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Taking the Ice Bucket Challenge With Liquid Nitrogen 182

Posted by samzenpus
from the coldest-shower dept.
Nerval's Lobster writes As a trend, the ALS Ice Bucket Challenge seems a bit played out—who hasn't yet dumped a bucket of icy water over his or her head for charity? But that didn't stop Canadian chemist Muhammad Qureshi from executing his own sublimely scientific, potentially dangerous variation on the theme: After donating to the ALS Association, he proceeded to douse himself with a bucket of liquid nitrogen. Anyone who's taken a chemistry class, or at least watched the end of Terminator 2, knows that liquid nitrogen can rapidly freeze objects, leaving them brittle and prone to shattering. Pouring it on your skin can cause serious frostbite. So what prevented that bucketful of liquid nitrogen from transforming Qureshi into a popsicle? In two words: Leidenfrost effect. Named after 18th century scientist Johann Gottlob Leidenfrost, the effect is when a liquid comes near a mass that's much warmer than the liquid's boiling point, which (in the words of Princeton's helpful physics explainer) results in an insulating vapor layer that "keeps that liquid from boiling rapidly." In other words, the vapor makes the liquid "float" just above the surface of the object, rather than coming into direct contact with it.
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Taking the Ice Bucket Challenge With Liquid Nitrogen

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  • by Anonymous Coward

    Does this mean Terminator 2 is debunked by Leidenfrost?

    • Re: (Score:3, Informative)

      by Anonymous Coward

      No, it works for a few seconds, the evaporation of the nitrogen still extracts energy from the skin. If you pour it for more than a few seconds your hand will freeze and then crack.

    • by Zero__Kelvin (151819) on Thursday September 04, 2014 @07:50AM (#47824223) Homepage
      Yes. This is the one achilles heal in the whole movie, which was otherwise a flawless portrayal of reality.
      • No, the T-1000 was a liquid metal. Due to it's heat conduction (we can assume from the metal) it would conduct heat and thus not create a protective gas layer.

        Now if you want to start talking about Armageddon's bad physics, we could be here all day.

        • WHOOOSH
          • Whoosh the humor went over my head, or "Whoosh!" the sound of a hundred NASA rocket scientists groaning at bad science in movies?

            • Whoosh the humor went over my head, or "Whoosh!" the sound of a hundred NASA rocket scientists groaning at bad science in movies?

              The Point
              ------------- (Dear moronic Slashfilter, It's not fucking "ASCII Art", it's a fucking line)
              Your Head

  • it tingles (Score:3, Informative)

    by sayfawa (1099071) on Wednesday September 03, 2014 @11:39PM (#47822923)
    Yeah, liquid nitrogen is pretty safe. Dip your hand in it, throw it at people, put it in your ice cream; all valid uses. Unless you drink it or jump in a pool of it, it's mostly harmless
    • Re:it tingles (Score:5, Informative)

      by 93 Escort Wagon (326346) on Thursday September 04, 2014 @12:22AM (#47823081)

      In my old job we used a lot of liquid nitrogen - mainly to transfer carbon dioxide around in various scientific apparatus (a mass spectrometer, for one).

      Anyone who has worked extensively with the stuff will tell you it is NOT safe unless you are careful. The Leidenfrost effect works... for a relatively short duration. But the co it used application of liquid nitrogen to a specific area rapidly cools the immediate surroundings, and then the effect stops working - especially if the nitrogen doesn't have a way to skitter away on that layer of gas (if you were to pour it into a cupped palm, for example).

      Also, small droplets (such as are generated from the stuff boiling when you're freezing carbon dioxide into a cold finger) don't seem to have much difficulty reaching one's skin, Leidenfrost or no. Most of us in the lab frequently had small burns on the thumb sides of our hands.

      • Re:it tingles (Score:5, Informative)

        by phantomfive (622387) on Thursday September 04, 2014 @01:50AM (#47823279) Journal
        In my physics book, the author told about his own personal experiments with the Leidenfrost effect. He would plunge his hand into a bucket of molten lead (after dipping it in water), and pretty soon had advanced to putting liquid nitrogen in his mouth and breathing it out.

