In another thread, the relative choice of use of atomic bombs vs other means   
   as weapons by a space-going society against a target world came up.  Assuming   
   you have access to FTL travel so you can travel from star to star in   
   reasonable times, that is.   
      
   So let's break it down.  A spacecraft that can come close to a target world   
   with a hold full of nuclear weapons and delivery systems can, in theory, rain   
   those bombs onto targets across the planet, modulo defenses in place.  In   
   principle, a relatively    
   small vessel can carry enough fission or fusion devices to wipe out a huge   
   number of cities or facilities.   
      
   (How many nuclear bombs and delivery systems could have been packed in the   
   Shuttle Orbiter cargo bay, for ex?)   
      
   The positive side from an attacker POV is that nukes are compact, relatively   
   cheap, safe to store if you know what you're doing, and fast.  The big   
   negative may or may not be radioactive contamination, depending on whether the   
   attacker actually cares    
   about that or not.   
      
   Alternatives:   
      
   1. Asteroid impact.  It's true that a space-going attacker might well be able   
   to pick out a nice rock and steer it into a collision orbit.  Such an attack   
   can be devastatingly potent when it hits, as Chicxulub mutely demonstrates.   
      
   Upside - Radioactive contamination is not an issue (if you care about that).   
      
   Downsides - Slow.  It takes time, maybe a long time, for the rock to get where   
   it's going, unless there just so happens to be one in just the right place for   
   a nudge to do the job, which is improbable.  It might be months or _years_   
   before your rock does    
   the nasty to the target.  Such a long period might be annoying, and it might   
   give the target time to do something about it, and you.   
   Also, even if there's no radiation, the planet is going to be messed up pretty   
   thoroughly if you use a big rock, so there's still issues in using it   
   afterward, if you intend that.   
      
   If you've got enough delta-V, of course, you can get your rock there a lot   
   faster, but past a certain point, if you can move miles-wide chunks of rock   
   across a star system quickly, you no longer need the rock.   
      
   2.  Antimatter.  Very effective, if you have a supply of the stuff.  Less   
   radioactivity than the nukes, if you care about that (there'll still be a   
   little).   
      
   Downsides - Hard to get (unless you have a natural supply somewhere) and hard   
   and incredibly expensive to make, unless you can do something funky like using   
   non-orientable wormholes or something).  It's a brass-bound bitch to store,   
   and dangerous to you    
   as long as you're storing it aboard, and storage of masses of antimatter are   
   fail-deadly.  Further downside is that other than lower radioactive   
   contamination, AM bombs don't do much that a fission and/or fusion device does   
   not.   
      
   3.  R-bomb.  Deadly effective, much like the asteroid bomb, but very, very,   
   very expensive.  If you don't have FTL it's as fast as any other attack   
   method, but if you do have it, it's not clear what advantage it offers over   
   'hold full of nukes'.  Maybe    
   you accelerate something up to .99c and FTL it into position and let it   
   hit...but a 'hold full of nukes' still looks likely to be cheaper, and maybe   
   leave the planet actually in better shape to do something with afterward (if   
   you care about that).   
      
   4.  Big laser (or equivalent).  Yeah, it's doable, but if you want to attack   
   in reasonable time, you need to set up your infrastructure to generate the big   
   beam in the target star system, which takes time, effort, might give the   
   target time to do    
   something about it all, and is expensive.   
      
   One advantage:  once you have your Big Laser Gun in the sky, you can likely   
   use it to pick off targets fairly precisely, esp. if you pick a frequency that   
   the local atmosphere will pass pretty well, or have so much juice it can burn   
   right through anyway.    
    But if you're in the city-destroying mood, well, there again, the nukes are   
   probably faster and cheaper.   
      
   Any see any solid advantage of the other attack methods over the nukes?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)