I thought that would be the answer. I would have argued against anything else, actually.
Ok, here's some (online) j-drive info:
Select snippets from the
Traveller Library :
The jumpspace tunnel is mathematically similar to an artificially created
wormhole . Due to the unique topology of jumpspace, the "fall" through the tunnel takes about 1 standard week (150 to 185 hours), regardless of the distance travelled in N-space.
Ships in jump are
untouchable and out of communication.
Entering jumpspace is possible anywhere, but gravity perturbations make it safest to begin a jump at least 100 diameters from a star or a world. Jumps made between 10 and 100 diameters are considered hazardous and should be avoided. Jumps from within 10 diameters are often disastrous. Oddly enough, ships cannot materialise in a gravity well. Any craft
whose jump vector calls for it to break into N-space within 100 diameters is precipitated violently out of jumpspace. In some cases, this can cause severe damage to the ship or its crew.
Emphases are mine.
These snippets, which as I recall are basically the same from the holy LBBs, MT Encyclopedia, TNE mainbook, and T4 book, show that the 100 diameter thing is only relevant when you plot your jump to exit within 100 diameters of an object. What it implies to me is that ships never worry about intersecting N-space objects, because they simply CAN'T intersect them. There is no way to touch something in jump space.
At the instant that something is trying to come out, THAT is the time when something can happen, because now J and N-space are intersecting with each other. J-space doesn't like gravity, so the hole you plotted is instantly moved away. This sudden shift causes the violence felt by such an event.
The converse would seem to be true as well, such that when a ship enters jump space from within 100 diameters, the ship is "rooted" into place (it has mass, and mass means something in N-space) and so the hole cannot drag the ship out to 100 diameters. Once the ship has entered jump, the hole is allowed to move, but it doesn't matter, since the ship is already gone. Still, we could suppose that some misjumps are caused when the hole snaps to a safe location; the deeper you were in the gravity well, the more violent the snap, and the more likely it is to catch the ship and do something to it before it gets away.
I look at Jump drive as being somewhat like being on an airplane. I see J1 space as being an altitude of 30,000 feet. No mountains reach that high, so the plane doesn't hit any of them. Only while climbing or descending are we in any danger of hitting something. Of course, this is far from a perfect analogy....
But because you can't affect something in jump space, you can't EVER run into another ship there, ships NEVER precipitate onto each other, and planets NEVER have any effect, other than at the entry and exit points.
Hey, you don't happen to have a link to that other forum you were talking about, do you Thrash? Would like to see the discussion that prompted your excellent input. Thanks! Does anyone have a link to the article quoted, the one MWM wrote? thanks again.