
-------- TML Message #1218 --------

Archive-Message-Number: 1218
From: "Brent L. Woods" <woodsb@gn.ecn.purdue.edu>
Subject: Re:  TML Conventions
Date: Thu, 12 Apr 90 18:29:59 EST

 In message 1193, William Ricker writes:
 >
 >James & all,
 >
 >The suggested weekend, Labor Day, is the date for the annual World
 >Science Fiction Convention.

     True, indeed.  This would make a TML convention/meeting rather
inconvenient for me, since I usually work Worldcons.  Takes care of my
Labor Day weekends, eh?

 >So...  if you want to meet other TML subscribers:
 >(1) Check Analog's calendar and go to any local SF cons in your area,
 >and anywhere else you'd like to visit.

     I know of a better source for convention calendars.  I can post con
listings periodically (monthly?) if enough people would want it.

 >(2) Tell the TML where you going, so others going their can look for
 >you, and you can pick whose hotel room to have the party in.  (And also
 >arrange to share hotel rooms/driving etc.)

     By all means.

 >WorldCon 91 is in Orlando.  '92 is probably off-shore (I forget);

     Not quite right.  The upcoming (1990) Worldcon is in the Netherlands.  The
next (1991) Worldcon is in Chicago (Chicon IV).  The 1992 Worldcon is in
Orlando, Florida (Magicon).  If anyone wants the contact addresses, let me know
and I'll post them.  Even if you only get a supporting membership (*much* less
expensive than an attending), you can still vote on the Hugos...  :-)

 >San Francisco and somewhere inthe south-west are in the running for '93.

     Yup.  Personally, I hope San Francisco gets it.  I think rather highly of
their bid.

     For those who live in the midwest, there's Marcon, starting  on 18 May.
I'm going to be there, and I'm usually pretty easy to find (look for the FidoNet
SF echo room party).


- --
     Brent

INTERNET:  woodsb@gn.ecn.purdue.edu  /  USENET:  pur-ee!gn.ecn.purdue.edu!woodsb
FIDONET:  Brent.Woods@p303.f40.n201.z1.fidonet.org  (from Internet)  or
          Brent Woods@1:201/40.303  (from FidoNet)
USNAIL:  320 Brown St., #406  /  W. Laf., IN  47906
PHONE:  +1 (317) 743-8421 (voice)


-------- TML Message #1219 --------

Archive-Message-Number: 1219
Date:     Thu, 12 Apr 90 23:59:23 PDT
From: Orcinus orca <jokim@jarthur.claremont.edu>
Subject:  MT edition/GDW catalog

Well, after reading archived TML articles 1 to about 220 straight
through, I figured screw this.  It was taking too long and my brain
was getting confused between present and past.  So if I ask stupid
stuff that's been answered sometime between mid-1988 and a few
weeks ago, you guys are just gonna have to live with it.  :-)

I think I'll get MegaTraveller.  The store I used to get my Trav
stuff from doesn't seem to carry GDW anymore.  So I'd like to know,
has the second edition come out yet?  There seemed to be an awful
lot of typos, mistakes, missing charts, etc. in the first edition.
(Those posted erratta lists took an awfully long time scrolling by
at 1200 baud :-).

Anyways, I sent off for a GDW catalog.  If it has a listing of
alll the current Traveller stuff in print, would you guys be
interested in me posting it?

John H. Kim
jokim@jarthur.claremont.edu
uunet!muddcs!jarthur!jokim

-------- TML Message #1220 --------

Archive-Message-Number: 1220
Date: Fri, 13 Apr 90 11:59:49 MDT
From: SULAIMAN <asulaima@orion.cair.du.edu>
Subject: Fighting Ships


It seems that GDW has outdone itself again.What a wonderful useful peace
of recyclable material. This book is the biggest con since Judge's Guild 
went out of business. 

First all large ships have armour over 70. All Battleships rate their armour
as over 100. First this is illegal. At TL15 max armour is 75 as per ref's manual
+ a little more if you have a rock for a ship. Two even if this was legal
it gives all hits a minus 20! on the die roll because of armour. Basically
NO weapon except Meson Guns do any damage. They have PA battleships that are
said to stand in line of battle against other battleships. And do what,
pick their noses. "Sir our weapons are bouncing off of their ship.
"Dont worry ensign they aren't hitting us either. lets wait a week and hope
that Meson Gun ship shows up." Seriously your secondary weapon will ALWAYS
bounce off and your primaries MAY hit(only if he has armor 100 or less) on a
12.

