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Taking the Ice Bucket Challenge With Liquid Nitrogen

Posted by samzenpus on 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.

40 of 182 comments (clear)

  1. so the T-1000 shouldn't have frozen? by Anonymous Coward · · Score: 2

    Does this mean Terminator 2 is debunked by Leidenfrost?

    1. Re:so the T-1000 shouldn't have frozen? by Anonymous Coward · · Score: 3, Informative

      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.

    2. Re:so the T-1000 shouldn't have frozen? by Zero__Kelvin · · Score: 5, Funny

      Yes. This is the one achilles heal in the whole movie, which was otherwise a flawless portrayal of reality.

      --
      Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
  2. it tingles by sayfawa · · Score: 2, Informative

    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

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    Free the Quark 3 from asymptotic confinement! Bring your charm! Don't get down! All colours and flavours welcome!
    1. Re:it tingles by 93+Escort+Wagon · · Score: 5, Informative

      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.

      --
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    2. Re:it tingles by phantomfive · · Score: 5, Informative

      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.

      --
      "First they came for the slanderers and i said nothing."
    3. Re:it tingles by PolygamousRanchKid+ · · Score: 5, Funny

      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."

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    4. Re:it tingles by infolation · · Score: 4, Funny

      Then we need to encourage the 'family ice bucket challenge'.

    5. Re:it tingles by Wootery · · Score: 2

      His dentist suggested he not do it any more.

      It took a dentist to tell him that?

  3. Is it really the Leidenfrost effect? by NotSoHeavyD3 · · Score: 2

    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.)

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    1. Re:Is it really the Leidenfrost effect? by Anonymous Coward · · Score: 5, Informative

      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.

    2. Re:Is it really the Leidenfrost effect? by Whorhay · · Score: 2

      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.

  4. Re:People who did High School Chemistry know this. by Anonymous Coward · · Score: 5, Funny

    I was educated in the inner city, you insensitive clod. We didn't get any liquid nitrogen at my school because we might make drugs out of it.

  5. I'd have preferred by Rick+in+China · · Score: 3, Informative

    If he were to turn into a popsicle.

  6. I'm starting to wonder... by mark-t · · Score: 5, Interesting

    ... 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.

    --
    File under 'M' for 'Manic ranting'
    1. Re:I'm starting to wonder... by Payden+K.+Pringle · · Score: 2

      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.

    2. Re:I'm starting to wonder... by radtea · · Score: 5, Interesting

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

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

      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!

      --
      Blasphemy is a human right. Blasphemophobia kills.
    3. Re:I'm starting to wonder... by Opportunist · · Score: 3, Insightful

      By weeding out the ones that don't know when to quit.

      --
      We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
    4. Re:I'm starting to wonder... by drinkypoo · · Score: 2

      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.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    5. Re:I'm starting to wonder... by flappinbooger · · Score: 2

      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

      --
      Flappinbooger isn't my real name
    6. Re:I'm starting to wonder... by StormCrow · · Score: 3, Informative

      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...

  7. I did it first ! by dargaud · · Score: 5, Interesting

    In 1994 I had a liquid nitrogen tube break above my head while preparing an experiment for Antarctica. 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?"

    --
    Non-Linux Penguins ?
    1. Re:I did it first ! by Neil+Boekend · · Score: 5, Funny

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

      --
      Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
    2. Re:I did it first ! by KingOfBLASH · · Score: 2

      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)

    3. Re:I did it first ! by MrKaos · · Score: 3, Funny

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

      Nah, someone else said - "that was cool!"

      --
      My ism, it's full of beliefs.
    4. Re:I did it first ! by drinkypoo · · Score: 3, Interesting

      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.)

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    5. Re:I did it first ! by tommeke100 · · Score: 2

      So have you gained any super-powers?

  8. Re:Translation for kids... by Opportunist · · Score: 4, Insightful

    My first reaction when I read this: I think we found the winner of 2014's Darwin Award. No, not that guy. But some copycat who has, unlike him, no clue about Physics and insists in topping the performance.

    --
    We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
  9. Why do German scientists have fitting names? by Opportunist · · Score: 4, Funny

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

    --
    We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
    1. Re:Why do German scientists have fitting names? by BetterThanCaesar · · Score: 3, Interesting

      Not only Germans. Have you seen the function named after Englishman Oliver Heaviside, which has one light and one heavy side?

      --
      "Stop failing the Turing test!" -- Dilbert
    2. Re:Why do German scientists have fitting names? by BlueLightning · · Score: 4, Interesting

      This is known as "nominative determinism"; here's a somewhat amusing article from a couple of years ago on the subject.

  10. Re:Darwin Awards by SuricouRaven · · Score: 2

    There's a point where you are intelligent enough to play with the dangerous stuff, but not intelligent enough not to.

  11. fuck you and the bucket challenge by ruir · · Score: 5, Insightful

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

    1. Re:fuck you and the bucket challenge by webmistressrachel · · Score: 2

      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! ;-)

      --
      This tagline was transcoded to result in at least one smirk. If you experience failure to smirk, please consult your Gen
    2. Re:fuck you and the bucket challenge by BringsApples · · Score: 2

      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 being cool (no pun intended).

      --
      Politics; n. : A religion whereby man is god.
    3. Re:fuck you and the bucket challenge by Chris453 · · Score: 3, Insightful

      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.

    4. Re:fuck you and the bucket challenge by thegarbz · · Score: 4, Insightful

      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. 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.

    5. Re:fuck you and the bucket challenge by pipingguy · · Score: 2

      It appeals to peoples' inner narcissism.

  12. Re:Translation for kids... by gmuslera · · Score: 2

    Considering the average adult that went through the Ice Bucket Challenge, it would be a great advice for them too. I won't be surprised at all if it ends killing more people than ALS.

  13. Ultimate Ice Buckey Challenge by chfriley · · Score: 4, Funny

    Hal Finney -an ALS sufferer- did the ultimate Ice Bucket challenge with liquid nitrogen last week (Aug 28, 2014) when he was cryopreserved after passing away from ALS:

    http://en.wikipedia.org/wiki/H...