Can gasses be contained with centripetal force?

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Discussion Overview

The discussion revolves around the concept of whether gases, specifically when considered as plasma, can be contained or propelled using centripetal force. Participants explore theoretical scenarios involving gas release, vortex formation, and the implications of centripetal and gravitational forces in various contexts, including potential applications like a plasma cannon.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that a vortex can help keep gas together longer than non-rotating gas, with references to phenomena like smoke rings.
  • Others argue that the centripetal force required to contain gas must be provided by external means, such as the walls of a container, which disappear once the gas is released.
  • A participant mentions that in a vacuum, gas would expand rapidly, and that spinning gas would also expand faster due to conservation of angular momentum.
  • There is a discussion about how gravitational forces can provide centripetal force in massive systems like spinning nebulae, which can eventually form stars.
  • Some participants express interest in the phenomenon of ball lightning, suggesting it may relate to the original question about plasma containment and stability over distances.
  • One participant proposes a hypothetical scenario involving a plasma cannon that utilizes vortex motion to prevent immediate dissipation of plasma when released into the air.
  • Concerns are raised about a misunderstanding of centripetal force by the original poster, which complicates the discussion and understanding among participants.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the feasibility of containing gases with centripetal force, with no consensus reached on the original question. There is also disagreement on the understanding of centripetal force itself.

Contextual Notes

Some limitations include the unclear definitions of centripetal force as applied to gases, the dependence on specific conditions like the environment in which the gas is released, and the unresolved nature of the ball lightning phenomenon.

Easy-cheesy
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Not sure if this is the right place to post or even a stupid question but anyway. If you had a chamber of gas and released it out of a barrel with force it would disapate into the air right? My question is, if you were to do this but somehow spin the gas particles so that they held themselves together with centripetal force, could the “gas cloud” travel further than what it would have if no centripetal force was applied?
 
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I am not sure if "contained" is the right way to put it, but a vortex will certainly stay together longer than non-rotating gas. You can also centrifugally separate multiple gases. That's essentially how modern uranium enrichment works.
 
:welcome:

I'm not sure I understand exactly what you mean. But it does sound a little like a smoke ring. If so, then yes for a short time a smoke ring holds itself together.
blow-smoke-rings-guide-2.jpg


If that is not what you mean, can you draw a picture? Use the UPLOAD button next to POST REPLY and PREVIEW to put your picture in the post.
 

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What would the gas be released into?

In a vacuum (eg space) i think the gas will expand until the pressure is low enough for gravity to hold it together.

If the gas is spinning before it's released I think it will expand even faster. As it expands the rate of rotation will slow down (conservation of angular momentum).

The only source of centripetal force will be the gravitational force between molecules which would be very weak.
 
Easy-cheesy said:
Not sure if this is the right place to post or even a stupid question but anyway. If you had a chamber of gas and released it out of a barrel with force it would disapate into the air right? My question is, if you were to do this but somehow spin the gas particles so that they held themselves together with centripetal force, could the “gas cloud” travel further than what it would have if no centripetal force was applied?
Jut realized you might be missunderstand Centripetal force. Centripetal force has to be provided by something it's not caused by spinning alone.

When you spin a cylinder full of gas the walls of the cylinder provide the inward centripetal force. When you release the gas the centripetal force provided by the walls disappears.
 
However, when a gas forms a vortex, it develops an inward facing pressure gradients that provides a centripetal force. That's how a tornado stays together.
 
CWatters said:
When you spin a cylinder full of gas the walls of the cylinder provide the inward centripetal force. When you release the gas the centripetal force provided by the walls disappears.
The difference for a gas is that you can't 'pull' it towards a central point by intermolecular forces, as with a solid. A situation where you can provide a centripetal force for gases would be through gravitational forces. This can happen in a (very massive) spinning Nebula of gases (Hydrogen and Helium) in Space, which are held by gravity and which will eventually fall towards the centre and form a star. All stars and solar systems spin and this angular momentum is largely the same as the angular momentum of the original nebula of gas.
 
Thanks for all the awesome replies everyone! I was thinking of plasma as the gas in this scenario and if you could some how spin it into a vortex, if it would hold itself together long enough to be propelled over a distance.
 
Easy-cheesy said:
Thanks for all the awesome replies everyone! I was thinking of plasma as the gas in this scenario and if you could some how spin it into a vortex, if it would hold itself together long enough to be propelled over a distance.
Have you come across the phenomenon Ball Lightning? This link is just one of many. Ball lightning seems to be described in similar terms to your OP but afaik, it has not been fully explained. It seems to consist of a ball of plasma that sticks together and can travel in a fairly stable form over large distances. Excellent destructive weapon if it could be produced at will.
 
  • #10
sophiecentaur said:
Have you come across the phenomenon Ball Lightning? This link is just one of many. Ball lightning seems to be described in similar terms to your OP but afaik, it has not been fully explained. It seems to consist of a ball of plasma that sticks together and can travel in a fairly stable form over large distances. Excellent destructive weapon if it could be produced at will.
Yes I have seen that and it’s very cool but I don’t think there is any knowledge of how it works so that sucks :/ the reason this whole question came about is because I’ve seen people microwave a lit match in a glass container and it makes plasma. I was thinking if you could get the plasma to run up some glass tubing, out of the microwave and somehow propel the gas in a vortex like motion so it didn’t instantly disapate when it hit the air you would essentially have a plasma cannon.
 
  • #11
Easy-cheesy said:
Yes I have seen that and it’s very cool but I don’t think there is any knowledge of how it works so that sucks :/ the reason this whole question came about is because I’ve seen people microwave a lit match in a glass container and it makes plasma. I was thinking if you could get the plasma to run up some glass tubing, out of the microwave and somehow propel the gas in a vortex like motion so it didn’t instantly disapate when it hit the air you would essentially have a plasma cannon.

That is not nice of you to hide that information from us in the OP. It wastes our time because we have to guess what you are really asking about.

But with this information is sounds like you want to make something like a Star Wars blaster gun, correct?
 
  • #12
I still think, as CWatters pointed out above, that the OP has a severe misunderstanding of what "centripetal force" is. Unfortunately, he/she is not acknowledging this one way or the other. So it is really difficult to try and build an explanation when everyone is assuming that we all understand it the same way.

Zz.
 

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