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Hydrophobic Fulgurite Bubbles

Hydrophobulgurites
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(+5)
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against]

Okay, so, we take a round bottom Pyrex beaker and fill it with water.
Add beach sand, that we've previously sprayed with copious amounts of ScotchGuard and allowed to dry, which will displace most of the water and assume the shape of the bottom of the vessel.
Attached to the base of the beaker is a long thin ground wire with a weighted end.
The beaker is then lowered into lake water at a depth which lets the weighted end of the ground wire to sink into the muck at the bottom. Meanwhile, another conductive filament protrudes from the top of the open beaker to a floating platform upon which has been raised a tall lightning rod.

Now we all patiently wait for next lightning storm.

It's okay, brought sandwiches and hot chocolate.
...
just go off the side, tsh, nobody cares.

Yeah, I'm not sure what will happen either, but I know I will want at least one high-speed camera set to capture whatever it is that that happening might happen to be.

In my head I see the sand become molten so quickly, and to such an extreme temperature, that the rapid transfer of heat to the surrounding water, and it's pressure, (I feel that's important somehow... the depth that is), would solidify the exterior of the sand so quickly that a Prince Rupert Sphere of very large diameter containing mostly hard vacuum would be left behind.

...or it will spectacularly explode tiny little PRD's in all directions, <later edit> (like a firework at full intensity frozen in time), to drift languidly towards the bottom all still interconnected by the most gossamer of tails until one of them touches something and the whole shebang randomly implodes about the place releasing thousands of miniature depth charges.

Either way I want to try this one so much it's actually triggered my fight or flight sweat response.

Fascinating.


Lechatelierite https://en.wikipedi...wiki/Lechatelierite
A more likely outcome [a1, Jan 22 2023]

Slow Mo Guys https://www.youtube.com/@theslowmoguys
Get these guys to try it? [Voice, Jan 23 2023]

RPD fragmentation reserearch https://www.pnas.or...073/pnas.2202856119
Reference (21) [2 fries shy of a happy meal, Jan 23 2023]

Spherical tempered glass https://engineering...prince-ruperts-drop
StackExchange discussion [xaviergisz, Jan 23 2023]

Diagram of stress in tempered glass https://www.glasson...ans-photoelasticity
See figure 1 [xaviergisz, Jan 23 2023]

[link]






       Sounds totally halfbaked to me...... Fry up this crossant while you wait....
xenzag, Jan 21 2023
  

       I have questions.   

       Is the ScotchGuard supposed to keep the sand dry even while it's submerged in a lake, or would you consider running the upper conductor through a rubber bung?   

       Also, this lower conductor seems to be attached to the *outside* of the bottom of the beaker. But I thought glass was a very poor conductor of electricity. So how does that part work? Is it possible you'll need to ask the glass blower for a beaker that's open at both ends so that the lower conductor, as well as the upper one, can be passed through a bung?
pertinax, Jan 21 2023
  

       //Is the ScotchGuard supposed to keep the sand dry even while it's submerged in a lake, or would you consider running the upper conductor through a rubber bung?//   

       Making the sand hydrophobic will allow the water pressure to remain consistent and have a better chance of creating something approximating a true sphere than dry sand in a dry vessel would.   

       //Also, this lower conductor seems to be attached to the *outside* of the bottom of the beaker. But I thought glass was a very poor conductor of electricity. So how does that part work? Is it possible you'll need to ask the glass blower for a beaker that's open at both ends so that the lower conductor, as well as the upper one, can be passed through a bung?//   

       You'd think that ideally the filament would continue through both the hydrophobic sand and the container as well right? ... but something tells me that the gap between conductors is as important a variable as the depth to make it work. Like a spark plug with isolated sand alone as the gap.<shrugs> Your guess is probably better than mine. I just tell you guys some of the things my subconscious shows me.   

       Also. <blows whistle>
Extraneous use of the word 'bung'.
Five yard penalty.
  

       hmm   

       come to think of it, the hydrophobic sand/water filled vessel will need to be dragged upside-down into the depths by the ground wire. Air trapped in the sand will cause it to become buoyant very quickly.   

       So upside-down it is.   

       How do you stop the charge dissipating across the surface of the water and ignoring your nice insulated gap?
pocmloc, Jan 22 2023
  

       [+]
Voice, Jan 22 2023
  

       If the charge could dissipate that fast we wouldn't have lightning. I think.
Voice, Jan 22 2023
  

       //How do you stop the charge dissipating across the surface of the water and ignoring your nice insulated gap?//   

       By offering a path of least resistance close enough to directly conduct our current experiment.
Ohm my god I crack me up.
  

       See, the Pyrex beaker will more than likely shatter into a billion pieces from the force of the bolt.
This will leave the hydrophobic sand temporarily suspended without a container.
All things being equal, the water pressure alone from all directions should hold the sand in a roughly spherical shape long enough for the bolt to pass through it to get to the conductive filament rather than dispersing into the surrounding water.
  

       I think that the depth of the water will determine whether the pressure is enough to hold the shape long enough for the magic to do its thing, and if it works a nice super-hard bubble of vacuum will rocket towards the surface.   

       We have a Really deep lake just down the street.
I am now considering submerging a series of these things on the same line at varying depths to determine some of the effects of pressure and temperature dissipation in the first experiment.
  

       It's going to be a fun one.   

       As for more likely forming Lechatelierite as in the link;   

       Is Lechatelierite created by lightning striking dry sand already encapsulated within its annealing substance?
If not, then why would Lechatelierite be a more likely outcome than a Prince Ruperlgurite bubble?
  

       Completely different thaumaturgy my good man.   

