> AFAIK, diving in an airless environment will simply slam you into the
constantly
> pulling you "down" toward the surface - in other words, use a vector
Firstly, I don't think altitude will make all that much difference to gravity
before it stops being 'lunar combat' and starts being 'space combat' again. As
to diving, a component of the energy in a dive is gravitational attraction
(potential energy if you will) so that will be less, although of course the
lack of atmosphere (and therefore resitance) is probably a bigger factor. I am
of the opinion though that all this is irrelevant. Any sort of space vehicle
is by definition not designed to slam into a lunar body at any sort of speed.
Even if a ship isn't completely wrecked, it's likely to have hull breaches,
stress damage etc etc etc.
TTFN
Jon
> Thomas Barclay wrote:
AFAIK, diving in an airless environment will simply slam you into the surface
harder! With no air to act on lifting surfaces (wings, whatever), the only way
to "pull out" of a dive is with raw thrust vectored downwards. Combat over the
lunar surface should (IMHO) be just like combat in open
space, except for a 1/6 gee vector (decreasing with altitude?)
constantly
pulling you "down" toward the surface - in other words, use a vector
movement system with an automatic "gravity" vector applied to every move in
addition to whatever thrust you apply.....
Ground spake thusly upon matters weighty:
> >> 2. Gravity on the lunar surface is like 1/6th of earth. It is
What I was referring to was the jet fighter jock concept of 'energy' where
people will dive (hence accelerate) to build up momentum
(energy) or climb and shed same. With only 1/6th the downward
acceleration, your buildup of energy will be significantly reduced.
Correspondingly, so will your losses. But yes, your point about pulling out is
quite valid too.
> Combat over the lunar surface should (IMHO) be just like combat in
As the square of radius, assuming you treat the body as a point mass, as all
gravitational attraction does (AFAIK).
constantly
> pulling you "down" toward the surface - in other words, use a vector
Woohoo! Gravity vectors. I can just imagine the vectors involved if you
include air drag (which increases in magnitude with your increased velocity or
changes in surface area) and lift (produced by lift surfaces and it varies
with a lot of things!). I don't think
vectored movement for planes in-atmosphere is something you want to
do without a computer.... (heh heh).
:) Tom.
/************************************************
> AFAIK, diving in an airless environment will simply slam you into the
constantly
> pulling you "down" toward the surface - in other words, use a vector
Any
> sort of space vehicle is by definition not designed to slam into a
Yep, so to simulate a battle within the Lunar gravity well (ie: within a few
miles of the surface), you either use a 3D system and apply a downward vector
(gravity) every turn that has to be countered by thrust (unless you WANT to
descend, in which case you can do it for free by simply not fighting the
gravity), or play in 2D assuming that all ships are directing
at least some of their thrust downward to counteract the gravity pull -
if they lose their drives, then they will accelerate downward and crash just
like an aerospace craft in atmosphere. Though I've forgotten an awful lot of
physics in the last 20 years, am I right in thinking that on an airless
world the higher you fall from the faster/harder you will impact, given
that there is a constant acceleration imparted by gravity and there is no air
drag to produce a terminal velocity effect?
A proper-physics lunar combat game could be fun.... :)
[Yes, I've seen Moondragon and I'm afraid it really didn't do a lot for
me. The stands are a clever idea but seem clumsy in use, and the whole thing,
with paper fire-arc templates used in 3 dimensions and the like, seems a
recipe for lots and lots of positioning arguments between all but the most
fair-minded players....
The ships are supposed to be vacuum fighters but are fully aerodynamic, and
the whole game seems to have been engineered round the 3D stands rather than
being thought out as a game system first.]
> On Tue, 5 May 1998, Ground Zero Games wrote:
> like an aerospace craft in atmosphere. Though I've forgotten an awful
Yup. Though it must be said that the orbital velocities on moon are
rather low... I think 2.5km/s is enough for elliptical orbit.
> A proper-physics lunar combat game could be fun.... :)
Perhaps, but my experience suggests that finding players for
proper-physics *anything* is nigh impossible. They either hate the
calculus, or they hate not being in control (which comes out of not doing the
calculus). A fully computerized game with simply controls (like Asteroids)
might be popular just for laughs...
Hmmm... maybe I should write proper-physics vector movement system for
FT (starting with ditching instant acceleration and discrete time) just to see
if one of the vector system proponents would really try it.
> Ground Zero Games wrote:
Correct. However, your acceleration will be lower vis a vis the Earth, since
the Moon has less Mass (and therefore generates a 'shallower' well) then the
Earth. On the flip side, given the hostile environment awaiting you, any sort
of crash could prove fatal. (Remember, your space suit was made by the
lowest bidder... (8-) )
Anybody want to actually do the calculations of the energy transfered to an
airframe at impact on the moon versus that on the Earth? I don't have any
of my physics textbooks here at work. (Oerjan? (8-) )
J.
> Jerry Han wrote:
> Anybody want to actually do the calculations of the energy transfered
While I have my physics textbooks at home, I have problems seeing them (or
the 'puter, for that matter) - I operated my right eye to get rid of
(half
of) my near-sightedness yesterday, and don't expect to recover the next
few
days or so :-/ I'm sort of half-blind right now.
Anyway, as your question is formulated now - calculate the energy
transfer
on impact <g> - well... all of the kinetic energy will go into wrecking
your craft when it hits the ground, regardless of where you are :-)
However, your kinetic energy will of course vary a lot - depending on
the strenght of the gravity well, how far up you started and your initial
downward vector (if any), the air friction (or lack thereof - and this
depends on how your craft is shaped and which aspect it turns in the downward
direction), etc. I'll try to do the calcs when I my eye gets better (unless
someone else beats me to it, of course!).
Later,
> Oerjan Ohlson wrote:
Yeow! Good luck with that. I looked at stuff like that, and decided that I
would stick with glasses. (If nothing else, it impresses the women.
Yeah, right. (8-) )
> Anyway, as your question is formulated now - calculate the energy
Yeah, that was the idea. (8-) I was actually thinking of a comparison
between two similar bodies, with similar ICs, one body falling in Earth
conditions, and one body falling in Lunar conditions. At what point does
'terminal velocity' imply a lower impact speed on the Earth then on the Moon?
If, for a given set of ICs, the Lunar craft will undergo less stress (i.e.
lower impact speed), can such craft be built less sturdily then their Earth
counterparts, and by how much? (Of course, the latter question is also
dependant on the combat capabilities of said craft.)
Essentially a lot of undirected curiousity here. (8-)
J.