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Subject: TML Bundle #171: Table of Contents

-AMN- --Date--- --Sender--------- --Subject-----------------------------------
2138  11-Feb-91 gt4534b@prism.gat 100 diameter rule << carlf@agora.rain.com wri
2139  11-Feb-91 C450160@UMCVMB.MI HELP ME... I WANT FILES << Dear fellow travel
2140  12-Feb-91 True Friends Chan jumping near gravity sources << pardon me whi
2141  09-Feb-91 d9bertil@dtek.cha Voyage of the Gamla Bettan [fiction] << Long 
2142  12-Feb-91 al646@cleveland.F Jump Distances and Psionics << I have been re
2143  12-Feb-91 METLAY@vms.cis.pi 100 Diameters....I think....*BOOOOOOOOM* << M
2144  12-Feb-91 Mark F. Cook      New MT software on Sunbane << I've just added
2145  13-Feb-91 bonnevil@acc.stol Re: Jump Distances and Psionics << I agree th
2146  13-Feb-91 Dan Corrin        Jumping near gravity sources. << In regards t
2147  13-Feb-91 Dan Corrin        Jump collisions and velocities << T.L. Hayes 

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

Archive-Message-Number: 2138
Date: Mon, 11 Feb 91 15:48:58 -0500
From: gt4534b@prism.gatech.edu (JARRIO,MARTIN MICHAEL)
Subject: 100 diameter rule


carlf@agora.rain.com writes:

>But who's to say the gravitons behave similar to quantum mechanics? It may
>be that the "size" of the graviton is dependent on the size of the "radiating"
>body.  Then the explanation for the 100 diameter rule could read something
>like this...

  (details deleted)

   The problem with your argument is that greater mass NECCESSARILY implies
greater flux (i.e. density) of gravitons in the vicinity of that mass. Thus
more massive bodies will always require greater distances to safe jump points
(all other things being equal...). The idea that the SIZE of the body matters
is rubbish. (It can be demostrated that a spherical mass distribution can be
treated as a point mass located at the center of the distribution, as long as
you remain outside the radius of the object.) Only mass, and the distance from
that mass, are of concern. That's why, as a physicist, I have always disliked
the idea of travelling "X" diameters to the jump point.

    With this in mind (a solar system composed entirely of effective point
masses), the problem is to develop a suitable mearure for the degree of local
space-time curvature due to gravitational influnces. Clearly, stars will have a
large influence ( with mass scales about 1E+5 to 1E+7 times larger than planet
a large influence (their mass scale is about 1E+5 to 1E+7 times larger than
planetary scales). In order to minimize their affect, curvature should fall
off very rapidly with distance. As an earlier article pointed out, a 1/r**2
fall-off (obtained by measuring gravitational FORCE) has some setbacks. It is
obvious that a 1/r fall-off (the result of measuring gravitational POTENTIAL)
would be even worse. Perhaps by defining a gravitational "CURVATURE" which
falls off as 1/R**3, we can get better results.

    What would such a fall-off do? It just might solve our problems. Look:
Mass is given by Density*(Radius**3). Thus a curvature like Mass/(Distance**3)
would be the same as:

       Curvature = Density/(RELATIVE Distance)**3

where relative distance is really just the number of DIAMETERS away.Sum this
expression over all bodies in the system (in practice, we need sum only over
stars and the planet or gas giant involved) to find the total curvature. If 
this sum is less than a critical value, jump is possible. If we ignore the 
affect of stars (say we are sufficiently far away) ,we can invert the equation
above to get the jump distance:

       N = (density/curvature constant)**0.333

This actually explains the 100 diameter rule: because curvature falls off as 
1/R**3, we can calculate jump distance as a constant distance relative to the
planetary diameter (although the diameter really  HAS NOTHING TO DO WITH IT)!
However, there is a small correction due to the density of the planet, but that
is no great problem.


For example consider a jump from Terra. (Density=1.00, Diam.=12,740 km).
Suppose than it exactly 100 diameters to the jump point (travelling straight
away from Terra and Sol). This implies a critical curvature constant (CCC)
of 1.2E-6 (Sol has density about .25 Terran, and 1 AU is about 108 solar
diameters). Or for a "10 diameter" jump, the CCC is 1E-3. For simplicity,
say the two CCC's are 1E-6 and 1E-3, respectively. Then risky jump is still
at 10 diameters (127,400 km), while safe jump is at 108 Terran diameters
(1,375,920 km). Note the coincidence: safe jump is 108 Terran diameters away
from Terra, and 108 SOLAR diameters from Sol. This is a true coincidence,
but I LIKE IT. Cosmic Synergy and Synchronicity and Fabulous Portents of the
Unknown....

    Any way the only trick left is to find out how far one must go in a 
given direction away from the planet in order to get curvature below the 
critical level. It will, of course vary with direction, if you want to pick
nits with me. There's two options: get a computer whiz to come up with a code
(I ALMOST did), or do what I did--stick with the 10/100 diameter rule ( you
can use the (density)**0.333 effect if you like), because otherwise you can
get bogged down in overly technical scientific mumbo-jumbo (like I do at the
office), rather than enjoy the role-playing (which I do in my SPARE time).

