> In a message dated 98-07-04 00:04:23 EDT, Richard S. writes:
<< You manage to rationalize FTL drives and non reaction mass normal drives,
so give limited contra inertia (not grav) effects on ships a chance perhaps?
1G acceleration from purely accelerating can be thought of as different from
the 1G force upon you from stading on earth. One is cause by gravity, the
action of a very big mass. The other because of inertia. So you don't need
gravity control exactly, just a way of divorcing the interial frame (PBS
abounds). I'm not advocating inertialess ships just partially inertial
compensated. It cuts down on inertial superweapons. >>
True - my rationalizations tend to be specific to my tastes :).
But I do see your point. My distaste for artificial internal gravity comes
more from a
desire for space combat to be a bit different than wet-navy combat. The
vector-movement helps a lot (I got my FB!). Internal artificial gravity
also
shows some design flaws - if it fails on a standard
decks-parallel-to-thrust
ship, you're screwed. Climb the floor and celings, and the bulkheads are the
floors, right. On a decks-perpendicular-to-thrust ship, if the floor
grav plates fail, you are still able to manuver somewhat, as the ship is
designed for that situation.
Actually, reactionless drives are OK, but I prefer a really high-
efficiency drive (ion, nuke-pulse, etc). Some of my house rules
actually
include burn elements, and fuel limitations - run forever now,
monkey-boy!
The kinetic-kill-vehicle problem is quite familiar to me, as a
Brilliant
Lances/Battle Rider player. Somebody figured out that a standard KKV
missile impacting on a standard Traveller cruiser (50,000 tonnes mass) would
pretty much blow it in half. Beams become much less attractive. I can
rationalize it out as this: Beams are c (speed o' light) speed
weapons - there is little target movement between firing & impact,
compared
to, say, a railgun. Missiles carry bomb-pumped lasers, and fighters
have
little beams, or maybe plasma/fusion weapons. Sub-c-speed weapons
(railguns,
plasma/fusion weapons, KKVs) have much lower velocities, and there will
be significant target movement between firing and impact. Missiles will also
have trouble actually hitting a manuvering target, due to last-second
corrections and such. They are more damaging, but have lower ranges. ECM,
evasive manuvers, and the difficulty of pinning down such a small object in a
vast area will affect accuracy as well. In my personal GZG-ish mileu,
beams (standard & HBW) and railguns are limited only by mass of ship and
money.
After a while, they become one-arc only weapons (spinal), but are the
'big guns' of space. I'm thinking of doing KKMs, but they're going to be a
little too powerful so far.
> Hrrm, if we change 1MU=1,000km to 10,000km earth sized planets become
> If we change the timescale to 1.5 minutes, there are ten turns per
Keep turns @ 15 mins, make 1 MU = 7,500 km. This should keep 1 thrust = 1 g.
and Terra is 2", Jupiter 16", etc. I think this might work for you.
> Trouble is, at such low accelerations, it takes FOREVER to get
100 diameter safe, 10 diameters....uh, wait a minute. That's been used.
How about 0.1 g? 1 m/s/s? That will be on most tables even with MU =
1000km. I also figure with weak drives, a good, efficient, cheap FTL is a
necessity.
One thing that Traveller seemed to forget when it went to fuel-limited
reation drives, is that even at 6 gs, it takes FOREVER to get from Terra to
Jupiter to refuel.
OK, there is a bit of PSB here:), but no too bad. Now if you'll excuse me, I
have some inertial frames to hang and straighten...
Noah
> On 4 Jul 98 at 0:41, Sabmason@aol.com wrote:
[snip]
> Internal artificial gravity also shows some design flaws - if it
Well, in my flavour of manuever drives, I made the partial divorcing of the
inertial frame of the ship an intrinsic part of how the drive operates, so
when manuevering you don't feel the acceleration, and if the drive breaks, you
can't manuever and it can't compensate either (not that there will be anything
to compensate for).
The jury is still out for me on whether there is artificial gravity on 'my'
ships. Either way, I think I'd have it turned off when in combat, and let
people endure the very dampened inertial accelerations.
For roleplay reasons (when and if required), I decided that I didn't want ship
drives able to level a city when taking off, since players tend to own small
ships sometimes. I favoured the Star Wars 'hairdryer' effect drive. You can
stand behind the millenium falcon as it takes off and have your hair ruffled.
My massive PSB rationalisation is that it reacts against some sort of parallel
dimension, thereby not hurting ours, but still having to pay the same energy
costs as it should to gain the acceleration it is seen to have.
[snip rest of thought provoking post]
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2 AU for jump - woof. But I'm used to Traveller's 100 diameters (volume
dependent as opposed to mass? Go figure). Your comment about speed 'o
light weapons is too true - in those 18 secs, a target with a velocity
of *1* has moved...1500 kms. The only problem with such long ranges is that
the only viable weapons are c-speed (beams) and bomb-pumped lasers on
missiles. But then again, it's a matter of taste.
