From: eripe.dk@gmail.com   
      
   On Monday, January 23, 2017 at 3:45:07 AM UTC+7, nu...@bid.nes wrote:   
   > On Sunday, January 22, 2017 at 5:41:14 AM UTC-8, eripe wrote:   
   >   
   > (zeppelins filed with x, where x is lighter than hydrogen)   
   >   
   > > I have an idea, Diz iz Zuper Nutz; you could fill it with photons. If you   
   > > have a perfectly reflective inner side, the pressure from the light would   
   > > keep it inflated with a vacuum inside.   
   >   
   >   The reflector would only have to be perfect at one wavelength.   
      
   Do we need Doc-Smithian technomacis Perfect Reflector fields, or will suitable   
   stacked coatings do the trick?   
      
   I have no idea what any of those words mean :P   
      
   >   
   > > Radiation P = 0,5*p*c   
   > > P = 0,5 * 1E5 Pa * 3E8 m/s = 15E12 or 15 TW/m2.   
   > >   
   > > Im not sure how to calculate how much energy must be fed in there to build   
   > > that pressure up. Say the mirror is 99,999999999 % reflective, then you   
   have   
   > > to supply 15 W/m2 to make up for the losses at 15 TW/m2. I suppose that   
   much   
   > > light would inflate it then, but how long would it take?   
   > >   
   > > Once you know the energy, you can find the mass from E = m c^2   
   >   
      Also, if the envelope is controllably deformable, it's an EMdrive!   
      
   This would explain how those space faring blimbs work on   
      
   >   
   >   
   >   Dr. HotSalt   
      
   Anyway, was thinking a bit more about the amount of energy needed.   
   So if the ship is 60 meters wide, that means in one second a photon will   
   bounce c/(2*60)=694 times of one side of the ship, so my 15 W/m2 input becomes   
   10400 W/m2.   
   I need to get to 15E12, so it will take 15E12/10400 = 400 hours to inflate it   
   with 15 watts/m2, with perfect reflection. 15 W in 400 hours is 21,6 MJ/m2, is   
   basically zero mass added. Also not too terrible in regard to blowing up.   
      
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