Any way. I've vomited my two cents worth. That's why nobody likes us
physicists--we overkill science.

                         Marty Jarrio (Physicist at large)
                        " Ray, get that tranquilizer gun..he's a vicious one"

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

Archive-Message-Number: 2139
Date: Mon, 11 Feb 91 19:53:27 CST
From: C450160@UMCVMB.MISSOURI.EDU
Subject: HELP ME... I WANT FILES

Dear fellow travellers,
   Here I am at the TAS and I seem to have lost my membership card... Seriously
, I'm having BIG problems getting any of the archive packages at sunbane.engrg.
uwo.ca. I can get into the system and get any file I want BUT... I work on an I
BM CMS system and these files have been compressed using a compression routine
for a UNIX based system. Now before anyone flames me, I have been looking for a
 way around this problem for two weeks. I'm no wizard, but I'm no rookie either
. I am asking you, my fellow travellers of this trouble universe, to aid me in
aquiring a program to use so that I may get the files to a CMS system, then dow
nload them to either a Mac or an IBM type machine.
   I am throwing myself at your mercy. Please help this poor soul.

Michael T. Finn                    aka Anton Pavelchek
c450160@umcvmb.missouri.edu        Capt. A2 far trader Star Vixen

"Captain, this economy computer just doesn't cut it!"
"Shut up and hand me those fire control punch cards..."

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

Archive-Message-Number: 2140
Date: Tue, 12 Feb 91 10:45:26 EST
From: True Friends Change Your Life  12-Feb-1991 1014 <baranski@meridn.enet.dec.COM>
Subject: jumping near gravity sources

pardon me while I reiterate...

If I understand the situation correctly, Traveller's 100 diameter distance from
a planet necessary for a safe jump, doesn't match the assumption that jumps
need to take place in a near zero gravity, below some threshold according to
the 1/r^2 attenuation of gravity as you move away from a gravity source.

First, the diameter of the planet doesn't matter, it's the total mass of the
planet, and the distance from the center of the gravity.

Second, the 1/r^2 attenuation comes up with a distance well under 100 diameters
for most planets, yet the threshold 1/r^2 attenuation of a star's gravity ends
up typically being well past the orbit of habitable planets.

So, someone proposes using a 1/r^3 attenuation for gravitic curvature?

Interesting, in BattleTech, the jump points are typically above the poles of
the star.

What about the points between the star and the planet where their gravity
cancels each other?  Would that be a viable jump point?

Jim Baranski
Norwich CT

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

Archive-Message-Number: 2141
From: d9bertil@dtek.chalmers.se
Subject: Voyage of the Gamla Bettan [fiction]
Date: Sat, 9 Feb 91 20:33:33 MET

  Long in the making and even longer in the promise of making, finally here it
is. A somewhat novelized version of my current Traveller campaign. The campaign
started in 87 and still is going strong (although only one of the original 
characters still is alive). We only had the Traveller Book way back then
when we started and the most fearsome marines were armed with autorifles, but
I've tried to make it somewhat up to date and resolve any conflicts with 
the official Traveller universe.

   If you like it, let me know, and if you dislike it, let me know what you
dislike. I am fairly certain that I'll be able to keep them comming with
some sort of regularity.

===============================================================================
Copyright (C) 1990,1991 Bertil K K Jonell, All Rights Reserved, Permission is 
hereby granted to the TML to distribute and store this document on the TML and 
associated ftp-sites and to the Members of the TML to store it if they should
find it interesting enough:)

Written and Directed by: Bertil K K Jonell
Corrected by: Olof Dahlberg, Tomas Eriksson and Reine Hansson
Starring: Olof Dahlberg, Tomas Eriksson, D J Fredrik Granholm, Mikael Rubin and
	  Henrik Sjo"strand.
Rating: R (People get shot, and when they do they use harsh language, although
	   nobody has ever mentioned the word "Belgium".. Except me, that is..)
Ships and Vehicles provided by the IISS, the IMC and the Roupian Army.

                 Voyage of the "Gamla Bettan" part One
                                Prologue:
Time: 023-1114  2340 hours Local
Location: Roup/Regina/Spinward Marches

Excerpt from Library Data: Roup/Regina (0407 C77A9A9-6): TAS Amber Zone. 
Waterworld situated on the express boat route from Regina to Efate. Its 
population of 3.4 billions is concentrated on the peaks of a few underwater 
mountains, the only dry land on the world. Real food (as opposed to the local 
fish and plankton concentrates) is highly prized by the population.

