Saturn moon 'able to support life' • Hacker News Board

Re: Saturn moon 'able to support life'

#71

Post by crooked-v » Fri, Apr 14, 2017, 1:45 AM UTC

flubert wrote: post #23

nostrademons wrote: post #17

Earlier quoted context omitted.

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

I wonder about satellites. How far above the earth's surface would a satellite have to be to keep atmospheric drag low enough to keep an artificial satellite in orbit for a long long time. And how big would it need to be for it to be naked eye visible at that distance. And what could be done to make it unlikely to be mistaken for a natural phenomena? Have clusters of satellites in geometric patterns? 65 Million years…

For something to last a really long time, you'd want to have it at one of the Lagrangian points. Have it be big and reflective - say, a tremendous expanse of reflective cloth behind a relatively small probe - and anybody with a telescope and patience will eventually spot it as a weird "star". Something shiny at a Lagrangian point will suggest something weird (compared to the non-shinyness of objects collected at the Lagrangian points of other planets), making it an obvious target for investigation by space probes.

There are actually a number of probes at the Sun-Earth and Earth-Moon L2 points already [1], because it's a perfect spot for telescopes and observatories. I don't know if any of them are big enough to easily observe from Earth, though.

[1]: https://en.wikipedia.org/wiki/List_of_objects_at_Lagrangian_...

Re: Saturn moon 'able to support life'

#72

Post by colordrops » Fri, Apr 14, 2017, 1:49 AM UTC

nostrademons wrote: post #17

charles-salvia wrote: post #12

Earlier quoted context omitted.

Based on the developments in exo-planet research along with discoveries like this over the past couple of years, I would conjecture that life is ridiculously common. But by life, I mean microbial life. I would imagine that multi-cellular life is much rarer, and life capable of reaching human-level intelligence and beyond is probably absurdly rare, on the level of something like one species per galaxy. It's all worthl…

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

If we can find tons of fossils of animals and plants, I'm absolutely sure there would be fossils left behind of cars, houses, etc

Re: Saturn moon 'able to support life'

#73

Post by JuliusKaiser » Fri, Apr 14, 2017, 1:50 AM UTC

GlennS wrote: post #53

nostrademons wrote: post #17

Earlier quoted context omitted.

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

Largest stone monuments gone after 10,000 years? Are you sure? The pyramids are already approaching 5,000 years old. Do they show any signs of disappearing?

No, because they are maintained for tourist and historical value.

Re: Saturn moon 'able to support life'

#74

Post by hyperpallium » Fri, Apr 14, 2017, 1:51 AM UTC

Swizec wrote: post #22

nostrademons wrote: post #17

Earlier quoted context omitted.

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

> I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. How intelligent is intelligent? Homo Neanderthalensis predated Homo Sapiens by about 100,000 years. They were intelligent enough to build tools and have communities. Oldest corvid fossils are 25 million years old[1]. They are known to be very intelligent and modern crows can solve 8-step puzzles…

I thought corvids a strong candidate, but if they've been around for 25 million years without getting human-level intelligence, they mightn't ever get it, like the dinosaurs.

General commemt: we can have increasing complexity, without a specific trend towards it, by positing evolution in all directions. We'd get mostly simple life, and fewer instances as complexity increases - which is what we do see. Most life is unicellular; there are more insect species than mammals etc.

I like that paper applying Moore's Law to biocomplexity, showing an exponential increase of the most complex life existing over time.

- It seems complexity increase is inevitable (but there could be barriers, as there seemed to be for dinosaurs).

- intelligence seems to increase with complexity.

Would mammals have expanded to today's diversity if the dinosaurs had survived? Would the ur-mammal instead have remained just one minor species or family, without those niches available?

And what caused the sudden increase in brain size of our own ape-like ancestors? (Surely, some killer application of intelligence, perhaps trade, that gave it incredible survival value, far above the value it already had).

Re: Saturn moon 'able to support life'

#75

Post by Houshalter » Fri, Apr 14, 2017, 1:55 AM UTC

nostrademons wrote: post #17

charles-salvia wrote: post #12

Earlier quoted context omitted.

Based on the developments in exo-planet research along with discoveries like this over the past couple of years, I would conjecture that life is ridiculously common. But by life, I mean microbial life. I would imagine that multi-cellular life is much rarer, and life capable of reaching human-level intelligence and beyond is probably absurdly rare, on the level of something like one species per galaxy. It's all worthl…

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

I've read an interesting theory about this before but I can't remember the source. If there was intelligent life on Antarctica, it would be impossible for us to detect it today. Antarctica was warmer once and could have supported much more life.

It's plausible any life that evolved there would be restricted to that continent. Humans evolved in warm climates and could adapt to cold climates by building shelters and wearing clothing. An animal that evolved in a cold climate would have a much harder time colonizing warm climates.

And since then glaciers have scraped the surface clean and there would be little remains of them.

I read another, much more crazy, theory, that the government is covering up something in Antarctica. There are so many untapped resources in Antarctica. And after WWII, lots of were exploring it and trying to lay claim to them. Then suddenly everyone left and a treaty was signed banning mining there. To protect the most desolate continent on Earth from... environmental harm? In the 1950's when environmentalism was such a big thing? And there are a suspicious number of military bases down there... And they are guarding what, exactly? What did they find...

