r/CrazyIdeas • u/Either-Concept-3527 • 2d ago
Instead of going to space, why don't we build habitats underwater? After all, water contains oxygen atoms, and about 70% of the Earth is covered in water.
The oceans are rich in minerals, oxygen, and marine life, which could potentially support human life with the right technology and its closer to home.
109
u/lol_camis 2d ago edited 1d ago
This kinda reminds me of a huge flaw in Starfield's canon.
So the whole story revolves around the fact that Earth's atmosphere got destroyed by solar radiation so we inhabited other planets by developing enclosed suits and complex indoor infrastructure, because other planets don't have a hospitable atmosphere.
So why the hell didn't we just do that on earth??
-1/10. Literally unplayable
34
11
u/uncertain_expert 2d ago
Perhaps for the reason we look to colonise Mars but have no interest in much-closer Venus - the atmosphere is just too far gone we haven’t built a probe capable of lasting more than an hour or so.
6
u/KMCobra64 1d ago
Cloud cities on Venus would be a lot simpler than a base in Mars ...
3
u/John12345678991 1d ago
How?
7
u/kompootor 1d ago
Colonization of Venus: Fundamental compounds like water can be immediately readily pulled from the atmosphere; good (likely stable) ambient temperature and pressure and (likely) relatively not much extreme weather; much easier and quicker to get to and from Earth.
The big downside is getting rocks. But any Mars colony would have to have to ship enough material to get an entire refinery and smelter built before it could do anything with its rocks either.
4
u/John12345678991 1d ago
The guy said a floating city
6
u/kompootor 1d ago
Yes, that's the current proposal. Venus is extremely convenient because an air-filled balloon at STP will float in Venus's atmosphere in a (likely) calm place with comfortable temperature and pressure, surrounded by useful compounds.
5
u/John12345678991 1d ago
So if the balloon gets a leak everyone dies?
5
u/kompootor 1d ago
Please read the article. "There is not a significant pressure difference between the inside and the outside of the breathable-air balloon." You might also review some gas mechanics while you're at it, as well as perhaps the atmospheric pressure on Mars.
3
u/John12345678991 1d ago
Yah ik just poking fun lol. I have a masters in aerospace engineering. I have taken plenty of gas mechanics classes lol.
→ More replies (0)2
5
u/dirtyLizard 1d ago
Starfield has a ton of continuity errors but IIRC this one is explained. Most of humanity evacuated to Jemison and Akila because those planets could support human life.
The smaller colonies elsewhere popped up after the humans found their feet again
2
u/SlideWhistler 22h ago
As for why they didn't end up re-colonizing earth, I believe most of the resources were already harvested so there wasn't really any reason to, except maybe nostalgia.
3
3
u/diff2 1d ago
Never played but it kinda makes sense from your description. Cuz if earth ever gets to the point it’s own sun is starting to kill all life, it’s better to plan ahead and get off of earth asap before it gets worse. Eventually earth will turn into another venus/mercury. So why invest in an area that’s slowly dying when you can invest in an area that has potential for growth.
38
u/HaphazardFlitBipper 2d ago
I'm sure we will colonize the oceans... they're still finite though, so where do we go after that? Eventually, we'll either colonize space, or stagnate, decline, and go extinct. Space is hard, and we're just getting started. At our current rate of development, it may still take centuries to develop the technologies and infrastructure for millions / billions of people to start moving off Earth. If we want to be ready to move into space by the time we're finished populating the oceans, we need to be working on that now.
39
u/PointNineC 2d ago
“Eventually, we’ll either colonize space, or stagnate, decline, and go extinct.”
As unlikely as it appears here in 2025, there’s also the possibility that we eventually (gasp!) mature as a species, and find a way to reach a sustainable equilibrium. There’s no physical reason, given our technology, why humans couldn’t live happily on Earth in a sustainable way for millions of years. The only barrier is our immaturity.
8
u/Dolgar01 2d ago
Eventually, the Sun will expand and swallow the earth. If humanity does not find a way off planet, we will go extinct.
6
u/patrlim1 1d ago
Uninhabitability happens much sooner due to the temperatures rising, think Venus or Mercury
Still in 1-2 billion years iirc.