   The closed snowjeep plowed through the deep drifts and its headlights 
illuminated the descending snow-flakes. It's tracks spread a cloud-like 
mass of snow in a wide arc when the vehicle skidded around a corner and 
briefly visited the sidewalk, narrowly missing a pedestrian.
   "Don't worry about the civvies, trooper. We *do* have over-population here 
on Roup." Major Schmallhaussen said dryly. "But try to avoid that signpost over 
there, it might damage our sneep."
   With a lurch to the left the sneep avoided the obstacle. The driver pulled 
hard on the wheel as the vehicle almost lost its purchase in the deep snow. 
After a brief look to make sure that they were driving in the right direction, 
Major Schmallhaussen turned around to face those in the backseat.
   "Do you know which pad those hooligans are using, Mr Troop?" he asked a 
person dressed in thin but warm-looking parka, obviously an off-world item.
   "Pad fourteen or forty, I think." James P Troop answered, "It was hard to 
hear, the wind drowned out the sounds."
   "There are only 35 pads on the port, Major" the other person in the back 
interjected.
   "I know that, Corporal." Schmallhaussen cut him off. "There is no need for 
you to repeat truisms all the time".

   The sneep braked to a stop in the well-illuminated space in front of the 
marine guardpost at the starport gates. The guard came out of the building and 
the driver opened the side window. When the marine saw the military markings 
on the sneep and that the people inside were armed she said something into her 
headset and unslung her gauss before continuing.
   "I want to see some army ID's on you guys and your permits..."
   The Major pushed his ID out through the window before she could finish the 
sentence. "My name is Major Schmallhaussen, I'm from the State Security and 
this is an emergency! A number of criminal hooligans are preparing to smuggle 
in a large consignment of illegal foodstuffs from a ship in this starport,
thereby undermining our society and the faith in our Great Leader and seriously
threatening the Roupian Way of Life. I demand that you open the gates at once!"
the marine cringed when she heard Schmallhaussens political monologue.
   "Well, Mr Propaganda, this port is Extraterritorial. You have no 
jurisdiction here."
   "As I said, this is an emergency. Those criminals might be unloading even as
we speak. And this man" he indicated Troop "is the only one that will recognize
them. Now, will you open the gate?"
   "Hang on a sec, I got to check with the Lieutenant about this." She turned 
away and began to speak into the headset. After a few long seconds the gate 
began to open. The marine pulled an small object out of a pocket of her CES, 
pressed a button and gave it to Schmallhaussen. "This is a marine communicator. 
I've preset it to the guard tactical frequency. All you have to do is press the
big button on the side and speak."
   "We *do* have radios on Roup, you know" Schmallhaussen interjected. The 
marine pretended not to notice and continued "When you have found the ship, 
observe and call on the guards, No shooting, No arrests, No anything, just call
the Starport guards."
   "Of course, we don't want an diplomatic incident, do we?" Schmallhaussen 
answered ironically. he indicated to the driver to start. "Put the pedal to the
metal now, trooper. Follow the signs to Pad 14"
   The tracks spun and the sneep rapidly accelerated away, leaving the marine 
in a cloud of snow.
   The starport covered a large area and lacked illumination. Because of the 
almost complete lack of dry land on Roup it had been placed on Roups southern 
icecap. Now it was summer on the northern hemisphere, so the weather at 
Antarctica Starport was at its worst. But the placement had one big advantage. 
It made it very easy for the dictator of Roup and his security forces to 
control access to the starport.

  A few minutes later the sneep had found its way to Pad 14 and Schmallhaussen, 
Moeller and the Corporal disembarked. Troop looked up at the hull of the 
starship that loomed above them and read the name out loud "Free Trader 'Jason'
from Regina. Yes, that was the name they mentioned."
   Schmallhaussen instructed the driver "Drive to the barracks, get the guards 
and take them here. We don't know if the criminals have means to detect 
transmissions so I won't use the communicator"
   The driver saluted and drove off. The sound of the engine faded quickly 
and soon only the wind could be heard. On the neighbouring pads the ships 
stood dark and silent, their crews undoubtedly sleeping. "Either in their warm 
staterooms or in the equally warm hotel rooms in Startown" the corporal 
thought. The major's voice pulled him back to reality. "Lets take a look at 
that ship", Schmallhaussen said, flipped off the safety from his SMG and began 
to advance towards the ship. "Follow me."
   They hadn't walked more than ten meters when Moller, who was in the rear, saw
something move behind the far landing-gear. He took a small penlight out of his
pocket and flashed it briefly two times towards the movements.
   From behind the landing-gear came a shot that hit number two, the corporal, 
who crumpled without a sound. The sound of the carbine was muffled by the wind 
and the snow. "Good shot Preben!" Troop said into a commdot that was hidden 
beneath his collar "For a scout, that is!". "The shot was easy enough" Preben 
Moeller answered. "The hard part was to locate number two. This snow plays hell 
with the IR! Perhaps I should've put a round in each of you, just to be sure."
   Schmallhaussen bent down and searched for the corporals pulse. "Don't worry"
Troop told him as he took the corporal's SMG, "Preben used a tranq round."
   "I think he'll keep warm enough until the guards get here" said 
Schmallhaussen and held up the communicator, smiling. "This was a bonus. 
Why don't we use it?"

