
-------- TML Message #628 --------

Archive-Message-Number: 628
Date: Sun Oct 15 19:19:33 1989
From: richard@agora.hf.intel.COM (Richard Johnson)


Greetings fellow travellers!  
This is a very long file about gravitics.


The following information is highly UN-official.  I have taken 
pains to try to reconcile what I know about the universe with
what I know about MegaTraveller from the rules and accessories,
but am not about to guarantee an official approval of any of it.  

You can use and distribute this material freely, so long as I 
get some credit for working it all out and making it available.
(and while your at it, remember to thank JamesP and Tek for the
list...)  

Some of this is still pretty rough, but I think you'll find
it mostly useful.

Richard Johnson
Hillsboro Oregon

- --------------------------cut here if you like--------------------------
Gravitics in MegaTraveller
- ------by Richard Johnson

It is a misconception among several of my players that the 
primary function of gravitics on space vessels is to hold 
crew members to the deck.  I suspect this attitude is common.
In actuality (sic) the science of gravitics has profound 
implications for space travel, and the development of 
gravitics has been a primary mover the direction of space 
technology.  

The "Starship Operator's Manual, vol 1" gives, on page 56, 
under "Gravitics Technician", introduces the idea of 
gravitics.  It states that: 

"The artificial grav plates and inertial compensators 
within the ship are not critical to its performance...  
More importantly, though, the maneuver drive's thruster 
plates operate on a principal that takes advantage of 
gravitic science..." 

This article explores the theory and applications of gravitics, 
and how gravitic design limitations affect the maneuvering of 
space vessels.  I strongly suggest you read the appropriate
sections of the operator's manual, and information about ship
design in the Referee's manual, to better understand what I'm
saying here (and to catch me where I've blown it).

- ----------------------------------

Theory of Gravitics:

Two fundamental properties of matter concern us when space 
vessels maneuver.  These are inertia and gravity.  Inertia is 
the tendency for matter to resist any changes in speed or 
direction.  Gravity is the tendency for all matter to attract 
other matter (or anti-matter, for that matter).  It is 
important to understand that these are *fundamental properties*.
All that exists demonstrates these tendencies; in fact, inertia
and gravity are what we use to define matter.

Both inertia and gravity are effects that we see, in "normal 
space", of matter being highly concentrated energy (1).  Energy 
concentrations sufficient to create solid matter are more than 
enough to interact with higher-order universal dimensions (2).  
These particles interact in higher dimensions in ways not 
possible in "normal space".  The *effects* of these 
hyperspacial interactions are then seen in "normal space" as 
inertia and gravity. (3)

- ------------------------------

Gravitic Devices:

There are four basic gravitic devices:

Maneuver drives
Repulsers
Grav plates, and 
Inertial compensators.

These all tap into these hypserspacial interactions, and 
concentrate and direct the resulting force.  In a sense,
so do jump drives, but there is a critical distinction.  
Jump drives use the hyperspace/space-time interactions
to loft the entire ship into a bubble in hyperspace, 
while gravitic devices use the hyperspace/space-time
interactions to manipulate space-time events.

Drives and repulsers generally utilize a repulsive force, 
while grav plates generally use an attractive force.  In all 
three devices, the "effects" being manipulated are gravitic.  

Inertial compensators, on the other hand, intercept inertial 
"effects" and use feedback techniques to reduce or nullify 
inertia on selected bodies.  Looked at this way, we can see 
that inertial compensators are not *truly* gravitic devices, 
but that the technology is similar enough so that we need 
make no distinction, except in the scientific community.  

For the remainder of this article, I  use "gravitic devices" 
to refer to inertial devices as well.  I do not use the term 
to apply to jump drives, even though they have many features
in common with gravitic devices.

- --------------------------

Basic Design of Gravitic Devices:

Gravitic devices operate much like valves in a water hose.  A
small change in the characteristics of the device (valve) 
produces a large change in output (flow).  That is to say that
the energy you feed your drives (from the power plant) is not
converted to thrust.  It is used to control and direct the
flow of "effect" from an interaction that occurs in hyperspace.

All gravitic devices have the same general design.  A typical
device has a "concentrator", a "plate", and a "governor".  



- ------------------------------
|Conc. ||        || Output   |
|Plate |--------| Gov.   |------| Plate    |
|      ||        |      |   |
- ------------|-----      ------------
\    |          /
 \----------    /
  \_____| Comp. |---/
- ----------

The concentrator plate is basically a hyperspace receive antenna.  
It collects and concentrates wade-ranging "effects" into a small 
region of space-time.  The concentrator does not create hyper-
space interactions; that would take too much energy.  It does tap 
directly into activity in hyperspace and intercept the 
interactions already there.

The output (or thruster) plate is basically a space-time output 
antenna.  It directs and releases the concentrated "effects" 
gathered by the concentrator.  Examine drive plates for a 
classic example.  (Refer to the "Starship Operator's Manual, 
vol. 1, pages 2-4.)  Notice how the output is strong in the 
plate's basic direction, but weakens sharply in other directions.  
Notice also that all plates are invariably placed so that 
*nothing* gets within about a meter of them.  We'll discuss 
this more in a minute. 

The governor is the part of the device that monitors and 
controls the concentrator and the plate.  It matches input, 
output, and demand (from the ship's computer).  Needless to
say, this is where most of the technology, and most of the
problems occur.


- ----------------------------

Limits of Gravitic Devices:

There is a serious side effect to using a gravitic device 
because the device operates both in hyperspace and in 
space-time.  Using a gravitic device "warps" space-time 
around the concentrator.  This warping is very like the 
warping of space-time around black holes, only the radius 
of curvature of space is much shorter, usually measured 
in meters rather than kilometers.  This warping becomes 
more intense as the acceleration produced by the device 
increases.  Beyond about 60 m/s/s acceleration (6 g) (4), 
the device becomes inoperable because of relativistic 
effects (5).

The warping of space-time caused by gravitic devices is 
identical to the warping to space-time by a gravity field, 
only intense and of short range.  It is critical, especially 
in jump-capable vessels to have space-time as smooth as 
possible in and around the ship.  The amount space-time is
warped represents how much is not known about the ship's
present position, or its destination.  Hence -- misjumps.

If these "warps" caused by using gravitics are left 
unaltered, time would flow at different rates in different 
parts of the ship, sensors would not operate properly, 
thrusters would fight themselves, and jumps (if possible) 
would be wholly unpredictable. 

The plates associated with all gravitic devices are large 
(and in the case of drives, massive) mainly to deal with this 
warping of space-time.  The plates function as antennae that 
receive hyperspacial energy and broadcast "spacial" energy.  
They could be microscopic and do this.  

However, the plates also "sink" or dissipate the space-time 
warping associated with the use of the gravitic device.  For 
this task the plates need to be large, to "spread out" the 
effects of the warping of space-time.  

In the case of jump-capable ships, even this is not enough.  
For a few microseconds before a jump, all gravitic devices on 
starships are switched completely off.  The transition to 
jumpspace is made, and gravitics are switched back on.  This 
enables the computers to more properly enable the jump vector, 
eases the load on the power plant during its most critical 
mission, and allows the gravitic devices to switch to the 
different circuits they need to operate from within jumpspace.  

It is probably this short hiatus in gravity that causes the 
momentary disorientation and nausea felt by even experienced 
space hands at the moment of transition.

- ---------------------------------

Effects of Gravity on Maneuvering Vessels:

Gravity has little effect on most vessels unless that vessel has 
lost its maneuver drives or is near a large celestial body (one 
large enough to orbit - or perhaps a runaway maneuver drive?).  
Thrust from maneuver drives so overwhelms most gravitational 
forces in deep space so as to make them inconsequential.

Near large bodies, though, gravity causes us to radically alter 
our flight paths and operational methods.  The force of gravity 
decreases as the distance from the attracting body increases (6).  
In many instances, this force can be greater that what we can deliver 
with thrusters; we must orbit the body.  

This also means that for a ship in orbit, for instance, the 
"bottom" of the ship (closest to the planet) and its occupants 
have more gravity on them than the top of the ship and its 
occupants do.  This phenomenon is called microgravity, and it is 
used to stabilize satellites in almost every spacefaring culture.




Satellite Top ------------Gravity - a little
||  
||
Center of Mass ---|   *|Gravity at orbit
||
||
Satellite Bottom ------------Gravity + a little



Ordinarily, microgravity is no problem.  However, in close orbits 
of very large bodies, stresses can build up in a ship's hull both 
from the gradient of microgravity and from the relativistic 
stresses caused by the sheer speed of the vessel.

The main problems from gravity are long-term.  On-board gravitic 
devices, interacting with gravitational forces, cause stress on the 
ship's frame and hull.  This stress is normally minor, but can be 
severe close to large bodies, especially if the vessel is 
maneuvering.  In deep space, away from gravity wells, a ship's 
gravitic devices are tuned to minimize stresses on the vessel.

