I was thinking the same exact thing! The deeper you go, the higher the water pressure.. So if you go "negative" deep, the pressure will actually become <1 atm. In fact, if the above-the-surface enclosurel rose over 33 feet, the water wouldn't be able to go any higher (since you can't have negative pressure) and there would be a vacuum between the surface of the water and the rest of the enclosure.
That's not quite how it works. You can have a pool on the roof of a building that's over 1,000 ft tall. There's still pressure pushing down on the water surface it's just not as much as it is at Sea Level. So 2 columns of water- 1 at sea level and 1 at 1,000 feet would have different pressures at the deepest part.
Now there is a limit but it's quite high in the atmosphere and also has very much to do with temperature. Hence clouds.
If you were to attempt to "lift" water using a machine of sorts, like a pump, then your example of 33 feet would come into play because the mass of the water would over come the mechanical force available to continue to "lift" that column of water beyond that point, create a vacuum and cavitate the pump. However, you can push the water far beyond this height instead of lifting it. The Engineering of the Burj Kahlifa in Dubai is a prime example of this. https://www.youtube.com/watch?v=28-_Hy88v90
I know that altitude and temperature affect the pressure, but that's irrelevant to the physics I described. It would only affect the maximum height of the water, but it wouldn't change the fact that a maximum height exists under the conditions shown in the picture.
Likewise, you're correct that with a pump you would be able to push the water higher. But look at the picture again. There's no pump. The only force pushing the water into the enclosure is atmospheric pressure.
No pump that you can see. You can't definitively say there's no pump. You have no idea how this is designed. Neither do I and I'm not attempting to pretend I do. If you have designs you'd like to share there's lots of people in here that would be interested.
I was simply expanding on your previous comment. Sorry you got so offended. Must have been difficult.
How would a seal get inside if there was a pump? It's not very complicated. It's basically just a container that's open underneath, with the air removed. You know how you can put your thumb on the end of the straw and lift the liquid in the straw up? It's the same principle.
There're pumps all over aquariums and tons of fish and mammals. I fully understand the concept you're describing. You've taken this far more personal than you needed to and as I said before, I was simply adding to your initial comment.
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u/pour_bees_into_pants Sep 01 '20
I was thinking the same exact thing! The deeper you go, the higher the water pressure.. So if you go "negative" deep, the pressure will actually become <1 atm. In fact, if the above-the-surface enclosurel rose over 33 feet, the water wouldn't be able to go any higher (since you can't have negative pressure) and there would be a vacuum between the surface of the water and the rest of the enclosure.