So, you can have an air bubble/space by trapping air under a dome and dragging it under water. You may have done this with a cup.
I propose a huge pool, maybe like 20 feet deep, that has a dome in it. In this dome, there is air space. The floor of the pool is built up to provide a floor in the dome. So you swim down, slip under the dome edges, and up out of the water, into this whole secret party area. It could have a bar, pool chairs, etc. And there's even another pool! A pool within a pool! It's the most ballin' stuff evah! It's like a whole secret club/party area.
OK, so to deal with the techinicalities: Refilling the air could be a completely passive system, in terms of the structure, and divers just bring in tanks full of compressed air to replenish the air. You don't need any "exhaust" by the way, you just need to provide enough fresh air to drive the O2/CO2 ratio in the right direction. Or you could have a compressor at the surface, with a tube going down into the dome, and the compressor would pump air into the tube down into the dome. The compressor would not necessarily have to be on the entire time, but whenever it's off it would have to have a valve from the tube closed off from the outside world, or else the water pressure will push out all the air from the dome and the dome will fill with water.
Another cool design feature that you could have is that the dome is made of clear material, so the people inside could see the surface from their dome. Or better yet, it could be made out of that material that can change from clear to opaque, so you could have a privacy switch.-- EdwinBakery, Sep 20 2010 Same idea, sorry Pool_20Observation_20Bubble[marked-for-deletion] redundant [ldischler, Sep 20 2010] The mobile, and dangerous, version of this Semi-submersible_20Ferris_20wheel [hippo, Sep 21 2010] Shallow Water Bends http://www.divenewz...ive-articles&id=135 [scad mientist, Aug 23 2012] The Jules Underwater Lodge http://www.jul.com/Things to see and do in Key Largo, FL USA [CraigD, Aug 23 2012] Beat ya by seven years. above_20ground_20swimming [2 fries shy of a happy meal, Aug 25 2012] ***it would have to have a valve from the tube closed off from the outside world, or else the water pressure will push out all the air from the dome and the dome will fill with water.***
High school physics went a little over your head, I take it?-- infidel, Sep 20 2010 Yeah, like Geostationary orbit ?-- 8th of 7, Sep 20 2010 no, it didn't.
If there's a hole from the dome to the outside air, the dome will fill with water.-- EdwinBakery, Sep 20 2010 / ***it would have to have a valve from the tube closed off from the outside world, or else the water pressure will push out all the air from the dome and the dome will fill with water.***
High school physics went a little over your head, I take it? — infidel, Sep 20 2010 /
I forsee this gem of wrongheaded snark being deleted, so I will here preserve it for posterity.-- bungston, Sep 20 2010 [infid8th] If you open a hole in the top of this thing the air won't escape? Why not?-- nomocrow, Sep 20 2010 that's exactly what I'm saying - if you want to use a compressor then there'd be a tube connecting to the compressor, which is open to the outside world. If you didn't keep a valve closed, then the dome and the tube would fill with water. Whenever the compressor isn't running, the valve would have to remain closed and be able to hold off air at the same pressure as water creates at the depth of the dome minus standard atmospheric pressure.
It's usually not an issue with a compressor, the valves are naturally closed in such a manner when it's off. I'm just saying is all. Just re-iterating that obvious point.
Come on, guys, try to keep up-- EdwinBakery, Sep 20 2010 If the compressor fails AND there are no valves preventing backflow, then the dome will fill with water UP TO THE LEVEL OF THE END OF THE AIR HOSE. At this point, the HOSE will fill with water, but the dome will remain filled with air.
Simple solution: Place the end of the hose below the rim of the dome, and allow the bubbles to float up into the dome.
to Nomocrow: Where was there there any mention that the hole was at the top of the dome?-- Freefall, Sep 20 2010 But that's so ... 17th century ....-- 8th of 7, Sep 20 2010 //so I will here preserve it for posterity//
The madness...-- ldischler, Sep 20 2010 S'OK, you can get tablets for it.-- 8th of 7, Sep 20 2010 I also think the artist James Turrell did a piece of work like this.-- xenzag, Sep 20 2010 /the hole was at the top of the dome?/
The dome is the smoking section of the restaurant as the air circulation is excellent in there. Someone got soused and held his lighter up to the top to see what would happen.-- bungston, Sep 20 2010 //...the dome is made of clear material, so the people inside could see the surface from their dome.//
This sort of kills the//whole secret party area//doesn't it? Makes it sort of a 'public underwater fishbowl.'
Still, I like this. Bungo! [+]-- Boomershine, Sep 20 2010 Perhaps I misread the rambling discourse presented by you, Edwin. If you don't have an exhaust method, but just add more air/oxygen then I foresee problems with habitual users developing the bends.
And, if you push just a little too much air into this thing, or even oxygen, as you suggested earlier, the dome will pop up out of the water and flip over... unless it's anchored very firmly.