Second They have carriers but with no launch tubes. Lets see we launch 1 fighter
every 20 min turn. In 2 weeks maybe we'll be able to launch our entire group.

They have tanker sqdns but no rules on how much fuel they can transfer per
unit time.

Most importantly there are no ships under 5000 t and only 2 of those. Except
for those 2 everything is 10ooot + ALL cruisers are 100000t. Unless u are 
running a Fleet campaign I see little use for the book in a campaign.

It appears that GDW just got a new spreadsheet program and went gonzo 
over it. Proofreading is at GDW's worst. Most ship designs have atleast 1
typo or error in it.

What is scary is that I have seen GDW products for 2300 and 1889 and they are
VERY professionally done. I fear that GDW might be trying to deliberately 
sabotage Traveller. Either that or the staff assigned to M-traveller is
at the bottom end of the game barrel.

My 0.02 dollars.
		
	Ameer Zaffar.

-------- TML Message #1221 --------

Archive-Message-Number: 1221
Date: Sun, 15 Apr 90 16:03:23 PDT
From: gwh%ocf.Berkeley.EDU@lilac.berkeley.edu
Subject: Fighting Ships

I'd like to put my fairly moderate two cents on Fighting Ships.

First: you can't deny that a lot of work went into it.  Fifty plus ships,
quite well done, indicates that Marc Miller did indeed put effort into it.  I
like the idea of tracing the evolution of combat vessels over time, and some
of the comments are quite telling.

Secondly: it corrects a longstanding discrepancy between estimated imperiumwide
naval budgets [simple calculation, everyone ought to have done this a long time
ago] and depicted naval force levels.  The ships shown make naval fleets that
are bigger and more expensive by about the right amount to correct the 
differences.

Third: despite the number of ships that are in it, it lacks depth in a lot of 
ways.  We are asked that imperial naval development produced no more than three
ships in the same size range [BB, Cruiser, whatever...] per tech level...about
a hundred years.  That, and a total abandonment of previously designed fighting
starship designes...[Marc! Where'd my Tigress go!?!? :-) ].

Fourth: there are some production and design flaws.  A lot of typos, most 
annoying to me being the appearance of a lot of spurious '300,00 tons is fuel
tankage for distribution.' lines, particularly irritating in 30kton Battle
Riders... :-)

Things like using spinal PA's can be forgiven; note that those are the 'light
battleships' not the mainline ones.  The armour factor violations...well, in
my humble opinion it's a) not the first time [check out 101 Vehicles, which was
approved] and b) a silly rule to start with.  now that mass _counts_, armour
is really its own penalty.

And a couple of observations...
	{SIGNIFICANT} almost ALL the main line ships have a Def DM of 7.  I 
have a feeling that this means something.  The gaming that GDW does internally
must (speculation) have shown that this is the best balanced level.  Note also
that most of the ships have agility=0 to not exceed that level.  This is counter
to my personal intuition, and someone should ask inside GDW and try and see
if i read this right.

	{FOR NORMAL PLAYERS, PERHAPS MORE SIGNIFICANT}  the imperial navy is now
WAY out of reach when it comes to 'player resistance to/attacks on' naval 
vessels.  

*******************************************************************************
George William Herbert              JOAT For Hire: Anything, Anywhere: My Price
   UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-)
- -------------------------------------------------------------------------------
"Who?" the man managed.                    "Whip me, Beat Me, Make me use C..." 
"The Rastafarian Navy," Case said,         ++++++++++ gwh@ocf.berkeley.edu  OR
"...and all we want is a jack into your    ========== gwh@soda.berkeley.edu OR
custodial system." -neuromancer            """""""" maniac@garnet.berkeley.edu

-------- TML Message #1222 --------

Archive-Message-Number: 1222
Date: Mon, 16 Apr 90 00:47:07 -0400 (EDT)
From: William Dow Rieder <wr0k+@andrew.cmu.edu>
Subject: Re: Fighting Ships

I don't have the book yet (local game store sold out - Grrr...), but I would
like to comment on one remark George made.