       Why? Because ANYTHING in the realm of unevenly fused silicates is more likely than what you want to happen. Tell me - what is a “very large diameter” for the purposes of this experiment, and why do expect it to be filled with “mostly hard vacuum?”   

       For that matter - MOSTLY hard vacuum? What’s that, a bit squishy?
a1, Jan 23 2023
  

       //Why? Because ANYTHING in the realm of unevenly fused silicates is more likely than what you want to happen.//   

       That's what they say about Prince Rupert Drops.   

       //Tell me - what is a “very large diameter” for the purposes of this experiment, and why do expect it to be filled with “mostly hard vacuum?”//   

       A very large diameter would be anything larger than what has already been created... by definition.
I expect it to be mostly hard vacuum because the rapid cooling of the exterior of a spherical enough chunk of molten glass will solidify sooner than its core. As the core cools it continues to contract but the exterior shell, (if strong enough to contain the this interior contraction), creates a bubble of vacuum at the heart of every PRD.
This experiment should just reproduce that on a larger scale.
How far the glop of hydrophobic sand will expand before expelling all gasses and the outer shell cools will determine the size of the bubble formed...
  

       ...if a bubble forms at all. <shrugs> I will give you that. I told you, it's just what I see in my head.   

       //For that matter - MOSTLY hard vacuum? What’s that, a bit squishy//   

       There is no such thing as a true vacuum, as particles flit into and out of existence all willy-nilly.
A partial vacuum is all we can strive to attain.
  

       I’ll buy you an ice cream cone if you can cite any published work proving there’s a “bubble of vacuum” inside a Prince Rupert Drop.
a1, Jan 23 2023
  

       hmmm... it's really hard to cite research which does not yet exist yet alone the logic-leaps leading to them.   

       I suppose I could measure the air pressure of a sealed chamber containing a PRD and then shatter it and see if there is any difference, but let me just ask you these questions instead;   

       When the entirely molten glass hits cold water and its exterior solidifies forming a Prince Rupert Drop...
...of which gases are its cavitation bubbles comprised?
  

       What gives these glass drops the strength to withstand thousands of tons of pressure if not vacuum?   

       What causes implosion if not negative pressure?   

       Why aren't you helping to find a line on renting cheap water-proof high-speed cameras which can withstand great pressure and a government grant to cover expenses?   

       Why?...   

       ...and why have these questions not already been answered before I thought of them?   

       Why I bet dollars to doughnuts that most of them questions already have been answered and us unwashed-masses are considered un-privy to them.   

       ...but that would be considered conspiracy theory talk and I might get labelled so I should just hold my tongue.   

       Okay, shutting up now.   

       So...   

       ...   

       ...where does that leave us?   

       Fucked I'd say.   

       ...   

       Back to you Phil.   

       As [MB] said on a previous PRD idea, I think that the smallness of the usual drops is precisely to stay within the elastic bounds of glass, i.e. the compression of the outside is caused by the tension of the inside. If the drop is big enough that the inside can not be solid and stretched, then the inside will crack and the crack will propagate to the edges and the thing will explode.   

       No chance of forming a "bubble of vacuum" - vacuum doesn't suck harder than atmospheric pressure and certainly not as hard as stretched glass.   

       At the end of the day this is no more than toughened glass. Its super toughness comes as much from its geometry as from its material. Think of it like a car windscreen or a security glass door. Its strong but not amazing.
pocmloc, Jan 23 2023
  

       bunnnnnnng.
pertinax, Jan 23 2023
  

       Sorry, was that your mallet? I think it needs re-tuning.
pertinax, Jan 23 2023
  

       // bet dollars to doughnuts that most of them questions already have been answered //   

       Yes, they have been. The answers are widely available online and considerably easier to find than coaxing a lightning bolt to hit a specific bottle floating in a lake.
a1, Jan 23 2023
  

       Not nearly as much fun though...   

       // I’ll buy you an ice cream cone if you can cite any published work proving there’s a “bubble of vacuum” inside a Prince Rupert Drop.//   

       I'll have mint chocolate chip in a waffle cone please. Three scoops.   

       " PRD research in the nineteenth century added descriptions of internal voids, confirmed their origin by contraction, and demonstrated that they were under vacuum "
[link]
  

       I *knew* there was a way to motivate into real studying instead of just pulling stuff out of your a... thin air :D   

       But you'll have to do more for three scoops. Is the overall effect of breaking the tail an EXPLOSION from the interplay of glass under both tension and compression, or is really an IMPLOSION driven by those tiny voids as you suggest?
a1, Jan 23 2023
  

       It's all in that link. First hit btw.
If you try to form a PRD using bubbly glass or introducing a bubble causes the drop to fail.
  

       Just think about the physics of it. The surface cools at such a fast rate that the internal structure is still molten. This molten centre can not contract as it cools and forms bubbles of vacuum, (not always though, and only in small PRD's will there be no voids). It stands to reason that they implode rather than explode since the pressure is inwards rather than outwards.   

       Go look at some of the vids of shattering Prince Rupert Drops. You can see the tail disintegrating and glass shards flying outward long before any internal bubbles are breached. The shockwave travels from tail to head.   

       Smart Every Day has some good ones.
a1, Jan 23 2023
  

       Yes I've watched pretty much everything I could find on this topic.   

       That's why I'm trying to figure out ways of making a drop without a tail.
I mean... combining all four elements and performing transmutation using lightning to create something which has never before existed!
  

       Muhahaha... MUHAHAHAHAHA!
<regains composure>
  

       What could possibly go wrong?   

       + well, I like bubbles………
xandram, Jan 24 2023
  

       I'm moved by the passion you've put into this and I must admit I'd like to watch the experiment [+]. Sadly I don't have any other contribution to offer here.
PauloSargaco, Jan 27 2023
  
      
[annotate]
  


 

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