Pew, Pew Pew Pew

January 5, 2013 10:22 PM

Here's a cool video of a red hot nickel ball in water.

via reddit.

It's a neat example of the Leidenfrost effect, which also explains why you can stick your hand safely into Liquid Nitrogen safely, or even, as the Mythbusters do, into molten lead.

posted by Lutoslawski (34 comments total)

I love the fact that this person has the equipment and expertise to make a red-hot nickel ball, but has to balance it on the back of a lightswitch cover.
posted by griphus at 10:28 PM on January 5, 2013 [20 favorites]

Is that a little vortex that forms on top? Neat.
posted by bardic at 10:36 PM on January 5, 2013

That's pretty awesome, though even after seeing that I don't think I would want to try the lead thing.
posted by ghharr at 11:00 PM on January 5, 2013 [1 favorite]

That was twenty times cooler than I expected. I feel like I just watched Pokémon genes being engineered or something.
posted by threeants at 11:03 PM on January 5, 2013 [5 favorites]

or even, as the Mythbusters do, into molten lead.

I have learned to just jump ahead in their videos to about 45 seconds before the end of the clip, and skip all the obnoxious banter. And what a wuss, dipping his pinky 1cm into the molten lead.

Back when I was a chemistry major, I read an article by a professor who detailed how to do this demonstration by swabbing your hands with liquid ammonia and then having an assistant pour the molten lead into your cupped hands. He asserted that performing this demonstration should be a mandatory requirement for all chem majors to receive their degree. It would demonstrate their trust in the principles of chemistry and physics. I would gladly have done this, if I could see a professor demonstrate it to me first.
posted by charlie don't surf at 11:04 PM on January 5, 2013 [8 favorites]

oh dang. My pan makes that same chirping noise when I am boiling water or heating up frying oil. It scares the crap out of me. Does anyone know what causes that chirp?
posted by rebent at 11:12 PM on January 5, 2013

Dang.. where do I get one of them there nickel balls, and will my propane torch heat it up?
posted by crapmatic at 11:22 PM on January 5, 2013

Does anyone know what causes that chirp?

It's likely just the expansion and/or contraction of solid metals of different temperatures in contact with each other causing harmonic resonance - and the sound of stuff boiling and the nucleation of dissolved gases off of that temperature difference interface between matter of differing temps.

You can get the same sounds out of liquified gases - like liquid nitrogen - hitting a room temperature vessel.

Or dry ice under a spoon or knife or skittering around in a hot pan. Or water ice in a hot pan.

Or human fingertips plunged into liquid nitrogen, or liquid lead. In the nitrogen it's because your hands are too warm, causing boiling of the LN2 itself. Or in liquid lead it's because your hands are too cold (and (hopefully) wet), causing boiling of those residual liquids into vapor.

See also: the Leidenfrost effect, linked above.
posted by loquacious at 11:54 PM on January 5, 2013 [1 favorite]

Does anyone know what causes that chirp?

I think it's cavitation. Gas bubbles emerging from the heated surface quickly collapse when they move into the cooler sounding water, which causes a sharp vibration to ping through it. Notice the chirps occur 1) when the ball is first dropped in and is therefore most hot, and 2) when bubbles break loose from the gas "donut", but only after the donut's been in stable contact with the metal for a few seconds, allowing the gas to become sufficiently heated.
posted by dephlogisticated at 11:58 PM on January 5, 2013 [4 favorites]

I asked, "That's it?" The universe replied, "NO!"
posted by BiggerJ at 1:16 AM on January 6, 2013

the equipment and expertise to make a red-hot nickel ball

A plain old oxy-acetylene torch that you can get on craigslist for maybe $200?
posted by DU at 3:51 AM on January 6, 2013

rebent: "oh dang. My pan makes that same chirping noise when I am boiling water or heating up frying oil. It scares the crap out of me. Does anyone know what causes that chirp?"