- ------------------------------------

Effects of Inertia on Maneuvering Vessels:

Inertia is a much more severe problem for maneuvering.  It is easy 
to imagine maneuvers that could quickly make almost any sapient 
creature strictly two-dimensional.  Additionally, rapid changes 
in speed and direction cause enormous stress on the ship's frame.  
We are most familiar with inertia as a force that tends to pull us 
toward the outside of turns or pushed back in our seats when we 
accelerate.  The magnitude of the force we feel depends only on 
how fast we are changing our speed or direction.

In a space vessel these inertial forces are almost always enormous 
because the ship is travelling very, very fast.  For instance, 
making a 5-g (2) 180-degree circular turn at just over Terran escape 
velocity (a veritable snail's pace in space) creates a circular 
path over 10,000 km long, and a corresponding flight time of over 
13 minutes to execute the maneuver (7).  

Incidently, it would also take 13 minutes to reverse course by 
rotating the ship 180 degress (it's now flying backwards) and
apply a continuous 5-g thrust.  No one can turn around quickly 
enough to surprise and overtake his pursuers.

High agility doesn't provide this ability either.  Agility is
simply a measure of a ship's ability to change *facing*, not
to change it's speed and/or direction.  That is, agility is a 
figure expressing a vessel's ability to pitch, roll, or yaw.
"Maneuverability" is a figure that expresses, in g-forces, the 
maximum linear acceleration a space vessel is capable of.  
"Normally" (who knows what those TL 21 miscreants are up to!?) 
this is a figure from 1 to 6 (10 to 60 m/s/s).

This means that space battles are inherently linear.  Much like 
the days of sailing, with ships in a line.  Only in space, guns
can be aimed (turned away from the beam of the ship) and it is
possible to sail (fly) over and under, as well as around (or into)
your opponents.  (Ships in a plane?) I guess there is a good 
reason to teach formation flying!

- ----------------------------

Inertial compensators: 

My first thought on seeing their availability was that this was 
the way out of the inertia trap just presented.  "I could build 
a ship with maneuver 12 and inertia dampers 6, exposing the 
maneuver drives to only 6-g acceleration," I thought.  It doesn't 
work that way though.

The maneuver drives, and the inertial compensators work on effects
of hyperspatial interactions.  Their use causes space-time to warp.
Remember that it is acceleration, not force, that determines the 
extent of warping of space-time within and around the ship.  Because 
of this, gravitic devices (like maneuver drives) can be of any size.  
They cannot however, produce more than 6-g of acceleration.  Period.

Inertial compensators don't do anything for the space-time warping
caused by the maneuver drives.  In fact, they make it worse.  As the 
maneuver drive creates more acceleration, space-time warps more, and
more strongly.  Inertial compensators counter-warp space-time locally,
and in so doing exacerbate the overall effect.  Your ship's computers
must be bigger and faster to handle the load, and you suck up even
more fuel. 

What this means is that you cannot design a ship with a maneuver 12 
and agility 12 and inertial compensators 6.  It would be nice if you
could, but those big massive driveplate antennas would wipe out all
of your available volume and then some.  The best you can hope for 
with inertial compensation is to provide a feeling of "motionlessness"
for your crew and passengers.

- -----------------------------------

Repulsers and Grav Plates:

These are basically straightforward maneuver drives, adapted for
special uses.  Grav plates primarily hold things down, and 
repulsers hold things away.

Grav plates are tied in with the inertial compensator circuitry.  
Grav plates need to be large in area, but light and small in 
cross section.  They are used throughout the ship, and produce
from -6 to +5 g (if your maneuver drive is that good - if it 
isn't, buy cheaper inertia systems) to compensate for the ship's
maneuvering.  Notice that the plates can produce one less g in 
the "down" direction (letting inertial hold you to the deck), 
but that on "outside" turns, you will sometimes experience free 
fall.  That's just as much force as we can produce. 
(The rules say so.)
 
Additionally, grav plates need to produce an exceptionally 
uniform field.  Studies as early as TL 7 terra (really!) showed 
that if your perception of "down" changes often or radically, 
you *will* get at least nauseated.  This is commonly known as 
sea- or air-sickness.  It is especially acute when the victim 
lacks outside reference and/or feels confined (like in a space
ship).

Repulsers are high energy, high curvature, effect projectors.
That is, they are maneuver drives with small area, high mass
plates.  This produces a "beam" of gravitational energy, almost
always away from the projector.

"Reversing" the field effect (to make a tractor beam) usually
causes more damage to the ship trying it than to the ship in
tow.  In my campaign, I allow limited use of "tractors" for
in-system towing around TL 16.

- ----------------------------

Maneuver Drives

Maneuver drive plates are usually mounted across the aft end
of a starship.  In this configuration, they can provide the
most force in the most desired direction.


Region of Low Force
__
| ----
Region of| |   ---------
High Force| |<-plates--------    Region of *really*
| |             --------    Low Force
| |   ---------
| ----
- -

 Region of Low Force

Since the plates also deliver force to the sides, a ship can "hover"
horizontally if the gravity is not too high.  This is how air rafts
work.  Space ships eventually rotate into a more conventional 
attitude to leave the atmosphere of a planet.  (See the "Starship
Operator's Manual, vol. 1, page 3.)

The plates of the maneuver drive must be extremely large, to 
"linearize" the fields around the whole ship, and must be massive
so that a great deal of energy can be pumped through them.  Look
at the information about the mass and volume of the drives (in the
Referee's manual, page 65) based on ship's mass and maneuver
number.  Notice that mass and volume increase linearly with ship's
mass, and exponentially with acceleration.

Maneuver drives take the most power of any ship's system.  (Well,
a jump drive takes a lot, too, but it's antenna is the entire 
ship's hull.)  This is because of the sheer quantity of energy
being converted.

When in use, maneuver drives leave tell-tale perturbations in 
space-time.  Sophisticated sensors can detect the slight 
perturbations in stellar signatures that indicate the passage
of a ship, and it's course.

- -----------------------------

Summary

Gravitics in the service of humaniti.  By TL 10, gravitics
are as ubiquitous as computers.  Every air raft, every ATV
(or AFV), every air craft, space craft, and starship use 
gravitics for propulsion.  Gravitics are great for hauling
and lifting heavy loads, and for medical assistance to the 
invalid.  And it all came about because spewing chemicals
into space is much too expensive a way to get anywhere.

  

- -------------------------------------------------------
Notes:

1.This equivalence courtesy A. Einstein.  
E=mC^2
says, mathematically, that mass (inertia) and 
energy are *equivalent* modified by a known
constant (the speed of light, C).


2.This calculation arrived a little later than
Einstein's.  Planck gave us E=hu with h being
a physical constant, and u being the frequency
of the wave being measured.  

But, frequency is (velocity/wavelength), so for
electromagnetic waves, E = hC/l with l being the
wavelength and C the speed of light.

For typical masses (grams - kilograms - tons), 
a typical wavelength for the energy composing
the matter is ~10^24 meters.  This is roughly
as many times smaller than an atom as an atom
is smaller than us.

Energy densities this high *cannot* exist in
normal space-time.  We can only speculate at
how they might actually interrelate in dimensions
we can't measure.  High-energy supercolliders
are attempts to release enough energy in a 
short period of time to hopefully catch some of
the affects of these interactions "in the act".


3.This is where I actually begin "honest" Mega-
Traveller speculation about what it all means.


4.A "g" is defined as the acceleration due to 
gravity at mean sea level on Terra 
(Solomani Rim/Sol 1827 A867A69-F).  This is
roughly 9.8 m/s/s.


5.Relativistic effects include time slowing down
(literally!) in some parts of the ship, disa-
greement at a molecular level what the length
and density of ship's (or crew's) members should
be, and so forth.  In general, "relativistic
effects" means we become totally uncertain about
everything; we can't "know" anything without
altering the conditions upon which we "know" it.


6.Actually, gravity decreases with the square of the
distance.  Newton's formula F=G(m*M/r^2) gives the
exact description of the force of attraction between
any two bodies, m and M at a distance r from each
other.  

This rapid fall off in the potential for hyperspace
interaction is serendipitous.  Imagine the trouble
at Capital if the Solomani figured out they could
cause space-time warping remotely because the 
interactions they tap into in hyperspace reach that
far...