>{SIGNIFICANT} almost ALL the main line ships have a Def DM of 7.  I 
>have a feeling that this means something.  The gaming that GDW does internally
>must (speculation) have shown that this is the best balanced level.  Note also
>that most of the ships have agility=0 to not exceed that level.  This
is counter
>to my personal intuition, and someone should ask inside GDW and try and see
>if i read this right.

The reason all the main line ships have a Def DM of 7 is because it is the best
practical for a large, heavily armored ship.
Def DM = 9	(best computer available at TL 15)
	-2	(size mod for ships 100,000 tons or more)
	+0	(agility)
	= 7

	The reason that the agility is 0 is due to the heavy armor.  Even though
mass doesn't affect manuver drive performance (handled, along with many other
tasks, by the manuver drive physics nullifier box), it still is used for
agility.  Thus
the heavy armor makes it prohibitively expensive to get any agility bonus.
Example:  A 100,000 ton ship with an armor factor 100 bonded superdense hull
would mass ~1.535 E7 tons just for the hull. In order to get agility 1,
it would require
*spare* power of  ~2.84 E6 MW = 158,000 kl of power plant (11.7% of the ship)
plus 1,024,000 kl for a 30-day fuel supply (75.8% of the ship if you
really want to try).
	Armor that heavy does have the advantage of making you immune to
everything except meson guns, as was noted in a previous post.
	I'm sure I will find other problems when I finally get the book. (I wish
these things had warranties)

>George William Herbert 

					W. Dow Rieder

 	When the only tool you have is a hammer, all your problems
start to look like nails...

-------- TML Message #1223 --------

Archive-Message-Number: 1223
Date: Mon, 16 Apr 90 18:34:03 -0400 (EDT)
From: William Dow Rieder <wr0k+@andrew.cmu.edu>
Subject: Just add water

	In my search for ways to increase the cargo tonnage of merchant ships,
I discovered an interesting technique: Store most of the fusion plant
fuel in the form of water, and only refine it to hydrogen as needed. 
Water is a more space efficient way to carry hydrogen than LH2.  Since 1
kl of LH2 masses ~0.07 tons, and the mass of the hydrogen in 1 kl water
= 1/9*1 = ~0.11 tons, this results in a space savings of about 1/3. 
Most ships have fuel purification plants, and since they can refine
water obtained from ocean refuelling they can certainly refine water
already in the tanks.
	This tactic can be very helpful for power plant fuel, but jump fuel is
needed too fast (all burned in about 10 minutes) for the purification
plant to keep up.  Since the minimum size TL 15 plant purifies 200 kl in
6 hours, it should be able to handle almost any powerplant needs.  The
leftover oxygen can be dumped, used, or saved in excess tankage to
convert back to water with fuel skimmed from a gas giant.  Once a ship
has entered Jumpspace, the fuel for the jump has all been used, so the
water can be refined to LH2 and LOX.  I am assuming that the fuel
tankage for most ships is modular, so that you can have different fluids
in different tank sections (otherwise skimming and purifying would be
difficult).  In the designs I have done, I put in a small (5-10 kl) LH2
"buffer" for the powerplant fuel, and stored the rest as water.
	Hindsight makes this kind of obvious, and I think the only reason it
hasn't (to my knowledge) been noticed before is because the way an MT
manuver drive works is counterintuitive (ie only volume is important,
not mass).  In any drive that depends on mass, this won't work well
since 8/9 of the mass of water is oxygen, which is useless to the
powerplant.
	Any warship or explorer using this technique should probably have more
than one fuel purification plant in case one gets damaged or destroyed. 
Alternatively, they could just use a buffer large enough to get the ship
back to port for repairs.
	Another case where water can come in handy is for making multiple jumps
without refuelling.  Only the fuel for the one jump at a time needs to
be refined, saving 1/3 the space on the fuel for all subsequent jumps. 
Also if you are carrying fuel in collapsible tanks, it would seem to me
that water would be *much* safer and easier to deal with than LH2.
	What to do if you are a GM and don't like this: This is kind of tough,
since the only things needed for this to work are 1) - Purification
plants can handle water, and 2) - Manuver drives don't care about mass.
The only real way to get rid of it is to axe 2), which means throwing
out all the existing official ship designs, as well as making certain
types of ships impossible to build (ie anything with heavy armor).
	I'm interested in any comments or suggestions you might have.


