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

Re: Saturn moon 'able to support life'

#241

Post by ChuckMcM » Fri, Apr 14, 2017, 9:07 PM UTC

smdz wrote: post #178

I always had this question - Can life exist outside our perception of biological life? Intelligent life might be an anomaly, and rare in the universe - but is it possible that life exists outside our perception of biology? Afterall everything is just rules and actions that lead to predictable reactions (unless quantum physics says something else) I look at artificial life - that exists in virtual environments. It loo…

I recommend you read 'The Vital Question' it touches on this topic.

The short answer is that if you define 'life' to be engines which convert energy into additional engines then yes there is life outside our perception of biological life, but at that point 'life' is just 'chemistry'. And 'engine' is defined to be a self-contained collection of elements that you can feed energy into.[1]

[1] I know not as crisp as it should be, but read the book its really interesting. Especially when you get to the point talking about geo-chemistry and bio-chemistry being the same thing pretty much.

Re: Saturn moon 'able to support life'

#242

Post by leonroy » Fri, Apr 14, 2017, 9:10 PM UTC

herbstein wrote: post #18

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…

Isaac Arthur has a very interesting video that touches on that specific topic, but with a space exploration angle. https://www.youtube.com/watch?v=k7fLNvpl0c8

That was incredibly good. Some of the ethical and practical implications raised in that video by humans actually achieving interstellar travel were pretty eye opening.

Re: Saturn moon 'able to support life'

#243

Post by eric_h » Fri, Apr 14, 2017, 9:30 PM UTC

logfromblammo wrote: post #223

adrianN wrote: post #101

Earlier quoted context omitted.

I'd guess that the Egyptians maintained them. If I'm not mistaken they where in pretty good shape during Roman times.

Human activity weathers stone monuments faster than desert winds. If I recall correctly, the original sheathing stones and capstones of the pyramids were gradually stolen. The Sphinx was used for target practice. Water, on the other hand, will tear through your stones much more quickly. In a wet, temperate climate, the weak acid falling from the sky will wear limestone. The moisture invading cracks and freezing will…

> The Sphinx was used for target practice.

This was the first I've heard that assertion, so it sent me down a bit of a rabbit hole.

Turns out it's a common story that Napoleon used the Sphinx for target practice, hence the lost nose. It also turns out that that is most certainly not true. Napoleon, being wholeheartedly in favor of the enlightenment, would never have destroyed antiquities (only plundered them for his own profit -- lets not forget that the Rosetta Stone was discovered during a Napoleonic campaign).

Further, a 15th century Arab historian notes that the nose was missing in his era and "attributes the loss of the nose to iconoclasm by Muhammad Sa'im al-Dahr—a Sufi Muslim from the khanqah of Sa'id al-Su'ada—in AD 1378, upon finding the local peasants making offerings to the Sphinx in the hope of increasing their harvest. Enraged, he destroyed the nose, and was later hanged for vandalism."[0]

0) https://en.wikipedia.org/wiki/Great_Sphinx_of_Giza#Missing_n...

P.S. thanks for sending me down that rabbit hole - I haven't idly done some armchair egyptology since I was a teenager

Re: Saturn moon 'able to support life'

#244

Post by eric_h » Fri, Apr 14, 2017, 9:45 PM UTC

Swizec wrote: post #31

rojobuffalo wrote: post #29

Earlier quoted context omitted.

We're sharing the planet with several intelligent species at this moment. Maybe a worthwhile distinction would be intelligence sufficient to dominant an entire planetary ecology; or sufficient to intentionally become multi-planetary.

Dominate the planet is tricky too. Corvids for instance are almost as widespread as humans. They don't do greenland and the southern parts of south america. But they happen to be less destructive to their environment than humans so maybe that disqualifies them from the "dominate" part? That said, humans also don't quality for multi-planetary. I like that definition, though.

> That said, humans also don't quality for multi-planetary.

True, but we've definitely sent probes to other planets, and a few people did manage to walk on the moon, so we're certainly farther to the right on the multi-planetary spectrum than any other species on our planet.

Re: Saturn moon 'able to support life'

#245

Post by thaumasiotes » Fri, Apr 14, 2017, 9:47 PM 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…

> You'll find occasional fossilized skeletons, but all that would tell future species is that a bipedal mammal with a large brain once existed.

Scrimshaw seems like it would be pretty good evidence of intelligence.

