# Objects that don't float in water, sink to the bottom ... **URL:** \ **Category:** Factual Questions\ **Created:** [March 29, 2004, 8:49pm UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159 "2004-03-29T20:49:17Z")\ **Posts on this page:** 9\ **Page:** 5
**Author:** ![CoatOfArms](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@CoatOfArms](https://boards.straightdope.com/u/CoatOfArms)\ **Post date:** [March 31, 2004, 12:04am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/81 "2004-03-31T00:04:37Z")
> [@Mangetout](#): > > It can happen - if you have a room full of still air and a helium balloon with _just enough_ gas in it to make it neutrally buoyant — Yea, but they must be in motion, I find them on the floor the next morning :rolleyes: ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 31, 2004, 12:19am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/82 "2004-03-31T00:19:28Z")
That’s because the gas continues to leak out of them. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 31, 2004, 12:21am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/83 "2004-03-31T00:21:32Z")
Actually, that is only half true; what typically happens with helium ballons is that there is a certain amount of static cling keeping them on the ceiling, by the time enough gas has leaked out for them to be heavy enough to pull away, they are no longer neutrally buoyant (and if they were, they would still stay up there anyway unless otherwise moved). ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [March 31, 2004, 12:50am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/84 "2004-03-31T00:50:52Z")
> [@CoatOfArms](#): > > Yea, but they must be in motion, I find them on the floor the next morning :rolleyes: Try it with a mylar balloon. They lose the helium much more slowly. We had a heart-shaped balloon from Valentine’s Day this year that spent several days wandering around our apartment in a state of neutral bouyancy before it finally lost enough helium to permanently return earthward. ---
**Author:** ![ArrogantTwit](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@ArrogantTwit](https://boards.straightdope.com/u/ArrogantTwit)\ **Post date:** [March 31, 2004, 6:03am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/85 "2004-03-31T06:03:22Z")
> [@PictsiePat](#): > > OK this is MY last reply on this subject: > … > No it’s not a razor fine distinction. Nor do you have to take it to 27,000 decimal places which as an engineer I find ludicrous, mostly 3 significant figures works fine. You can do it at home in a hot tub or an aquarium. Please see the link I have posted. Again, I reiterate, this is not Rocket Science. This is a Statics problem. The sum of the forces = ZERO. It is no more complicated that that. > … You can place the object at a point of static equilibrium, but it’s interesting to ask whether the equilibrium is _stable_. I think I disagree with LSLGuy’s analysis, though I think I agree with Mangetout; an object that is **more** compressible than water would be in a positive feedback loop, or in **unstable equilibrium**. As the pressure increases with depth, the more compressible object would become denser than the water and the net forces would push it further down. It’s like trying to balance a bowling ball on top of another bowling ball. If you get them lined up exactly, then they are in static equilibrium, but I wouldn’t expect them to stay there for long. Obviously, the net force imbalance on submerged objects near their static equilibrium point must be much smaller, or neither Perrier bottles nor submarines could stay submerged at a constant depth for long. I don’t know if Perrier bottles are more or less compressible than water, but I’d guess that submarines are more compressible. So, in the very long run, I’d expect that the crew needs to actively manage its depth control. -ArrogantTwit ---
**Author:** ![sturmhauke](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)\ **Post date:** [March 31, 2004, 6:45am UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/86 "2004-03-31T06:45:56Z")
> [@ArrogantTwit](#): > > I don’t know if Perrier bottles are more or less compressible than water, but I’d guess that submarines are more compressible. So, in the very long run, I’d expect that the crew needs to actively manage its depth control. > > -ArrogantTwit Submarines are certainly more compressible than water. If a sub goes lower than the “crush depth”, the hull collapses from the pressure, and then… well, it’s not pretty. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [March 31, 2004, 3:21pm UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/87 "2004-03-31T15:21:38Z")
> [@ArrogantTwit](#): > > It’s like trying to balance a bowling ball on top of another bowling ball. If you get them lined up exactly, then they are in static equilibrium, but I wouldn’t expect them to stay there for long. Get a load of this: [Record for stacking bowling balls.](http://www.guinnessworldrecords.com/index.asp?id=52895) ---
**Author:** ![ArrogantTwit](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@ArrogantTwit](https://boards.straightdope.com/u/ArrogantTwit)\ **Post date:** [March 31, 2004, 5:02pm UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/88 "2004-03-31T17:02:52Z")
> [@commasense](#): > > Get a load of this: [Record for stacking bowling balls.](http://www.guinnessworldrecords.com/index.asp?id=52895) Great! I had thought of specifying that the bowling balls be without finger holes, but my post was getting long enough. At least in the close up of the men working, it looks like they are lining one finger hole on the top of one ball to serve as a small “base” for the next. And, each stack starts on some kind of pad. Each device helps to create a very small zone of stable equilibrium. [Spoiler!] Of course, the zone ends up being too small. I hope the camera operator was not hurt. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [March 31, 2004, 7:05pm UTC](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159/89 "2004-03-31T19:05:49Z")
No, I don’t think they do use the finger holes. There may be a pad under the bottom one, but I’m not even sure about that. [Previous page](https://boards.straightdope.com/t/objects-that-dont-float-in-water-sink-to-the-bottom/237159.md?page=4)