Liquid nitrogen is famously one of the world’s coldest substances, freezing and shattering anything it comes into contact with. But if you know what you’re doing, you can safely stick your hand in it – as one brave blogger demonstrated.
Of course, before we get to the awesome footage of someone actually putting his hand in liquid nitrogen, we should point out that this is definitely an experiment that you should not attempt at home. The secret to pulling this off only works for less than a second, and it won’t work at all if liquid nitrogen comes into contact with your clothes. So with those disclaimers out of the way, how is he doing it?
Well, he’s protected by the Leidenfrost Effect, in which a liquid that comes into contact with something much hotter than itself forms an insulating layer of vapor to prevent the liquid from immediately boiling. (You can read all about the Leidenfrost Effect in a later post) This vapor layer provides short-term protection for the hand against the dangerously cold liquid nitrogen, allowing you to safely place your hand in the liquid nitrogen again and again – although only for a split-second each time.