					W. Dow Rieder

 	When the only tool you have is a hammer, all your problems
start to look like nails...

-------- TML Message #1224 --------

Archive-Message-Number: 1224
Date: Tue, 17 Apr 90 10:35:08 -0700
From: "Ted Kim (Random Dude" <tek@lanai.cs.ucla.edu>
Subject: Undigestifier


I like the fact that the digest messages only come in once a day. But
once I have read the messagers, I would like to save only a few.
That's when you would like to be able to undigestify them. Some people
use mailers that do it for them. Since I am currently using a low-tech
mailer (and am too lazy to switch just now), I am trying to find an
undigestifier program. 

Does someone have or know where an undigestifier is available?
Preferably, the program should be in C source form.

- -ted

#include <std/disclaimer.h>

Ted Kim                           
UCLA Computer Science Department  Internet: tek@penzance.cs.ucla.edu
3804C Boelter Hall                UUCP:    ...!{uunet|ucbvax}!cs.ucla.edu!tek
Los Angeles, CA 90024		  Phone:   (213) 206-8696

-------- TML Message #1225 --------

Archive-Message-Number: 1225
Date:     Tue, 17 Apr 90 11:27:40 PDT
From: Orcinus orca <jokim@jarthur.claremont.edu>
Subject:  Re: Just add water

I didn't believe it until I checked it out myself.  Yup, it works.
But why stop at water (OH2)?  Let your imagination run wild.

Ammonia (NH3)
  b.p. -28 deg. F (sorry about the English units, that's what
                   the book has).
  Density, liq:  42.6 lb/ft^3  =  .682 tons/m^3
  %wt of Hydrogen:  17.65%     (3/(14+1+1+1))
  Density of Hydrogen:  .120 tons/m^3

  About 1.70 times the hydrogen in the same space.
  (Density of H (LH2) is about .0708 tons/m^3)
  (Water worked out to about 1.57 times the hydrogen)


Methane (CH4)
  b.p.  -164 deg. C  (yup, these are in SI)
  Density, liq:  .5547 (not sure about this.  The table
                        also says .466 next to the gas
                        phase, but that is awfully dense
                        for a gas).
  %wt of Hydrogen:  25%     (4/(12+1+1+1+1))
  Density of Hydrogen:  .1387 tons/m^3

  About 1.96 times the hydrogen in the same space!
  Wow, almost doubled capacity!

Hmm, just found ammonia on another chart that says its
liquid density is .7710 tons/m^3 which would give a H
density of .1358 tons/m^3 or 1.92 times capacity.

A quick check into the thermodynamic properties of
these three (water, ammonia , methane) says:

143  kJ/mole to split H2O into H2 and O2
15.4 kJ/mole to splie NH3 into N2 and H2
18.7 kJ/mole to split CH4 into H2 and C(graphite)

Looks like it should be easier to extract hydrogen from
methane and ammonia than water.  Anyone know for sure?

I suspect methane is about the best you can do since it uses
four bonds with hydrogen--the normal maximum.  Of course, there
might be some superdense liquid or really messed up bond structure
out there that I don't know about.
- --
John H. Kim
jokim@jarthur.claremont.edu
uunet!muddcs!jarthur!jokim

-------- TML Message #1226 --------

Archive-Message-Number: 1226
From: Bertil Jonell <d9bertil@cd.chalmers.se>
Subject: More On Maps & The Emperors Clothes.
Date: Wed, 18 Apr 90 11:29:27 MET DST

I forgot about 10 planetary maps when I talked about maps published in the
Digest, but none of them are maps of major worlds.
There *is* a system survey of glisten, which I'd say is a semi-major world,
but this is the only system survey that dont include a surface map.
(for obvious reasons :-)

And, about the major breakthrough in starship fuels I have to lift on my hat
for William Dow Rieder. 

Now we'll just have to convince GDW about the advantages of using hydrogene 
stored as water or methane (methane is free for taking at a normal GasGiant,
I think) and watch a revolution in starship design take place.

Seriously, I am rather pessimistic about getting any kind of official adaption
of this scheme. How would they explain that nobody had used this method 
before?