The spirit of the Phoenix trying to be born from fire. It's only a baby though.
posted by Splunge at 5:18 AM on January 6, 2013 [10 favorites]

I think I found the underlying beat for my dub-step debut.
posted by Mick at 5:29 AM on January 6, 2013 [1 favorite]

I think it's cavitation. Gas bubbles emerging from the heated surface quickly collapse when they move into the cooler sounding water, which causes a sharp vibration to ping through it. Notice the chirps occur 1) when the ball is first dropped in and is therefore most hot, and 2) when bubbles break loose from the gas "donut", but only after the donut's been in stable contact with the metal for a few seconds, allowing the gas to become sufficiently heated.
posted by dephlogisticated

Definitely cavitation and this guy would know.
posted by DU at 5:58 AM on January 6, 2013 [1 favorite]

I'm trying to figure out why it looks like the outer few millimeters of the ball appear to become transparent when it first hits the water!
posted by Salvor Hardin at 6:10 AM on January 6, 2013

I'm trying to figure out why it looks like the outer few millimeters of the ball appear to become transparent when it first hits the water!

The water in contact with the ball immediately vaporizes, creating an insulating layer of water vapor.
posted by the man of twists and turns at 6:34 AM on January 6, 2013 [3 favorites]

This effect is actually a problem in car racing. Engine blocks get hot enough that the coolant flashes to steam and forms a barrier between the still-liquid coolant and the block. There's a product called "water wetter" that lowers the viscosity of the coolant so the steam barrier can't form.

Neat stuff!
posted by notsnot at 7:27 AM on January 6, 2013 [9 favorites]

I like the idea that there's a product to make water wetter.
posted by ambivalentic at 8:51 AM on January 6, 2013 [2 favorites]

See also sticking a red hot pan straight in the washing up water.
posted by fearfulsymmetry at 9:04 AM on January 6, 2013

fearfulsymmetry: "See also sticking a red hot pan straight in the washing up water."

What are you cooking?
posted by Splunge at 9:18 AM on January 6, 2013

This recipe leaves you with a nice hot pan, Splunge:
http://www.foodnetwork.com/recipes/alton-brown/pan-seared-rib-eye-recipe/index.html
posted by xorry at 9:49 AM on January 6, 2013

>fearfulsymmetry: "See also sticking a red hot pan straight in the washing up water."

What are you cooking?



Charcoal, at a guess.
posted by kcds at 10:13 AM on January 6, 2013

This recipe leaves you with a nice hot pan, Splunge:

Hot, yes? Red hot? NO.
posted by eriko at 10:29 AM on January 6, 2013

"The water was as hot as I like my coffee after this..."

I'd like to imagine there's a parallel universe out there where we drop red-hot nickel balls in our room-temperature drinks like we would ice cubes.
posted by griphus at 10:49 AM on January 6, 2013 [9 favorites]

crapmatic writes "Dang.. where do I get one of them there nickel balls, and will my propane torch heat it up?"

Propane is probably too cool but a not much more expensive MAPP/Air (or what passes for MAPP nowadays) torch would do the job. Steel balls like that are available as ball bearings not sure hwere to get nickel balls.
posted by Mitheral at 11:44 AM on January 6, 2013

What are you cooking?

Steak - like 'em seared on the outside and bloody in the middle, so I get a frying pan hot as well with the oil smoking. Once you've cooked it, if you put the pan straight in some water you'll get the same fun noises (if not quite so pronounced - because when I say red hot I don't literally mean glowing)
posted by fearfulsymmetry at 12:21 PM on January 6, 2013

You do know that's a recipe for warped pans right? Let your pans cool before you dunk 'em in water if you value flat bottoms.
posted by aspo at 12:23 PM on January 6, 2013 [4 favorites]

Back in college I freaked out some people by pouring liquid nitrogen on my hand. The trick is to pour it on the palm of your hand instead of the back (and let it immediately flow off), since the hairs on the back of your hand will catch some of it. Not enough to do any real damage, but enough that you wish you hadn't done that.
posted by ckape at 12:29 PM on January 6, 2013

OK, walk me through this. The hot ball hits the water, and a layer of vapor forms around it, keeping the heat away from the water. As the ball cools, the vapor layer gives way, allowing water to start reaching the heated ball. We see bubbles coming up from the water boiling. At some point, the vapor layer collapses, water encompasses the ball, and it cools very rapidly as some of the water turns to steam. The ball is black at the end--is that the color it started as, or has something happened to it?

