Where Did Earth Get Its Oceans? Maybe It Made Them Itself | Hacker News Reader

Where Did Earth Get Its Oceans? Maybe It Made Them Itself

quantamagazine.org

136 pointsibobev68 comments

My Impacts project depicts a scene from the prolonged bombardment, a time when Earth was cratered by asteroids and comets:

* https://impacts.to/downloads/lowres/impacts.pdf#page=9

* https://impacts.to/bibliography.pdf

That's really cool!

"Other scientists agree that some amount of water could have formed on Earth — but perhaps not nearly enough to produce its oceans." "Earth might have been a water factory for only a moment, but that moment may have been enough to forge oceans."

Well, our planet has magnetosphere and it also had life for a long time already. Although the magnetosphere reduces the influx of Hydrogen in form of solar wind proton bombardment, it also prevents the loss of Hydrogen that managed to get captured on Earth by not letting it be blown away from the upper layers of atmosphere. Life at one point, almost two and a half billion years ago, caused the Great Oxygenation Event, in which the entire atmosphere got Oxygen rich. This very special atmosphere (for all that time) made it possible for the incoming Hydrogen (be it from the Sun, other stars, or just as the most common form of dust in the universe blown in here from whatever direction and cause) to ultimately be collected as water. Two and a half billion years, that's a lot of time to accrue water. It ought to show, at some point. So it's at least one pair of factors that could have led to a surplus of water we see today, besides what might have existed from very beginning.

> Well, our planet has magnetosphere and it also had life for a long time already.

But life needed water as a requirement to arrive, right? So are you saying that there was a little bit of water for life to get started, before that same life caused the oxygenation event to create more water over millions of years?

Please explain, thank you.

Is this a chicken and egg like question?

Well, yes -- some amount of water must have been in there from very beginning, plus what may have fallen in as icy bodies from outer space afterwards, this much is mentioned in the article itself. The question was not if there was water, but how much of it. Most of today's planetary body of water resides in deep depressions -- seas and oceans, which is very different to what must have been initially. Back then, the surface supposedly had very little relief, due to Earth's crust being much thinner at that time. That meant that, whatever water was there, it must have been shallow, spread to very large areas.¹ This condition was especially propitious for life, as it provided ample space for life to proliferate. The first organisms must have been at the bottom of this large, never drying shallow "ocean" or mesh of (at least often) connected seas. Deep enough to shield the emerging life from UV light, but shallow enough for light to reach the developing life, including the first unicellular algae. Even today, most of life lives on the shallow waters, where plants could find minerals and underwater sunlight, and thus the whole food chain above them could be sustained.

¹ Today's amount of water spread all over an Earth with no relief gives you a kilometers-depth ocean. Even with only some modest amount of relief (as it should have been at the beginning), if it didn't reached the water surface to produce shallow waters, then that's a non-starter for life. The life should have waited a lot of time for the Earth to cool down, for the crust get ticker and thus for a more prominent relief to appear in order for it to finally get any chance to emerge. Therefore, it was very important for life to encounter an environment with just modest amount of water.

Thanks for taking the time.

So the theory explained here is that Hydrogen mixed with the Oxygen in the melted rock (magma) of earth, under extremely high pressure to create our earth specific flavor of H2O (appropriate amount of trace minerals and deuterium).

Am I reading that correctly?

Link to the paper mentioned in the article: https://www.nature.com/articles/s41586-025-09630-7

Correct, and we can demonstrate this via various gem-bearing and REE-bearing pegmatites which almost universally contain magmatic-sourced water trapped within them.

Could this have happened under the pressure of the interplanetary collision with the protoplanet "Theia" that led to the creation of the moon?

Wow what an awesome art piece by Ada Zejun Shen that they commissioned(?) for this article!

I thought it was ai generated lol

even when websites provide attribution for images, people don't read them

Their portfolio is beautiful https://adazshen.com/

Wow, what a portfolio! This one in particular caught my eye: https://adazshen.com/Viral-Placenta

I have little artistic ability myself, but I am continuously in awe of what artists create. It makes me hope for the optimistic outlook of AI where UBI frees people to pursue creative and intellectual pursuits, rather than constantly trying to push a stock price uphill.

Maybe some of Earth's oceans came from its rings collapsing (not kidding)

https://www.youtube.com/watch?v=hPhwhq-f1Uo

I've read Europa has more water than Earth. Is the idea that it accumulated its water through an entirely different means? Or that it formed with its water, and didn't lose it during the initial coalescence, like the Earth did?

This is one of those areas where I don't know enough to oppose the scientists that are experts in this domain, and so I know I should accept the general consensus... but there's still a niggling doubt in my mind because it just doesn't feel right.

