Another scientific question

[Amblin]

You know how water stays in a drinking straw when you put your finger on top of it?
What if you built a much bigger drinking straw filled with water and a sealed top, but an open bottom?
Couldn't someone theoretically be swimming in it, but as soon as he's about to drown he would just fall out of the bottom which is open?

[PANZERCATWAGON]

Hmm, well I don't think it is actually possible to do something like that on that scale.

The only reason the water does not fall in a drinking straw is because, by covering up the top of the straw with your finger, no more air is being allowed into it. Therefore, since there is no more added weight ontop of the water once you take it out, it carries on being attracted to the sides of the straw and to itself. This causes it to be pulled up the straw until the weight of the air above it equals that force and the water is held in position.

It doesn't apply to your scale however, because the surface tension of the water would be very very small in comparison to a droplet size. Therefore the air would easily be able to break the surface tension and fill the straw from underneath.

Was a good idea though. 8D

[Amblin]

Something must be wrong with the forums. The first reply wasn't braindead - it even explains everything correctly.

Where am I?

<@Amblin> I wonder how long it will take them to mention surface tension

[Espadon]

Indeed. It was a good idea, but the fact that surface tension doesn't increase proportionally to the scale of your concept foiled it. =\

We can test this like so: obtain two 500 mL containers; 1 which is narrow and thin, 1 which is short and squat. Fill the both so they have, say 500 mL of water in them. Use a flat card or something to cover the opening up while inverting both containers; now, remove the cards and lift both containers. The squat 500 mLs will fall out, while the narrow 500 mL stay in. Hydrogen bonds are relatively powerful, but there's still a threshold.

[PANZERCATWAGON]

Hmm, what if you tried this in space? Would you get a different result due to there being no gravity?

[Kszchroink]

Well, obviously the person would sink through the water and then he'd suffocate because there is no air in space!

[{LAW} Gamer_2k4]

Hmm, what if you tried this in space? Would you get a different result due to there being no gravity?

You wouldn't need anything in space.  The liquid would just become a sphere by itself.

[PANZERCATWAGON]

Well, obviously the person would sink through the water and then he'd suffocate because there is no air in space!

Hahaha. I meant in a space-ship. And also I didn't mean with the guy swimming in it, I meant with just a small straw.

Hmm, what if you tried this in space? Would you get a different result due to there being no gravity?

You wouldn't need anything in space. The liquid would just become a sphere by itself.

I meant would the water continously travel up the straw do to the fact that there is no gravity pulling the air down.

I'm not sure though, because I don't know how air expands in space differently to here on earth. There would definitely be force on the water due to the expansion of the air, but that happens with all gases.

My question is; would the force of the air on the water in space be greater or weaker in space?

[Espadon]

Same, just that it would be applied equally from all sides. Do remember, a person swimming in a bubble of water in space will cause the water to break up into many many little blobs.

[PANZERCATWAGON]

What does the swimming in water have to do with anything!!?

Forget the guy swimming in water.

Ugh forget it I'll just draw a diagram .......

[Espadon]

I wouldn't know about that scenario. I think the gas would attempt to diffuse through the liquid.

[Wraithlike]

It wouldn't keep it in, the only reason it works in a straw is because of surface tension. It's somewhat similar to teh way a murcury barometer works. I could give a better explaination, but just go here.

[Mangled*]

Actually a pretty good question.

I think the main reason it wouldn't work is the sheer weight of the water, it would create a vacuum above it which would draw air up through the water causing the water to drop out the bottom. And yes, the water tension would not be sufficient to either prevent air from passing through it and also would not be enough to counteract the gravitational pull.

[Cookie.]

Same, just that it would be applied equally from all sides. Do remember, a person swimming in a bubble of water in space will cause the water to break up into many many little blobs.

The cohesive force of the water would probably keep it together.

[ghg]

You'd drown.

[Graham]

Panzer if we put the water in space wouldn't it freeze before we got to swim?

[Kszchroink]

What if this is hypothetical water which doesn't freeze?

[a-4-year-old]

I thought space didn't have a temperature, since space is nothing, or did I just quote a textbook from the 60s because our schools lack proper budgetting?

[blackdevil0742]

The space has temperature.

[a-4-year-old]

The space has temperature.

LIEZ! The internet is never wrong!

"Empty space itself cannot have a temperature, unless you mean some
abstruse question about quantum vacuums.

However, if you put a physical object into space, it will reach a
temperature that depends on how efficiently it absorbs and emits
radiation and on what heating sources are nearby."