Helium. Deep divers often breathe a mixture of 3% oxygen and 97% helium, which prevents the bends. Also makes them sound like Donald Duck.
You can stay down indefinitely at moderate pressures (say, a few atmospheres - much greater than we’d be worried about here) as long as you decompress on the way up. The Navy has put people in underwater habitats at ambient pressure and left them down there for long periods of time.
The dangers increase with the pressure. Divers diving around 150-200 ft (5 atmospheres or so) on normal air mixtures can suffer ‘nitrogen narcosis’ which can cause euphoria, disorientation, and death.
At even higher pressures, you can suffer from oxygen poisoning, which can cause convulsions and death.
Making a large structure resist crush loads is a serious problem. To resist internal pressure, the wall thickness has to scale with size (Pascal’s law) but to resist external pressure the walls have scale as the cube IIRC. So every time you double the size you need to increase the wall thickness by 8 times.
So your “dome” would end up more like a mountain with a cave in it? Could a three-mile-wide cave stand up in any material on the surface of the earth?
I can just see the advertising - “See the Titanic ZombieDome!”
Well, if the cave is three miles wide, and the water’s only 2 1/2 miles deep, we don’t need a dome any more… just build a gigantic cylinder about 10 miles across, with a 3 mile diameter hole in the center, et voila!
I think it might be easier just to raise the dang thing.
Like a lot of things the limiting factor is not the possibility of doing it, but who’s gonna pay for it.
If you put the best engineering minds in the world to the task and told them “money is not an issue” I’m sure they could come up with some hair-brained Rube Goldberg contraption that would would be workable but hideously cost prohibitive.
Ok…since no one else has pointed it out… Ten years ago, the OP said:
It’s been just over 10 years. So the answer is bound to be yes by now, right?
What would keep this giant air bubble from floating, it would be displacing millions of cubic feet of water? It would have to be heavier than the water it displaced.
Carbon-fiber nanotubes. Lots of them. It’s the answer to everything.
One of the problems with geodesic domes has been the difficulty of sealing them. That’s to keep out rain, which is incredibly light compared to the water pressure 2½ miles under the ocean.
Also, Bucky Fuller designed (mostly just sketches, not a full engineered design) city-sized domes, the largest ever actually built is only 710 feet – only about 4½% of what would be needed to cover the Titanic wreck site. I think there would be a lot of problems scaling a design up by a factor of 20-25 times.
They do it in mining although a couple miles is about as far as they go without staggering elevators. But these elevators are multi-story and can carry 100 people too, maybe smaller ones could go farther, I dunno.
I didn’t post that!
(But I agree with it.)
That would only work if the rotting bodies got up out of the ship, and shambled toward the viewers. It could be done, but it would ruin the experience for the history buffs. It would totally kill your market.
Yes.
Well, this one is only 9 years old, but here it is: Linky.
[sub]Guess what one I was looking for. But it’s less than a decade old.[/sub]
Question: Wouldn’t a 2.5 ATM pressure make you feel dizzy as well? I mean, it is a lot of air…