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Specifically, will ferrofluid at the bottom or on the sides of a shot glass perturb the fluid above it to any significant degree? I want a character of mine who is a sort of Bill Nye/Neil DeGrasse Tyson expy to show off a party trick using ferrofluid that he calls "The Real Corona". What he does is pour ferrofluid into the bottom of a shotglass, fills it near to the brim with vodka, lights it on fire and then introduces a magnet which he uses to turn the flaming alcohol into a roiling facsimile of the Sun's surface by manipulating the ferrofluid underneath it with a magnet.

Would this work the way I imagined it? Could you do anything impressive with the flames from a flaming shotglass if you filled the bottom with ferrofluid? Please let me know if this belongs in Physics Stack Exchange, although I expect the answer isn't too complicated. I'm kinda just asking to double check that this works like I thought it might ^^'

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    $\begingroup$ There's a simpler solution to this. Try it and see, let us know how it goes. $\endgroup$ – Separatrix Nov 8 '16 at 18:16
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    $\begingroup$ I hope you realize that you just gave about 1000 geeks and nerds an idea involving alcohol and fire. $\endgroup$ – AndreiROM Nov 8 '16 at 18:38
  • $\begingroup$ In other news, however, it will most likely not work. My suspicion is that the second you mix it, you'll extinguish the fire. $\endgroup$ – AndreiROM Nov 8 '16 at 18:41
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    $\begingroup$ Remember that flame is a surface phenomenon. In order to roil the flame, you need the vodka either to be in a thin film on top of the ferrofluid, which then gyrates wildly - in which case the fire goes out quickly. Or you need a very complicated structure created by the ferrofluid - which a simple magnet could not induce. $\endgroup$ – John Feltz Nov 8 '16 at 20:26
  • $\begingroup$ How complicated? Assume we have the kind of neodynium magnets on hand you see in hard drives to perform the trick (if you're already nerdy enough to be carrying ferrofluid around with you on the off chance you get to show it off at a party, chances are you're also the kind of person who'd carry around hard drive magnets). $\endgroup$ – Z.Schroeder Nov 8 '16 at 20:53
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Ferrofluid is a mix of fine iron oxide dust in some arbitrary oil. If the oil is petroleum based, the alcohol in the vodka will act as a solvent and the two will mix (resulting in something that I'd rather not drink), plus, the oil will probably burn too, making a right royal mess.

The only solution I can see is to replace the petroleum oil in the ferrofluid with a silicone oil which has much of the same properties, but without the fire hazard and (to some degree at least) is food safe (seeing as it's already used as an additive in some cooking oils, cosmetics and... flatulence control products)

Now, as for the whole surface of the sun thing, there will probably be some effect, but the issue I see is that because the flame will burn quite tall (and because it's the vapours that burn), you'll probably end up with a relatively uniform burn with some rippling around the bottom edges.

If you don't want to use ferrofluid, you might be able to get the same effect from using a magnetic stirring bead (at least it won't spoil the taste)

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