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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?

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Just quickly: if you did this with one gas eventually it'd settle and become consistently spread, thus creating a translucent ball, which would kind of suck. What you want are two gases of equal-ish density that you can shake and stir up! – Alec Teal Jan 2 '15 at 13:46

Smoke is made up of particles, so eventually they will settle. When they settle, they will probably stick to the surface of the glass and become impossible to stir up into smoke again.

You might be able to do this with a vapor. Because vapors are in the gas phase, they will not settle unless chilled. Unfortunately, a vapor will dissipate over time, resulting in a consistent color inside the bubble and not the "smokey" appearance that I assume you want.

There might be a way to use two gasses that won't mix, but even if that worked they would likely cause health problems if the bubble cracked open.

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What if one uses a vapor, and cools to condensate, then reheats the glass bubble? – Cristi Stoica Sep 24 '13 at 21:21
I hadn't thought of that. It would require almost constant heating and cooling of the bubble, but if Isak is okay with that, I guess you would only need a suitable vapor. – Wutaz Sep 24 '13 at 21:24
I've seen a similar principle (condensing in one location, vaporizing in another) used in continuous cloud chambers. In principle it might work for this effect, but the engineering of it will be difficult, and thermodynamics requires that you power the system. – Chris White Sep 25 '13 at 4:32
Thanks for the feedback, the constant heating and cooling of the bubble may work, however it depends on the temperatures required to create the effect, as glass is very temperature sensitive and constant heating and cooling could cause it to crack. I do like the idea of a continuos cloud chamber, I imagine the heating and cooling could take place outside of the bubble and the smoke-like vapor could constantly be fed into it whilst it collected – Isak Lystad Sep 25 '13 at 5:44
Condensation and continued the process outside of the glass bubble. – Isak Lystad Sep 25 '13 at 5:45

Any mixture of gases (or smoke particles suspended in air) becomes a uniform mix in minutes. So whatever sample you trap in a glass bubble will be featureless in probably less than a minute. It will be indistinguishable from a uniform stain of the glass itself

As Wutaz writes, smoke particles will likely start sticking to the surface. At best that will result in the appearance of frosted glass, chances are the particles sticking to each other will look like deposited soot.

Iodine vapor has a strong color.
(Iodine compounds used as antiseptic are yellowish, but the vapor of pure Iodine is Magenta in color.)

But again, the mix of Iodine vapor and air will become a uniform mix in minutes, if not faster. Also, you can't contain the toxic Iodine vapor in the furnace. It's clearly too dangerous to try something like that in a shop for handcrafted glasswork.

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