Even if you did have a hole at the top, the water level will simply equalise with that outside the dome. Of course, the dome could be completely submerged, which would allow it to fill with water, though your idea doesn't actually specify that.
Hence my comment about your misunderstanding of physics. The idea is riddled with problems.-- infidel, Sep 20 2010 How is this thing functionally different than a diving bell? Same concept. Do db users get the bends? Even in a shallow pool?-- Boomershine, Sep 20 2010 infidel,
what the hell, man? Stop saying I don't understand my physics. You've got to stop making weird assumptions
The dome isn't going to float becuase the whole thing will be made out of freaking reinforced concrete. How the hell else would you make it? That's the only truly structurally sufficient method. I wouldn't trust the other stuff you could do.
nobody's going to get the bends at like 15 or 20 feet of total depth
my idea specified that the dome is completely submerged, read it.-- EdwinBakery, Sep 21 2010 This idea isn't an observation bubble. They have those and you can buy those. But they have a tiny bit of room only.
This would be very big, and have its own second pool in it. And like a tiki bar. Maybe a hot tub.
The Playboy Mansion Grotto won't have nothin' on my idea.-- EdwinBakery, Sep 21 2010 Whatever.-- infidel, Sep 21 2010 You know when people get out of the pool when it rains? (I suppose they don't want to get wet). Well, this idea means that you can stay in the pool, even in a heavy downpour.-- Ling, Sep 21 2010 Might be a problem with the reinforced concrete in the case of a nearby lightning strike.-- infidel, Sep 21 2010 Faraday cage-- Ling, Sep 21 2010 Isolation cage.-- infidel, Sep 21 2010 [Edwin], although it may be pretty close to the extent of my breath-holding capacity to swim down 20 feet before slipping under the dome, it sounds like a hoot. Turn the sharks loose in the outer pool only after most of the guests arrive. Those guests late for the party will likely become part of the evening's entertainment. Here's one soggy bun. [+]-- Grogster, Sep 21 2010 bun for shark infested public party underwater fishbowls with cage fights-- Voice, Aug 22 2012 Oh I'm sure you could swim down 20 feet and slip under no problem, that's not that deep. You don't have to swim far laterally or whatever, just go right above the edge, plunge down to 20 feet, and slip under and up, where the surface of the water (inside the dome) would be.-- EdwinBakery, Aug 22 2012 Definitely have a pump/compressor just continually bubling air in beneath the dome. Far safer than an occasional re-fill, and also allows for a clear visual if the air supply cuts off.-- MechE, Aug 22 2012 I think the continuous bubbling is the way to go too. You'd need about 1.7 x atmospheric pressure, which I assume is fine? The top of the dome can then feature a delicate pressure release valve... so you get lots of lovely exhaust bubbles coming out the top.-- bs0u0155, Aug 22 2012 also, you might want to have a strict 'no diving' policy. Plunging face-first into a submerged poly carbonate dome would ruin your day.... funny from below though.-- bs0u0155, Aug 23 2012 Just FYI, it IS possible to get the bends diving to 20 feet (see link). It sounds like it is most likely to happen if you make many trips up and down with the majority of time spent at depth. So the guests probably have fairly low risk, but make sure the waiter at the bar doesn't make frequent trips up to get more supplies. It would probaly be a good idea to install an exit path with small bubbles at appropriate depths so people have the option to decompress slowly.-- scad mientist, Aug 23 2012 or a shaft with two airtight doors forming a compression/decompression chamber, and a dumbwaiter in it;-- EdwinBakery, Aug 23 2012 polycarbonate? Why? Why does everyone keep assuming light materials? Concrete would clearly be the choice here-- EdwinBakery, Aug 23 2012 Your original idea did specify a transparent dome as an option, and in some respects that is the more interesting version.
A polycarbonate shell wouldn't have to be very thick since it could be a tension structure rather than compression. It would just have to be anchored well to the bottom. Concrete isn't very good for tension, but since it's so heavy you probably wouldn't have to make it too thick before it was heavy enough to cancel out the air pressure underneith, resulting in compression over the whole structure.-- scad mientist, Aug 23 2012 Seems something like the Jules Underwater Lodge ([link]), except rather than being in a pretty lagoon, it’d be in a stark concrete pool, and with bars in place of bedrooms.
Entering and exiting through a moonpool, though, is beautiful, expecially with the right lighting on it. [+]-- CraigD, Aug 23 2012 The thing no-one knows (except the cool people) is that pool inside the dome under the pool actually has another dome down inside it. It is a sort of recessive dome in pool system until finally there is room for just one in the tiny dome in a pool in a dome in a pool in a dome in a pool and so on. And you have to curl in the fetal position to fit.-- bungston, Aug 24 2012 would there be a pool table involved?-- not_morrison_rm, Aug 25 2012 random, halfbakery