Champagne in space

[Eagle]

Basically, the effect you're describing is buoyancy--which doesn't work well in zero-g. There are numerous videos on YouTube of bubbles inside water spheres (watch the alka-seltzer one especially), and you can easily see that the liquid doesn't "push" them out.

I'm describing viscosity which is NOT the same as buoyancy. The density difference between liquid/foam is a factor in the viscosity difference. But that has nothing to do with gravity, just directly with mass and inertia.

Imagine the zero g boiling video, but have the water boil all over the inside of the sphere. The bubbles recombined and continued to grow. So from a completely inertia based in order to expand they must either push a mass of liquid or a mass of other bubbles out of the bottle. Pushing through the liquid may be more direct, but much more mass must be pushed compared to pushing out on nearby bubbles. (any bubbles that have a path that goes directly out of the bottle have an easy choice).

But hey, claim that I'm making a trivial mistake by forgetting that there's not gravity on ISS.

Regarding friction against the bottle. That may make a big difference. One possible outcome could be a later of stuck bubbles and movement at an inner layer near the bubble/liquid interface.

 

[Hielor]

I'm describing viscosity which is NOT the same as buoyancy. The density difference between liquid/foam is a factor in the viscosity difference. But that has nothing to do with gravity, just directly with mass and inertia.

Imagine the zero g boiling video, but have the water boil all over the inside of the sphere. The bubbles recombined and continued to grow. So from a completely inertia based in order to expand they must either push a mass of liquid or a mass of other bubbles out of the bottle. Pushing through the liquid may be more direct, but much more mass must be pushed compared to pushing out on nearby bubbles. (any bubbles that have a path that goes directly out of the bottle have an easy choice).

But hey, claim that I'm making a trivial mistake by forgetting that there's not gravity on ISS.

Regarding friction against the bottle. That may make a big difference. One possible outcome could be a later of stuck bubbles and movement at an inner layer near the bubble/liquid interface.

As the boiling video shows quite plainly, the bubbles will not be pushed out despite their lesser density. Buoyancy is what "pushes" something out of a liquid, not viscosity.

CJP: Can't bubbles still form at the interface between the champagne and the existing bubbles, not just at the champagne/glass interface?

 

[cjp]

CJP: Can't bubbles still form at the interface between the champagne and the existing bubbles, not just at the champagne/glass interface?

I guess so. In fact, as I understood, this is the main reason why shaking the bottle works so well: you create a lot of gas/liquid surface, which acts as a location where CO2 can dissolve from the liquid. Additionally, you may also create vortices.

So, the bubbles that are formed on the glass surface continue to grow, right? I guess it will form a boundary layer of Champagne with low CO2 concentration close to the glass, and after a short time, CO2 dissolving will be limited by diffusion of CO2 towards the glass.

I think the bubbles at the glass surface will combine together, and if you really make sure you don't move the bottle, the Champagne will eventually no longer touch the walls of the bottle.

The continued growth of the CO2 layer (slow, as it's diffusion limited) will slowly push the liquid out of the bottle. Aarghh! This is more like answer B!

The multiple choice answers are all very good! I guess they were created by asking this question to three different physicists.

This REALLY needs to be tried. Either by someone on this forum who can do things in zero-G, or by the makers of this quiz. They will present what they think is correct in a television show at January 1st. I wonder what they will do to make the other two answers implausible.

 

[Eagle]

As the boiling video shows quite plainly, the bubbles will not be pushed out despite their lesser density. Buoyancy is what "pushes" something out of a liquid, not viscosity.

CJP: Can't bubbles still form at the interface between the champagne and the existing bubbles, not just at the champagne/glass interface?

I'm apparently not saying this clearly enough. In order for a bubble to expand it must push out on all sides. If you look at a bubble that is surrounded entirely by liquid it will act exactly like the video.

But if the bubble forms in the middle of a U shaped pipe and there is only liquid on the right side of the pipe and only foamy bubbles on the left side of the pipe. The expanding bubble will push on both the foam and liquid with the same force. But the liquid has more total mass, so the liquid will be accelerated slower than the foam. So the bubble will expand more in the direction of the foam.

Liquid will still get pushed out of the bottle, but its being pushed on every side but the direction of the neck. But there are foam bubbles in that direction too, so there is still some pressure pushing back in that direction.

If anyone can explain this concept better, please do.

Regarding nucleation of bubbles on the liquid/bubble interface, it may be possible to nucleate bubbles there, but diffusion into existing bubbles seems to be most likely.

EDIT: And for the record, my answer is C

 

[simonpro]

Maybe simonpro can try to do it, if he still does the parabolas regularly?