- -bertil-
- -- 
Bertil K K Jonell @ Chalmers University of Technology, Gothenburg
NET: d9bertil@dtek.chalmers.se 
VOICE: +46 31 723971 / +46 300 61004     "Don't worry,I've got Pilot-7"
SNAILMAIL: Box 154,S-43900 Onsala,SWEDEN      (Famous last words)      
"Optional BMG (which is usable when the AFV is HD across its VCA) and AAMG are
available as of 7/44 with RF of 1.3" - Advanced Squad Leader about the StuPz IV

-------- TML Message #1227 --------

Archive-Message-Number: 1227
From: Adrian Hurt <adrian%cs.heriot-watt.ac.uk@nsfnet-relay.ac.uk>
Subject: Re: Wimpy Gauss Weapons
Date: Wed, 18 Apr 90 10:09:39 BST

Mark F. Cook writes:
>							      When the player
> in question discovered that the Gauss Rifles (TL 13) aboard their starship
> couldn't penetrate Battle Dress or Combat Armor from the same tech. level,
> he pointed out that this would be like sending soldiers into battle with
> flak jackets, and arming them with weapons that couldn't kill an enemy
> wearing the SAME flak jackets.

> <Penetration tables deleted to save space>

>		  The gauss rifle in particular has been significantly watered
> down from it's original descriptions in Classic Traveller (Mercenary) and
> Azhanti High Lightning.  Does this mean that gauss rifles are passe as battle-
> field weapons?

In Mercenary and Classic Traveller, the to-hit and penetration rolls were
combined.  The gauss rifle's rate of fire was what made it so lethal, not its
penetration.  I don't know the figures for Azhanti High Lightning, but the
similar Striker system used the same figures as MegaTraveller.

Perhaps the combat armour was developed later in TL12 than gauss rifles, as a
defence against them?  Or maybe the gauss rifle is for use against less
armoured targets, e.g. civilian criminals, or low-tech societies you want to
conquer; and against serious opposition, you use laser rifles.

I still think that either the gauss weapons fire high velocity, i.e. supersonic
rounds, in which case they aren't silent except in vacuum or near vacuum; or
they are silent, therefore subsonic, therefore should have even lower
penetration values.  Even present day pistols fire bullets which move faster
than sound; silencers have to slow down the bullets, which is why silenced
weapons aren't as powerful - and why low-powered, subsonic weapons are more
easily silenced.  Gauss weapons could be fitted with a switch controlling the
current into the coils, so you could have a choice.

Actually, it's probably down to game balance again.  If a weapon with the
penetration to breach high-tech battledress and high rate of fire appears,
all the munchkins will trade in their PGMP's for such devices.  You either
get high penetration, and need the skill to use it; or you get lower
penetration, but it's easier to hit things.

> This brings us to the next topic: AUTOMATIC WEAPON FIRE.
> 
> First, some weapons (i.e. Gauss Rifle and Pistol) have specific auto-fire
> numbers given in the Imperial Encyclopedia (4 for the pistol, 4 or 10 for
> the rifle).  Should these be used instead of the standard 5 listed in the
> Players' Manual.

Yes.  IMHO, of course!  Mind you, I graduated on Striker, where all weapons
had their individual DEX and autofire modifiers anyway.

> Second, if multiple targets are available, and you hit the primary target,
> are the adjacent targets hit automatically or must you reroll for each?

The Striker system was, for every 2 by which your roll exceeded the required
number, you hit an extra target.  My system was, reroll for each, with a DM
of -2 for the second target, -4 for the third, etc.

> Third, if you are in auto-fire mode and there is only a single target,
> is he hit by all the auto-fire rounds?  If not, how many hit?  Do you
> roll a separate attack for each round?  Are there any die modifiers
> (positive or negative) for successive rounds?

The Striker system was, you chose the size of group you were firing at.  If you
got multiple hits, they were divided evenly among the target group.  If you
were only firing at one individual, he got the lot.  My system was, the
second, third and other targets could be the same as the first one.  The -2, -4
modifiers still applied though.  So, for a burst of 4 rounds, I could fire two
shots at the main target (1), one at the guy on his left (2), and one at the
guy on his right (3).  The first shot at target 1 is unmodified; the second
shot at target 1 gets a DM of -2; the shot at target 2 is at -4; the shot at
target 3 is -6.  Add on appropriate autofire, skill and DEX modifiers as well.