7.To compute the length of the path, we first determine 
the radius of the circle (r) followed by the ship, 
using the general formula for centripetal acceleration
(a = v^2/r).  We assign a to 50 m/s/s (about 5-g) and
v to our ship's speed (13 km/s - roughly escape velocity).
Then:

r = v^2 / a
r = 13 km/s * 13 km/s / 0.05 km/s
r = 3380 km

Next, we use the formula for the circumference of a
circle to determine the length of the path travelled.
We cut our determined value in half because we only
travel half the circle.

d = 2 * pi * r
d = 0.5 (2 * 3.14159 * 3380)
d = 10 618 km

To determine the time it takes to travel this far, 
we use the formula

t = d / v
t = 10 618 km / 13 km/s
t = 817 s

If we  divide by 60 to get minutes, we arrive at
13.61 minutes to execute that U-turn.


All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #629 --------

Archive-Message-Number: 629
Subject: MegaTraveller Discussion on rec.games.frp
Date: 16 Oct 89 12:11:58 PDT (Mon)
From: jamesp



Here's some of the recent discussion on (Mega)Traveller from
rec.games.frp.  Summary: Some people love it, others hate it.  I like to
provide this list with all the Traveller-related articles I see on the
frp newsgroup, as long as it could possibly be of wide interest.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Traveller Mailing List Administrator	  James T. Perkins @ Tektronix, Inc
traveller-request@dadla.wr.tek.com	  Beaverton, Oregon, USA
uunet!dadla.wr.tek.com!traveller-request  "Load Auto/Evade, Beowulf!"

- ------- Forwarded Messages

Article: 15438 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!cs.utexas.edu!mailrus!cornell!uw-beaver!milton!toby!wendigo
From: wendigo@uwav1.u.washington.edu
Newsgroups: rec.games.frp
Subject: Traveller
Message-ID: <8393@uwav1.u.washington.edu>
Date: 12 Oct 89 21:20:34 GMT
Organization: University of Washington, Seattle WA
Lines: 20

Is it just me, or does everyone else actually like the Digest Group task
system that is used for MegaTravller and 2300AD (Which I actually like.
Anyone else out there actually play it?)?
 
I find the 4-point thresholds simply ludicrous, the stat add thresholds
(every 5!) silly as well, and while many aspects are covered, there sure
is a lot of dice rolling (and as far as I can tell, there are provisions
for critical failures but not critical successes).
 
I myself simply cannot stomach it (and consequently have been trying to
devise a replacement, with mixed success...), and I'm just curious if
there is something I am missing, or is this truly the state of the art?
 
- - --
 
     Death to Videodrome
     Long Live the New Flesh
     -------------------------
     Hans Visser
     wendigo@max.acs.washington.edu

- ------- Message 2

Article: 15457 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!bloom-beacon!primerd!choinski
From: choinski@primerd.prime.com
Newsgroups: rec.games.frp
Subject: Re: Traveller
Message-ID: <40500024@primerd>
Date: 13 Oct 89 15:06:00 GMT
References: <8393@uwav1.u.washington.edu>
Lines: 76
Nf-ID: #R:uwav1.u.washington.edu:-839300:primerd:40500024:000:4338
Nf-From: primerd.prime.com!choinski    Oct 13 11:06:00 1989


|Is it just me, or does everyone else actually like the Digest Group task
|system that is used for MegaTravller and 2300AD (Which I actually like.
|Anyone else out there actually play it?)?
 
  (waving hand) ME!  ME!

|I find the 4-point thresholds simply ludicrous, the stat add thresholds
|(every 5!) silly as well, and while many aspects are covered, there sure
|is a lot of dice rolling (and as far as I can tell, there are provisions
|for critical failures but not critical successes).
 
  I use a slightly modified task system in 2300AD (don't play MT).  My task
  levels use steps of 2 (I.E. Trivial=1, Simple=3, Easy=5, Routine=7, 
  Challenging=9, Difficult=11, Hard=13, Formidable=15, Overwelming=17,
  Unreasonable=19, Near Impossible=21, Impossible=22) and I have shifted
  skill rolls to using 2d6 instead of 1d10 (the curve makes the difference
  between difficulties more reasonable).  I'm trying to figure out how to
  fit the hit locations table to 2d6 so I can dispense with d10's completely.

  Another change I made, mainly to the Melee Combat system, the the ability to
  choose your maneuvers.  Instead of striking at Routine all the time, you may
  choose to do a "Hard" strike, requiring a "Overwelming" block.  This allows
  those trained in the martial arts to perform those hard-to-stop strikes on
  the lesser trained.  A side note to this rule is that if you choose a more
  difficult strike, and you fail the skill roll, you are considered 
  "off-balance" and your next block is made at one level (2 point level)
  increased difficulty.  As a ref you can handle this system two ways:

     1) Descriptive: "I do a high snap kick to his head!"  "Ok, that's a 
        Difficult Strike"
     2) Specific: "I do a Challenging Punch"

  The first method adds more color to the game as the players come up with
  flashy kicks and punches, but forces the referee to make judgement calls
  on the actual difficulties.  The second is quicker, but pretty dry.

  I also use a slightly shifted attribute modifier chart.  It goes something
  like this:
   
    Level Mod       Level Mod        Level Mod        Level Mod
       1   -6          7   -1          13    0          19   +2
       2   -5          8   -1          14   +1          20   +3
       3   -4          9   -1          15   +1          21   +3
       4   -3         10    0          16   +1          22   +3
       5   -2         11    0          17   +2          23   +4
       6   -2         12    0          18   +2          24   +4

  Example:  Joe Scout is walking though the woods, making geographic notes when
  he suddenly spots a Kafer mob heading toward his position.  Since running
  would alert them to his presence, he decides to hit the bushes and hide.
  There is no "Hiding" skill -- it's simply a matter of choosing the right 
  place and being quiet.  Joe is reasonably Intelligent (14) and has a skill of
  2 in Survival.  He must make an Uncertain task roll to find the right cover.
  The ref decides that given the fact he can't move very far, but given the
  amount of cover available, it is a Routine task.  Joe get to add 2 for his
  skill and +1 for his intelligence for a 4+ for success.  If both he and the
  referee roll 4+, he's well hidden from simply being seen.  If either Joe or
  the ref fail their roll, he's hidden, but could be spotted (his butt's 
  sticking out or something.  If both fail, this turkey is trying to hide 
  behind a sapling.  If Joe did not have a skill in survival, He would have to
  make a challenging task roll, adding ONLY his intelligence modifier.

|I myself simply cannot stomach it (and consequently have been trying to
|devise a replacement, with mixed success...), and I'm just curious if
|there is something I am missing, or is this truly the state of the art?
 
  The Task system is okay, you just have to tweak it a bit here and there.
  Once a few changes are made it works fine.

- - -============================================================================-
 Burton Choinski                                       choinski@env.prime.com
   Prime Computer, Inc.                                  (508) 879-2960 x3233
   Framingham, Ma.  01701
 Disclaimer:  Hey, not me man; musta been my evil twin.
- - -============================================================================-

- ------- Message 3

Article: 15467 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!ginosko!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!mailrus!cwjcc!marina!davisp
From: davisp@marina.CWRU.EDU (Palmer Davis)
Newsgroups: rec.games.frp
Subject: Re: Traveller
Message-ID: <823@cwjcc.CWRU.Edu>
Date: 14 Oct 89 04:10:38 GMT
References: <8393@uwav1.u.washington.edu>
Sender: news@cwjcc.CWRU.Edu
Reply-To: davisp@marina.UUCP (Palmer Davis)
Organization: Smith Undergrad Lab, CWRU, Cleve., OH
Lines: 85

In article <8393@uwav1.u.washington.edu> wendigo@uwav1.u.washington.edu writes:
>Is it just me, or does everyone else actually like the Digest Group task
>system that is used for MegaTravller and 2300AD (Which I actually like.
>Anyone else out there actually play it?)?
> 

Well, since I think it's absolutely the greatest thing since sliced toast, 
I suppose the answer to that question would be yes.

>I find the 4-point thresholds simply ludicrous, the stat add thresholds
>(every 5!) silly as well, and while many aspects are covered, there sure
>is a lot of dice rolling (and as far as I can tell, there are provisions
>for critical failures but not critical successes).
>

You must be playing with the old Digest Group version of the rules (published
in GRAND SURVEY, GRAND CENSUS, and TRAVELLER: 2300), which makes you make a
"failure roll" whenever you fail.  The new version of the task system, which
appears in MEGATRAVELLER (and, presumably, 2300 AD, although I haven't seen
the new edition), eliminates half the die rolling by replacing the failure
roll with rules for exceptional success and exceptional failure.  (This also
addresses the other gripe you had.)  

In the new system, whenever you succeed by more than 2, it's an exceptional
success.  When you fail by more than 2, it's an exceptional failure.  (I
say "more than 2," but it's really 2+, which I feel is too small a margin).
A natural 2 is still always a fumble.  Exceptional failure on a hazardous
task or ordinary failure on a fateful task results in a 2D mishap.  Fumbling 
a hazardous task, or getting exceptional failure on a task that is both
hazardous AND fateful, results in a 3D mishap.  The rules don't say this 
either, but I suppose that you could make a case for rolling four dice on
the mishap table if you fumble a haz/fate task....