Earth inherited water, released it, and retained it, while the atmosphere and oceans formed together as a coupled system. Heating released water via volcanism. Outgassing formed an atmosphere rich in water vapor. Cooling caused condensation and rainfall. Oceans stabilized.

Oxygen accumulated only after oceans already existed for over a billion years.

Life began in the Ocean, but why did civilization begin on land? Is it because of fire? But I wonder if a different kind of civilization could have emerged

That's one theory, yes. Cooking food (with fire) makes more calories available, meaning less hunting required to support more individuals, and/or freeing up more time and calories for thinking. This allowed us to evolve bigger and more complex brains.

While it's not a given that fire is a hard prerequisite for an industrial civilization, it certainly accelerated our technological development. Fact of the matter is, we know of exactly one civilization, which is not enough to draw any conclusions. There's no real reason we know of that aquatic species cannot evolve into a technological civilization, we just haven't seen it happen. Fact is we don't really know how an intelligent technological species evolves. We only have guesses from our own history.

And a sample size of one.

That's what I said, yes.

We have counter examples of human pods that never really achieved “civilization”.

What’s missing that make them more akin to orcas or wolves?

It is possible it is just time. Modern humans are considered to have existed for 300k~ years. Civilizations are about 6k years old.

So who knows. Maybe if you gave them an extra 10k years, they would have achived "civilization". It is not much for the scale of human existance. But it is longer than any of our civilizations has existed for.

For humans, I wonder if population size and density is also a factor.

That is, if there’s a critical mass and population size.

And makes sense with agriculture and civilization coming together. Agriculture improved the carrying capacity of an acre of land dramatically from what it was from foraging and hunting.

Written language ?

Got it too easy ?

It doesn’t have to be writing. At least one culture used ropes and knots.

I think that (Incas) was more numerical record keeping rather than written language.

What's special about written language (which some existing hunter-gatherer tribes still don't have), as opposed to spoken language, is that it allows cultural knowledge to be spread, stored, accumulated, and built upon.

Fire, agriculture, electricity, AI.

Rank these inventions in terms of importance to humanity.

It looks like you've already done so with the order of the sequence that you used.

AI is not important at all. Just make things more convenient, but is completely unnecessary.

Check back in 5 years. This is going to age poorly.

The reason is that, despite what many think, AI actually is able to create novel ideas and solutions. That's why AlphaGo was so important; it couldn't beat the world's best Go player just be being a fancy autocomplete and a big processor. It had to create new discoveries and then use them effectively. That was the turning point. It's been a decade of improvements since then, and AI is already making discoveries we couldn't have made without it. The impacts are already here and in your world, you just haven't recognized them as such yet. But in a few years it will be undeniable to even the most uneducated observer, since changes that could not be possible will be present in every person's life as the effects ripple out across basically every industry.

In no timeline nor carbon-based universe does GP's comment age poorly.

I am a bit skeptical but cautiously optimistic about AI “creating novel ideas”, if we are using “create” pedantically. Any interesting examples?

Those math proofs from a few weeks back seem plausible.

Nuclear weapons and the control structure around their use and fossil fuels and the C-corporation and what it optimizes for will probably turn out to be more important to the long-term future of humanity and it's civilization.

Fossil fuels are another feature like fire. One of the leading theories is that the availability of extremely energy dense fuels is one of the primary reason we were able to industrialize, and that without those fuels industrialization would be vastly more difficult if not impossible.

Personally I disagree with 'impossible', but it would definitely be harder. There's a pretty good argument to be made for leaving significant quantities of fossil fuels in the ground for the next civilization. If we wipe ourselves out, whoever comes next is going to very badly need those fuels to rebuild an industrial base.

There were copper & bronze age industrial sites. Esp Tin & arsenic bronze smelting sites. Complete with child labour, open pit mines, assembly line style processing, and heavy metal poisoning. E.g. Semiyarka, in present day Kazakhstan, ~1600 BCE. You can still see the environmental damage to this day from the air.

Romans had industrial processes, too, for things like fabric / laundry cleaning.

What's new in the 18th/19th century is full-on mechanization of industry. And the wage labour system to make it possible. Accompanied by acts of enclosure etc to drive the peasantry off the land and into factories. Also the mechanization of agriculture that went with that.

That's the fun thing, since we have only observed a single advanced civilization, and that one only indirectly through archaeological evidence, there's no hard facts to be had! We can only make guesses. We don't know what is and is not required to make an advanced technological species, and we won't have any answers until we meet another one to compare with.

Arguably they're all fire -- requiring/involving forms of combustion.