Thank you. I want to show this video to my kids but they will ask me all kinds of hard questions about it.
posted by not that girl at 12:46 PM on January 6, 2013 [2 favorites]

DU: I think it's cavitation. Gas bubbles emerging from the heated surface quickly collapse when they move into the cooler sounding water, which causes a sharp vibration to ping through it. Notice the chirps occur 1) when the ball is first dropped in and is therefore most hot, and 2) when bubbles break loose from the gas "donut", but only after the donut's been in stable contact with the metal for a few seconds, allowing the gas to become sufficiently heated.
posted by dephlogisticated

Definitely cavitation and this guy would know.

Best. Eponysterical. Meta. Ever.
posted by IAmBroom at 1:26 PM on January 6, 2013

Let me tell you the story of a cast iron pan that died and was reborn.

Back in the 1970s I lived with my first wife in an apartment at the top of Fort Tryon Park in NYC. It was an expensive corner apartment. People wondered why we could afford to live there. I do not wish to explain live sex shows here, so anyway.

One day we return to our apartment and open the door. The first thing that we smell is burning metal. The second thing that we notice is that the apartment is hot as a sauna. But without the moisture. The cats are nowhere to be found.

A moment for explanation: Our cats were a Carmel Tabby named Krishna and a grey and blue idiot with excessive toes named Svarltaf.

Anyway, we walked into the hall and then down to the kitchen. There on the stove was a cast iron skillet. And under the skillet was a full flame.

In the middle of the skillet was a cheerful cherry glow. And I mean bright red as in ready to strike it with a hammer red. All of the fine coating that had made it a perfect cast iron pan had flaked off. Someone had jumped off of the stove and hit the gas. Only Krishna would sit on the stove.

One of the fucking cats (probably Krishna) had jumped off of the stove and hit the knob (which had flanges) and turned the gas on high.

I used a long spoon to turn the gas off.

If I could have grasped the glowing pan, which I could not have done, I would not have done it anyway. I don't know how hot it was. But I have some idea.

It took hours before i was even ready to touch the pan with a pair of pliers.

When I did, there was a PING sound. It was the pan removing itself from the cast iron grate that it was sitting on.

That pan had stuff on it from my wife's mother, her mother and her mother.

In one day, it was made new.

It took months to season it again.

It was never the same.
posted by Splunge at 7:54 PM on January 6, 2013 [6 favorites]

if you value flat bottoms...

Yes, flat bottom grills make the rocking world go round.
posted by blueberry at 6:30 AM on January 7, 2013 [2 favorites]

The hot ball hits the water, and a layer of vapor forms around it, keeping the heat away from the water.

Well, kind of (and that's the initial squeaking). There's a significant amount of heat transfer by radiation from the ball to the water that dwarfs the amount of heat transfer by conduction to the vapor phase (about 5 s of silence, more or less). As the temperature differential decreases, the vapor layer gets thinner, until the liquid water is able to touch the bottom point of the ball. At that point, heat transfer is dominated by conduction from the ball to the liquid, the metal immediately surrounding that point drops in temperature substantially, and the liquid cools the ball from the bottom up.

You can see the same thing if you superheat a pan. It doesn't even need to be red hot, just hot enough to make water really dance. Take the pan, put it under the faucet, and turn on a moderate stream of water. The spot directly underneath the stream will cool off first in an increasingly larger area, and the water will flash into vapor around that area.
posted by disconnect at 10:54 AM on January 7, 2013

It took months to season it again.

My grandmother speaks of her and other family members putting their cast iron into very hot brush fires and letting it burn off all the seasoning when they "got crusty".

Fire + pans --> coals + pans --> ashes + (pans sans carbon aka bare metal)

It should be said this can cause warping or cracking but I trust her that it was absolutely effective.
posted by RolandOfEld at 5:18 PM on January 7, 2013