# Tagged Questions

A coherent region of fluid embedded in a fluid with different properties (air in water) or a coherent region of fluid surrounded by a membrane embedded in a fluid which may or may not be different (such as air in a soap membrane).

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### Two rising bubbles of differing temperatures

Consider two bubbles rising through some medium (water, for example). Given that the two bubbles have the same initial size, pressure, and temperature but differing velocities, which bubble will be ...
54 views

### Physics behind blowing soap bubbles

Is it possible, using the surface tension of a soap bubble, to calculate the maximum pressure (created by the air flow) it can withstand while still attached to the orifice to prevent it from bursting?...
277 views

### What is the real cause of the boiling (forming of bubbles) of water?

I've got a question about the boiling of water. I'm a first year physics student and from the Netherlands. I've searched alot about the boiling of water and this confused me. Everyone said something ...
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### What is the difference between pressure in water droplet and that in an air bubble?

The question is at least supposed to be simple but yeah, I need some detailed answers. I have tried thinking about it in the lines of surface tension but it seems what is required of me is more than ...
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### Most Efficient Way to Pop Bubbles [closed]

I was bathing the kids the other night, and used more bubble bath than normal. Being small, they got a bit freaked out by the enormous piles of bubbles that they had to sit in. To try to diffuse the ...
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### What makes some air bubbles in water more persistent?

In a plastic bottle of water, near the walls, it is common to observe the presence of little bubbles (I would estimate them to be $\approx0.5$mm in diameter. In my experience, most of these bubble ...
51 views

### Why do bubbles group when one pops? [duplicate]

I was recently observing the way bubbles move as they pop and disappear. I noticed that when bubbles destabilize and pop, the remaining bubbles immediately surrounding it will move to fill its place. ...
475 views

### Can I blow soap bubbles (of air) inside a vacuum chamber?

When I blow soap bubbles from a liquid dish soap mixed with distilled water at atmospheric pressure at ground level both internal and external air pressure nullify and the tension of the bubbles holds,...
36 views

### What causes fizz?

When you go to a soda fountain and pour some soda into your cup, frothy fizz is generated at the top of the cup. What causes this? Obviously has something to do with carbonation, but when my cup is ...
159 views

### Why do liquids form less bubbles when poured at an angle?

For example, I noticed that when I pour a soda on the side of a glass instead of directly into the cup, it forms less bubbles. This is also evident with rootbeer floats. Is this an actual scientific ...
648 views

### Why does a bubble take a spherical shape?

I suspect this has something to do with thermodynamics and the isoperimetric inequality and I'm interested in a mathematical derivation of this result.
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### Excess pressure in drops

while calculating the excess pressure in a bubble or a drop we consider one half of the bubble or a drop and equate the surface tension times the circumference of the half of the drop or bubble to ...
151 views

### How to move a bubble which is trapped by the capillary pressure?

I have a question about how to move a trapped bubble in a tube. If we assume to have a horizontal tube, with water on each side of the bubble. The point to the left of the bubble is point 1, while ...
734 views

### Are bubbles in ice at a lower or higher pressure than atmospheric pressure?

When water phase-transitions into ice it expands. The water usually contains dissolved air. Freezing forces the air out of the solution into bubbles. Are these bubbles at a lower or higher pressure ...
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### How does a rising bubble take a dome-like shape?

Since I have swam on the swim team for most of my life, I am very familiar with bubbles. I know a raindrop falling through the sky gets its shape because it is the most aerodynamic shape, but how come ...
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### Does nucleation depend on the rate of change in pressure in a carbonated liquid?

Carbonated beer flowing from a keg through a short length of tubing results in large quantities of foam. Unintuitively (at least to me), increasing the length of tubing results in a less frothy drink. ...
14k views

### Why does water sometimes form bubbles when I pour it into a glass?

Sometimes when I'm filling up a container with water from the tap, bubbles will form on the top of the water. They look a little like soap sud bubbles, but there's no soap suds present. I notice, ...
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### Do bubbles splash downward?

When a solid ball drops into water, the kinetic energy of the ball pushes water upwards into what we call a splash: Does a similar effect occur when bubbles 'drop' upwards from the water into the ...
146 views

### Can a fruit fly move through a large bubble without popping it?

Assume what logistics you need to in order for something like this to be possible. Can a fruit fly move through a large bubble without popping it?
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### Can you blow bubbles on top of Mount Everest?

Can you blow bubbles on top of Mount Everest? How would they be different in low temperatures and pressures?
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### Viscosity, bubbles and (super)fluids

3-part question, but I think it's simple enough... Does the tendency for cavitation in a fluid depend on its viscosity? If so what does this imply for superfluids, having 0 viscosity? And for that ...
253 views

### Bubble in a pipeline

I am just thinking about this phenomenon: We have a horizontal pipeline with a flowing liquid, which contains a small bubble of gas. How do the dimensions of this bubble change when it reaches a ...
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### What are these arcs in bubble chamber photos?

In photos such as this one, or this one (too large to fit inside post), what are the highly frenzied arcs that are really prominent in these photos? Are they simply physical walls in/of the ...
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### The shape of a bubble? [duplicate]

I have always wondered about a shape of a soap bubble. Why is it always spherical and not some other shape (like, cylindrical)? And why are the layers of the soap bubbles so thin? Also when someone ...
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### Is the acceleration of a soap bubble the standard value of gravitational acceleration?