   While Preben Moeller and Troop fired shots and salvoes into the air in the 
background, Schmallhaussen yelled into the communicator about an ambush and 
demanded immediate reinforcements. He finished the transmission by placing the 
communicator in the snow and firing a burst from his SMG into it. They then 
proceeded to make footprints all around the ship and finally Schmallhaussen 
poured out blood from a bag he had nicked in the battalion hospital earlier 
in the evening.
   "Lets get out of here" Moeller said and pointed towards his air/raft "The 
marines will be here any minute now."
   "I'm already here!" Troop said, grinning.
   "Yeah, But you're retired! By the way, not even a kid would be frightened 
by your stupid face."
   Troop snorted and added proudly "Once a Marine, always a Marine!" as he 
borded Moellers IISS-issue air/raft. "At last, a *real* vehicle. Not some 
stone-age 'sheep'".
   "Sneep" Schmallhaussen corrected. "We call them sneeps. It's short for 
snow jeep"
   "Well whatever, You ain't gonna believe me Moeller, but that contraption
ran on tracks, *tracks*. And it was powered by real bloody *combustion engine*,
you know, the ones that burn good booze and spews smoke all around. Might as 
well have been a sled pulled by grazing herbivores. If we had those things in 
the IMC we'd still be the Sylean Marine Corps, I tell you..."

   After a short flight at the lowest possible altitude and a long monologue 
from Troop at his best, in a loud voice, the three accomplices reached 
Moeller's ship.
   "Here she is: Gamla Bettan, The best scout ship behind the claw!" Preben 
said proudly.
   "It's certainly the oldest..." Troop blurted forth.
   "All it needs is some paint. Hurry up and get inside, The countdown is 
proceeding and Tower will call any minute now."
   Even in the airlock Schmallhaussen thought he smelled something, and when 
the cycle was finished and the inner iris opened the suspicion went to 
certainty. From the ships interior came a smell as from well used barracks, not
ventilated for weeks. "Phew! Smells like boot camp." Schmallhaussen turned 
towards Troop, "Is this because of the corps or a corpse?"
   "Verrrrry funny, dustkicker" Troop answered sourly.
   "We would be glad to have any dust to kick on Roup."
   "It's the air-regenerators" Preben called from the bridge."They are of the 
same type as the ones they use in the standard Type S." He turned his attention
to the controls. An irritated voice boomed forth from the commo panel.
   "Tower calling Gamla Bettan, Answer me, you deadhead's!"
   "Eh, Umm, Gamla Bettan here."
   "That's better, Where the hell have you been? We've been trying to call you 
for at least ten minutes."
   "We had some, ehh, problems with the, ehh, powerplant, but it is fixed now."
   "You're sure it keeps together until orbit at least? Fishing ships out of 
the 'eitch to oh' is a bloody nuisance."
   "Don't worry, It'll work"
   "Well then, where were I... Oh yeah, You are clear to start at 0005 hours 
local, that's in zero three minutes, The airspace is clear and the weather's on
your computer. When you have lift-off follow ascent-path nine, red marker, to 
low orbit at 140 clicks. You are logged for three complete orbits."
   "Can't you cut that a bit? I've got a date on Feri."
   "Oh, you do eh, nudge, nudge, Ok then, the system is quiet tonight, scratch 
the orbit, go directly to Onehundred Dee, Do not, I repeat, do not pass 'GO'"
   "Thanks Tower, Over 'n Out from Gamla Bettan."

   Back at the "Jason" the marines had found the tranqed corporal and the signs
of the "battle". They made a quick search of the area which turned up nothing 
so they turned their attention to the ship.
   After hailing it (to no avail since the crew was sleeping off the effects of
an evening in startown provided by a certain ex-marine by the name of Mr Troop) 
Lieutenant Gargishiid took the decision to blow the hatch.
   "Lieutenant! The ship is empty, sir!" sergeant Fulimara reported as he came 
out of the destroyed airlock, "there's neither contraband nor weapons in there,
and no trace of that major."
   The iridescent radiance of hot thruster-plates that pierced the thin blanket 
of falling snow answered the liutenant's unspoken question. As the glow 
accelerated upwards and disappeared into the low clouds he began yelling in 
the communicator "Tower! Tower! Gargishiid here! Stop that ship, I repeat, 
stop that ship! They have the major and the contraband on board!"
   He jumped into the air/raft and took off towards the tower.