Re: Saturn moon 'able to support life'

#76

Post by hyperpallium » Fri, Apr 14, 2017, 1:57 AM UTC

milquetoastaf wrote: post #38

ars wrote: post #32

Earlier quoted context omitted.

> It's hard to say which species was first to become intelligent, but I'm pretty sure humans weren't the first. And yet, somehow Humans are in a completely different category than all other life. It's not just a matter a degree ("more" intelligent), it's a completely different category. So that means your definition of intelligent is flawed because it is unable to capture that distinction. Perhaps you need a new word…

>And yet, somehow Humans are in a completely different category than all other life. Lol no we are not. We share 98 percent of our DNA with various simians. We share 97 percent of our DNA with mice. Are we the only species to communicate? No. Are we the only species to communicate symbolically ? No. Great Apes use hand gestures. Are we the only species to recognize themselves? No. Plenty of animals do. In fact, even…

You can argue for their intelligence, but they can't argue for yours.

Re: Saturn moon 'able to support life'

#77

Post by TheSpiceIsLife » Fri, Apr 14, 2017, 2:05 AM UTC

Swizec wrote: post #35

ars wrote: post #32

Earlier quoted context omitted.

> It's hard to say which species was first to become intelligent, but I'm pretty sure humans weren't the first. And yet, somehow Humans are in a completely different category than all other life. It's not just a matter a degree ("more" intelligent), it's a completely different category. So that means your definition of intelligent is flawed because it is unable to capture that distinction. Perhaps you need a new word…

How do you know it's a completely different category? We used to think all animals are incapable of intelligence and everything they do is "instinct". Now we know they can think, organize, have complex social structures, even imagine and form plans. Many show evidence of being self aware. So we're not special enough anymore and we have to come up with a new word? I don't buy it. It's likely that humans' extraordinary…

We used to think all animals are incapable of intelligence and everything they do is "instinct".

Whenever I see this written I like to point out that the "we" in this case was only a vocal minority of people throughout history.

Anyone who's ever lived or worked with animals, at the very least mammals and birds, would have observed them being intelligent.

I'm sure this idea that people used to think animals weren't intelligent is a myth in the same way we think people used to believe the Earth is flat is a myth[1].

1. https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth

Re: Saturn moon 'able to support life'

#78

Post by throwaway91111 » Fri, Apr 14, 2017, 2:07 AM UTC

nostrademons wrote: post #17

charles-salvia wrote: post #12

Earlier quoted context omitted.

Based on the developments in exo-planet research along with discoveries like this over the past couple of years, I would conjecture that life is ridiculously common. But by life, I mean microbial life. I would imagine that multi-cellular life is much rarer, and life capable of reaching human-level intelligence and beyond is probably absurdly rare, on the level of something like one species per galaxy. It's all worthl…

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

It would still be visible in the fossil record, IMHO. Stone can still form around structures that long faded away, and there is zero evidence of any tool before our recent relatives (apes).

EDIT: fossil record -> geological record.

Re: Saturn moon 'able to support life'

#79

Post by ageofwant » Fri, Apr 14, 2017, 2:09 AM UTC

jerf wrote: post #21

nostrademons wrote: post #17

Earlier quoted context omitted.

I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few t…

I've thought about this and my conclusion is that we will likely leave behind a very strange pattern of certain natural resources. "Oh, look, here's a vein of copper! It's getting better, and better, and, that's weird, it's gone now and there's a complete break in the strata for some reason." Over time new mountains may form some new deposits, but it may be noticeable in the older mountains (that are today the younge…

If there were any high-intelligence species before they must have exited in a time predating current coal and oil formation, or were not technologically capable, or found some other way of harvesting energy. The fact that we found massive amounts of planet-killing coal and immediately started exploiting it with abandon means that that did not happen before, ergo no technologically capable species on this planet for at last 300M years back. Now you could argue that 'intelligent species' tend not to shit in their own beds. We talk about Fermi filters for a reason.

Do keep in mind that diversity enables diversity. If biosphere complexity falls enough changes are it will never recover. Earth had live almost immediately after formation. It took more than 2.5B years for something more complex to emerge from the ur uni-cellular broth. Evolution or linear increasing complexity is not guaranteed by any means. What will a chimp bashing rocks in the bush be doing in 1000 000 years? Building quantum computers or bashing rocks. Overwhelming evidence points to bashing rocks.

Re: Saturn moon 'able to support life'

#80

Post by TheSpiceIsLife » Fri, Apr 14, 2017, 2:13 AM UTC

nostrademons wrote: post #37

jerf wrote: post #21

Earlier quoted context omitted.

I've thought about this and my conclusion is that we will likely leave behind a very strange pattern of certain natural resources. "Oh, look, here's a vein of copper! It's getting better, and better, and, that's weird, it's gone now and there's a complete break in the strata for some reason." Over time new mountains may form some new deposits, but it may be noticeable in the older mountains (that are today the younge…

Curious if anyone's ever observed something similar to this? It'd be super easy to detect if you're looking for it, but most miners aren't thinking "Hmm, I wonder if a previous intelligent species existed on earth millions of years before us."

Surely if a previous society extracted megatons of ore from the ground there would be something left of that civilisation. At least a wheel track or a scrape mark, not to mention maybe a spanner.