# Is It Possible for Us to Engineer Something Like This? **URL:** \ **Category:** Factual Questions\ **Created:** [October 25, 2003, 7:29pm UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540 "2003-10-25T19:29:47Z")\ **Posts on this page:** 17\ **Page:** 3
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [October 28, 2003, 2:58am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/41 "2003-10-28T02:58:39Z")
> [@](#): > > \*Originally posted by NoCoolUserName \* > **"The bends" happen when nitrogen, which is dissolved in the blood at high pressure, turns into bubbles at lower pressure. If there’s not nitrogen, you won’t get the bends. Not that I remember, but I believe there are some gasses that don’t exhibit that behavior, so we just use a mix of those with oxy, pressure up the underwater dome so it doesn’t implode, and we’re off to the races.** Helium. Deep divers often breathe a mixture of 3% oxygen and 97% helium, which prevents the bends. Also makes them sound like Donald Duck. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [October 28, 2003, 6:13am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/42 "2003-10-28T06:13:52Z")
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. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [November 10, 2013, 8:16pm UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/43 "2013-11-10T20:16:12Z")
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. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [November 10, 2013, 9:09pm UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/44 "2013-11-10T21:09:33Z")
> [@Kevbo](#): > > 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? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 11, 2013, 12:56am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/45 "2013-11-11T00:56:59Z")
I can just see the advertising - “See the Titanic ZombieDome!” ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [November 11, 2013, 1:12am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/46 "2013-11-11T01:12:33Z")
> [@Sunspace](#): > > 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? 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. ---
**Author:** ![zoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zoid/32/336_2.png) [@zoid](https://boards.straightdope.com/u/zoid)\ **Post date:** [November 11, 2013, 2:15am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/47 "2013-11-11T02:15:55Z")
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. ---
**Author:** ![Digital\_is\_the\_new\_Analog](https://avatars.discourse-cdn.com/v4/letter/d/a88e4f/32.png) [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)\ **Post date:** [November 11, 2013, 2:42am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/48 "2013-11-11T02:42:15Z")
Ok…since no one else has pointed it out… Ten years ago, the OP said: > [@Tuckerfan](#): > > And I mean _today_, not in 10 years or 50 years when we figure out how to make “unobtainium” or some other kind of material which doesn’t exist yet, but with modern day materials we already have. It’s been just over 10 years. So the answer is bound to be yes by now, right? ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [November 11, 2013, 2:55am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/49 "2013-11-11T02:55:50Z")
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. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [November 11, 2013, 3:07am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/50 "2013-11-11T03:07:27Z")
> [@Digital\_is\_the\_new\_Analog](#): > > 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? Carbon-fiber nanotubes. Lots of them. It’s the answer to everything. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [November 11, 2013, 3:13am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/51 "2013-11-11T03:13:33Z")
> [@Tuckerfan](#): > > Bucky Fuller designed a geodesic dome to cover NYC, and another one for St. Louis. (Neither of them has been built as of yet, but they’re certainly possible.) 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. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [November 11, 2013, 3:22am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/52 "2013-11-11T03:22:00Z")
> [@Kevbo](#): > > 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. Just curious, is today [dig up decade-old threads today](http://boards.straightdope.com/sdmb/showthread.php?t=219576) and everyone else missed it? ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [November 11, 2013, 4:31am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/53 "2013-11-11T04:31:44Z")
> [@t-bonham@scc.net](#): > > Then there’s the question of elevators 2-1/2 miles high. Could they even lift the weight of their own cables? Current tall buildings, like the Empire State Building, are only about 1/25th of that height. 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. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [November 11, 2013, 7:44pm UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/54 "2013-11-11T19:44:29Z")
> [@Fubaya](#): > > Originally Posted by [t-bonham@scc.net](mailto:t-bonham@scc.net) I didn’t post that! (But I agree with it.) ---
**Author:** ![Cheshire\_Human](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Cheshire\_Human](https://boards.straightdope.com/u/Cheshire_Human)\ **Post date:** [November 12, 2013, 12:43am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/55 "2013-11-12T00:43:24Z")
> [@beowulff](#): > > I can just see the advertising - “See the Titanic ZombieDome!” 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. ---
**Author:** ![Cheshire\_Human](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Cheshire\_Human](https://boards.straightdope.com/u/Cheshire_Human)\ **Post date:** [November 12, 2013, 1:20am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/56 "2013-11-12T01:20:17Z")
> [@Ferret\_Herder](#): > > Just curious, is today [dig up decade-old threads today](http://boards.straightdope.com/sdmb/showthread.php?t=219576) and everyone else missed it? Yes. Well, this one is only 9 years old, but here it is: [Linky.](http://boards.straightdope.com/sdmb/showthread.php?p=4508846&highlight=fried+sperm#post4508846) [sub]Guess what one I was looking for. But it’s less than a decade old.[/sub] ---
**Author:** ![Artemis\_Tardis](https://avatars.discourse-cdn.com/v4/letter/a/4bbf92/32.png) [@Artemis\_Tardis](https://boards.straightdope.com/u/Artemis_Tardis)\ **Post date:** [November 12, 2013, 1:29am UTC](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540/57 "2013-11-12T01:29:03Z")
Question: Wouldn’t a 2.5 ATM pressure make you feel dizzy as well? I mean, it is a lot of air… [Previous page](https://boards.straightdope.com/t/is-it-possible-for-us-to-engineer-something-like-this/209540.md?page=2)