[HN Gopher] The Kopp-Etchells Effect (2012)
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       The Kopp-Etchells Effect (2012)
        
       Author : eproxus
       Score  : 25 points
       Date   : 2022-11-13 13:58 UTC (9 hours ago)
        
 (HTM) web link (sciencebasedlife.wordpress.com)
 (TXT) w3m dump (sciencebasedlife.wordpress.com)
        
       | zokier wrote:
       | The spontaneous combustion part here feels bit weird; I imagine
       | the phenomenon is more like when you hit metal with angle grinder
       | and sparks fly out, where the abrasive action heats the particles
       | up to ignition point. At least I wouldn't call that very
       | spontaneous.
        
         | lupire wrote:
         | The author's claim is that the powdered metal oxidizes, not
         | directly abraded.
         | 
         | https://en.m.wikipedia.org/wiki/Pyrophoricity
        
       | Sharlin wrote:
       | My first guess was triboluminescence, but yeah, pyrophoricity
       | sounds very plausible as well.
        
       | qwertyuiop_ wrote:
       | _The Kopp-Etchells effect was first documented during combat
       | operations in Afghanistan. The photographer Michael Yon named the
       | effect after two soldiers who died there, Koop, a US Ranger, and
       | Etchells, a British soldier. Both were killed in combat in this
       | province of Afghanistan._
       | 
       | Props to the photographer for naming the effect after the
       | soldiers who lost their lives.
        
         | hanoz wrote:
         | Pity the article has been getting Kopp's name wrong without
         | correction for the last 10 years though, despite containing
         | several other changes suggested by the photographer.
        
       | AlbertCory wrote:
       | The movie scene writes itself:
       | 
       | (the scene: a firebase in Afghanistan. A platoon of weary grunts
       | are landing in a chopper, returning from a tough mission)
       | 
       | Marine A: Did you guys notice that halo around the rotors when
       | the chopper took off, after we landed at the site?
       | 
       | B: No, douchebag, we were checking our weapons again.
       | 
       | A: That's called the Kopp-Etchells effect.
       | 
       | B: You're going to explain it to us, aren't you?
       | 
       | A: You see, the leading edge of the blades has titanium on it, so
       | ...
       | 
       | B: (chopper lands) Well, here we are! Looking forward to hearing
       | all about this, next mission, douchebag.
        
         | [deleted]
        
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       (page generated 2022-11-13 23:02 UTC)