have any Neanderthal genes in them.Not that I don’t think a rape or two happened but perhaps the offspring were always infertile?

The only results like that I know of were based on mitochondrial DNA, which still leaves open the possibility of offspring from sapiens mothers and Neanderthal fathers.