[quoted original message omitted]
> Keep turns @ 15 mins, make 1 MU = 7,500 km. This should keep 1 thrust
This is about .025 light seconds per MU (1/40th of a light second). I
prefer to use larger units (75,000km or about 1/4 light second). To my
mind this gives a greater "cosmic" feel to the combat and allows ships to
reach a viable jump point (~2au in my game) quicker. However, planets
represent not only the planet but its gravity well also. It also accounts for
the large percentage to miss a ship in FT. If you have to
fire several light seconds away (even with speed-of-light weapons), it
will take some time to reach the target (target is 24" away: send an active
targeting pulse [6 seconds there, 6 seconds back], fire [6 seconds there],
gives 18 seconds from when you first gave the order to fire [12 seconds from
when it was locked by active sensors or 1 second
per 2"].).
Be glad I've never gotten my strategic system worked out, Noah. I was going to
force the jump point outsystem. Got REAL dicey when you realized that I
was including the Oort cloud. Something like a full ly out, right? ;->=
I wanted invaders to have to take some time getting to objectives, giving
defenders time to deploy, but this got crazy. And, unless the rational was
jumping was blocked by fairly large masses rather than just proximity to a
grav well, the cloud just seemed like something that should be included.
The_Beast
> Brian Bell wrote:
> > Keep turns @ 15 mins, make 1 MU = 7,500 km. This should keep 1
> This is about .025 light seconds per MU (1/40th of a light second). I
This is, incidentally, the distance scale used in the latest edition of
Starfire (3rd Revised). We rely *extremely* heavily on PSB to explain how
weapons are able to hit anything at all even at range 0, but then our time
scale is only 30 seconds per turn, with ships able to fly up to 15 hexes in
one turn... with a (much) longer game turn, speeds and hit probabilities get a
lot more believable. 'Course, "a lot more" than "completely impossible" still
won't reach higher than at best "incredibly improbable" <g>
Regards,
[snip]
> This is about .025 light seconds per MU (1/40th of a light second).
Some figures to give a sense of this... even though the target may have moved
for 12 seconds since sensor return to the beam hitting it, it doesn't mean the
amount you could miss by is the amount that it moved in those 12 seconds. You
can lead the target. The trouble is the amount the target could deviate it's
course in those 12 seconds. Assuming a randomly dodging target, a 1G manuever
ship can manage (at maximum) a whopping 706 meters, which begs the question,
how did you manage to hit it at all, unless the ship is superdreadnought
sized. 6G would be over four kilometers.
Using 75,000km per MU gives about 10G per thrust point for a 15 min
turn. This means /really/ big areas of uncertainty in target
position, up to 7km per thrust point. So your beam weapons either throw out a
hell of a lot shots, hoping to catch the target in the spray, or have to be
FTL.
Also, with a 75,000km scale, who cares about gravity wells around planets? why
represent them, (other than for jump limits) your ships
have 10-80G drives, so unless you want to approach a really high
gravity body, it's not really important.
7,500km per MU is sounding better all the time;)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Brian Bell wrote:
> The main thing that I did not like about 7500km/mu/15 minute turn was
Four days is a lot at 8 g, but the in-game time needed for travel won't
change just because you use a different distance measuring unit... and I
wouldn't use FT combat movement rules to simulate interplanetary travel
(Wobbler's "Journey to Alpha Centauri", anyone? :-) - I'd use some sort
of strategic scale for this. Yes, I'm a Starfire player <g>
Regarding the high speeds (in game turns): This is where the vector movement
really comes into its own. If two forces manage to match vectors (which you
have to do in some sort of strategic scale), just to a galilean transformation
of the coordinate system and play as if the ships
travelled at speeds close to "zero" :-)
Regards,
> Also, with a 75,000km scale, who cares about gravity wells around
Perhaps you are correct. We played a diminishing return rule when our ships
gravity drive was in a gravity well. But this is just PSB. It explained why
streamlining cost so much (not only hull design but extra thrusters and
gravity well compensators). Again just PSB.
The main thing that I did not like about 7500km/mu/15 minute turn was
that you had to reach extreemly high game speeds to reach other planets or
jump points. An AU (distance from the sun to earth) is 19,946.666 mu using
this scale. This is 207 DAYS at a speed of 1. 4 days at a maximum increase of
8 each turn. Four days is a lot at 8G. And your speed would be about 3072
(quite a lot to decelerate from) when you passed it by. And this is only 1 AU.
I was using 2 AU out of the rotational disk. Someone else had that you had to
get completely out of the gravity well of the SYSTEM. Of course if you can
jump (go FTL) from anywhere in the system this is not a limitation, but does
give rise to the kamakazi FTL jump (no flames, please).
> On 9 Jul 98 at 9:30, Brian Bell wrote:
> Perhaps you are correct. We played a diminishing return rule when
Well, that's a bit of PSB I was toying with too:)
> The main thing that I did not like about 7500km/mu/15 minute turn
I binned FTL drives exploding spectaculalry as something far too open to
abuse, I just have them break down if you jump at the wrong place.