        He stopped the last one after it went slightly wrong, and all his teeth cracked. His dentist suggested he not do it any more.
        • by Wootery (1087023)

          His dentist suggested he not do it any more.

          It took a dentist to tell him that?

        • by Quirkz (1206400)

          I think we had the same physics book, because this article brought back memories of the story. In my memory he cracked one rear molar and not *all* of his teeth, but it's otherwise similar.

        • He could have just chewed on Coolmints.
      • by PolygamousRanchKid (1290638) on Thursday September 04, 2014 @01:53AM (#47823285)

        Anyone who has worked extensively with the stuff will tell you it is NOT safe unless you are careful.

        Gee, and there I was, going to tell those Knoxvillesque folks to try the "Liquid Nitrogen Enema Challenge."

        • Anyone who has worked extensively with the stuff will tell you it is NOT safe unless you are careful.

          Gee, and there I was, going to tell those Knoxvillesque folks to try the "Liquid Nitrogen Enema Challenge."

          Some things are worth the risk.

    • Liquid nitrogen is an oxygen deficiency hazard. We have kilns at work that operate in the few thousand Fahrenheit range. These kilns are over 200,000 cubic feet. In case of a fire, liquid nitrogen is used to extinguish it by cutting off the oxygen that feeds the fire. The control systems dispense it rapidly enough that it is a human hazard and alarm systems warn to evacuate immediately. You don't want to be around when that stuff dispenses.
  • by NotSoHeavyD3 (1400425) on Wednesday September 03, 2014 @11:49PM (#47822965)
    I ask since it always seems that they use that one to explain everything even when it doesn't make sense. (IE fire walking where I saw Jearl Walker use plastic bags to build up sweat on his feet to do that but it still works even if you don't do this. BTW it seems the only requirement to fire walking is just don't stop.)
    • by Anonymous Coward on Thursday September 04, 2014 @12:26AM (#47823095)

      It really is this time. The Leidenfrost effect comes into play when a surface is much hotter than a given material's boiling point. The Leidenfrost effect explains safe contact of hot skin with liquid nitrogen, wet hands surviving molten lead, and why water skitters on a hot skillet. Any time a liquid contacts a surface much hotter than its boiling point, such that it can be suspended in the air by convection currents, the Leidenfrost effect is responsible. In the LN2 case, your skin is far enough above the -195C boiling point that the nitrogen boils off before it touches your skin. In the molten lead case, the water on your hands must evaporate before your hands can start burning, this creates a temporary steam bubble that insulates your hand much like a winter coat. The water on a hot skillet case is the simplest case, where radiative and convective heat transfer is so intense that hot air and water vapor form a convective bubble underneath the boiling water bubble and instabilities in the air bubble then cause the water bubble to flow towards a theoretical edge and skitter around the pan.

      The firewalking claim is a little dubious, it seems more likely that the short contact time combined with the small surface area exposed during normal walking is responsible for the undamaged feet. Most firewalkers don't seem to sit around getting their feet good and sweaty before firewalking.

    • BTW it seems the only requirement to fire walking is just don't stop.

      I never understood the mystique surrounding firewalking. It's basic heat transfer. You see the effects all the time.

      Touch the coin on your desk. It feels a bit "cool," right? Now touch the wooden part of the desk. That feels more like the temperature of the room, right? But they're obviously both at the same temperature. Our bodies are sensitive to rate of heat transfer, absolute temperature is irrelevant.

      It's the reason why no one ever worries about getting his tongue stuck to a wooden post in w

      • by Whorhay (1319089)

        It helps that the coals for firewalking are typically ashed over nicely. The ash actually serves as a pretty decent short term insulator. If you just blew the ash off the coals I imagine it would be a very different experience.