As for the 4-point separation between difficulty levels, I frequently find
myself applying arbitrary -1, +1, or +2 modifiers to some tasks as a means
of "fine-tuning" them in specific cases.  These modifiers get added in on
an ad hoc basis for specific cases of tasks and don't go in my task library
(except in unusual cases...).  They let me fine-tune the difficulty of 
individual attempts to get the right balance.  But I wouldn't publish them 
in an adventure or supplement -- the levels they give are supposed to be
general guidelines, not straitjackets.  They work well for me, at least.  A 
typical pilot, for example, with a Dex of 7 and a Pilot skill of 2, making a
Routine, Pilot, Dex check will succeed on a 4+... whereas someone with no
skill needs a 10 or better.  Seems about right to me.

As for the 5-point characteristic bonuses, I like the way they balance out
too as they give characters with superior abilities an edge, but not so much
that they dominate the game.  Remember -- this is Traveller, not AD&D.  The
power curve between strong and weak characters is supposed to be MUCH flatter.
As it stands, you get a +1 on attempts if you have an ability of 10+, and a
- - -1 if you have an ability of 4-, as compared to the average Joe.  In the 
original edition, most die rolls that were affected by abilities started to
hand bonuses or penalties out at somewhere around these levels.
 
>I myself simply cannot stomach it (and consequently have been trying to
>devise a replacement, with mixed success...), and I'm just curious if
>there is something I am missing, or is this truly the state of the art?
> 

I'm finding I have a hard time stomaching anything else any more.  I seem
to be having the opposite experience you are with this... instead of causing
a lot of die rolling, the task system I've been using eliminates most of the
die rolling I've had to do (except in cases of fumbles).  Unless the players
are worried about time or a mishap occurs, every task rides on a single die
roll, which can be very rapidly calculated.  

The whole idea behind the task system is that you should be able to easily
memorize it, and apply it without really worrying about mechanics.  The system
lets me take my hands off the mechanics and worry about creating a challenging
adventure and realistic settings and NPC's and not the rules of running the
game.  And the sorts of things the system lets you do replace several pages of
new rules for each new task.  I love it.  Star Wars does something similar
with its standard difficulty levels and equally simple mechanics.  

My one gripe about MegaTraveller is its damage system.  PC's can take too
much punishment from guns, not enough from melee weapons.  I get around this 
by dividing each damage value for a weapon by 3 (retaining fractions) and 
applying it as 2300-style damage.

- - -- Palmer Davis --


Palmer T. Davis                  |  The opinions expressed herein are my own
Case Western Reserve University  |  and do not necessarily represent the truth.
davisp@skybridge.scl.cwru.edu    |  Flame away to your heart's content.

- ------- Message 4

Article: 15468 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!cs.utexas.edu!ginosko!gem.mps.ohio-state.edu!rpi!leah!bingvaxu!sunybcs!boulder!pikes!udenva!isis!csm9a!sfellows
From: sfellows@csm9a.UUCP (5 CR)
Newsgroups: rec.games.frp
Subject: Re: Traveller
Summary: task system very good
Message-ID: <1963@csm9a.UUCP>
Date: 13 Oct 89 16:18:17 GMT
References: <8393@uwav1.u.washington.edu>
Organization: Colorado School of Mines
Lines: 31

In article <8393@uwav1.u.washington.edu>, wendigo@uwav1.u.washington.edu writes:
> Is it just me, or does everyone else actually like the Digest Group task
> system that is used for MegaTravller and 2300AD (Which I actually like.
> Anyone else out there actually play it?)?
>  
> I find the 4-point thresholds simply ludicrous, the stat add thresholds
> (every 5!) silly as well, and while many aspects are covered, there sure
> is a lot of dice rolling (and as far as I can tell, there are provisions
> for critical failures but not critical successes).
>  
> I myself simply cannot stomach it (and consequently have been trying to
> devise a replacement, with mixed success...), and I'm just curious if
> there is something I am missing, or is this truly the state of the art?
>  
Yes, you are missing something.  First off there are critical successes:
In combat, if you have a powerful enough weapon, you can make an instant kill.
The four point thresholds are decent and in my campaign they work.  As for
the stat add thresholds of every five, yeah, they are crap.  What I do is
modify the modifier by substracting two or three (I am just trying it recently).
This way if you have very low stats it hurts you, which seems a little more
realistic.  I do like the task system, because it makes for a consistent system
for determining whether you have accomplished something.  It allows for better
roleplaying because it gives the players a better idea of what the likelihood
of accomplishing a task would be. (I would give an examle, but right now I 
am in a hurry.)

As for 2300AD... Do I like it? Well, yes. I have a 2300AD campaign which is
over a year old going very well right now.

Steven B. Fellows
sfellows@csm9a.colorado.edu

- ------- End of Forwarded Messages

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Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
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The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #630 --------

Archive-Message-Number: 630
Date: Mon, 16 Oct 89 13:01:39 -0700
From: (Happiness is a Goal in Sight and a Path Underfoot) baranski@yoda.enet.dec.COM
Subject: gravitics handwaving


RE: very long file about gravitics.

Very interesting...  But it seems like an awful lot of handwaving to explain
something that should be very simple.  I'd much prefer discussion on how to
make the subject reasonable and simple, then handwaving on how to make it
complicated... :-)

Jim Baranski
DEC Tewksbury MA

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-------- TML Message #631 --------

Archive-Message-Number: 631
Subject: Taxes
Date: Mon Oct 16 14:33:12 1989
From: richard@agora.hf.intel.COM (Richard Johnson)



How about some discussion of taxes?  What are the tax rates across
the Imperium?  How are taxes collected?  What devious methods have
been devised to get people to "volunteer" some portion of their
just (or unjust) profit?

How does a small-time operator deal with differnt governments, taxes,
and probably weights and measures, as he/she ploys commerce around
the many worlds?  Is there a widley accepted bookkeeping method?

Richard


All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #632 --------

Archive-Message-Number: 632
From: (Steven J Owens) scratch@unix.cis.pitt.edu
Date: Tue, 17 Oct 89 1:41:21 EDT
Subject: Space Habitats (was Re: Gravitics...)


	I think Space Habitats can be used very nicely for a campaign setting
(although at the moment I'm biased, having just finished _Vacuum_Flowers_).
I also think that they will rarely show up in traveller campaigns.  Personally,
I think the Imperium is too friggin' big!  The GM should pick a nice-sized
chunk and flesh it out a lot (detail on each world, sprinkle a few space
habitats and curiosities around, etc).  Back to the subject...

	Two good books for Space Habitat background:  Christopher Rowley's
_Starhammer_ and Michael Swanwick's _Vacuum_Flowers_.  The latter is cyber-
punk, and has space habitats ranging from orbiting cans to dyson worlds to
cometary settlments.  It's a good book which I highly reccomend for reading for
personal pleasure, and it could serve as a nice little unusual but highly
fleshed out system for Traveller (hmm... that's an idea, take fifty or a
hundred of your favorite SF books and "place" them in a chunk of imperial
space, either carefully subsituting for near matches or merely putting them
where you like...).
 
	The problem with Vacuum Flowers is that it is cyberpunk, and much of
the material of the world therein might not match your traveller campaign,
especially the wetware (computer-brain enhancements) and the apparent dichotomy
of technology (wetware, but their space travel is pretty weak, and interstellar
travel non-existent).  You might get around this by making the citizens very
humanoid aliens (but their brain structure is different enough to allow them to
easily use wetware, while normal humans cannot) or by making the fancy tech
VERY dependent upon the rest of the society's technology (either because it is
not compatible with tech from other systems, or because it reli

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Status: R


-------- TML Message #628 --------

Archive-Message-Number: 628
Date: Sun Oct 15 19:19:33 1989
From: richard@agora.hf.intel.COM (Richard Johnson)


Greetings fellow travellers!  
This is a very long file about gravitics.


The following information is highly UN-official.  I have taken 
pains to try to reconcile what I know about the universe with
what I know about MegaTraveller from the rules and accessories,
but am not about to guarantee an official approval of any of it.  

You can use and distribute this material freely, so long as I 
get some credit for working it all out and making it available.
(and while your at it, remember to thank JamesP and Tek for the
list...)  

Some of this is still pretty rough, but I think you'll find
it mostly useful.

Richard Johnson
Hillsboro Oregon

- --------------------------cut here if you like--------------------------
Gravitics in MegaTraveller
- ------by Richard Johnson

It is a misconception among several of my players that the 
primary function of gravitics on space vessels is to hold 
crew members to the deck.  I suspect this attitude is common.
In actuality (sic) the science of gravitics has profound 
implications for space travel, and the development of 
gravitics has been a primary mover the direction of space 
technology.  

