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Earth was born dry until a cosmic collision made it a blue planet

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Re: Earth was born dry until a cosmic collision made it a blue planet

#161

Post by prerok »

zkmon wrote: post #67
zkmon wrote: post #3

All life on Earth is illegal immigrants from another planet.

Sorry, I was only joking. Someone got busy seriously down voting! Maybe wrong times to utter the phrase "illegal immigrants". I get it.

Well, I for the count of one, didn't think it bad, but thought provoking. We're all immigrants, when you get deep into it (speaking from Europe, where we usurped previously native folk some 1500 years ago), and we all came from Africa anyway.

But, yeah, political implications nowadays are a slippery slope.

Re: Earth was born dry until a cosmic collision made it a blue planet

#162

Post by runarberg »

pfdietz wrote: post #82
pavlov wrote: post #47

Earlier quoted context omitted.

Do other galaxies matter here? A civilization would need to be incredibly powerful to be detectable from another galaxy.

Galactic colonization, carried to saturation, would detectably modify the appearance of a galaxy. So called "type 3 civilizations" would convert a significant fraction of starlight to lower grade heat, which would be radiated. Searches have been conducted for this signature, with the result that no more than 1 in 100,000 galaxies has such a civilization, and with the result being consistent with none.

I am not an astrophysicist but I have a hunch any speculations of galactic colonization fails to entertain just how big space actually is. I feel like there is ample reason to suspect the probability of galactic (or even interstellar) colonization is exactly 0, and no civilization in the history of the entire universe will ever colonize an entire galaxy (and probably not even more than a handful of solar systems outside their home world; if any).

Re: Earth was born dry until a cosmic collision made it a blue planet

#163

Post by 3oil3 »

We humans are not from Earth, what more signs need those who can't see? Humans,from all the species, the unique without a natural habitat. Humans, can not live on this planet unless we all get together and start adapting the environment. Otherwise, we can only survive and it's not fun. We have to wear clothing, cut downn trees. We get ill and stuff. Monkey us from? We closer to the pigs and not just the hips.

Re: Earth was born dry until a cosmic collision made it a blue planet

#164

Post by poly2it »

3oil3 wrote: post #163

We humans are not from Earth, what more signs need those who can't see? Humans,from all the species, the unique without a natural habitat. Humans, can not live on this planet unless we all get together and start adapting the environment. Otherwise, we can only survive and it's not fun. We have to wear clothing, cut downn trees. We get ill and stuff. Monkey us from? We closer to the pigs and not just the hips.

What?

Re: Earth was born dry until a cosmic collision made it a blue planet

#165

Post by crazygringo »

macintux wrote: post #132
HarHarVeryFunny wrote: post #120

Earlier quoted context omitted.

As long as we have air and water (i.e. as long as we're alive), then we can make propellants such as Methane or Liquid Hydrogen and LOX, Hydrazine & Dinitrogen Tetroxide (or Hydrogen Peroxide).

None of which are, I assume, as easy/efficient/effective to integrate into a new civilization's tech tree as coal & oil.

So? We build nuclear power plants and it's not exactly easy/efficient to extract uranium. Hard things are done all the time.

Having coal/oil is pretty irrelevant in terms of whether a civilization can build spacecraft.

Re: Earth was born dry until a cosmic collision made it a blue planet

#166

Post by pinkmuffinere »

poly2it wrote: post #164
3oil3 wrote: post #163

We humans are not from Earth, what more signs need those who can't see? Humans,from all the species, the unique without a natural habitat. Humans, can not live on this planet unless we all get together and start adapting the environment. Otherwise, we can only survive and it's not fun. We have to wear clothing, cut downn trees. We get ill and stuff. Monkey us from? We closer to the pigs and not just the hips.

What?

You heard the man! Monkey us from?

Re: Earth was born dry until a cosmic collision made it a blue planet

#167

Post by pfdietz »

runarberg wrote: post #162
pfdietz wrote: post #82

Earlier quoted context omitted.

Galactic colonization, carried to saturation, would detectably modify the appearance of a galaxy. So called "type 3 civilizations" would convert a significant fraction of starlight to lower grade heat, which would be radiated. Searches have been conducted for this signature, with the result that no more than 1 in 100,000 galaxies has such a civilization, and with the result being consistent with none.

I am not an astrophysicist but I have a hunch any speculations of galactic colonization fails to entertain just how big space actually is. I feel like there is ample reason to suspect the probability of galactic (or even interstellar) colonization is exactly 0, and no civilization in the history of the entire universe will ever colonize an entire galaxy (and probably not even more than a handful of solar systems outs…

Your argument shows a lack of understanding of exponential growth.

Any given colony has to create only slightly more than 1 additional colony in order to drive exponential growth. There doesn't have to be any coordinated action by a central authority for it to happen. For it not to happen (if it is physically feasible), in contrast, every species has to refrain from doing it at all points in their history, almost without exception. And those that do the colonization will seed additional colonies with a mindset that led to colonization; such mindsets will be selected for for further expansion.

Re: Earth was born dry until a cosmic collision made it a blue planet

#168

Post by marcoalopez »

Interestingly, Earth scientists have long understood that plate tectonics is highly unlikely to exist on a rocky planet without water (to put it simply, water is needed to deform the Earth's upper mantle), given all that this entails. If this hypothesis is true, plate tectonics as such should be post-collision.

Re: Earth was born dry until a cosmic collision made it a blue planet

#169

Post by dotancohen »

LeifCarrotson wrote: post #125
dotancohen wrote: post #115

Earlier quoted context omitted.

About forty years ago I read a terrific book about life forms that live on a star. Maybe Starquake was it called? Did to the abundance of energy on the surface of a star, they live their lives a million times faster than humans. Thus for both them and the humans who discover them, communication is difficult. I think the humans push these life forms to develop civilization, which from the human's perspective had them…

That's "Dragon's Egg" by Robert L. Forward, a classic Sci-fi story: https://annas-archive.org/md5/4c381ac344506d10037fc8e7747098... The cheela lived on the surface of a neutron star, and they lived faster because the nuclear physics that powered their metabolism are far faster than the chemical and mechanical physics that power our own.

Yes, that was it!

Re: Earth was born dry until a cosmic collision made it a blue planet

#170

Post by nntwozz »

shireboy wrote: post #4

This could mean in the Drake equation ne -number of planets capable of life- is very small. A planet has to be hit with a comet big enough to deliver a large amount of water but not so big or fast to destroy it. And be in the Goldilocks zone of the star. Also the mass of the planet would play a part - gravity of more massive ones would be more likely to capture a comet. But again, too massive and I could see that ham…

This also points to panspermia.

"The hypothesis that life, in the form of “seeds” or spores, is distributed throughout the universe, traveling between planets, moons, and other bodies via space dust, asteroids, comets, and possibly even spacecraft."

I want to think that the water contained life and not the barren earth.

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