From: nuny@bid.nes   
      
   On Monday, February 5, 2018 at 10:31:29 PM UTC-8, timj...@gmail.com wrote:   
   > The practical maximum length to diameter ratio in current long rod   
   projectiles   
   > is typically thought of as somewhere between 30:1 and 40:1. If you were to   
   > scale up the projectile several times, could the long rod maintain the same   
   > aspect ratio?   
   >    
   > e.g. If you had a 75cm length/2.5cm diameter long rod and scaled it up 10x   
   > to 750cm/25cm, could it be expected to maintain the same degree of rigidity   
   > during acceleration, flight, and impact?   
   >    
   > The "Rods from God" concept envisioned tungsten rods of 6.1m length and 0.3m   
   > diameter, so at the very least they thought that a 20:1 aspect ratio was   
   > possible at that scale.   
      
     After seeing a video of an archer explaining how to account for arrow flex   
   when doing precision target shooting (arrows greatly exceed 20:1), I think   
   it's safe to say that there has to be a point of diminishing returns where   
   real materials just aren't    
   stiff enough. Where that point is I'm not sure but I will point out that given   
   the fact that the RFG concept was never actually tried out we might discover   
   that it doesn't scale up as far as we'd like it to.   
      
     What kinds of targets are you thinking of? Raw kinetic penetration should be   
   applicable in any non-Star Trek/Wars "we have shields" scenario but I'm pretty   
   sure scaling it up to kilometers-long relativistic penetrators for Really Big   
   Ships won't work    
   out unless the archer's tricks also scale up.   
      
      
     Mark L. Fergerson   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)