The "Starship Operator's Manual, vol 1" gives, on page 56, 
under "Gravitics Technician", introduces the idea of 
gravitics.  It states that: 

"The artificial grav plates and inertial compensators 
within the ship are not critical to its performance...  
More importantly, though, the maneuver drive's thruster 
plates operate on a principal that takes advantage of 
gravitic science..." 

This article explores the theory and applications of gravitics, 
and how gravitic design limitations affect the maneuvering of 
space vessels.  I strongly suggest you read the appropriate
sections of the operator's manual, and information about ship
design in the Referee's manual, to better understand what I'm
saying here (and to catch me where I've blown it).

- ----------------------------------

Theory of Gravitics:

Two fundamental properties of matter concern us when space 
vessels maneuver.  These are inertia and gravity.  Inertia is 
the tendency for matter to resist any changes in speed or 
direction.  Gravity is the tendency for all matter to attract 
other matter (or anti-matter, for that matter).  It is 
important to understand that these are *fundamental properties*.
All that exists demonstrates these tendencies; in fact, inertia
and gravity are what we use to define matter.

Both inertia and gravity are effects that we see, in "normal 
space", of matter being highly concentrated energy (1).  Energy 
concentrations sufficient to create solid matter are more than 
enough to interact with higher-order universal dimensions (2).  
These particles interact in higher dimensions in ways not 
possible in "normal space".  The *effects* of these 
hyperspacial interactions are then seen in "normal space" as 
inertia and gravity. (3)

- ------------------------------

Gravitic Devices:

There are four basic gravitic devices:

Maneuver drives
Repulsers
Grav plates, and 
Inertial compensators.

These all tap into these hypserspacial interactions, and 
concentrate and direct the resulting force.  In a sense,
so do jump drives, but there is a critical distinction.  
Jump drives use the hyperspace/space-time interactions
to loft the entire ship into a bubble in hyperspace, 
while gravitic devices use the hyperspace/space-time
interactions to manipulate space-time events.

Drives and repulsers generally utilize a repulsive force, 
while grav plates generally use an attractive force.  In all 
three devices, the "effects" being manipulated are gravitic.  

Inertial compensators, on the other hand, intercept inertial 
"effects" and use feedback techniques to reduce or nullify 
inertia on selected bodies.  Looked at this way, we can see 
that inertial compensators are not *truly* gravitic devices, 
but that the technology is similar enough so that we need 
make no distinction, except in the scientific community.  

For the remainder of this article, I  use "gravitic devices" 
to refer to inertial devices as well.  I do not use the term 
to apply to jump drives, even though they have many features
in common with gravitic devices.

- --------------------------

Basic Design of Gravitic Devices:

Gravitic devices operate much like valves in a water hose.  A
small change in the characteristics of the device (valve) 
produces a large change in output (flow).  That is to say that
the energy you feed your drives (from the power plant) is not
converted to thrust.  It is used to control and direct the
flow of "effect" from an interaction that occurs in hyperspace.

All gravitic devices have the same general design.  A typical
device has a "concentrator", a "plate", and a "governor".  



- ------------------------------
|Conc. ||        || Output   |
|Plate |--------| Gov.   |------| Plate    |
|      ||        |      |   |
- ------------|-----      ------------
\    |          /
 \----------    /
  \_____| Comp. |---/
- ----------

The concentrator plate is basically a hyperspace receive antenna.  
It collects and concentrates wade-ranging "effects" into a small 
region of space-time.  The concentrator does not create hyper-
space interactions; that would take too much energy.  It does tap 
directly into activity in hyperspace and intercept the 
interactions already there.

The output (or thruster) plate is basically a space-time output 
antenna.  It directs and releases the concentrated "effects" 
gathered by the concentrator.  Examine drive plates for a 
classic example.  (Refer to the "Starship Operator's Manual, 
vol. 1, pages 2-4.)  Notice how the output is strong in the 
plate's basic direction, but weakens sharply in other directions.  
Notice also that all plates are invariably placed so that 
*nothing* gets within about a meter of them.  We'll discuss 
this more in a minute. 

The governor is the part of the device that monitors and 
controls the concentrator and the plate.  It matches input, 
output, and demand (from the ship's computer).  Needless to
say, this is where most of the technology, and most of the
problems occur.


- ----------------------------

Limits of Gravitic Devices:

There is a serious side effect to using a gravitic device 
because the device operates both in hyperspace and in 
space-time.  Using a gravitic device "warps" space-time 
around the concentrator.  This warping is very like the 
warping of space-time around black holes, only the radius 
of curvature of space is much shorter, usually measured 
in meters rather than kilometers.  This warping becomes 
more intense as the acceleration produced by the device 
increases.  Beyond about 60 m/s/s acceleration (6 g) (4), 
the device becomes inoperable because of relativistic 
effects (5).

The warping of space-time caused by gravitic devices is 
identical to the warping to space-time by a gravity field, 
only intense and of short range.  It is critical, especially 
in jump-capable vessels to have space-time as smooth as 
possible in and around the ship.  The amount space-time is
warped represents how much is not known about the ship's
present position, or its destination.  Hence -- misjumps.

If these "warps" caused by using gravitics are left 
unaltered, time would flow at different rates in different 
parts of the ship, sensors would not operate properly, 
thrusters would fight themselves, and jumps (if possible) 
would be wholly unpredictable. 

The plates associated with all gravitic devices are large 
(and in the case of drives, massive) mainly to deal with this 
warping of space-time.  The plates function as antennae that 
receive hyperspacial energy and broadcast "spacial" energy.  
They could be microscopic and do this.  

However, the plates also "sink" or dissipate the space-time 
warping associated with the use of the gravitic device.  For 
this task the plates need to be large, to "spread out" the 
effects of the warping of space-time.  

In the case of jump-capable ships, even this is not enough.  
For a few microseconds before a jump, all gravitic devices on 
starships are switched completely off.  The transition to 
jumpspace is made, and gravitics are switched back on.  This 
enables the computers to more properly enable the jump vector, 
eases the load on the power plant during its most critical 
mission, and allows the gravitic devices to switch to the 
different circuits they need to operate from within jumpspace.  

It is probably this short hiatus in gravity that causes the 
momentary disorientation and nausea felt by even experienced 
space hands at the moment of transition.

- ---------------------------------

Effects of Gravity on Maneuvering Vessels:

Gravity has little effect on most vessels unless that vessel has 
lost its maneuver drives or is near a large celestial body (one 
large enough to orbit - or perhaps a runaway maneuver drive?).  
Thrust from maneuver drives so overwhelms most gravitational 
forces in deep space so as to make them inconsequential.

Near large bodies, though, gravity causes us to radically alter 
our flight paths and operational methods.  The force of gravity 
decreases as the distance from the attracting body increases (6).  
In many instances, this force can be greater that what we can deliver 
with thrusters; we must orbit the body.  

This also means that for a ship in orbit, for instance, the 
"bottom" of the ship (closest to the planet) and its occupants 
have more gravity on them than the top of the ship and its 
occupants do.  This phenomenon is called microgravity, and it is 
used to stabilize satellites in almost every spacefaring culture.




Satellite Top ------------Gravity - a little
||  
||
Center of Mass ---|   *|Gravity at orbit
||
||
Satellite Bottom ------------Gravity + a little



Ordinarily, microgravity is no problem.  However, in close orbits 
of very large bodies, stresses can build up in a ship's hull both 
from the gradient of microgravity and from the relativistic 
stresses caused by the sheer speed of the vessel.

The main problems from gravity are long-term.  On-board gravitic 
devices, interacting with gravitational forces, cause stress on the 
ship's frame and hull.  This stress is normally minor, but can be 
severe close to large bodies, especially if the vessel is 
maneuvering.  In deep space, away from gravity wells, a ship's 
gravitic devices are tuned to minimize stresses on the vessel.

- ------------------------------------

Effects of Inertia on Maneuvering Vessels:

Inertia is a much more severe problem for maneuvering.  It is easy 
to imagine maneuvers that could quickly make almost any sapient 
creature strictly two-dimensional.  Additionally, rapid changes 
in speed and direction cause enormous stress on the ship's frame.  
We are most familiar with inertia as a force that tends to pull us 
toward the outside of turns or pushed back in our seats when we 
accelerate.  The magnitude of the force we feel depends only on 
how fast we are changing our speed or direction.

In a space vessel these inertial forces are almost always enormous 
because the ship is travelling very, very fast.  For instance, 
making a 5-g (2) 180-degree circular turn at just over Terran escape 
velocity (a veritable snail's pace in space) creates a circular 
path over 10,000 km long, and a corresponding flight time of over 
13 minutes to execute the maneuver (7).  

