From: snidely.too@gmail.com   
      
   JF Mezei explained on 9/23/2020 :   
   > On 2020-09-23 17:24, Snidely wrote:   
   >   
   >> Popped on the third night of testing.  In contrast to SN7, SN7.1 popped   
   >> at the top, like a champagne bottle.   
   >   
   >   
   > It was a nice show. Quite interesting that in the previous nights, while   
   > the geeks were proclaiming that it was being filled and frost forming,   
   > yesterday made it clear that it hadn't happened in previous nights.   
   >   
   > There was also a big difference with previous nights: the venting   
   > started from the top of dome yesterday whereas in previous nights, it   
   > came out of the big pipe near the skin on the hidden portion of the beer   
   > keg.   
   >   
   > My guess is that they first tested it with gaseous nitrogen and they   
   > likely found leaks which they had to fix and once fixed, they then   
   > filled it from the bottom with liquid N2 for yesterday's test.   
      
   Remember this tank did a cryo proof test including thrust simulator.   
      
   My bet is on problems with improvised GSE.   
      
      
   > What got mu curious though is all the fog that was being created only in   
   > the back of the beer keg during the final phases of test. Wondering if   
   > this was a leak or planned release. If it had been atmpspheric, it would   
   > have been from all around, not just from the back.   
   >   
   >   
   > BTW, after it blew its top, there was an overflow of nitrogen which   
   > behaved  like a foam as it overflowed over the rim and then moved down.   
   > Would liquid nitrogen, let loose, behave as a foam as it forms bubbles   
   > inside as it tried to boil with little heat available?   
      
   That's LN2, GN2 boil off, and atmospheric moisture forming the foam.   
   Open a soda bottle, a beer bottle, or champagne bottle where the CO2   
   stops being dissolved for a smaller demonstration, or ask someone with   
   an LN2 tank (used for various purposes, primarily rapid chilling) to   
   partially fill a small open dewar.   
      
   I had access to LN2 in high school (at an off-campus science center)   
   and the popular thing was to put some in a plastic chemistry bottle   
   (normally used for lab spirits (alcohol) and similar cleaners) and toss   
   it out the door into the parking lot.   
      
   /dps   
      
   --   
   "That’s where I end with this kind of conversation: Language is   
   crucial, and yet not the answer."   
     Jonathan Rosa, sociocultural and linguistic anthropologist,   
   Stanford.,2020   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)