Do not do this at home. This is for certified scientists only. Do not put your finger in this.

Comments

  1. #1 Joshua Zelinsky
    November 21, 2009

    I’m a bit surprised that he does this whole thing without any form of gloves. This is a real demonstration. The descriptor of “cryogenic napalm” is also amusing.

  2. #2 george.w
    November 21, 2009

    No way would I handle that super-cold alcohol without gloves. Though I did put my whole forearm into liquid nitrogen once. Pulled it back out, screaming and affecting a “frozen hand”… (I know, never clown around in a laboratory.)

    For those who don’t know, it’s a relatively safe stunt. It takes a few moments for liquid nitrogen to touch your skin, CSI episodes notwithstanding.

  3. #3 tms
    November 22, 2009

    Is no one else going to mention that “real” liquid nitrogen is roughly three times colder than dry ice?

    T

  4. #4 Aaron Golas
    November 22, 2009

    Bah. We use an ethanol/dry ice bath to flash freeze competent bacteria. Nothin’ “liquid nitrogen” about it, neither in temperature nor substance. Still pretty cold, but latex gloves are typically enough insulation to suit me.

  5. #5 MadScientist
    November 22, 2009

    Awww… and I was hoping it would be a real “how to”. You can in fact make liquid nitrogen right at home – but you have to have access to a workshop to manufacture some bits that you’ll need. It’s really not that difficult and was first done about 120 years ago. Liquid oxygen is extremely dangerous though, and should you accidentally trap large amounts of liquid ozone by repeated use of the apparatus without flushing – well, that’s even worse than liquid oxygen. Liquid nitrogen is very safe in comparison – you only need to worry about contact with the cold gas and asphyxiation due to displacement of oxygen. Well, the asphyxiation thing can be tricky – you’ll have no idea what the oxygen content of the air you’re breathing is unless you have an oxygen sensor of some sort.

  6. #6 nihat
    November 22, 2009

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  7. #7 osmaniye çiçekçi
    November 22, 2009

    osmaniye çiçek siparişleri için online çiçek satış mağazası

  8. #8 Mike Haubrich, FCD
    November 22, 2009

    So, how cold does this actually get when you use dry ice and alcohol? I have an, um, “need to know.”

  9. #9 peter
    November 22, 2009

    gloves are a bad idea for the same reason that it is recommended that you not wear pants with cuffs while welding.

  10. #10 omar
    November 22, 2009

    Because the horse divers fall into them?

  11. #11 dhogaza
    November 22, 2009

    It’s really not that difficult and was first done about 120 years ago.

    And old saying about DeWar …

    “Sir James DeWar is smarter than you are. None of you asses can liquify gasses …”

    When in high school friends and I had unlimited access to a large dewar full of liquid nitrogen at a local science museum, and a master key that allowed us to um liberate plastic bottles sold in the science supply store.

    1. Take plastic bottle

    2. Add a bit of liquid nitrogen

    3. Shake well – but quickly!

    4. Throw

    The result would be a nice explosive “thump” and a cloud of condensation …

    One fourth of July the museum had a national guard team with some sort of field piece come by to shoot blanks … several of us kids got our liquid nitrogen “bombs” ready to go, two each, one for each hand, and came pouring out of the museum’s basement charging across the parking lot to the crew firing blanks.

    Thump! Crump! Bang! Hell, were those guardsmen freaked out …

    I suppose kids doing stuff like this today would end up in jail, but we had a hell of a time.

  12. #12 havoc
    November 22, 2009

    We have dry ice in the lab for the purpose Aaron stated, but it also comes in handy when an impromptu dance party is in order. Throw some dry ice in the sink and turn on the water… DIY smoke machine.

    I don’t use gloves when I handle it and it’s no worse than the way my hands feel after a good snowball fight.

  13. #13 Aaron Golas
    November 23, 2009

    So, how cold does this actually get when you use dry ice and alcohol? I have an, um, “need to know.”

    About -78 degrees Celsius. For comparison, liquid nitrogen boils at -196degC.

    I won’t ask about your “need to know,” I’ll just thank you for bringing some mystery into the world. ;-)

  14. #14 Cath Princeton
    January 17, 2010

    The whole idea looks really cool but it is not as this can turn into a dangerous accident.