   In the common room of the Gamla Bettan Schmallhaussen was searching for a 
refrigerator to raid.
   "By the way, I don't think I have introduced myself." He extended one hand, 
while the other was occupied opening various cupboards, hatches and lockers 
"Major Werner Schmallhaussen, State Security. Or perhaps I should say, Ex-State 
Security"
   "Force Commander James P Troop, Imperial Marine Corps". They shook hands 
"How are you related to Moeller?"
   "He's my cousin. My mother's sister managed to get off Roup, but had a few, 
ehh, misadventures, and ended up in the slums of Efate." Schmallhaussen finally 
found a fridge, or something that he suspected served the same purpose. "Yummy,
*Real* food!" He began to rifle through it. "Hey, what's this? Plankton Beef? 
Crustacean Candy?? Seaweed Bread??? That's not food, that's from Roup!"
   "Yeah, we had to stock new grub 'cause the old load was beginning to smell.
How much time to jump, Preben? I don't wanna get caught red-handed with a 
deserter onboard!" he yelled at the bridge.
   "I'm not a deserter..." Werner began to protest. Moeller interrupted 
"We've got 400 seconds more in the atmosphere. Then it'll take, lets see... 
4 hours 9 minutes and 26 seconds to Onehundred Dee, Fast enough?"
   "What? Have we started? I didn't notice anything." a perplexed Werner asked,
began looking for a window and continued "As I was going to say, I'm not a 
deserter."
   "Riight" Troop grinned.
   "No really! I'll finish my last term of service today at 2400" he looked at 
his watch and smiled "Correction, I finished it ten minutes ago. But then, 
however, there was this little matter with a forced-reenlistment bill from 
Supreme HQ that's waiting in the mail, and there's no way I could have gotten 
an emigrant visa until after I had got that letter from SHQ. By the way, aren't 
there any windows on this thing?"
   "The only big one 's on the bridge. How did you know you were going to get 
the letter? Hey, what do you think you're doing?" Troop almost fell over 
laughing when he saw that Werners fiddling with the controls of the iris to the
bridge only managed sealing it harder. "Press that other button. NOOOO! NOT 
THE RED ONE!!!" he practically jumped the few meters to the fore bulkhead and 
forcibly prevented Schmallhaussen from pressing the "Emergency Blow" button for
the iris valve.
   "OK, Schmallhaussen, listen very carefully now, cause I shall say this only 
once: Until Preben or I have thaught you all you need to know about the ship,
Don't...Touch...Anything! This" he indicated the valve "is called an iris valve.
Unless it opens by itself you open it by pressing this green button. Any 
questions?"
   "Yes, what are all the other buttons for?"
   "They're advanced options for expert users, don't touch them!"
With Werner in tow, Troop entered the bridge where Preben was engaged in an 
agitated discussion with Traffic Control. Werner immediately went to the main 
viewport and placed himself in front of Moeller.
   "No we are *not* going to turn around just because you have had some 
immense foul-up at the port." He held a hand over the mike and asked 
Schmallhaussen "Werner, do you mind? I'd like to see were I am flying."
   "Oh, sorry"
   "According to paragraph forty-two in the Imperial..." Preben cut them short 
with "I know what that paragraph says, but it seems that you don't."
   "It says that *you* should land *here* *now* or we'll punch holes in your 
ship big enough to drive an AFV through!" another voice at Traffic Control 
shouted. It was Lieutenant Gargishiid who came bursting through the door 
followed by a blast of Roupian arctic weather.
   "Read that paragraph again guys. It clearly states that it is only 
applicable to civilian ships and this isn't a civilian ship. This is a ship of 
the Imperial Interstellar Scout Service, and if you start punching holes in 
Imperial ships, there will rain marines out of the sky!"
   "Riiight ON!" Troop yelled.
   "You are under suspicion for one or two cases of kidnapping and murder. Both
are high justice crimes. I'll give you one chance of turning back, If you 
haven't complied within one minute we will give you what we have of surface-to-
space missiles!"
   "He sounds pissed," Werner said, "High justice crimes! Wasn't there any 
other way of getting me off Roup? Whose damn idea was this anyway?"
   "His!" Preben and Troop exclaimed in unison, pointing on each other.
   "No way Preben! It was your idea to use a false smuggling to lure him to the
starport!" Troop complained.
   "But it was your idea to mask it as a kidnapping! Any moron could have 
guessed that they wouldn't like a kidnapping! Just like that marine landing on 
Grevgh, Major fiasco from top to bottom!"
   "Eh, guys? One of the screens say 'Missile Alert'" Schmallhaussen said. Even
if this was his first time on a spaceship he was sure that that meant trouble.
   "Who's ops do you call a fiasco? It was a perfectly executed vertical 
envelopment from orbit. Who would have guessed that the enemy had left six
months ago?"
   "LOOK AT THE BLOODY SCREENS!!!!" Werner yelled.
   "Shuddup, Werner, we are having an discussion!" Troop said.
   "What? What about them?" Werner cast a glance on the main screens "That's 
just a missile alert.....MISSILE ALERT???" He threw the ship into a sharp roll 
and dive and Werner, who had been looking out the window, suddenly turned very 
green.
   "What kind of antiship missiles do you have on Roup?" Troop asked worriedly.
   "Blurrp" Schmallhaussen answered as he tried to reconcile what his eyes told
him with what the rest of his senses said. "Big ones," he struggled with his 
stomach, "20 meters long passive radar homing missiles with proximity fusing 
and a 200kt warhead! Brand new stuff, we bought them just after the 5th FW."
   Preben swore silently and pushed Gamla Bettan even lower, down into the 
surface fog. "We have to get below the port's radar horizon, then they can't 
paint us with the designators." He pulled up suddenly when a big freighter 
appeared out of a fogbank. They heard the 'clang' as Gamla Bettan struck a 
piece of rigging.
   "That was CLOSE!" Troop breathed.
   "Tell me about it! Where is that bloody missile?"
   Troop looked at the screens "Still after us, but too high, and we are losing
their signal."
   "I think they are designed to blow if they lose their signal..."
   "Preben! It's diving! Break Left!!"
   As the LSP Thunderstrike came hurtling down, Preben made a 90 degree turn 
and pushed the thrusterplates overload-meters way up into the red area. The 
missile did not change course to follow them. When it discovered that the 
target was gone, it triggered the warhead and disappeared in an expanding 
fireball of plasma while still high above the ocean.
   On Gamla Bettan even five centimeters of superdense hull didn't mute the 
sound of the explosion. Simultaneously, several status lights switched from 
green to red. Moeller fought with the controls and gradually most of the lights
began to revert to green.
   "No major damage, thank our lucky stars, and the starport is below the 
horizon now. Phew! That was a close one!" Preben let out a sigh as he let the 
ship continue forward in a slight climb. "I don't think we should go to Feri, 
though. Anybody got anything against jumping to Whanga, scooping, and continuing
to Efate? We got to get to Pixie before 070 to meet Miandwhypt and this way 
we'll get three weeks on Efate to install new air-regenerators."
   Troop and Werner didn't have any objections.
   "Do you think they'll put out a 'wanted' on us, Troop?" Werner asked as they
left the atmosphere.
   "That depends. If they suspect that this isn't a kidnapping or murder, just 
a set-up to get you off Roup, and especially if they blasted their way into 
that innocent trader, they will try to put a lid on it and "forget" it very 
fast." He grinned. "After all, that's standard marine procedure for situations 
like this!"


