On 19Jun2020 1837, xxxxxx@gmail.com wrote:
> I like your concept. We agree on the observed nature of tanks and what
> cannot be done with the fuel and your answer is much clsoer to a
> complete description.
>
> Questions:
> a) Would the hydrogen become a plasma somewhere? (I am not master of
> plasma physics)
> b) Would the hot plasma not cool over a week in jump space? (or does
> this follow the 'no place to radiate it to' concept?)
These are details I've not considered, because it hasn't come up in my
games, though it doesn't get hot enough to fry a ship that takes an
extended trip through jumpspace (from a bad misjump), because that's
happened and the ship didn't get cooked.

> c) How significant of a gravity wave would you get? How far away could
> it be detected? If you came up with figures for that, what was your
> notion on the magnitude at exit and the rate of fall off?
Sensors such as a large hi-tech warship, a scout/spy ship, or a quality
system defence network should have can detect emergence from many AU
away. Normal civilian sensors are considerably less sensitive. Gaining
more than the rough mass of a ship means being closer, so you can get a
good view of the emergence as it happens or shortly thereafter, and it
won't tell you where they came from, though if you know how far they've
come you might be able to make an educated guess, given jump shading
(which, because I'm lazy and because it throws off the 'jump every
second week' cycle only applies from worlds, not stars unless the star
is massive and it's a plot-point).

Thus emerging from jump far enough out to avoid discovery in a properly
defended and patrolled system means emerging far enough out that you'll
lose at least a week sneaking in (much more if the locals are
security-conscious enough that you have to follow a natural-looking
approach). Emerging near a distant gas giant so you can hide behind it
is a good idea - it won't hide your emergence gravity spike, but it can
hide everything else from the inner system (and you can probably find
ice to refuel from in orbit round it, saving you from risky and noisy
fuel scooping). Of course, those security-conscious systems with a
budget will have listening stations at these gas giants.

> d) Does anything in the jump bubble being formed on the departure end
> (or any leftovers) give any clue to the destination of the jumping or
> already having jumped vessel? Is tracking into jump possible?

No, though if you know the ship's maximum jump range and it's jumping
from just outside a jump limit, you can make that same educated guess as
when you see it come in. You don't actually need to observe the jump for
this - just knowing what wasn't shadowed and the possible range let's
you do this. For short-ranged ships this is often only 1-2 systems, but
for one with long legs unless you have a fleet you can split up, or you
know where they're trying to go, they're often just gone.

--
Rupert Boleyn <xxxxxx@gmail.com>