Incidently, it would also take 13 minutes to reverse course by 
rotating the ship 180 degress (it's now flying backwards) and
apply a continuous 5-g thrust.  No one can turn around quickly 
enough to surprise and overtake his pursuers.

High agility doesn't provide this ability either.  Agility is
simply a measure of a ship's ability to change *facing*, not
to change it's speed and/or direction.  That is, agility is a 
figure expressing a vessel's ability to pitch, roll, or yaw.
"Maneuverability" is a figure that expresses, in g-forces, the 
maximum linear acceleration a space vessel is capable of.  
"Normally" (who knows what those TL 21 miscreants are up to!?) 
this is a figure from 1 to 6 (10 to 60 m/s/s).

This means that space battles are inherently linear.  Much like 
the days of sailing, with ships in a line.  Only in space, guns
can be aimed (turned away from the beam of the ship) and it is
possible to sail (fly) over and under, as well as around (or into)
your opponents.  (Ships in a plane?) I guess there is a good 
reason to teach formation flying!

- ----------------------------

Inertial compensators: 

My first thought on seeing their availability was that this was 
the way out of the inertia trap just presented.  "I could build 
a ship with maneuver 12 and inertia dampers 6, exposing the 
maneuver drives to only 6-g acceleration," I thought.  It doesn't 
work that way though.

The maneuver drives, and the inertial compensators work on effects
of hyperspatial interactions.  Their use causes space-time to warp.
Remember that it is acceleration, not force, that determines the 
extent of warping of space-time within and around the ship.  Because 
of this, gravitic devices (like maneuver drives) can be of any size.  
They cannot however, produce more than 6-g of acceleration.  Period.

Inertial compensators don't do anything for the space-time warping
caused by the maneuver drives.  In fact, they make it worse.  As the 
maneuver drive creates more acceleration, space-time warps more, and
more strongly.  Inertial compensators counter-warp space-time locally,
and in so doing exacerbate the overall effect.  Your ship's computers
must be bigger and faster to handle the load, and you suck up even
more fuel. 

What this means is that you cannot design a ship with a maneuver 12 
and agility 12 and inertial compensators 6.  It would be nice if you
could, but those big massive driveplate antennas would wipe out all
of your available volume and then some.  The best you can hope for 
with inertial compensation is to provide a feeling of "motionlessness"
for your crew and passengers.

- -----------------------------------

Repulsers and Grav Plates:

These are basically straightforward maneuver drives, adapted for
special uses.  Grav plates primarily hold things down, and 
repulsers hold things away.

Grav plates are tied in with the inertial compensator circuitry.  
Grav plates need to be large in area, but light and small in 
cross section.  They are used throughout the ship, and produce
from -6 to +5 g (if your maneuver drive is that good - if it 
isn't, buy cheaper inertia systems) to compensate for the ship's
maneuvering.  Notice that the plates can produce one less g in 
the "down" direction (letting inertial hold you to the deck), 
but that on "outside" turns, you will sometimes experience free 
fall.  That's just as much force as we can produce. 
(The rules say so.)
 
Additionally, grav plates need to produce an exceptionally 
uniform field.  Studies as early as TL 7 terra (really!) showed 
that if your perception of "down" changes often or radically, 
you *will* get at least nauseated.  This is commonly known as 
sea- or air-sickness.  It is especially acute when the victim 
lacks outside reference and/or feels confined (like in a space
ship).

Repulsers are high energy, high curvature, effect projectors.
That is, they are maneuver drives with small area, high mass
plates.  This produces a "beam" of gravitational energy, almost
always away from the projector.

"Reversing" the field effect (to make a tractor beam) usually
causes more damage to the ship trying it than to the ship in
tow.  In my campaign, I allow limited use of "tractors" for
in-system towing around TL 16.

- ----------------------------

Maneuver Drives

Maneuver drive plates are usually mounted across the aft end
of a starship.  In this configuration, they can provide the
most force in the most desired direction.


Region of Low Force
__
| ----
Region of| |   ---------
High Force| |<-plates--------    Region of *really*
| |             --------    Low Force
| |   ---------
| ----
- -

 Region of Low Force

Since the plates also deliver force to the sides, a ship can "hover"
horizontally if the gravity is not too high.  This is how air rafts
work.  Space ships eventually rotate into a more conventional 
attitude to leave the atmosphere of a planet.  (See the "Starship
Operator's Manual, vol. 1, page 3.)

The plates of the maneuver drive must be extremely large, to 
"linearize" the fields around the whole ship, and must be massive
so that a great deal of energy can be pumped through them.  Look
at the information about the mass and volume of the drives (in the
Referee's manual, page 65) based on ship's mass and maneuver
number.  Notice that mass and volume increase linearly with ship's
mass, and exponentially with acceleration.

Maneuver drives take the most power of any ship's system.  (Well,
a jump drive takes a lot, too, but it's antenna is the entire 
ship's hull.)  This is because of the sheer quantity of energy
being converted.

When in use, maneuver drives leave tell-tale perturbations in 
space-time.  Sophisticated sensors can detect the slight 
perturbations in stellar signatures that indicate the passage
of a ship, and it's course.

- -----------------------------

Summary

Gravitics in the service of humaniti.  By TL 10, gravitics
are as ubiquitous as computers.  Every air raft, every ATV
(or AFV), every air craft, space craft, and starship use 
gravitics for propulsion.  Gravitics are great for hauling
and lifting heavy loads, and for medical assistance to the 
invalid.  And it all came about because spewing chemicals
into space is much too expensive a way to get anywhere.

  

- -------------------------------------------------------
Notes:

1.This equivalence courtesy A. Einstein.  
E=mC^2
says, mathematically, that mass (inertia) and 
energy are *equivalent* modified by a known
constant (the speed of light, C).


2.This calculation arrived a little later than
Einstein's.  Planck gave us E=hu with h being
a physical constant, and u being the frequency
of the wave being measured.  

But, frequency is (velocity/wavelength), so for
electromagnetic waves, E = hC/l with l being the
wavelength and C the speed of light.

For typical masses (grams - kilograms - tons), 
a typical wavelength for the energy composing
the matter is ~10^24 meters.  This is roughly
as many times smaller than an atom as an atom
is smaller than us.

Energy densities this high *cannot* exist in
normal space-time.  We can only speculate at
how they might actually interrelate in dimensions
we can't measure.  High-energy supercolliders
are attempts to release enough energy in a 
short period of time to hopefully catch some of
the affects of these interactions "in the act".


3.This is where I actually begin "honest" Mega-
Traveller speculation about what it all means.


4.A "g" is defined as the acceleration due to 
gravity at mean sea level on Terra 
(Solomani Rim/Sol 1827 A867A69-F).  This is
roughly 9.8 m/s/s.


5.Relativistic effects include time slowing down
(literally!) in some parts of the ship, disa-
greement at a molecular level what the length
and density of ship's (or crew's) members should
be, and so forth.  In general, "relativistic
effects" means we become totally uncertain about
everything; we can't "know" anything without
altering the conditions upon which we "know" it.


6.Actually, gravity decreases with the square of the
distance.  Newton's formula F=G(m*M/r^2) gives the
exact description of the force of attraction between
any two bodies, m and M at a distance r from each
other.  

This rapid fall off in the potential for hyperspace
interaction is serendipitous.  Imagine the trouble
at Capital if the Solomani figured out they could
cause space-time warping remotely because the 
interactions they tap into in hyperspace reach that
far...


7.To compute the length of the path, we first determine 
the radius of the circle (r) followed by the ship, 
using the general formula for centripetal acceleration
(a = v^2/r).  We assign a to 50 m/s/s (about 5-g) and
v to our ship's speed (13 km/s - roughly escape velocity).
Then:

r = v^2 / a
r = 13 km/s * 13 km/s / 0.05 km/s
r = 3380 km

Next, we use the formula for the circumference of a
circle to determine the length of the path travelled.
We cut our determined value in half because we only
travel half the circle.

d = 2 * pi * r
d = 0.5 (2 * 3.14159 * 3380)
d = 10 618 km

To determine the time it takes to travel this far, 
we use the formula

t = d / v
t = 10 618 km / 13 km/s
t = 817 s

If we  divide by 60 to get minutes, we arrive at
13.61 minutes to execute that U-turn.


All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #629 --------

Archive-Message-Number: 629
Subject: MegaTraveller Discussion on rec.games.frp
Date: 16 Oct 89 12:11:58 PDT (Mon)
From: jamesp



Here's some of the recent discussion on (Mega)Traveller from
rec.games.frp.  Summary: Some people love it, others hate it.  I like to
provide this list with all the Traveller-related articles I see on the
frp newsgroup, as long as it could possibly be of wide interest.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Traveller Mailing List Administrator	  James T. Perkins @ Tektronix, Inc
traveller-request@dadla.wr.tek.com	  Beaverton, Oregon, USA
uunet!dadla.wr.tek.com!traveller-request  "Load Auto/Evade, Beowulf!"