                              Intermission:
Time: 041-1114  0750 hours Local
Location: At the 100 diameter line above Efate/Regina/Spinward Marches

   Despite various warning lights throughout the trip, Gamla Bettan exited 
jumpspace in no worse condition than usual, and at the intended place. 
Everyone was gathered on the bridge, even Schmallhaussen who had spent the 
entire jump-time in bed.
   "I can see Efate!" Troop said when he found the small, blue-gray, orb 
contrasted against the black background.
   "3 hours 50 minutes and we will get comparatively fresh air again"
   "That's not important, Moeller, What's important is that in just four hours 
we can buy every weapon we can dream about" Troop said starry-eyed.
   "No," Schmallhaussen corrected them, "Most important is that we in four 
hours will get...*Real* food!"
===============================================================================

- - -bertil-
- - -- 
>From the foolfile:
"The Baltic states are not occupied"  -  Swedish Foreign Minister Sten Andersson

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

Archive-Message-Number: 2142
Date: Tue, 12 Feb 91 12:51:49 -0500
From: al646@cleveland.Freenet.Edu (T. L. Hayes)
Subject: Jump Distances and Psionics



I have been reading with some interest the discussion on 10/100 diameter
jump limits.  I continue to jingle my 2 cents but I'm not ready to toss them
into this...yet. :-)  On a related topic, however, has anyone considered
what would happen if a ship were heading out toward a safe jump point and 
suddenly another ship "appeared" (ie dropped out of jump) right in front of
it?  Certainly neither ship could stop nor maneuver in time to avoid the
impending collision.  It seems that there should be designated travel lanes
for outbound and incomming vessels as well as intra-system travel lanes for
boats doing interplanetary travelling.  The outbound lane would naturally
end at a jump zone (at a safe jump distance whatever that may be) and the
incomming lane would start at a safe jump exiting point.  All ships would
then be guided and controlled by the Space Traffic Controllers who would
have regions of control within the system (and no doubt a union).  Then for
most planets (those with Starports of types C or better at least) the Ref
could simply use the 100 diameter travel time as a lower bound on the time
to travel to the safe jump point.  (Ref: "Following the instructions given
you by the Regina Space Traffic Controllers you reach the safe jumping
point in 22 hours and 15 minutes.  You a 15th in line for jump." ;-) )
This doesn't solve the 10/100 problem because not all planets will have
controllers and if you are running for your life from the local authorities
(or some one else) you're unlikely to wait for permission to jump out system
let alone worry about reaching a safe jump point (Imperium Marine Force
Commander: "Add the following moving violations to the list of charges...")

Now on a totally different topic - Psionics.  Impromptu survey:

1) How many people use Psionics in their games?

2) Do you use standard Psionics or some modification (includes added or
   deleted skills or a different system altogether)

3) Is there any interest in some additional Psi skills?  I have some that
   I have been using and (so far) they haven't disrupted the game (read
   unbalanced) or dominated it.  They use standard MT Psi system (task
   rolls etc).  If anyone is interested in seeing them let me know.

4) Do any of you have any additional Psi skills that you could post or send
   to me?  Standard MT Psi system only please.  Also let me know if these
   have been "play tested".