    • Don't stop, and tread lightly. Otherwise the coals might stick to your feet.
  • I'd have preferred (Score:4, Informative)

    by Rick in China (2934527) on Wednesday September 03, 2014 @11:57PM (#47822987)

    If he were to turn into a popsicle.

  • by mark-t (151149) <markt@l y n x . b c .ca> on Thursday September 04, 2014 @12:00AM (#47822999) Journal

    ... how long will it take before somebody dies?

    I don't mean to sound morbid here, I am just starting to think that this whole thing is pretty darn pointless, If you want to donate money to ALS, do it... but this ice bucket challenge thing is turning into a competition of who can one-up who in how they go about it, and I think it's now only a matter of time before somebody gets seriously hurt or killed.

    • Just so it's clear, ALS causes a person to lose feeling in their body. The ice bucket challenge's purpose is to simulate that effect so that you know what they go through in a much less permanent way. How it "feels" to have ALS (hint: it doesn't).

      I agree, although I can't imagine how someone would die from it unless they had a pre-existing condition, in which case they shouldn't be doing it to begin with.

      • I think that excuse was made up after the fact.

      • by gsslay (807818)

        Someone would die from it because it has escalated to a game of one-upmanship where people add extra bits.

        Like using nitrogen. Or gasoline. Or massive ice cubes. Or while at driving a speeding car. Or in a swimming pool shackled to a sack of concrete.

        You get the idea. People think that somehow it's not dangerous or idiotic because it's for charity.

    • by radtea (464814) on Thursday September 04, 2014 @12:12AM (#47823047)

      ... how long will it take before somebody dies?

      Already happened: http://news.nationalpost.com/2... [nationalpost.com]

      I've stuck my hand in liquid nitrogen (it feels strangely warm) and so can attest to the protective effect of the gas blanket (which is highly insulating) but it is insanely dangerous to pour a bucket of LN2 over your head, and doing so is an invitation to people who aren't as smart or careful as you to do even more stupid and risky things.

      Donate to ALS research [*], by all means! But please, please, don't participate in this ridiculous pyramid scheme of increasingly dangerous stupidity.

      [*] I do not donate to ALS because it is not one of my causes, but I encourage you to think carefully about what you care most about and sign up as a steady, long-term donor to a few causes that are really important to you... this is of far more long-term benefit than episodic giving. If ALS is what matters most to you, go for it!

      • by drinkypoo (153816)

        Donate to ALS research [*], by all means!

        So IOW, don't give your money to the ALS foundation, since only around a quarter of it at best will go there.

        • by StormCrow (10254) on Thursday September 04, 2014 @07:51AM (#47824237) Homepage

          So IOW, don't give your money to the ALS foundation, since only around a quarter of it at best will go there.

          Demonstrably false with about 5 seconds of Google searching.

          http://www.snopes.com/politics... [snopes.com]

          • by drinkypoo (153816)

            Demonstrably false with about 5 seconds of Google searching.

            I read an article about that Snopes article this morning already, and hilariously, that snopes article is attacking a straw man and you are also using it to attack a straw man. I said research, and that's what the articles that snopes was responding to say as well, but snopes attacks the claim "research and services"

            That is to say, English... YOU FAIL IT

      • I encourage you to think carefully about what you care most about and sign up as a steady, long-term donor to a few causes that are really important to you... this is of far more long-term benefit than episodic giving.

        I recommend the Free Software Foundation.

        • I encourage you to think carefully about what you care most about and sign up as a steady, long-term donor to a few causes that are really important to you... this is of far more long-term benefit than episodic giving.

          I recommend the Free Software Foundation.

          dump a bucket of microsoft disk cases and old win95 floppies on your head for the FSF challenge

    • I don't mean to sound morbid here, I am just starting to think that this whole thing is pretty darn pointless, If you want to donate money to ALS, do it... but this ice bucket challenge thing is turning into a competition of who can one-up who in how they go about it, and I think it's now only a matter of time before somebody gets seriously hurt or killed.

      Actually this is the perfect way to collect donations for a good cause: create a silly meme and create a culture of making a donation when doing it. People love this kind of shit.