- ------- Forwarded Messages

Article: 15438 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!cs.utexas.edu!mailrus!cornell!uw-beaver!milton!toby!wendigo
From: wendigo@uwav1.u.washington.edu
Newsgroups: rec.games.frp
Subject: Traveller
Message-ID: <8393@uwav1.u.washington.edu>
Date: 12 Oct 89 21:20:34 GMT
Organization: University of Washington, Seattle WA
Lines: 20

Is it just me, or does everyone else actually like the Digest Group task
system that is used for MegaTravller and 2300AD (Which I actually like.
Anyone else out there actually play it?)?
 
I find the 4-point thresholds simply ludicrous, the stat add thresholds
(every 5!) silly as well, and while many aspects are covered, there sure
is a lot of dice rolling (and as far as I can tell, there are provisions
for critical failures but not critical successes).
 
I myself simply cannot stomach it (and consequently have been trying to
devise a replacement, with mixed success...), and I'm just curious if
there is something I am missing, or is this truly the state of the art?
 
- - --
 
     Death to Videodrome
     Long Live the New Flesh
     -------------------------
     Hans Visser
     wendigo@max.acs.washington.edu

- ------- Message 2

Article: 15457 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!bloom-beacon!primerd!choinski
From: choinski@primerd.prime.com
Newsgroups: rec.games.frp
Subject: Re: Traveller
Message-ID: <40500024@primerd>
Date: 13 Oct 89 15:06:00 GMT
References: <8393@uwav1.u.washington.edu>
Lines: 76
Nf-ID: #R:uwav1.u.washington.edu:-839300:primerd:40500024:000:4338
Nf-From: primerd.prime.com!choinski    Oct 13 11:06:00 1989


|Is it just me, or does everyone else actually like the Digest Group task
|system that is used for MegaTravller and 2300AD (Which I actually like.
|Anyone else out there actually play it?)?
 
  (waving hand) ME!  ME!

|I find the 4-point thresholds simply ludicrous, the stat add thresholds
|(every 5!) silly as well, and while many aspects are covered, there sure
|is a lot of dice rolling (and as far as I can tell, there are provisions
|for critical failures but not critical successes).
 
  I use a slightly modified task system in 2300AD (don't play MT).  My task
  levels use steps of 2 (I.E. Trivial=1, Simple=3, Easy=5, Routine=7, 
  Challenging=9, Difficult=11, Hard=13, Formidable=15, Overwelming=17,
  Unreasonable=19, Near Impossible=21, Impossible=22) and I have shifted
  skill rolls to using 2d6 instead of 1d10 (the curve makes the difference
  between difficulties more reasonable).  I'm trying to figure out how to
  fit the hit locations table to 2d6 so I can dispense with d10's completely.

  Another change I made, mainly to the Melee Combat system, the the ability to
  choose your maneuvers.  Instead of striking at Routine all the time, you may
  choose to do a "Hard" strike, requiring a "Overwelming" block.  This allows
  those trained in the martial arts to perform those hard-to-stop strikes on
  the lesser trained.  A side note to this rule is that if you choose a more
  difficult strike, and you fail the skill roll, you are considered 
  "off-balance" and your next block is made at one level (2 point level)
  increased difficulty.  As a ref you can handle this system two ways:

     1) Descriptive: "I do a high snap kick to his head!"  "Ok, that's a 
        Difficult Strike"
     2) Specific: "I do a Challenging Punch"

  The first method adds more color to the game as the players come up with
  flashy kicks and punches, but forces the referee to make judgement calls
  on the actual difficulties.  The second is quicker, but pretty dry.

  I also use a slightly shifted attribute modifier chart.  It goes something
  like this:
   
    Level Mod       Level Mod        Level Mod        Level Mod
       1   -6          7   -1          13    0          19   +2
       2   -5          8   -1          14   +1          20   +3
       3   -4          9   -1          15   +1          21   +3
       4   -3         10    0          16   +1          22   +3
       5   -2         11    0          17   +2          23   +4
       6   -2         12    0          18   +2          24   +4

  Example:  Joe Scout is walking though the woods, making geographic notes when
  he suddenly spots a Kafer mob heading toward his position.  Since running
  would alert them to his presence, he decides to hit the bushes and hide.
  There is no "Hiding" skill -- it's simply a matter of choosing the right 
  place and being quiet.  Joe is reasonably Intelligent (14) and has a skill of
  2 in Survival.  He must make an Uncertain task roll to find the right cover.
  The ref decides that given the fact he can't move very far, but given the
  amount of cover available, it is a Routine task.  Joe get to add 2 for his
  skill and +1 for his intelligence for a 4+ for success.  If both he and the
  referee roll 4+, he's well hidden from simply being seen.  If either Joe or
  the ref fail their roll, he's hidden, but could be spotted (his butt's 
  sticking out or something.  If both fail, this turkey is trying to hide 
  behind a sapling.  If Joe did not have a skill in survival, He would have to
  make a challenging task roll, adding ONLY his intelligence modifier.

|I myself simply cannot stomach it (and consequently have been trying to
|devise a replacement, with mixed success...), and I'm just curious if
|there is something I am missing, or is this truly the state of the art?
 
  The Task system is okay, you just have to tweak it a bit here and there.
  Once a few changes are made it works fine.

- - -============================================================================-
 Burton Choinski                                       choinski@env.prime.com
   Prime Computer, Inc.                                  (508) 879-2960 x3233
   Framingham, Ma.  01701
 Disclaimer:  Hey, not me man; musta been my evil twin.
- - -============================================================================-

- ------- Message 3

Article: 15467 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!ginosko!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!mailrus!cwjcc!marina!davisp
From: davisp@marina.CWRU.EDU (Palmer Davis)
Newsgroups: rec.games.frp
Subject: Re: Traveller
Message-ID: <823@cwjcc.CWRU.Edu>
Date: 14 Oct 89 04:10:38 GMT
References: <8393@uwav1.u.washington.edu>
Sender: news@cwjcc.CWRU.Edu
Reply-To: davisp@marina.UUCP (Palmer Davis)
Organization: Smith Undergrad Lab, CWRU, Cleve., OH
Lines: 85

In article <8393@uwav1.u.washington.edu> wendigo@uwav1.u.washington.edu writes:
>Is it just me, or does everyone else actually like the Digest Group task
>system that is used for MegaTravller and 2300AD (Which I actually like.
>Anyone else out there actually play it?)?
> 

Well, since I think it's absolutely the greatest thing since sliced toast, 
I suppose the answer to that question would be yes.

>I find the 4-point thresholds simply ludicrous, the stat add thresholds
>(every 5!) silly as well, and while many aspects are covered, there sure
>is a lot of dice rolling (and as far as I can tell, there are provisions
>for critical failures but not critical successes).
>

You must be playing with the old Digest Group version of the rules (published
in GRAND SURVEY, GRAND CENSUS, and TRAVELLER: 2300), which makes you make a
"failure roll" whenever you fail.  The new version of the task system, which
appears in MEGATRAVELLER (and, presumably, 2300 AD, although I haven't seen
the new edition), eliminates half the die rolling by replacing the failure
roll with rules for exceptional success and exceptional failure.  (This also
addresses the other gripe you had.)  

In the new system, whenever you succeed by more than 2, it's an exceptional
success.  When you fail by more than 2, it's an exceptional failure.  (I
say "more than 2," but it's really 2+, which I feel is too small a margin).
A natural 2 is still always a fumble.  Exceptional failure on a hazardous
task or ordinary failure on a fateful task results in a 2D mishap.  Fumbling 
a hazardous task, or getting exceptional failure on a task that is both
hazardous AND fateful, results in a 3D mishap.  The rules don't say this 
either, but I suppose that you could make a case for rolling four dice on
the mishap table if you fumble a haz/fate task....

As for the 4-point separation between difficulty levels, I frequently find
myself applying arbitrary -1, +1, or +2 modifiers to some tasks as a means
of "fine-tuning" them in specific cases.  These modifiers get added in on
an ad hoc basis for specific cases of tasks and don't go in my task library
(except in unusual cases...).  They let me fine-tune the difficulty of 
individual attempts to get the right balance.  But I wouldn't publish them 
in an adventure or supplement -- the levels they give are supposed to be
general guidelines, not straitjackets.  They work well for me, at least.  A 
typical pilot, for example, with a Dex of 7 and a Pilot skill of 2, making a
Routine, Pilot, Dex check will succeed on a 4+... whereas someone with no
skill needs a 10 or better.  Seems about right to me.