Later

TLH

- - --
T.L.Hayes                  |  Personal Mail: hayes@ll.mit.edu
MIT/Lincoln Laboratory     |              - or -
Lexington, MA              |  General Mail : al646@cleveland.Freenet.Edu

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

Archive-Message-Number: 2143
Date: Tue, 12 Feb 91 13:13 EDT
From: METLAY@vms.cis.pitt.edu
Subject: 100 Diameters....I think....*BOOOOOOOOM*


Martin's bit of technospeak is a nifty way to slap a bandaid
justification on why jump drives follow the 100-diameter rule;
I'm going to plug in some other numbers and work out if the
"coincidence" carries to other possible situations. Martin, have
you worked out the math for jumping away from, say, Jupiter? Or
Pluto? What about nearby moons of significant size?

Personally, though, I think I'm going to mess with the 1/r**2
critical point a bit and see if I can come up with something
reasonable for TDR....

metlay

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

Archive-Message-Number: 2144
From: Mark F. Cook <markc@hpcvss.cv.hp.COM>
Subject: New MT software on Sunbane
Date: Tue, 12 Feb 91 16:26:24 PST

I've just added 2 software packages to the traveller archive on Sunbane
(and updated a 3rd one), which should help ease the load on you busy
MT referees.

First, there's a C program called 'tnc' (for 'trade-n-commerce') which
automates the tedious trade & commerce drugery of randomly generating
freight, cargo, and passenger lists for your merchant players.  The
program is interactive and requires that you know the UWP for your
source and destination star systems, along with skill levels {Admin,
Streetwise, Broker, Liaison, & Steward} used by your players to modify
the results.  The program, along with documentation and a Makefile,
are in ~ftp/pub/traveller/software/trade.tar.

The second program is called namegen, and generates random words/names,
based on patterns formed by the contents of a template file.  If you
want a list of vaguely oriental-sounding names, just give a list from
your telephone book to namegen and it will crank out permutations based
on that list.  The source, along with documentation, a Makefile, and
an ~1200-line names template file, are in ~ftp/pub/traveller/software/
namegen.tar.

The third program is an updated version of the X-windows base subsector
viewer program, 'ssv'.  This new version allows you to include political
borders in the datafiles, so that they don't have to be re-rendered by
hand each time you regenerate a subsector.  As a result, a '-p' parameter
has also been added, so that a printer file can be produced directly
without the subsector actually being displayed in a window.  The new
copy is located in ~ftp/pub/traveller/software/ssv.c.

Have fun with these things and please let me know about any defects
you find.  I can't fix 'em if I don't know about 'em! :-)

Later,

        - Mark F. Cook (TDR Archivist)

USMail: User Interface Technical Support
        Hewlett-Packard - Interface Technology Operation
        1000 NE Circle Blvd.  Corvallis, OR 97330

INTERNET: markc@hpcvss.cv.hp.com
          markc%hpcvss.cv.hp.com@relay.hp.com

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

Archive-Message-Number: 2145
Date: Wed, 13 Feb 91 12:48:39 -0600
From: bonnevil@acc.stolaf.edu
Subject: Re: Jump Distances and Psionics


I agree that an Insystem Traffic Control organization would be a vital
necessity for a busy system, especially in two critically dangerous
areas -- everything within the approaches to the main world in the
system, and at the system's primary gas giant.  The chance of hitting
a ship leaving jump as one approaches a jump point is pretty small,
especially in low-traffic systems.  Space is big; I leave it to the
math people to figure out the area of a 100-diameter sphere about a
typical planet, and compare that to the area of a typical starship.
But near a gas giant, you have many ships swooping around at high speed,
who don't know much about the weather down there and are flying nearly
blind as they try to refuel.  Near a main world, traffic would be even
worse; communications sats, weather sats, power sats, restricted orbits
for military use, shuttles, stations, other ships landing and lifting,
suborbital or low orbital surface-to-surface flights, debris from
centuries of space travel, and so on.

Some low tech or remote planets wouldn't need much at all, though.  When
one ship visits a week and you don't have aircraft yet, the sky should
be pretty clear.

You'd still want approach/departure routes to the jump points in 
controlled systems, so that the risk of collision would be reduced.
But once the ship crosses a certain point, it should be more or less
free to file whatever flight plan works best.  Besides, it lets the
government know where it should put its patrol cruisers so that it
can check out incoming ships for customs violations....

By the way, I do use psionics, but very sparingly.  It's more impressive
that way, and gives the game more of a high-tech feel when its not
overdone.  Having it can be useful for little surprises like Zhodani
commandoes teleporting onto the bridge.

- - --Steve

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

Archive-Message-Number: 2146
Date: Wed, 13 Feb 91 16:52:10 EST
From: Dan Corrin <dan@engrg.uwo.ca>
Subject: Jumping near gravity sources.

In regards to the 100 diameter jump guide that I brought up:

First of all I will clarify the situation again.