- -- 
 "Keyboard? How quaint!" - M. Scott

 Adrian Hurt			     |	JANET:  adrian@uk.ac.hw.cs
 UUCP: ..!ukc!cs.hw.ac.uk!adrian     |  ARPA:   adrian@cs.hw.ac.uk

-------- TML Message #1228 --------

Archive-Message-Number: 1228
Date: Wed, 18 Apr 90 09:28:02 EDT
From: Dan Corrin <dan@engrg.uwo.ca>
Subject: Re: Just add water

John H. Kim writes:

>Ammonia (NH3)
>  %wt of Hydrogen:  17.65%     (3/(14+1+1+1))
>  About 1.70 times the hydrogen in the same space.
>  (Water worked out to about 1.57 times the hydrogen)
>
>
>Methane (CH4)
>  %wt of Hydrogen:  25%     (4/(12+1+1+1+1))
>  About 1.96 times the hydrogen in the same space!
>  Wow, almost doubled capacity!

This is an interesting breakthrough in starship design. 
Sell your stock in refined fuel companies!
The facilities should be designed to allow sufficent fuel capacity if
water was being used, as the other gasses may not always be avaiable. 
Thus is methane is designated as providing a 30 day supply, then Ammonia 
would give you 26 days, and water 24 days, this should be plenty.

This brings up three points:

First: Are there any astophysicsts out there who can describe the
strucutre of a gas giant. i.e. what gasses are found at the top of the
atmosphere, how far down do you have to go to get ammonia, or methane? 

Second: If a load of mixed gasses come in to the tank, can the
refinery eliminate the unwanted material, and leave ammonia water or
methane. They are designed to extract hydrogen, and dump everything else.
Would two purifiers be necessary? One to sort the incoming wilderness
fuel, and the second to provide hydrogen for the holding tank.

Third: Another method of saving fuel space is logically considering
the energy usage of a ship. The fuel consumption is based on full output
24hrs a day for 30 days. Warships in particular devote a lot of energy to
weapons screens or agility.
We know that the fusion engines can vary their fuel consumption, as the
idling rules imply. anyways if you don't agree with this, then you can
always designate two fusion engines, one for the consant energy, and the
other for the on-demand energy.
Thus only allocating fuel for 12-48 hours of combat, a reasonable 
assumption I believe, even more fuel savings can be made.

			-Dan

Dan Corrin, System Manager, Mechanical Engineering, UWO, London, Ontario
TML FTP site coordinator:  dan@engrg.uwo.ca   ...!watmath!julian!engrg!dan




-------- TML Message #1229 --------

Archive-Message-Number: 1229
Date: Wed, 18 Apr 90 09:46:01 EDT
From: Andrew Salamon <salamon@sun.udel.edu>
Subject: RE: Undigestifier

I would like a undigestifier as well, any pointers would be appreciated.

Magic in my Mind                     |   /Andrew/
Music in my Heart                    |   soi-disant Bleydion op Rhys
Laughter in my Soul                  |   salamon@sun.acs.udel.edu
And...A Sword in my Fist (sigh)      | 

-------- TML Message #1230 --------

Archive-Message-Number: 1230
Date: Thu, 19 Apr 90 02:49 EST
From: Ministry of Silly Minds - Open for Business <GDS3939%RITVAX.BITNET@cornellc.cit.cornell.edu>
Subject: Meeting at Conventions


Well, I don't know whether anyone has heard or us before or now, but Rochester
Wargamers Association & Guild(RWAG) sponsers a Roleplaying and Wargaming
Convention every year at the Rochester Institute of Technology in Rochester,
NY.  RUDICON 6 will be held this October 19-21 at RIT.  I will definitely be
there, and, if anyone's interested, the MegaTraveller adventure will be written
by myself.  It's almost done, and I think things will be quite interesting.  If
anyone wants more information, just contact me.  LaTeR.

Gary Schreiber
gds3939@ritvax.bitnet
gds3939@vaxc.isc.rit.edu
gds3939@ultb.isc.rit.edu
jedi@drycas.bitnet
jedi@drycas.club.cc.cmu.edu

PS - If you want, you can write directly to the club for more info.  The
address is below:

        RWAG
        c/o Student Directorate
        1 Lomb Memorial Dr.
        Rochester, NY  14623

-------- TML Message #1231 --------

Archive-Message-Number: 1231
Date:     Thu, 19 Apr 90 10:48:32 PDT
From: Orcinus orca <jokim@jarthur.claremont.edu>
Subject:  Skimming Fuel (was: Just add water)

>Dan Corrin <dan@engrg.uwo.ca> writes:
>
>First: Are there any astophysicsts out there who can describe the
>strucutre of a gas giant. i.e. what gasses are found at the top of the
>atmosphere, how far down do you have to go to get ammonia, or methane? 

