Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

sciencedaily.com

Post reply on HN
Print view View original

221–230 of 279 posts

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

#221

Post by ricksunny »

brianpan wrote: post #193
ricksunny wrote: post #110

>was rich in volatile elements essential for life, such as hydrogen, carbon and sulphur. Today years old on learning that 'carbon' is a 'volatile element'. (I come to learn that astrogeology has a unique definition of volatile). • The summary's own source article points makes no reference to carbon being volatile. • The wikipedia article for 'volatiles' in the astrogeological sense makes no reference to carbon being…

Astrophysicsts would also call these "metals" (anything heavier than helium) so don't read too much into it. :D https://sentinelmission.org/astrophysics-glossary/metallicit...

Thank you, that does make me feel at the same time better as an individual and sadder about my expectations for the astrophysicists’ ability to draw anything resembling reasonable conclusions about the makeup of the celestial bodies.

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

#223

Post by fnordian_slip »

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.

> We get ill and stuff

Just out of curiosity: you do realise that illness is not specific to humans, but also occurs in animals, right?

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

#224

Post by 8bitsrule »

andrewflnr wrote: post #57

I've tried reading the paper, which is obviously less hand wavy than this mess of a blog post but pretty tough going for a layman. I still don't see how they conclude that the water arrived all at once instead of in a bunch of comets... https://www.science.org/doi/10.1126/sciadv.adw1280

>this mess of a blog post

It's that. Just one more in a long line of wild-eyed 'the Earth collided with' theories.

> Scientists have shown that Earth’s basic chemistry solidified within just three million years ...

They haven't 'shown' anything. They may have evidence to support part of one model ... if they can demonstrate that a Theia probably existed in the first place.

Try to read it? Thick going. https://www.science.org/doi/10.1126/sciadv.adw1280. Quoting from that:

"Today’s element abundances of the BSE and isotope constraints strongly suggest that the bulk Earth comprises ~90% PE, ~10% Theia, and ~0.4% late veneer material... Other models suggest that Earth formed from ~60% PE and ~40% Theia ..."

>a later collision with Theia likely delivered the water

Etc. If water was so hard to get ... where in the hell did this hypothetical, no evidence 'likely' get the water it 'delivered'?

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

#225

Post by sho_hn »

squigz wrote: post #178
LeifCarrotson wrote: post #125

Earlier quoted context omitted.

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.

I'm not against piracy, and I love Anna's Archive... but publicly linking directly to a pirate source for something like this seems wrong. Could've just linked the Wikipedia page and let people acquire however they prefer. Anyway, sounds interesting, gunna add that to my list

It's 45 years old and the author is deceased. I assume you would be untroubled by a link to a copy of Macbeth. Where do you draw the line?

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

#226

Post by 3oil3 »

fnordian_slip wrote: post #223
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.

> We get ill and stuff Just out of curiosity: you do realise that illness is not specific to humans, but also occurs in animals, right?

Of course, yes -hell, even cats have their own AIDS; but what I meant was we get 'easily' ill. I mean, imagine we have to drink the water from a puddle?

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

#227

Post by squigz »

sho_hn wrote: post #225
squigz wrote: post #178

Earlier quoted context omitted.

I'm not against piracy, and I love Anna's Archive... but publicly linking directly to a pirate source for something like this seems wrong. Could've just linked the Wikipedia page and let people acquire however they prefer. Anyway, sounds interesting, gunna add that to my list

It's 45 years old and the author is deceased. I assume you would be untroubled by a link to a copy of Macbeth . Where do you draw the line?

Well I don't really have a line, but that doesn't mean I'm going to go linking directly to such sources in public - not everyone agrees with my stance on copyright. Those who do can easily go find it themselves.

Also Macbeth was written 400 years ago. Let's not pretend this is a fair comparison. This author has been dead only 20 years - it might be that their partner is still alive and needs that money, or their children.

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

#228

Post by 3oil3 »

pinkmuffinere wrote: post #216
3oil3 wrote: post #205

Earlier quoted context omitted.

Hey that bit was for the lols, although it is quite valid to say, just missing plural and a comma. Innacurate in some ways -mainstream theory is not about coming from apes, rather is about sharing a, yet undiscovered, common ancestor. I mentionned the pigs because of promising advancement in organ transplantation, notably kidneys that reached a milesone recently, and I mentionned the hips because human hips and ape h…

I really appreciate your open response! Your writing style is so fascinating, it reminds me of how my dad used to talk (he was Persian, not a native English speaker). What’s your background? How did you end up with these beliefs?

Thanks for the kind words. My heart is Belgian and I'm living in Panama now; Well, I always wondered why we 'evolved to die', in the sense that from my understanding, the initial life forms, quasi-minerals, wouldn't die of old age, just of trauma like cell rutpture or something. There is so much to say so I really cut it short, but eventually I read about how it was probable that first living things came from an asteroid, I started thinking that 'something', call it God if its meaning hasn't been perverted by manmade things, put us there. Something currently above our understanding, and quite extraordinary -what kind of energy to run the universe.

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

#229

Post by adastra22 »

JamesLeonis wrote: post #35
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…

The Drake Equation is filled with assumptions, like life must appear on a planet in the Goldilocks zone of a star. The whole equation has only one datapoint to extrapolate from. Tweak the equation's parameters and it will predict universes that only have one civilization per galaxy or worse! We have no way of knowing what those parameters are because we haven't seen other examples. A major reason we are interested in…

FYI just about every outer solar system moon or planetoid has a liquid ocean somewhere underneath. Europa is neither exceptional or even that interesting anymore.

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

#230

Post by gustavorg »

blindriver wrote: post #49

Absolute garbage. The Earth has a nearly perfect circular orbit. Any collision with another planet would have pushed it off its orbit and caused it to at the very least created a more elliptical orbit that likely would have made the swings in temperature more deadly for life on Earth. This entire article is science fiction.

Furthermore, robotic exploration of Mars is already yielding sufficient evidence that Mars once had oceans. There is a well-founded suspicion that Europa and Titan have seas hidden beneath their surfaces. Does this article mean that all of this is just our imagination? I don't think so.
Post reply on HN