Re: Slingshotting ships with gravity wells in SJ

>Next again, I'm gunna have the size of the body modify the speed attained
>(as I originally proposed), and the ammount of time spent in orbit - but
>with a maximum somewhere around a little over standard IS speed.

here's a thought.  you want this to feel more like SJ rather than
modern physics.  well, since almost all bodies have the same gravity,
gravity wells will all be the same "depth", unlike in our world.  so
that in and of itself eliminates the benefit of slingshotting bigger
worlds.  but what if the gravity well's size is stil lproportional to
the body?  same depth, different reach, means different "slope" to
the well.  i.e., the smaller the body, the steeper the gravity
well--it goes from 0 to 1 in much less distance.  so, just the
inverse from our world--the smaller the body, the bigger the boost.
down to some cut-off point, due to lack of mass (say, it has to be at
least 100000x the size of the ship--that gives you a minimum boulder
of ~0.5mi dia to slingshot a 100ton ship)--smaller masses get tweaked
too much by the ship's gravity to provide the right effect.  thus,
interstellar navigation gets more efficient as your astronomy gets
better--better optics and better maths--because you can start
utilizing these tiny, invisible (non-radiant) celestial bodies for
super-extreme slingshots.  and, of course, if gravity only comes in
two quantities, off and on, you just have to orient your deck
tangential to the slingshot trajectory, and, viola, no g-forces.  but
this probably does mean that, with a very small body, your slingshot
either skims or enters the atmosphere.  probably gravity is still
"on" right to the edge of the atmosphere envelope (just like the book
says), but then falls off dramatically (a few hundred yards for most
bodies, maybe a mile or so for really huge objects), so that most
people have never noticed that it doesn't just turn off instantly.
this spillover slope would be across less than an inch for an SJ
ship, so only mosquitos could take advantage of it.

in fact, as i think about this, probably *all* slingshots skim the
atmosphere, with not entering it being your goal.  but "skim" for
something the size of the sun means within a couple miles, while
"skim" for Jupiter would be, say, 300yds, and "skim" for the moon
would be ~50yds--pretty exciting for a ship that is itself ~25yds
tall.  you can have dramatic scenes when they didn't take down enough
of the sails, and risk losing them to the atmosphere or, worse,
having them snag the atmosphere and drag the ship down with
them--think of what would happen if a bullet train dropped an anchor.
maybe the ships have folding masts so that they can get closer, or
are built with wing-like masts out to the sides (instead of up like a
sailing ship).  either way, they probably pull in all the sails
before slingshotting, in the hopes that if they do hit the atmosphere
it doesn't grab the ship.  maybe have streamlined decks, with nothing
sticking up (sorta like the deck of a submarine), too.  and, of
course, that makes the whole operation that much more nerve-wracking,
because once you're within a certain proximity of the planet, you can
no longer adjust your trajectory because you've stowed all the sail,
so you *have* to just trust your figures and wait it out.

woodelf                <*>
woodelf@???.net
http://members.home.net/woodelph/

The Laws of Anime <http://www.abcb.com/laws/index.htm>:
#24 Law of Americanthropomorphism
Americans in Anime appear in one of two roles, either as a really nasty
skinny 'Bad Guy' or a big stupid 'Good Guy'.
First Corollary - The only people who are more stupid than the big dumb
Americans are the American translators. (Sometimes referred to as the
Green Line Effect.)
Second Corollary - The only people who are more stupid than the American
translators are the American editors and censors.