That's what the Galileo mission is for.  It will drop a probe into
the Jovian atmosphere and we will (hopefully) get our first "cross
section" of a gas giant's upper atmosphere.

But I don't think you guys want to wait until 1996 (or whenever it's
supposed to get to Jupiter) so here's what I dug up in back-issues
of magazines.  Remember, it's all theoretical right now.

Jupiter:     ammonia crystals (white)              Top
             ammonium hydrosulfide crystals (brown)
             water ice crystals ?
             liquid Helium/Hydrogen

Neptune:     Diacetylene clouds                   Top
             Acetylene clouds (CHCH)              20 km down
             Ethane clouds (CH3CH3)               50 km down (from top)
             Methane ice cloud (CH4)              150-200 km down
             Hydrogen Sulfide cloud (H2S)         20 more km down

I suspect the really high atmosphere stuff is determined from the
radio-occultation of Voyager II behind Neptune, so it is probably
valid.  The rest (100 km+) is probably a good guess from spectro-
scopic analysis of sunlight reflected from the atmosphere.

My magazines don't go back to the Voyager-Jupiter/Saturn encounters
(heck, I was only 12 back then) so if you really want to get into
this stuff, dig up some good science mags (esp. Sky & Telescope,
Astronomy) of the Voyager encounters.
Jupiter:'79-'80  Saturn:'81-'82  Uranus:'86-'87  Neptune:'89

I think I'll ask the guys on sci.astro

>Second: If a load of mixed gasses come in to the tank, can the
>refinery eliminate the unwanted material, and leave ammonia water or
>methane. They are designed to extract hydrogen, and dump everything else.
>Would two purifiers be necessary? One to sort the incoming wilderness
>fuel, and the second to provide hydrogen for the holding tank.

Separation of all this gobbledygook shouldn't be a problem.  Most
of the stuff seems to be in solid or liquid phase so all you do is
raise the temperature and each material boils off at its respective
boiling point.  (It isn't really this simple but it'll do for most
game purposes.)

What I don't know is how you go about separating ammonia into
nitrogen and hydrogen gas (or methane into graphite and H gas).
Hydrolysis works with water, but I don't know about the other two.
(I am not a chemist.  I've been looking up these numbers in a CRC.
I hate chemistry.  No, I'm not an astrophysicist either.  Just an
engineer-in-training who had to learn this separation stuff.)

Hey, just had a thought to add realism to the game.  In real life,
separation/refining takes lots of time (like using a still to make
alcohol) unless you use really big machinery.  This is a physical
constraint, so higher tech levels will only help a little.  (Maybe
I'll run that program my school has that simulates chemical processing
and separating systems.)

So... why not add a time penalty to refine this stuff after you get
it from a gas giant.  That way, if you regularly skim fuel, not only
are you risking a misjump, but you're going to have to wait a few
hours before you can jump away from that patrol cruiser on your tail.

And since only 5%-25% of the stuff you skim is really hydrogen,
make 'em go back into that gas giant where they know three system
defense ships are lurking!  Then make 'em go back five more times
before their tanks have enough hydrogen to make a jump.

I think this would cut down on players skimming fuel.  I always
hated how players would say "What?  500Cr/ton for fuel?  No thanks,
I'll just hop over to a GG and skim it."
- --
John H. Kim
jokim@jarthur.claremont.edu
uunet!jarthur!jokim  <--Yes, it's changed.  muddcs is gone.

-------- TML Message #1232 --------

Archive-Message-Number: 1232
Date: Thu, 19 Apr 90 15:55:53 EDT
From: Chris Bartlett (Mouser) <cdba_ltd@uhura.cc.rochester.edu>
Subject: Methane vs. hydrogen, etc.


Excuse me, but I don't understand how you can have more hydrogen in one
cubic meter of liquid methane than in one cubic meter of liquid hydrogen.
Just how is this accomplished, or did I miss something in Chemistry class?
In one meter cubed of LH2, it's ALL hydrogen, right?  Now in one meter cubed
of NH3, it's not all hydrogen, but some of the space is taken up by nitrogen
atoms.  So how can you save space by carrying methane, or anything else?