  • After dipping a rose into liquid nitrogen, the petals are flaky as potato chips.

    Then the guy combed his hair to remove anything frozen there. Such action
    might break those hair frozen by the LN. I don't think he would like to show it
    in the video.

  • I did it first ! (Score:5, Interesting)

    by dargaud (518470) <slashdot2NO@SPAMgdargaud.net> on Thursday September 04, 2014 @12:40AM (#47823127) Homepage
    In 1994 I had a liquid nitrogen tube break above my head while preparing an experiment for Antarctica [gdargaud.net]. About 30 liters poured on my head in a second. I felt it go instantly trough my clothing, run over me, and on the floor. Everybody else in the lab ran away, but I couldn't because it formed a dense could, I couldn't see anything and I was behind a lot of equipment and cables. Then the floor exploded: I couldn't see what was going on but very loud cracking and banging noises later proved to be the tiles shattering. Fortunately I was wearing security shoes and just stood my ground. After the fog cleared I saw some faces at the door: "Are you still alive?"
    • by Neil Boekend (1854906) on Thursday September 04, 2014 @01:26AM (#47823229)

      Did you take the chance to reply "I'm not feeling so hot"?

    • Is it normal to have liquid nitrogen stored up high?

      Seems kind of dangerous and that this stuff would be buried in the ground (as people would do with a tank of diesel, for instance)

      • by dargaud (518470)
        I have no idea. I was a student and just wanted to test some of my hardware at cold temperatures. The guys in charge of cryogenics were on vacation but other guys were all like "we know this stuff, we can run the test..." Yeah, right.
      • It's perfectly normal for plumbing in a commercial or industrial setting to be run underneath the ceiling. Burying stuff under a concrete floor is expensive to install, weakens the floor, and is difficult to maintain. A raised floor has limited load-bearing capacity and is also expensive vs. a suspended ceiling (if you care about aesthetics at all... you don't really need one of those either.)

        You see plumbing buried in the floor of slab houses because it's cheap to install when the slab is being poured.

      • Re:I did it first ! (Score:4, Interesting)

        by drinkypoo (153816) <martin.espinoza@gmail.com> on Thursday September 04, 2014 @05:50AM (#47823741) Homepage Journal

        Seems kind of dangerous and that this stuff would be buried in the ground (as people would do with a tank of diesel, for instance)

        Which people? Gas stations, maybe. Everyone else stores diesel above ground. It's more stable than gasoline so the thermal cycling isn't as big of a worry, and you literally cannot light diesel on fire. You need a wick of some kind to even produce massive volumes of black smoke, with very little flame. You can extinguish lit cigarettes by dropping them into a can of diesel. It's legal to gravity-feed diesel, but you legally have to pump gasoline. (Obviously not out of a jerrycan, but in terms of tanks.)

    • So have you gained any super-powers?
    • by pipingguy (566974)
      Liquid nitrogen piping was not insulated?
    • by Richy_T (111409)

      Genuine potential risk of asphyxiation depending on circumstances.

  • by Opportunist (166417) on Thursday September 04, 2014 @12:57AM (#47823163)

    Serious. Mr. Schwarzschild ("black shield") only kinda-sorta fits his radius, but Mr. Leidenfrost ("suffering frost") really takes the cake here.

  • by ruir (2709173) on Thursday September 04, 2014 @02:58AM (#47823429) Homepage
    Idiocracy was right on. The fucking bucket challenge is no better than ow my balls. Mod me down at will.
    • I would mod you up, but my recent post count isn't good enough, and I'm not being allocated any mod points. This should solve the problem; though not for you, unfortunately! ;-)

    • Idiocracy was right on. The fucking bucket challenge is no better than ow my balls. Mod me down at will.

      Don't feel bad for yourself though, they're modding you down because you're using 'idiocracy' for no good reason, criticizing people who are doing good things.

      • Re: (Score:3, Insightful)

        by Chris453 (1092253)

        criticizing people who are doing good things.