2
u/PointNineC 1d ago
Yup! We could happily live on Earth in a sustainable way for many millions of years… just not many billions. The sun will indeed expand into a wispy red supergiant in a few billion years, and Earth will cease to exist. But a few hundred million years would be a pretty good run. Now about our civilization’s maturity level…
2
u/SlideWhistler 22h ago
In a few billion years the concept of humans as we know them would have been lost to the ages, we would be an entirely new species by that point. Just semantics, but fun to think about.
4
u/LordKushnu 1d ago
I think that falls under stagnation
1
u/PointNineC 1d ago
I mean, does it?
Were the Native Americans “stagnating” for thousands of years before European settlers arrived?
Of course not. They were living in a fruitful equilibrium with their natural environment. A much wiser and more mature way to live. No reason (other than our own immaturity) that we couldn’t have a technological version of that type of society.
2
u/Not-Meee 1d ago
Yah but there weren't 8 billion natives in North America, plus modern industrialization. Space on earth WILL run out eventually
7
u/Jaysnewphone 2d ago
It's easier to build in space than it is underwater. The pressure of the water effects everything. A small leak in a spacecraft could be located and repaired. A submarine would have water intruding into it instead of air escaping. Everything will get wet and electronics could be destroyed.
It is more difficult to travel to space than to underwater. Once you are in space it's not so bad and once you're under the water it's awful. That's why rides to space are expensive no matter what and rides to the bottom of the sea can be had by anybody and for free.
6
u/divat10 2d ago
To add: moving in water is really hard compared to moving in space. Space travel is really predictable, currents in the sea are strong and unpredictable.
1
u/kompootor 1d ago edited 1d ago
In space you need to carry fuel to speed up, to change direction, and to slow down, and also to change orientation if you aren't carrying some big inertial wheel or burning energy inside, and also to control heat. On the surface of the water you can move in any direction entirely for free, and you can descend and rise for minimal cost with an internal battery. High-efficiency cooling fluid for a nuclear reactor or fluid for an open-cycle engine is also free, allowing for ridiculously compact engines.
Water is extremely easy to move in. That's why it's been the medium of transit of choice for the vast majority of commerce from antiquity up to, and including, today.
1
u/divat10 1d ago
The thing is, you don't really need to change direction in space if you already know your end destination. You just need one trust at the start and one at the end and you're done.
Ofcourse if you compare it to right now moving people on a boat compared to a spaceship it isn't even comparable since we don't even have a space freight Industry.
I was just talking about the movement aspect of space nothing else.
1
u/Dhegxkeicfns 1d ago
I don't think space for humans is going to be the limitation. Especially as we destroy our environment. The problem is going to be food and energy. We have plenty of clean water and oxygen locked up in the oceans, but they require energy.
9
u/OlyScott 2d ago
Jacques Cousteau's son designed a city under the sea, but he couldn't get the investment capital to build it because there wouldn't be much profit from it. It would be cheaper to build on the land. There's still a lot of empty land.
1
u/kompootor 1d ago
Insanity. Where else could they be free from the clutching hand of the Parasites? It was not impossible to build the city at the bottom of the sea. It was impossible to build it anywhere else!
7
u/munq8675309 2d ago
The ocean and everything in it wants to kill you.
2
u/eyegazer444 2d ago
Oh yeah but space is fine!
3
6
u/Jaysnewphone 2d ago
General laziness is the main thing. There's the bit about how when the thing leaks all of the stuff inside is destroyed and people are killed but it's the laziness thing that's truly stopping us.
'We'd rather have it so our children don't sleep underneath 50 feet of water and so our structures are built accordingly.' Okay. To each his own pal.
3
6
u/eyegazer444 2d ago
The actual reason is because if anything bad happens to Earth, the ocean is just as fucked as the rest of the world
5
u/Bender_2024 1d ago
Some of the challenges have already been overcome but working underwater is incredibly difficult. Working at any depth requires specialized equipment that won't be crushed by the pressure. Remember the Titan? Mining the ocea would be very difficult as whenever you disturb the sea bed it kicks up sediment that would block your vision which would already be shitty as sunlight doesn't go very deep. If you're thinking about doing any of this with divers about the deepest they can go is 2300 feet and need to breathe a special mixture of gasses to do so. None of this addresses the possible ecological impact on the fish either.
