Remember those high school liquid nitrogen demonstrations? You know, the one where your teacher dipped a banana into the cloudy stuff, pulled it out, and then shattered it on the floor? Well, Popular Science blogger Theodore Gray recently decided to stick in his hand. As you can see in a video over on their site, his hand survived the encounter. Though he stressed, and we reiterate, that this really isn't a good idea unless you know what you're doing, or unless you want your friends to call you Captain Hook, sticking your hand in the cold stuff isn't necessarily a recipe for digit removal. Since Gray's hand was much warmer than the liquid nitrogen (which checks in at around negative 320 degrees Fahrenheit), the hand instantly created a layer of evaporated nitrogen gas--which shielded his skin, temporarily, from frostbite. Gray says on his blog:
"The phenomenon is called the Leidenfrost effect (after Johann Gottlob Leidenfrost, the doctor who first studied it in 1756). I’d known about it for years, but when it came time to test it in real life, I have to admit that I used my left hand, the one I’d miss less."
For more videos of people doing questionable things in the name of science, check out DISCOVER's new show Joe Genius. Related content: JOE GENIUS: Chemistry Cafe Discoblog: Crazy Optical Illusion of the Day Discoblog: To Levitate Water, Turn on the Strobe Lights Discoblog: Prepare to Be Amazed… An iPhone App That Can Read Minds!
Image: flickr / Lee Gillen