As for the 5-point characteristic bonuses, I like the way they balance out
too as they give characters with superior abilities an edge, but not so much
that they dominate the game.  Remember -- this is Traveller, not AD&D.  The
power curve between strong and weak characters is supposed to be MUCH flatter.
As it stands, you get a +1 on attempts if you have an ability of 10+, and a
- - -1 if you have an ability of 4-, as compared to the average Joe.  In the 
original edition, most die rolls that were affected by abilities started to
hand bonuses or penalties out at somewhere around these levels.
 
>I myself simply cannot stomach it (and consequently have been trying to
>devise a replacement, with mixed success...), and I'm just curious if
>there is something I am missing, or is this truly the state of the art?
> 

I'm finding I have a hard time stomaching anything else any more.  I seem
to be having the opposite experience you are with this... instead of causing
a lot of die rolling, the task system I've been using eliminates most of the
die rolling I've had to do (except in cases of fumbles).  Unless the players
are worried about time or a mishap occurs, every task rides on a single die
roll, which can be very rapidly calculated.  

The whole idea behind the task system is that you should be able to easily
memorize it, and apply it without really worrying about mechanics.  The system
lets me take my hands off the mechanics and worry about creating a challenging
adventure and realistic settings and NPC's and not the rules of running the
game.  And the sorts of things the system lets you do replace several pages of
new rules for each new task.  I love it.  Star Wars does something similar
with its standard difficulty levels and equally simple mechanics.  

My one gripe about MegaTraveller is its damage system.  PC's can take too
much punishment from guns, not enough from melee weapons.  I get around this 
by dividing each damage value for a weapon by 3 (retaining fractions) and 
applying it as 2300-style damage.

- - -- Palmer Davis --


Palmer T. Davis                  |  The opinions expressed herein are my own
Case Western Reserve University  |  and do not necessarily represent the truth.
davisp@skybridge.scl.cwru.edu    |  Flame away to your heart's content.

- ------- Message 4

Article: 15468 of rec.games.frp
Path: wrgate!zephyr.ens.tek.com!uunet!cs.utexas.edu!ginosko!gem.mps.ohio-state.edu!rpi!leah!bingvaxu!sunybcs!boulder!pikes!udenva!isis!csm9a!sfellows
From: sfellows@csm9a.UUCP (5 CR)
Newsgroups: rec.games.frp
Subject: Re: Traveller
Summary: task system very good
Message-ID: <1963@csm9a.UUCP>
Date: 13 Oct 89 16:18:17 GMT
References: <8393@uwav1.u.washington.edu>
Organization: Colorado School of Mines
Lines: 31

In article <8393@uwav1.u.washington.edu>, wendigo@uwav1.u.washington.edu writes:
> Is it just me, or does everyone else actually like the Digest Group task
> system that is used for MegaTravller and 2300AD (Which I actually like.
> Anyone else out there actually play it?)?
>  
> I find the 4-point thresholds simply ludicrous, the stat add thresholds
> (every 5!) silly as well, and while many aspects are covered, there sure
> is a lot of dice rolling (and as far as I can tell, there are provisions
> for critical failures but not critical successes).
>  
> I myself simply cannot stomach it (and consequently have been trying to
> devise a replacement, with mixed success...), and I'm just curious if
> there is something I am missing, or is this truly the state of the art?
>  
Yes, you are missing something.  First off there are critical successes:
In combat, if you have a powerful enough weapon, you can make an instant kill.
The four point thresholds are decent and in my campaign they work.  As for
the stat add thresholds of every five, yeah, they are crap.  What I do is
modify the modifier by substracting two or three (I am just trying it recently).
This way if you have very low stats it hurts you, which seems a little more
realistic.  I do like the task system, because it makes for a consistent system
for determining whether you have accomplished something.  It allows for better
roleplaying because it gives the players a better idea of what the likelihood
of accomplishing a task would be. (I would give an examle, but right now I 
am in a hurry.)

As for 2300AD... Do I like it? Well, yes. I have a 2300AD campaign which is
over a year old going very well right now.

Steven B. Fellows
sfellows@csm9a.colorado.edu

- ------- End of Forwarded Messages

All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #630 --------

Archive-Message-Number: 630
Date: Mon, 16 Oct 89 13:01:39 -0700
From: (Happiness is a Goal in Sight and a Path Underfoot) baranski@yoda.enet.dec.COM
Subject: gravitics handwaving


RE: very long file about gravitics.

Very interesting...  But it seems like an awful lot of handwaving to explain
something that should be very simple.  I'd much prefer discussion on how to
make the subject reasonable and simple, then handwaving on how to make it
complicated... :-)

Jim Baranski
DEC Tewksbury MA

All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #631 --------

Archive-Message-Number: 631
Subject: Taxes
Date: Mon Oct 16 14:33:12 1989
From: richard@agora.hf.intel.COM (Richard Johnson)



How about some discussion of taxes?  What are the tax rates across
the Imperium?  How are taxes collected?  What devious methods have
been devised to get people to "volunteer" some portion of their
just (or unjust) profit?

How does a small-time operator deal with differnt governments, taxes,
and probably weights and measures, as he/she ploys commerce around
the many worlds?  Is there a widley accepted bookkeeping method?

Richard


All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- TML Message #632 --------

Archive-Message-Number: 632
From: (Steven J Owens) scratch@unix.cis.pitt.edu
Date: Tue, 17 Oct 89 1:41:21 EDT
Subject: Space Habitats (was Re: Gravitics...)


	I think Space Habitats can be used very nicely for a campaign setting
(although at the moment I'm biased, having just finished _Vacuum_Flowers_).
I also think that they will rarely show up in traveller campaigns.  Personally,
I think the Imperium is too friggin' big!  The GM should pick a nice-sized
chunk and flesh it out a lot (detail on each world, sprinkle a few space
habitats and curiosities around, etc).  Back to the subject...

	Two good books for Space Habitat background:  Christopher Rowley's
_Starhammer_ and Michael Swanwick's _Vacuum_Flowers_.  The latter is cyber-
punk, and has space habitats ranging from orbiting cans to dyson worlds to
cometary settlments.  It's a good book which I highly reccomend for reading for
personal pleasure, and it could serve as a nice little unusual but highly
fleshed out system for Traveller (hmm... that's an idea, take fifty or a
hundred of your favorite SF books and "place" them in a chunk of imperial
space, either carefully subsituting for near matches or merely putting them
where you like...).
 
	The problem with Vacuum Flowers is that it is cyberpunk, and much of
the material of the world therein might not match your traveller campaign,
especially the wetware (computer-brain enhancements) and the apparent dichotomy
of technology (wetware, but their space travel is pretty weak, and interstellar
travel non-existent).  You might get around this by making the citizens very
humanoid aliens (but their brain structure is different enough to allow them to
easily use wetware, while normal humans cannot) or by making the fancy tech
VERY dependent upon the rest of the society's technology (either because it is
not compatible with tech from other systems, or because it relies on the
extensive support tech of that world).  
 
	Either way, it might make a very good "It's an interesting place to
visit, but I wouldn't want to live there." sort of star system.  

	The other book, StarHammer by Christopher Rowley, is much more suitable
to the traveller universe.  The first half of the book (after the first chapter
or so) is spent on a set of space habitats that are nicely fleshed out in terms
of general information (the Vacuum Flowers space habitats have more cultural
information, but less "practical" information;  the culture of the Starhammer
habitats is pretty much normal human, aside from the aliens that make up an
important part of the book) and is almost a campaign packet for running a game
based on a space habitat.  

	Unfortunately, even though the book is good, they only spent the first
half of the book in the habitats (Frankly, I would have been happy with a book
concerned solely with the main character's life on the space habitaat - he is a
borderline psionic, an empath able to sense strong hate and fear, and is a
member of the "mass murder squad," a special squad of habitat police who
operate almost like a Covert Intelligence operation to avoid attacks by the
very criminals they hunt, the Mass Murder cultists, who get their kicks by
staging mass murders...) but it's well worth the read anyway, and the main
story of the book is pretty decent also.  Try it out...
 
	If somebody is interested in some specifics from the books, ask me in a
week or two, after mid-terms and my eye-strain have gone away...


Steven J. Owens  |  Scratch@PITTVMS  |  scratch@unix.cis.pitt.edu

"Okay, Major Jonathan "Wrong-Is" Wright rubs his magic ring of Imperial
 Intervention and twenty stormtroopers with battledress and gauss rifles pop
 out of the microwave oven..."  
 
	- Sean T. Grape, in a truly bizarre traveller campaign...

All opinions and material above is the responsibility of the originator.
Submissions: traveller@dadla.wr.tek.com, or uunet!dadla.wr.tek.com!traveller
Administrator: traveller-request@dadla.wr.tek.com (James Perkins)
The TML is made possible by facilities provided by Tektronix, Inc.

-------- End of TML Messages --------