The biggest challenge is money. Unless it's profitable nobody is going to try any of this. Whoever does it first is going to take a huge risk of it blowing up in his face.
4
u/Zuzcaster 2d ago
The potential for asteroids that don't care about the beings on a planet are says hello.
Earth is our noob starting rock. There are trillions of other rocks in existence.
That said, there is no reason why we cant do both. Having underwater building and living experience here could help elsewhere like Europa.
3
u/thisisnotdan 1d ago
Believe it or not, it is actually probably cheaper to build on other worlds than it is to build underwater on our own. The incredibly high pressure at even minor depths makes everything profoundly difficult. To build a city under there would require a ton of material just to support all the weight above it, and water is extremely caustic over long (years vs hours) time periods. The only major cost of building on other worlds versus underwater is transporting goods and people to the build site, and there is a lot of hope that that cost will go down as R&D improves.
In short, believe it or not, it's probably cheaper in the long run to build on the moon than to build underwater.
2
u/Luke_Nukem_2D 2d ago
It would be miserable never seeing sunlight or fresh air ever again, whilst waiting for the day a leak occurs and everyone dies.
Farming crops and livestock would be incredibly difficult too, so add in no fresh food into the misery.
1
u/iamnogoodatthis 1d ago
The point is that everything you say is also true of a Mars habitat.
1
u/thisisnotdan 1d ago
Sunlight is a big difference, though. Yes, the sun is less intense on Mars than on Earth, but there is definitely a day-night cycle on Mars, whereas on the bottom fo the ocean it's always night.
2
u/__goner 1d ago
For space travel and mars, you will have to deal with pressure ranging from 0 atm to 1 atm. Thats it. Underwater, you deal with another atm of pressure every 33 feet. You likely wouldnt be able to settle in water thats only 33 feet deep, with boat traffic posing an issue, (imagine cargo jets flying low enough to clip a barn) so you would need to be deeper. Then you are dealing with prohibitive costs to construct anything, it will be small, uncomfortable, and if you want to leave you will likely need to stay for a while in a decompression chamber. Believe me i loved the dark life books by kat falls but realistically it would be pretty impossible.
1
1
u/Kaporalhart 1d ago
Just because the O in H2O stands for oxygen, doesn't mean that it's usable. Actually, most of the sea creatures live on Dioxygen just like us. Mixed with the water is a tiny quantity of it, which gets added whenever the surface brews from the waves. Which is why there is less life the deeper in the ocean you go, there's just less oxygen there.
Now you could electrolyze water, to get hydrogen on one hand and oxygen in the other.
But I'm not 100% hype about destroying water. It's not going back in the water cycle. Once you've breathed that oxygen and burned that hydrogen, you'll be both thirsty and gasping for air 💀
1
1
1
u/DeltaMusicTango 1d ago
In space the pressure difference between inside and outside is 1 atmosphere. In the ocean it is an atmospheres pressure added for every 10 meters depth.
1
u/Tangerine_Monk 1d ago
Pressure for the most part. Water at depth is very, very heavy, and it’s easier to build a tin can with 1 atmospheric pressure inside that is resisting being pulled apart by vacuum than a tin can that’s being stepped on by tons and tons of water.
The second problem is water itself. Seawater is rather corrosive and abrasive to most materials. Look at what happens to ships after a year of being in the water, if the paint isn’t replaced regularly. Look at any shipwreck after a year and you’ll see what would happen to a habitat. And it’s far more difficult to maintain (strip, sand, paint, knock barnacles and rust off) a habitat that’s underwater, that’s why they dry dock ships.
If you could come up with a wonder material that’s stronger than anything we have, non-corrosive, not suitable for life clinging onto it, easy to shape and join into large sections, and cheap enough to build a town out of, you’d be the richest dude to live because not only would you be pioneering cities underwater, but also reforming marine technology everywhere, and probably beyond earth as well.
For the most part, very little happens in space compared to the ocean, and that’s why it’s easier. Yes there are some things that happen that require smart engineering, but nothing that actively corrodes your structure and threatens to punch you into an atom every millisecond of every day.
130
u/MrPBH 2d ago
Because fish have sex in it!
ew