Mount Etna having a quiet relaxing smoke.

Curious. I've found an explanation for this here:
QUOTE
Such gas rings are produced by the explosion of gas bubbles within a narrow conduit [above a magma chamber], which shoots the gas at high speed toward the surface," Behncke wrote on Twitter. "Attrition along the conduit walls slows the movement of the gas jet, relative to the center of the conduit," which is what forms the ring shape, he added.
UNQUOTE

From: https://www.livescience.com/planet-...-out-of-europes-most-active-volcano-heres-why

So you get a fast gas jet through the centre but a much slower gas stream at the edge, leading to a toroidal vortex. Presumably you need fairly sticky magma for this, to get the bubbles to explode rather than simply burst.

I seem to recall an uncle who could sometimes achieve the same thing with his mouth while smoking, back in the 60s when smoking indoors in the presence of small children was not yet frowned upon.
 
exchemist said:
Curious. I've found an explanation for this here:
QUOTE
Such gas rings are produced by the explosion of gas bubbles within a narrow conduit [above a magma chamber], which shoots the gas at high speed toward the surface," Behncke wrote on Twitter. "Attrition along the conduit walls slows the movement of the gas jet, relative to the center of the conduit," which is what forms the ring shape, he added.
UNQUOTE

From: https://www.livescience.com/planet-...-out-of-europes-most-active-volcano-heres-why

So you get a fast gas jet through the centre but a much slower gas stream at the edge, leading to a toroidal vortex. Presumably you need fairly sticky magma for this, to get the bubbles to explode rather than simply burst.

I seem to recall an uncle who could sometimes achieve the same thing with his mouth while smoking, back in the 60s when smoking indoors in the presence of small children was not yet frowned upon.
Click to expand...

You can blow smoke rings by a sort of glottal exhalation or just by tapping the cheek.(smaller ones ,from memory)
 
geordief said:
You can blow smoke rings by a sort of glottal exhalation or just by tapping the cheek.(smaller ones ,from memory)
Click to expand...
That makes sense. You want a sudden, semi-explosive burst of air in the centre and a slow-moving part at the sides, it seems.
 
exchemist said:
Curious. I've found an explanation for this here:
QUOTE
Such gas rings are produced by the explosion of gas bubbles within a narrow conduit [above a magma chamber], which shoots the gas at high speed toward the surface," Behncke wrote on Twitter. "Attrition along the conduit walls slows the movement of the gas jet, relative to the center of the conduit," which is what forms the ring shape, he added.
UNQUOTE

From: https://www.livescience.com/planet-...-out-of-europes-most-active-volcano-heres-why

So you get a fast gas jet through the centre but a much slower gas stream at the edge, leading to a toroidal vortex. Presumably you need fairly sticky magma for this, to get the bubbles to explode rather than simply burst.
Click to expand...
So, by contact with the walls of the vent the gas bubble’s outer edges are slowed, leaving the centre gas moving faster. When the surface is reached the gases condense to steam.
But, why does the centre gas not condense also?
Is it that all the gas is worked (by friction) to the sides and so a ring appears? I don’t know if I’m making sense even to myself?

I can see why it has to be a 'packet' of gas rather than a continuous flow of gas, otherwise that would be a column of steam.
Btw. I can’t find any accounts of what people made of these rings in the olden days.
 
foghorn said:
So, by contact with the walls of the vent the gas bubble’s outer edges are slowed, leaving the centre gas moving faster. When the surface is reached the gases condense to steam.
But, why does the centre gas not condense also?
Is it that all the gas is worked (by friction) to the sides and so a ring appears? I don’t know if I’m making sense even to myself?

I can see why it has to be a 'packet' of gas rather than a continuous flow of gas, otherwise that would be a column of steam.
Btw. I can’t find any accounts of what people made of these rings in the olden days.
Click to expand...
Good point. If it is condensed water droplets that form the ring, I suppose it could be lower temperature in the gas at the edge…..

But then that would not explain smoke rings from a cigarette. I suspect in that case one has a mouthful of smoke through which a burst of relatively smoke-free air from the throat is expelled. So perhaps in the volcano there is a cloud of condensed vapour hanging about in the mouth of the vent and then a sudden burst of hot gas from below passes up the vent, causing the condensed vapours to roll out in the form of a ring. But I am speculating.
 
exchemist said:
But then that would not explain smoke rings from a cigarette. I suspect in that case one has a mouthful of smoke through which a burst of relatively smoke-free air from the throat is expelled. So perhaps in the volcano there is a cloud of condensed vapour hanging about in the mouth of the vent and then a sudden burst of hot gas from below passes up the vent, causing the condensed vapours to roll out in the form of a ring. But I am speculating.
Click to expand...

The tongue plays a big part of creating smoke rings, I can do them. Your jaws also. My cousin is amazing at doing them, his jaw movement seems to play a better role then mine do. Better smoke ring jaw movement I guess.
 
davewhite04 said:
The tongue plays a big part of creating smoke rings, I can do them. Your jaws also. My cousin is amazing at doing them, his jaw movement seems to play a better role then mine do. Better smoke ring jaw movement I guess.
Click to expand...
That's interesting. What does one do with one's tongue, then, to generate a smoke ring?
 
exchemist said:
That's interesting. What does one do with one's tongue, then, to generate a smoke ring?
Click to expand...
I sort of fold it up, as to create the emptiness in the middle of the ring. There may be different ways to achieve the ring but I would think curling your tongue would be universal. I'll ask my cousin next time I see him. :)
 
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