Not a chance, ESA would be rather annoyed if their plane got covered in champagne

The Americans amongst us might have more luck, zeroG corporation normally ends the day with a plane covered in vomit, so they'd probably treat the champagne as a welcome change.


Anyway, I've seen quite a few experiments with liquid propagation inmicrogravity and would suggest based on those that option C would be the solution. Generally liquids (even with bubbles) don't do anything particularly interesting in zero-g due to the lack of convection.

 

[cjp]

But if the bubble forms in the middle of a U shaped pipe and there is only liquid on the right side of the pipe and only foamy bubbles on the left side of the pipe. The expanding bubble will push on both the foam and liquid with the same force. But the liquid has more total mass, so the liquid will be accelerated slower than the foam. So the bubble will expand more in the direction of the foam.

Ah, I forgot something.

Suppose that, at some point, a layer of CO2 gas is formed at every point between the liquid and the glass, and the neck is filled with gas too. CO2 will escape slowly from the liquid into the gas (no, that won't form extra bubbles, it just increases the gas volume).


Now, this gas can mostly escape freely through the neck, where it doesn't have to push the heavy liquid. So, this is like C, and not like B.

Now, this system is not very stable, as the bottle is almost completely filled with liquid, so the liquid is likely to touch the glass very often. First, the popping of the cork will also push the bottle backwards, causing some motion inside the liquid itself. Second, in the initial state, the liquid probably touches the glass. Third: even if you managed to create this system, the slow stream of CO2 is likely to create some aerodynamic forces onto the liquid.

So, what happens when the liquid touches the glass somewhere? On most places in the bottle, nucleation sites on the surface will simply generate CO2, pushing the liquid back from the surface. It will probably push the liquid to the other side of the bottle, where the process will start over when it touches the glass again.

When the liquid somehow closes the neck of the bottle, the expansion of CO2 in the bottle will push some liquid out of the bottle. Or maybe it will just create a channel through the liquid, depending on how violent all the reactions are.

I think the dynamics of the whole process are quite complicated. The life-time of the bubbles could also influence the system, as bubbles are probably more effective in keeping the liquid from the glass than normal gas. The violence of the reaction happening when the liquid touches the glass depends on whether the low-CO2 concentration boundary layer is intact.

A related question is: what shape does a normal liquid tend to have in a bottle in zero-G? I mean, in air it tends to be a sphere, but what will the surface of the bottle do to the shape of a non-carbonated liquid?

 

[tblaxland]

A related question is: what shape does a normal liquid tend to have in a bottle in zero-G? I mean, in air it tends to be a sphere, but what will the surface of the bottle do to the shape of a non-carbonated liquid?

Surface tension makes it stick to the bottle material. See this video (by Mike Fincke, I think?):

 

[DaveS]

Surface tension makes it stick to the bottle material. See this video (by Mike Fincke, I think?):
YouTube - Astronaut demos drinking coffee in space

Actually, that's Don Petitt, the inventor of the first ever space-cup! He's known for his unusual "Saturday-science" experiments.

 

[tblaxland]

Actually, that's Don Petitt, the inventor of the first ever space-cup! He's known for his unusual "Saturday-science" experiments.

Thanks for correcting my error. I knew it was one of the recent flyers.

 

[Linguofreak]

I think to some degree the result you get will depend on how full the bottle is, whether the liquid is all in one globule (if the bottle is less than half full and has recently been shaken, you may have more than one big globule floating around), and which end of the bottle most of the liquid is on. If the bottle is nearly full and the gas pocket is towards the base, I'd expect mostly liquid to be expelled. If the gas pocket is towards the neck, I'd expect mainly gas and foam.

Also, you have to consider environmental factors such as the exact pressure differential and whether the bottle is restrained or free floating.

 

[cjp]

The official answers were presented yesterday evening on television. Of 20 questions, I had 4 wrong, of which 1 deliberately (my answer is better than theirs ), and I want to try another one before believing they are right. The best results of people submitting their answers was 2 wrongs.

On the champagne question: C is correct. They defended this answer the following way (presenter talking, with picture of somebody in a Zero-G airplane in the background):

We (the TV quiz people) asked ESA scientists, but they didn't know the answer immediately. A Belgian ESA astronaut, named Vladmir Pletser, tried this in zero gravity, and his first description was "no big fizz". Large bubbles formed, and closed the neck of the bottle, which stopped most of the liquid from leaving the bottle.

Unfortunately, no video or images of the experiment were available. The presenter commented on this by saying that Vladmir wasn't "going back to space" to try it again.