        Actually no. Doing a good thing would be donating to charity. Most of the people doing this are just doing it because they saw it online or have a friend that did it and they want to be cool. Monkey see, monkey do. I bet a large number of the people doing the "challenge" don't even know the reason behind it. Instead of sharing stupid videos of clowns pouring water over their heads maybe we should be sharing videos of people writing checks to the charity. Of course that isn't as "exciting" for the ADD/ADHD generations.

        • There's nothing apart from your assumption saying that people aren't also giving to charity. Even if alot of them aren't, increasing awareness has its own benefits.

          • Actually, you're assuming that he said that, when in fact he didn't.

            • Whu? The clear implication from his post is that people are making videos instead of giving to charity.

              Instead of sharing stupid videos of clowns pouring water over their heads maybe we should be sharing videos of people writing checks to the charity.

              If he thought people were doing both then he wouldn't have a problem would he?

        • by anethema (99553)

          I cant even fathom the complaints about this.

          Hasn't ALS hit like 100 times their usual funding for the year due to all these people dumping ice on themselves? Saying the popularity and viral nature of it aren't a benefit in itself seems short sited.

      • by ruir (2709173)
        If you ever had seen idiocracy you would have understood my post. Panis et circenses for the stupid masses.
    • I agree. It's called "the ALS ice bucket challenge" and it's meant to spread awareness about Amyotrophic Lateral Sclerosis (Lou Gehrig's Disease) and yet when I ask most folks about it, all they know is that "...ALS is when you dump ice water on your head". WTF? Also, the point of dumping the ice water on your head, as far as I understand, is to put one temporarily into the condition closest to that of one who is suffering from Lou Gehrig's Disease. Spreading awareness my ass, at this point, it's about
    • by thegarbz (1787294) on Thursday September 04, 2014 @07:08AM (#47823989)

      It's slacktivism at its best. Seriously the whole point of the challenge was do something that causes discomfort and donate a little or forgo the discomfort and donate a lot. Yet we have an internet full of loaded celebrities like Oprah (who has a freezer draw of ice in her kitchen, like seriously how much money does one need to make before they can install something like that in their house?) who then go and douse themselves.

      So far the only one I have seen who did it right was Patrick Stewart [youtube.com]. Write a big check instead of putting yourself through the discomfort.

      The financial results of the campaign would be amazing if it weren't for the fact that many of the people participating make more money in a year than was donated in the entire campaign.

      • by pipingguy (566974)
        It appeals to peoples' inner narcissism.
    • Agree. I think this was the fad that finally allowed me to give up Facebook. Just looking forward to signing on one more time in mid-February and replying to all my friends' challenges with, "sorry, I've been offline for a while, but if you're still up for it I'd be happy to kick in a dollar."

  • Yes, LN2 will run off your skin and generally dissipate very quickly, but I believe you have to be very careful regarding clothing. Because the liquid will soak into and saturate fibers, which then are a real problem because you have a freezing liquid in contact with your skin which can cause burns.
  • Lots of celebrities. They used warm water with plastic icicles.

    BTW a german politician was dumb enough to film himself doing it beside his Marihuana plant.

  • Liquid nitrogen might be colder, but does not seem to have much heat capacity. When I had access to it, I 'played' a bit with it... who does not? Instant ice cream... putting finger in it... hand. No problem. Once I had a wet rag on the floor and I poured half a 5l Dewar with liquid nitrogen over it. The whole room was full of mist, but to my surprise the rag hardly got colder.
    However, I would not try this with liquid helium. ;-)

  • Reading the summary, I had flashbacks of Jim Carrey's Firemarshal Bill
  • "who hasn't yet dumped a bucket of icy water over his or her head for charity?"

    Me. Because fuck you if you think you can publicly shame me into giving money to a cause when I could name a hundred other equally worthy causes. Also, I don't brag about my charitable donations.

  • by Tablizer (95088)

    Here in California we are in a drought, so we dump a bucket of dust over our heads to conserve water.

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