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Re: [GZG] Hello List and some ruminations on FTL

From: JBrewer@w... (John Brewer)
Date: Thu, 28 Jul 2005 00:36:50 -0500
Subject: Re: [GZG] Hello List and some ruminations on FTL

In regards to jump displacement, I figure that the standard MILITARY
jump [in non-emergency circumstances] is 6.5 lightyears or 2 parsecs.
Jump displacement for ships with civilian-built jumpdrives is 1 parcec.  

But this brings me to the rules involving entering and exiting a battle
scenario using the jumpdrive.  Since it only makes sense that most space
battles occure in the vicinity of strategic targets, like planets, it
presumes that jumpdrives CAN function in a stellar gravity well, but
with limitations.  

Jumps with a displacment of 1-2 parsecs can only occure outside a
stellar gravity well.  And the closest approach a trans-stellar jump can
make to a stellar gravity well is the outer limit of the star's
planetary-stable orbit ring.  This usually lies between the orbit of the
outermost major sidereal body and the star's Oort cloud.  The limit
varies, based upon the type & size of the star in question...


O	     Ia 	    120.0     
O	     Ib 	    110.0     
O	     V		    105.0     

B	     Ia 	     105.0    
B	     Ib 	     100.0    
B	     I		      95.0    
B	     II 	      95.0    
B	     IV 	     95.0    
B	     V		     90.0    

A	     Ia 	     85.0    
A	     Ib 	     85.0    
A	     II 	      75.0    
A	     III	      70.0    
A	     IV 	     70.0    
A	     V		     65.0    

F	     Ia 	      65.0    
F	     Ib 	      65.0    
F	     II 	       60.0	
F	     III	       60.0    
F	     IV 	      55.0    
F	     V		      55.0    

G	    Ia		      55.0    
G	    Ib		      55.0    
G	    II		       50.0    
G	    III 	       50.0    
G	    IV		      45.0    
G	    V		      45.0    
G	    VI		      40.0    

K	     Ia 	       40.0    
K	     Ib 	       40.0    
K	     II 		35.0	
K	     III		35.0	
K	     IV 	       35.0    
K	     V		       30.0    
K	     VI 	       30.0    

M	     Ia 	       30.0    
M	     Ib 	       30.0    
M	     II 		25.0	
M	     III		25.0	
M	     V		       20.0    
M	     VI 	       15.0    

Dwarf			      25.0    
Superbright		    +5.0    
Binaries		     +20.0    
Trinaries		     +30.0    
Pulsars 		       45.0    
Neutron Stars		   45.0     
Protostars		     20.0    

>From there, there are 3 types of intra-stellar or inter-system jumps.
Since the jumpdrives have to be recalibrated to operate inside the
gravity well, the jump displacements measure in AU, and vary based upon
the position of the ship IN the stellar gravity well.  

An ingress system jump [a jump where the ship is moving TOWARDS the
star] has a maximum displacement of HALF the distance from the ship's
current position to the star.  

EXAMPLE:  A ship on its way to Earth from deep space has reached the
outer limit of the Sun's gravity well.	Since the Sun is a Type G-V, the
ship ends its interstellar jump 45.0 AU from the Sun - about 6 AU beyond
the orbit of Pluto.  The ship will now make an ingress system jump with
a max-displacement of 22.5 AU, putting it half-way between the orbits of
Uranus & Neptune.  The ship's next jump towards Earth will bring it
11.25 AU from the Sun, just beyond the orbit of Saturn.  Next jump -
5.63 AU, near Jupiter.	Next Jump - 2.81 AU, between Mars orbit & the
asteroid belt.	Next jump - 1.4 AU.  The max-displacement for the next
jump is 0.7 AU, but the ship will only need a 0.4 AU ingress jump to
bring it close enough to use its maindrives to arrive in Earth orbit.  

An egress system jump [a jump where a ship is moving AWAY from a star]
has a maximum displacement of TWICE the distance of the ship FROM the

EXAMPLE:  Jumping from Earth to the Sun's gravity well outer limit - 2
AU - 4 AU - 8 AU - 16 AU - 32 AU - and 64 AU, well outside the edge of
the gravity well, and now able to its jumpdrives to span parsecs per

A lateral jump is used to travel AROUND a star system to reach planets
that lie on the opposite side of a star.  A ship making a lateral jump
can displace realspace a distance EQUAL to its own position from the
IS some leeway to this rule;  If you draw a line equal in distance from
the star to the ship's position, to a point in system space that lies in
equal distance from the star to that ship's position in the direction
you wish to travel, you can jump to any point along that line within a
wedge that lies 45° stellar-outbound or 22.5° stellar-inbound.
Beyond those angles, you are limited to the laws regarding ingress or
egress jumps.  

As always, I invite your comments.  [Let'er rip, boys!]  

"Always strive to be a good person.  If you can't do that, at least
strive to be someone other than an asshole."  

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