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.
Recent Israeli Synagogue Attack, a Possible False Flag? 2014 11 21 Dear Friends - I woke up yesterday morning to see a newspaper lying on the kitchen table with the front page proclaiming that five people were slain in an Israeli synagogue after a so-called "Palestinian attack." Some members of the media said that four people were killed, others said five, so it seems like that there was some confusion (or ...
Detekt: A New Malware Detection Tool That Can Expose Illegitimate State Surveillance 2014 11 21 Recent years have seen a boom in the adoption of surveillance technology by governments around the world, including spyware that provides its purchasers the unchecked ability to target remote Internet users’ computers, to read their personal emails, listen in on private audio calls, record keystrokes and passwords, and remotely activate their computer’s camera or microphone. EFF, together with Amnesty International, ...
New UK spy chief says tech giants aid terrorism, privacy not ‘absolute right’ 2014 11 21
Robert Hannigan, the new head of GCHQ
The new head of Britain’s GCHQ, the UK equivalent of the NSA in the U.S., said he believes privacy is not an absolute right and that tech giants must open themselves up to intelligence agencies.
“GCHQ is happy to be part of a mature debate on privacy in the digital age,” Hannigan said. “But privacy ...
LOL: Atheist Feminist Pornographer Used as Moral Authority in T-shirt Row 2014 11 21
Dr. Matt Taylor was thrust into the headlines this last week, largely for his lead role in successfully landing a spacecraft on a comet 300 million miles from earth that travels at a speed of 85,000 mph. In short, Taylor and his colleagues pulled off one of the most amazing achievements in contemporary science and space exploration, and in a ...