Protected By Science My hand is like a red-hot poker to the liquid nitrogen, but an insulating layer of nitrogen gas forms- a phenomenon known as the Leiden-frost effect- keeping my hand safe and warm for a fraction of a second. Mike Walker
When I first saw this photograph of a man’s hand submerged in liquid nitrogen at somewhere below -320° F, my immediate thought was, “That guy must be crazy! One second in that stuff, and you’re shopping for new skin!” My shock was tempered only slightly by the fact that it was my hand, and we’d taken the picture just a minute earlier.
I hadn’t realized that my hand was quite so deep into the liquid. Amazingly, I barely felt the cold at all. My skin didn’t get hurt for the same reason that water droplets dance on a hot skillet. An insulating layer of steam forms almost instantly between the water and the metal, keeping the droplets relatively cool as they float for several seconds without actually touching the hot surface. To liquid nitrogen, flesh is like that skillet—a surface hundreds of degrees above its boiling point. So the moment my hand touched the liquid, it created a protective layer of evaporated nitrogen gas, just as the skillet created a layer of steam. That gave me just enough time to put my hand in and pull it out again. Any longer than that, and frostbite would have set in.
Hot Water: Droplets on a very hot skillet take longer to evaporate than they would on a less-hot surface where no insulating gas layer forms. Mike Walker
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.
I drew the line at another classic example of the effect. According to the books, it’s possible to stick a damp finger directly into molten lead without getting burned, if you do it fast enough. After some consideration, and remembering the times I’ve been burned by molten lead, I decided that it probably wouldn’t make a very good picture anyway.
ACHTUNG! Do not try this. If liquid nitrogen soaks into your clothes, you will not be protected by the Leidenfrost effect, and you can get frostbite very quickly.
Document Confirms British were Plotting to Invade Germay Before Germany Invaded Poland 2014 09 02 The declaration of war against Germany had nothing to do with Poland, and was in fact a brutal war of aggression launched for economic reasons against the peaceful German people. As you can see in Judea Declares War on Germany.
An early version of the ‘King’s Speech’ reveals Britain was preparing to declare war on Germany before Hitler invaded ...
Study Claims Cave Art Made by Neanderthals 2014 09 02 A series of lines scratched into rock in a cave near the southwestern tip of Europe could be proof that Neanderthals were more intelligent and creative than previously thought.
The cross-hatched engravings inside Gorham’s Cave in Gibraltar are the first known examples of Neanderthal rock art, according to a team of scientists who studied the site. The find is significant because ...
Nigeria launches new biometric ID card - brought to you by Mastercard 2014 09 02
Yesterday afternoon, president Goodluck Jonathan became the first recipient of Nigeria’s new national eID card, in a ceremony at the presidential villa in the capital Abuja. The cards will be issued to 13 million Nigerians as part of a pilot project, with the ultimate aim of producing a national identity management system (NIMS).
Nigeria’s NIMS is an ambitious attempt to consolidate ...
LA Times Now Describing Illegal Aliens As ’Informal Workers’ Who ’Labor Unofficially’ 2014 09 02 Via Weasel Zippers, we learned the Los Angeles Times has a new term for illegal aliens in the work force: they’re “informal workers,” and that doesn’t mean they don’t arrive on the job in a tuxedo.
Times reporter Tiffany Hsu (a "UC Berkeley grad") began her Saturday story with the new I-word (and illegal immigrants also “labored unofficially” in "gray employment"):