	1) The whole point of the discussion is not to compe up with a
	   rationaliztion for the rules, rather to figure out an accurate
	   way to caluclate jump distance, so one can use it in unusual
	   circumstances. (eg. Jump distance from an unusually dense world,
	   gas giant, neutron star, or even a Battleship?)
	   
	2) The diameter is a approximation of the mass assuming that
	   all worlds have the same density. The small ones, usually
	   without an iron-nickel core are less dense however.
	   
	3) using 1/r^2 for a large planet (size 8-9, std. density), the
	   attraction of gravity at "100 diameters", is 1/20th the
	   gravity felt by the sun at 1 AU.
	   
The first suggestion proposed by Marty Jarrio, that we use a 1/r^3 method
is reasonable but is handwaving as "according to modern knowledge" gravity
follows a 1/r^2 method.

Calculating the gravity felt by the craft by summing gavity vectors of
significant bodies as Jim Baranski mentioned, has a nice appeal.

First, there will always be points regardless of the masses involved that
the net effect of gravity is less than a certain threshold, by adjusting
the threshold accoringly, we should be able to arrive at a value that will
make safe jumps best at around 100 diameters of the planet.

Second, There will be points, especially in a system with a large moon,
where a jump can be safely made much much closer to the planet, than 100
diameters. These would be small (perhaps even smaller than some ships),
and uncertain to use, which would limit their use. Ships could only use
these on an outbound leg as they would effectively be "islands" of
acceptable gravity level.

Third, in a talk given by Mark Miller, he always intended there to be a
limited (but large) number of points that a ship could jump from/to,
otherwise piracy couldn't exist (qv my other article in this digest).

The only bad part is that the points of low attraction between a habitable
planet and the sun, may also be "islands". Due to the fact that an incoming
ship precipitates out of jump space when it gets to "100 diameters" this
might make leaving quicker than arriving.


				-Dan Corrin



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

Archive-Message-Number: 2147
Date: Wed, 13 Feb 91 17:20:56 EST
From: Dan Corrin <dan@engrg.uwo.ca>
Subject: Jump collisions and velocities

T.L. Hayes brings up another point with jump procedures, one that leads to a
point that I was going to bring up after the 100 diameter limit got worked on
for a while.

> what would happen if a ship were heading out toward a safe jump point and 
> suddenly another ship "appeared" (ie dropped out of jump) right in front of
> it?  Certainly neither ship could stop nor maneuver in time to avoid the
> impending collision.  It seems that there should be designated travel lanes
> for outbound and incomming vessels as well as intra-system travel lanes for
> boats doing interplanetary travelling.

1) Travel zones would be a haven for pirates (assuming no overpowering
   military force in the system - but pirates assume that anyway :-)
   
2) All ships are supposed to jump from "rest". Ie. you accelerate half way
   to the jump point, and deccelerate the other half, so your ship is at
   "rest" w.r.t. the system you are in. In the case sited above the ship
   popping out would have a near zero velocity, and the one approaching
   near zeo. This should be an easy collision to avoid. A meteor, space
   junk, or comet however...

3) The chance of this happening would be close to zero. Considering the
   number of jump points available, and the sizes of the ships. Rember also
   that the ship would appear no closer than "100 diameters" of the outbound
   ship whatever distance that works out to...

Not all jump points are equal! Consider your ship with a zero velocity
w.r.t. the star coming out of jump. If you are travelling to a planet,
your would want to be conveniantly situated. ie. If you come out "100
diameters" behind the planet in its orbit, your would first have to accerate
up to its orbital velocity, and then try to close in the 100 diameters.
You would want to come out ahead of the planet in its orbit, thus the planet
will do most of the work by moving towards you at a good velocity.

This is not reflected in the travel times, however. (Unless you use the
pilot/navigator performance enhancement rules from the starship oerator's
guide). Even then I'd have to check the math.

This next part is based on poor knowledge, but presumably, one would want to
travel retrograde (behind the planet in its orbit) in order to get to safe
jump distance quickly. Thus one would have all the arrivals on one side of the
planet, and the departures on the other, therefore "space lanes" of a sort,
and no collisions.

Now for the can of worms...(all references paraphrased)

The rules state that a ship entering jump space with a velocity, will retain
that velocity when exiting jump space. This is why all ships slow to zero
speed...
For stars with large proper motions jumpspace negates the effect.
Right! Which is it? Are velocities preserved, or are they not? If you assume
that they are normalized w.r.t. each sun, as I have done in the past, then
why, considering that you are moving to a point where gravity and thus
the effects of the sun are inconsequential on jumping, are they normalized?


I'm sorry if I bother some people with these types of questions, but they
are not just looking for scientific explanations of game effects. They
are contridictions in the rules that should be explained in a semi-rational
manner. (actually people bothered by these questions probably won't have
read this far anyways).

				-Dan Corrin

Dan Corrin, System Manager, Mechanical Engineering, UWO, London, Ontario
TML/CZ FTP site coordinator:     dan@engrg.uwo.ca.        (519) 661-3834

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

End of TML Bundle
*****************