Is the acceleration of a basic soap bubble the same as the standard value of gravitational acceleration 9.81 m/s^2 when it is dropping in a windless space? I have used the Newton's 2nd law to prove ...
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### Bubbly Flow and two phase flow modelling

When we pour vine or some other drink why bubbles move upward and what law they follow or what is the law that describe that motion? One other question If we consider a simple two phase flow between ...
416 views

### Can an air bubble in a liquid be faster than its terminal velocity

The title says it pretty much. I am wondering if an air bubble in a liquid can move faster (relative to the surrounding liquid) than its terminal velocity?
10k views

### Why is light produced when an underwater bubble is collapsed with a sound wave?

Why is light produced when an underwater bubble is collapsed with a sound wave? I have come across this fact on a page (similar to this) but can't understand "Why". I'm just curious about this ...
128 views

### Change in radius of a charged bubble

I was thinking about what'd happen to the radius of a bubble, if a charge is uniformly distributed over it. At the beginning, I thought that the bubble would expand, for sure, because of the like-...
853 views

### What could be added to tap water to reduce air bubble formation on a submerged object?

Submerge your hand in a bucket of water. Some air bubbles appear immediately and others add to the surface of the hand over time. Is there anything that could be added to the water to reduce the ...
2k views

### Surface tension and soap bubbles

In a common experiment, you can make a paper clip float on water due to the strong surface tension. Adding just a tiny bit of soap immediately destroys the surface tension and lets the paper clip sink....
231 views

### Bubbles of Different Size

Suppose that I have 2 bubbles of different sizes located in a liquid, and assume that both of those bubbles are close to one another. What exactly will happen to both of those bubbles? From a ...
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### Why do soap bubbles rise?

If I have a soap bubble then it will move rather randomly upwards perhaps due to the initial force from me blowing it, and eventually take ground moving downwards. Another answer to a similar ...
1k views

### Would a perfectly clean and perfectly smooth champagne glass have no bubbles?

My understanding is that nucleation sites for bubbles in a champagne glass are either due to defects in the glass or due to fibers in the glass. (See this article for details on that statement.) Does ...
106 views

### Frost bubble formation

I woke up recently to find the following structures on my lawn; they resemble bubbles, but are formed from ice (we had a moderate frost overnight). There were eight of these 'bubbles' on my lawn and ...
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### Why is there a limited range of possible soap bubble size?

Soap bubbles are never "too small" or "too large". What defines the range of possible diameters of a soap bubble? Related questions: Why do steam bubbles increase in size as they rise, Why is the ...
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### Bubble pressure ascending?

In water bubbles rise up to the surface. As it rises, does the bubble's pressure decrease or stay the same? I think stays the same.
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### Explaining to a five year old - why don't bubbles run like water

My five-year old daughter was asking about astronauts the other day and why they float in space. After me showing her a few bits on the kids section on the NASA web site I started explaining about the ...
1k views

### Solving the Young-Laplace equation for arbitrary axisymmetric geometry

Say I have a non-ellipsoidal soap bubble and I want to numerically analyse the pressure in the inner lobe of this bubble here: The Young Laplace equation gives the pressure difference across a ...
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### What are the equations of motion of a hole in a soap bubble?

Imagine the following situation: I have a thin stationary water film, like a soap bubble, suspended inside a large ring. I throw a small loop of string onto the film and punch a hole inside it. How ...
5k views

### What is the physics behind a soap bubble?

A soap bubble is an extremely thin film of soapy water enclosing air that forms a hollow sphere with an iridescent surface. What fluid dynamical process occurs during the popping of a soap bubble?
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### Why do bubble wands have ridges?

The bubble wands supplied with children's bubble mixtures seem to fairly universally have a set of ridges around the hole used to create bubbles - for example, see the circle in the upper right of ...
44k views

### Surviving under water in air bubble

An incredible news story today is about a man who survived for two days at the bottom of the sea (~30 m deep) in a capsized boat, in an air bubble that formed in a corner of the boat. He was ...
292 views

### Two air bubbles inside a liquid

I know that if two air bubbles which are formed inside a liquid are somehow joined using something (say a small tube), then, as the bubble with the larger radius has less pressure and the one with the ...
779 views

### Why will two bubbles floating on water surface attract each other?

Two identical bubbles floating on water surface will form clumps, according to the "cheerio effect". But what's the detail about the force? It's necessary to calculate the shape of water surface, in ...
73 views

### Why would air try to escape from under a pot?

I put a wet Calphalon pot down flat on a wet synthetic countertop. None of the surfaces or liquids was hot. Bubbles started appearing a second or two later from under the rim of the pot in one area. (...
1k views

### Can water pressure ever be high enough to trap gas bubbles or keep them from surfacing?

Can water pressure ever become high enough to trap gas bubbles and/or keep them from surfacing?
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### Is it possible to trap smoke or a smoke like gas inside a glass bubble?

I am a glassblower, and I would like to trap smoke in a glass bubble, my hope is to create an infinitely lingering smoke inside. Is this possible?
I am reading a text about gas nuclei I encountered the following formula: $$r = \alpha + \beta \left( \frac{T}{P} \right)^\frac{1}{3} + \kappa \left( \frac{T}{P} \right)^\frac{2}{3}$$ $r$ is the ...