XPost: rec.arts.comics.strips   
   From: psperson@old.netcom.invalid   
      
   On Thu, 16 Oct 2025 20:18:07 -0400 (EDT), kludge@panix.com (Scott   
   Dorsey) wrote:   
      
   >Mark Jackson   wrote:   
   >>On 10/15/2025 5:04 PM, Scott Dorsey wrote:   
   >>> But time of arrival is more difficult since the projectile velocity   
   >>> isn't constant at every point along that parabola.  Vectors and the   
   >>> calculus make these simple problems but they would be difficult to   
   >>> solve without them.   
   >>   
   >>Again, why would you need calculus?  The time to arrival depends on the    
   >>distance to target and the horizontal component of the muzzle velocity,    
   >>both of which are constant.  Only the vertical component of the shell's    
   >>velocity varies, and that doesn't enter into things.   
   >>   
   >>(For negligible air resistance, of course, and - to be precise - firing    
   >>at a target at the same height as the cannon.  Firing uphill the shell    
   >>will land a bit earlier, downhill a bit later.)   
   >   
   >That's the point of indirect fire!  You're firing upward and the shell    
   >travels often higher vertically than it travels horizontally.  The enemy   
   >may not be very far away but they are on the other side of a barrier.   
   >You can shoot over the barrier with artillery, while you are protected    
   >from small arms fire.  Angles of 75 to 85 degrees are not uncommon.   
      
   Modern indirect fire, which does indeed require some form of spotting.   
      
   But the ancients shot arrows up and over the enemy, not because they   
   could not see them, but because they wanted to wound/kill /all/ of   
   them, not just those in the front line. The ones behind the front line   
   were, not hidden, but covered.   
      
   The Roman testudo    
   was used to protect the troops against indirect arrow fire. (And also   
   to protect them from items falling off the walls of besieged cities --   
   things like stones, burning oil, and other nasties).   
      
   Siege engines could reduce the walls of a fortress/city (if they   
   actually hit them instead of falling before them) but could also go   
   over the walls and fall inside. This did not requre a spotter:   
   anywhere they fell, they would cause damage to someone and/or   
   something.   
      
   In modern war, is of course, things are somewhat different.   
   --    
   "Here lies the Tuscan poet Aretino,   
   Who evil spoke of everyone but God,   
   Giving as his excuse, 'I never knew him.'"   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)