Re: Saturn moon 'able to support life'

#246

Post by Razengan » Fri, Apr 14, 2017, 9:51 PM UTC

smdz wrote: post #178

I always had this question - Can life exist outside our perception of biological life? Intelligent life might be an anomaly, and rare in the universe - but is it possible that life exists outside our perception of biology? Afterall everything is just rules and actions that lead to predictable reactions (unless quantum physics says something else) I look at artificial life - that exists in virtual environments. It loo…

> Even stuff like mars rover could be engineered to mine, manufacture and duplicate - eventually creating a colony of rovers that populate the planet and consume the planet's resources.

That's one of my favorite thought experiments in approaching the definition of life:

Suppose we build some robots with AI, and send them into space, and they land on some planet.

Those robots can mine raw materials and build other robots like themselves.

They're able to learn and teach each other, and improve their design and invent new things on their own.

Fast forward a few hundred years. That planet now hosts a civilization of robots, with their own culture, planning their own excursions into space.

To an external observer searching for Life™ and Intelligence™ in the cosmos, what would make our robot civilization fail to be qualified as such?

Re: Saturn moon 'able to support life'

#247

Post by [deleted] » Fri, Apr 14, 2017, 9:53 PM UTC

bonzini wrote: post #207

winfred wrote: post #89

Earlier quoted context omitted.

Here you go: http://www.coolantarctica.com/Antarctica%20fact%20file/scien... Mining wasn't banned until 1991. And as the article outlines, Antarctica is a really, really inhospitable place, to the point that it might be easier to colonize a different planet than to colonize Antarctica (I'd probably prefer equatorial Mars over Antarctica) and even mineral extraction would be very complicated.

At least if you get to Antartica you don't need a pressurized suit and an airlock to go outside. It's difficult to imagine a less hospitable world than one without an atmosphere and a magnetic field (well, not talking about Venus-level inhospitable).

[deleted]

Re: Saturn moon 'able to support life'

#248

Post by pchristensen » Fri, Apr 14, 2017, 10:00 PM 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 this comment is interesting to you, you may enjoy the book The World Without Us. https://www.goodreads.com/book/show/248787.The_World_Without...

Re: Saturn moon 'able to support life'

#249

Post by pchristensen » Fri, Apr 14, 2017, 10:02 PM UTC

nojvek wrote: post #103

ageofwant wrote: post #79

Earlier quoted context omitted.

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 a…

I absolutely believe that any intelligent species that has enough intelligence to become interstellar will heavily invest in camouflage and become a lurker. Only reacting when something threatens its survival. The universe is like a jungle full of scary things, the only wise move is to watch out, be invisible and not make a lot of noise.

If this is interesting to you, read The Dark Forest: https://www.goodreads.com/book/show/23168817-the-dark-forest...

Re: Saturn moon 'able to support life'

#250

Post by thaumasiotes » Fri, Apr 14, 2017, 10:13 PM UTC

bonzini wrote: post #209

mcbits wrote: post #129

Earlier quoted context omitted.

I think written language is our primary difference. Prehistoric wild humans had spoken language for hundreds of thousands of years, but we didn't have the explosion of "intelligence" until the advent of written language ~5,000 years ago. Or in more general terms, we have the ability to use our environment as a durable supplemental memory. This is what I would look for in assessing whether another species has the pote…

While I agree in general with what you wrote, there are examples of orally preserving collective memory. Think of the ancient epic poems for example. Painted or etched drawings on cave walls came long before writing, and no other existing species on Earth does that except if we teach them. Non-homo species also do not domesticate fire. Fire means not being afraid of something that you usually have seen only in scary…

> Fire [...] can lead to writing tens of thousands of years down the road (papyrus happens to preserve well in a pyramid in the desert, but cooking clay tablets or melting metals works better everywhere else).

I feel pretty safe in saying fire had no direct influence on the development of writing anywhere. Chinese characters first show up carved into bones. (They are well-developed at this point; obviously they originated some other way. But we don't know how.) Cuneiform tablets were originally unbaked; baking for preservation was an innovation that happened long, long after writing was established.

And the difficulty of working with metal means it is totally unsuitable as a writing medium. Although particularly important cuneiform documents (peace treaties) were sometimes cast in metal, only the final draft would be -- as the treaty was "in negotiations", messages back and forth were in clay. A society that can only write on metal is a society that will never develop writing in the first place. There is no reason other than wishing to impart a ceremonial permanence to write in metal.