Blowing Bubbles in Space: Can You Create a Giant Bubble in the Vacuum of Space?

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Discussion Overview

The discussion revolves around the feasibility of creating bubbles in the vacuum of space, exploring various types of bubbles such as soap, polymer, and glass bubbles. Participants consider the physical and chemical challenges involved, including evaporation rates, pressure dynamics, and the properties of materials used for bubble formation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that a liquid in a vacuum will boil and then freeze, and discusses the relative timescales for bubble inflation versus evaporation.
  • Another participant proposes that even a tiny amount of gas could inflate a bubble indefinitely, raising questions about the feasibility of bubble creation.
  • A different viewpoint indicates that if the internal pressure of the bubble matches the ambient pressure, a stable bubble could be formed using a suitable high vacuum oil.
  • Concerns are raised about the practical challenges of measuring pressures and the outgassing from spacecraft potentially affecting local vacuum conditions.
  • Some participants explore the idea of using spray foam for construction in space, questioning the availability of liquids with low vapor pressure suitable for bubble formation.
  • Another participant mentions that high vacuum equipment uses certain greases and oils that could be applicable, though bubbles may not last long.
  • A suggestion is made that if the mechanical properties of the foam are not critical, it could remain intact until solidifying through polymerization or freezing.
  • One participant references the use of gel-type chemicals in science fiction for repairing space suits, drawing parallels to the current discussion.
  • Another participant notes that dealing with leaks in a vacuum is less demanding than it may seem, emphasizing the pressure dynamics involved.

Areas of Agreement / Disagreement

Participants express a range of views on the feasibility and practicality of creating bubbles in space, with no clear consensus reached. Multiple competing ideas and uncertainties about the conditions required for bubble stability and longevity are present.

Contextual Notes

Participants highlight limitations such as the need for low vapor pressure liquids and the challenges of maintaining bubble integrity in a vacuum. The discussion also touches on the complexities of pressure measurement and the effects of outgassing from spacecraft.

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How big a soap bubble, polymer bubble, or glass bubble could you blow in the vacuum of space? Rate of evaporation in vacuum. ISS.
This is an experiment I would have liked to do from the ISS, but an approximation could be done in a vacuum chamber on Earth. How big a soap bubble, polymer bubble, or glass bubble could you blow in the vacuum of space? How to calculate the evaporation rate in vacuum?

A liquid exposed to vacuum will boil then freeze. Delay boiling by using a cold liquid and delay freezing by inflating with a hot gas. This is a question of relative timescales, the timescale for inflating the bubble vs the timescale for evaporation. Can the timescale for inflation be shorter than the timescale for evaporation? Consider separately the following cases.
  • Blowing a soap bubble
  • Blowing a soap bubble containing a monomer that polymerizes by evaporation of water.
  • Blowing a bubble in a thermoplastic such as PET.
  • Blowing a bubble in glass, starting with really hot glass because there's no gravity in orbit to cause it to sag.
A typical PET bottle wall thickness is 250 μm. A typical soap bubble wall thickness is 1.2 μm. A typical soap bubble inflation speed is 7 cm/s. A typical soap bubble wand has a perimeter of 1.5 inches. From “How to make a giant bubble” in Phys. Rev. Fluids 5, 013304.
 
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I guess even tiny amount of gas inflate bubble without limit so we can make no bubbles.
 
If the pressure inside the bubble were the same as the local (outside) ambient pressure but the other conditions were kept the same, you could inflate the bubble to 10-12Bar approx) and, if the liquid for the bubble was chosen to be a suitable HiVac oil, then I guess it would be a stable bubble.
A bubble machine would need a powerful fan - large and fast enough to actually move a significant some of those few molecules in 'space' and transfer some of their momentum to the film of oil and make it form a bubble. Probably not the best way when you think of the surface tension on a film of oil.
Alternatively, a tiny hole and a valve could admit a few air molecules into a drop of oil on the tip of a hypodermic needle. Perhaps foam has been observed around small leaks in the hull of spacecraft . HAHA - like finding a puncture in a bike tyre. Imagine an Astronaut crawling over the surface with a squeegee with oil in it and looking for bubbles.
 
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anuttarasammyak said:
I guess even tiny amount of gas inflate bubble without limit so we can make no bubbles.

I don't know much about the specifics, but won't the tension in the bubble material eventually balance the in internal pressure, so long as this pressure is not large enough so that "breaking stress" of the bubble material is exceeded?
 
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etotheipi said:
so long as this pressure is not large enough
10-12 Bar would be a bit difficult to measure out in practice. I imagine that the outgassing of the surface of a spacecraft would exceed that so the local 'vacuum' around a spacecraft would be higher than the pressure 10km away from it.
In practical terms, the problem would most likely be in finding a liquid with a low enough vapour pressure to allow a bubble to live any significant time. I guess astronauts have better things to do with they time than closely examining the outer skin of the craft to find some actual bubbles / foam. Things could be different if there were an actual use for such bubbles.
 
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sophiecentaur said:
Things could be different if there were an actual use for such bubbles.

How about spray foam for constructions in space or on the Moon? That could be worth to be discussed.

etotheipi already pointed the basic problem: the components need to have a very low vapour pressure (in order to be balanced by the surface tension). Are there liquids with suitable properties and if yes could they be used for a spray foam (e.g. as solvent or even reactant for a polymerization)?
 
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DrStupid said:
Are there liquids with suitable properties
High vacuum equipment uses some pretty suitable greases and oils. You could perhaps have to accept that the bubble would not last long.
 
sophiecentaur said:
You could perhaps have to accept that the bubble would not last long.

That doesn't need to be a problem. If the mechanical properties of the foam doesn't matter (e.g. if it is used for heat insulation) it just needs to remain intact until it gets solid (due to polymerisation or because it freezes). Than it may crack and release the gas. In this case it wouldn't even be necessary to reach a short-term equilibrium. It would be sufficient to slow down the expansion. That requires a high viscosity. Maybe a polymer at a temperature between melting point and glass-transition could do this job.
 
I saw in some Sci-Fi movies astronauts repair their space suits breach applying gel-type chemicals outside. It should work under 300K temperature and 1 atm pressure difference between outside and inside. Similar factors with this thread should be considered for it.
 
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anuttarasammyak said:
gel-type chemicals outside.
This is less demanding that you would think. You can deal with a leak in a plumbing system with several Bar of internal pressure but wrapping tape round the leak and this can harden up to be as good as new. Thing about vacua is that it can never be more than 1Bar below the pressure at sea level!