As an aside, in our setting we limit how close to a body you can enter FTL,
but do allow it inside system, between planets. We are
also toying with the idea of having special entry/exit points for
FTL, initially we used Lagrange points, but it felt like too much PSB. So I'm
searching for definable places in systems that can be used as places that FTL
drives can be used nearish to planets for travel between them, and for between
systems. Any ideas?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hi.
> Richard Slattery wrote:
> As an aside, in our setting we limit how close to a body you can
In several SF systems, the writers suggest that FTL drives only work in
near-flat space.
Because a planet is in orbit around a sun, the attraction between the sun and
the planet would be near neutral
(near-flat space),
at a point proportional to the masses of the sun and planet and the distance
between them.
An easy way to under stand this to place two heavy but unequal weights on a
soft bed. The heavy weight represents a sun, the light weight represents a
planet. Note that the bed surface curves under the weights and changes
curvature between the weights. The point where the bed surface becomes flat is
analogous to a FTL transition point in space. If I recall correctly, these are
also Lagrange points. Around our Earth and Moon, there are, if I recall
correctly, six L points.
Naturally, as multiple planets move around their sun, these FTL transition
points move as well. So, you will need a navigator to plot and predict where
these transition points are. If your background allows, this can allow FTL
travel between planets in one system. It also seems to be the system used in
Star Wars.
I hope this helps.
In message <199807092047.VAA30494@mgkc.demon.co.uk>
> "Richard Slattery" <richard@mgkc.demon.co.uk> wrote:
> On 9 Jul 98 at 9:30, Brian Bell wrote:
At 1g, it takes 2.8 days to travel 1au - assuming you're both starting
and finishing at rest. You can do it in 2 days if you don't bother
decelerating... At 8g, you'll do it from rest to rest in a day.
> As an aside, in our setting we limit how close to a body you can
You could always make it 'random' - i.e. based on complicated
criteria which don't need to be explained, but which allow you to put the
points in interesting positions.
On the one hand, it means you have to have some way to agree before a scenario
where points are, which is fair to both sides.
On the other hand, it avoids any PSB.
On the gripping hand, it means you can have a scenario where the only
alder^H^H^H^H^Hjump point in a system is inside the outer shell of a red
supergiant...
<lots of stuff snipped>
On the gripping hand, it means you can have a scenario where the only
alder^H^H^H^H^Hjump point in a system is inside the outer shell of a red
supergiant...
Ah, the Langston Field. Well, it would have a maximum amount of damage
(energy) total before it overloads and damages the ship, and a maximum amount
of damage (energy) it can radiate away per turn. Accelerations in
the Second Empire of Man were low - a fast courier can boost at 3 gs,
and hydrogen fuel is a consideration. Warships are big, and mainly
laser-equipped. Some BIG lasers, as I remember. Battleships (the
Lenin)
would probably have Class-4s. You would be able to tell the state of a
Langston field by it's color - as the amount of energy it is holding
raises, it cycles thru the spectrum, starting at black, to red, orange,
yellow, etc., up to violet, and then it fails spectacularly. You'd still have
to guess how much damage was done by a shot, but any change in field color
would give you an idea of total capacity. It gets more complex when you start
talking about fields touching, and other kinetic interactions.
Noah
[quoted original message omitted]
> On 10 Jul 98 at 11:01, Andrew Martin, Alex Shvarts & wrote:
> In several SF systems, the writers suggest that FTL drives only work
Lagrange points are not actually 'null' gravity points. They are places where
the orbital period of a body within them is the same as that of the orbiting
body that they are related to. Some are 'stable' and actively gather
asteroids, the L4 and L5 points, which in jupiters case are called the trojan
points, have many asteroids within their area. The others are less stable, and
keeping satellites in them is like balancing a ball on the top of a cone, (but
still requires less thrust for keeping it there than a continual forced orbit
manuever).
For instance, a satellite in orbit closer to the sun than the earth would
normally move faster in it's orbit than the earth, and get ahead of us.
However, in the L1 point between us and the sun, a satellite gets just enough
pull from the gravity of the earth to keep it between us an the sun. In fact
we actually have a satellite there. SOHO, which monitors the solar wind, and
gives us early warning of it, since the solar wind is quite a lot slower than
light speed. (Actually, SOHO just went wrong while having a course
correction., oh well).
The L points also wobble around due to peturbations from other major planetary
bodies, in the case of the L4 and L5 points it tends to pull the satellites
along with it, for the others, the satellites 'fall off' the L point.
I think there are actually only five L points per orbiting body. For
earth-sun the are. L1 between earth and sun, close to the earth. L2
on the other side of the earth. L3 on the other side of the sun, L4 and L5
leading and trailing the earth by 60 degrees, at the same orbital distance of
the earth.
> Naturally, as multiple planets move around their sun, these FTL
Shucks, maybe I'll use them anyway, or invent similar points which
actually /are/ null grav points, and call them Alderson points, or
something;)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> On 10 Jul 98 at 18:27, Samuel Penn wrote:
> You could always make it 'random' - i.e. based on complicated
You Motie you;) I thought the term 'Alderson point' was familair;)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~