(Well, debatable about agriculture, slash'n'burn wasn't the only form of it, but it was common for land clearing at least... all we have now is one that involves combustion engines, though...)

AI hasn’t taken its final form yet.

Interesting to think what could be if cephalopods raised their young instead of leaving them to completely fend for themselves. It would start intergenerational knowledge transfer, i.e. culture. Maybe selection pressure then trends towards group cooperation instead of going it solo.

I still think there would be huge barriers to "civilization" as I think you mean? (Do any of the apes have "civilization"?).

Orcas do this already.

I mean there might be a already a civilization that is in the building that will peak 100k years later, and we just don't know about it.

having arms is probably an advantage in developing tool-use, but who knows!

The real problem with cephalopods is their lifespan. For their age, they are almost as smart as humans, the problem is that they don't live past the age of 5 years.

I would argue that not having any overlap between generations is a bigger problem. It guarantees no accumulation of knowledge.

Agreed. If they were social enough to form large communities of unrelated families, it would also fix the generation overlap. But they don't do that either. They seem to be in a weird evolutionary dead end for intelligence.

Brains are resource hungry, especially oxygen hungry. Earth's air is orders of magnitude richer in oxygen molecules than its water. This likely made it easier for intelligence to develop on land. It's worth noting that the smartest aquatic animals are air breathing mammals that spent much of their evolutionary history on land before returning to water.

When did octopuses start breathing air?

Octopuses are smart, but I've yet to see anything that suggests they are smarter than dolphins or whales.

Both whales and prairie dogs turn out to have rather advanced degrees of verbal language capability, more complex than any of the Great Apes bar homo sapiens. Crows somehow culturally remember the face of an antagonist multiple generations later. Almost every highly social vertebrate has degrees of intelligence that would get you burned as a witch if you'd suggested it not too long ago, in the era when "Fishes clearly don't feel pain" was just a cultural default assumption.

I've heard that the biggest limiting factor in octopus ocean domination is their short lifespans. Tool use, building structures, communication, facial recognition, multiple brains, it's all there.

https://www.nhm.ac.uk/discover/octopuses-keep-surprising-us-...

Female octopi also die reproducing. Knowledge cannot be passed from one generation to the next. Everything they know is either instinctual or learned.

Physically manipulating objects is a lot harder underwater, even if you somehow evolve fine motor control despite not having any real use for it. So that severely limits what an intelligent aquatic species could actually do with that intelligence. Aside from fire you're missing the wheel, a writing system and many other things.

Being immersed in solvent can't help with things like graphic arts and pottery.

Humans are one of a handful species equipped to change their immediate environment to suit their needs, across virtually every environment, and introduce stability.

Beyond that…

Being able to have down time seems like a prerequisite to creating. civilization.

Also, having both the intelligence and desire to seem and recognize ways to improve—even if not strictly necessary—via tools to free up even more time also seems to be a requirement.

And having a system to reliably and in-scale transmit this knowledge is the final ingredient.

So some baseline stability, down-time, intelligence, reliable knowledge transmission, tool-use for the above, and active willingness to improve all of the above all seem like necessary ingredients.

You're talking about a thing that happened for 1 species for such a small period of Earth's history to be just a blip. There's not enough data to draw a conclusion here.

One hypothesis is that the brain began too look (and eventually plan) farther ahead with land animals, because you have a much farther view in air than in water. On land there is more evolutionary pressure to change one’s behavior regarding animals farther away that you see and that can see you, to predict their behavior and plan one’s own behavior within a larger time horizon.

1) Land has more diverse and rapidly changing environments, creating generalists, creating advanced intelligence

2) Civilization requires hands, but in water fins and flippers are more useful

3) Sure, it could have worked out differently, but here we are

Can’t answer that, nobody will likely to be able to ever, outside religions. We are NBKs. How that happened, idk, some cosmic curse. Dolphins didn’t develop atlatals, broad heads, catapults, napalm, and F35s.

> but why did civilization begin on land?

Octopus have civilization, despite the usual solo trip, group behavior has been observed, small neighborhoods of octopi staying within their shells and occasionally pestering each other.

Some aquatic mammals have civilization as well.

A lot of what's going on just hasn't been observed well

Earth made water.. right.. and a big explosion made the earth? How stupid do you think we all are?

They have played us all for absolute fools!

How could the Earth be round? All the water would fall right off!

As opposed to what, a gift from aliens?

i imagine this is what happens when a giant iceball starts to melt

200 years from now on HN.

"Where Did Earth Get Its Deserts? Maybe It's Ai, Datacentres and Climate Change"

Reply on news.ycombinator.com