Hmmm?

Chris



-------- TML Message #1233 --------

Archive-Message-Number: 1233
Subject: Re: Methane vs. hydrogen, etc. 
Date: Thu, 19 Apr 90 13:24:32 PDT
From: James T Perkins <jamesp@metolius.WR>


Chris, I tend to think you're correct.  Liquid H2 has a density much
lower than that of CH4.  CH4 molecules are not much bigger than H2
molecules, but contain twice the number of hydrogren atoms.  Also, the
forces that cause the molecules to liquify may be stronger in the CH4,
so the CH4 molecules are more closely packed.  I think this is likely;
doesn't CH4 liquify at a higher temperature than H2? Wouldn't more polar
molecules do even better, getting real friendly with each other (oops
they just solidified)?

Sorry, my chemistry's a little rusty too.

James

-------- TML Message #1234 --------

Archive-Message-Number: 1234
Date: Thu, 19 Apr 90 16:07:54 EDT
From: Chris Bartlett (Mouser) <cdba_ltd@uhura.cc.rochester.edu>
Subject: Methane, etc. a slight error


Oops, in my previous posting, I made the mistake of giving the formula for
ammonia, NH3, when I was talking about methane, CH4.  Either way, the result is 
the same. 

Chris


-------- TML Message #1235 --------

Archive-Message-Number: 1235
From: Bart Massey <bart@fatal.tv.TEK.COM>
Subject: DANGER: Mass-Independent Drive Is Perpetual Motion Machine
Date: Thu, 19 Apr 90 15:43:35 PDT

> ...the way an MT manuver drive works is counterintuitive (ie only volume is
> important, not mass).  In any drive that depends on mass, this won't work
> well...

Aiigh.  I don't know my Traveller well enough to comment very authoritatively,
but if the above statement is true, a Traveller perpetual motion machine
(i.e. an infinite energy source) exists.  Proof:

Take a body with finite volume V and mass m.  Let the energy required by the
maneuver drive to move the body a distance h against a gravitational field
of constant g be E(V,g,h) .  For a practical drive, there must exist a V,g,h
such that E(V,g,h) is finite.  Choose such a triple.  Note that the energy
gained in moving the body downward from a height h in the field by
conventional means (i.e. dropping the body :-) is mgh .

Thus, one can construct an engine whose energy consumption per cycle is
E(V,g,h) - mgh .  A perpetual motion machine can be constructed if there
exists an m such that E(V,g,h) - mgh < 0, i.e. m > E(V,g,h)/gh .  But for
fixed V,g,h the RHS of this inequality is constant, and we can make m
arbitrarily large -- Q.E.D.

Note that the energy yielded by such a machine increases with increasing m
for any given V.  Thus, one apparently wants an extremely dense object to
act as a piston in this machine...  Note also that such a machine could
apparently fairly easily realize a Doomsday device for the entire Traveller
universe (proof left to the reader), and thus had probably better not exist...

					Bart Massey
					..tektronix!videovax.tv.tek.com!bart
					..tektronix!reed.bitnet!bart


-------- TML Message #1236 --------

Archive-Message-Number: 1236
Date:     Thu, 19 Apr 90 22:17:08 PDT
From: Orcinus orca <jokim@jarthur.claremont.edu>
Subject:  Methane Correction--Ammonia takes top honors

As per request:
            Liquid Hydrogen     Water        Methane       Ammonia
Property         H2              H2O           CH4           NH3
- -------------------------------------------------------------------
Boiling point
            C  -252.87           0.00         -164.0        -33.35
            K    20.28         273.15          109.15       239.80
Density at b.p.
     (kg/m^3)    70.0         1000.0           424.         682.1
# of molecules
  (moles/m^3)    34724         55508          26429        40052
# of H atoms
  (moles/m^3)    69448        111016         105716       120156
- --------------------------------------------------------------------
ratio
  (LH2 = 1)        1          1.599          1.522         1.730

These are the correct numbers at the respective boiling points.
The densities are bound to change with temperature, but I don't
have those sorts of charts handy.  Oh yeah, all at 1 atm.

Apparently I was in error about the density of Methane.  Too
bad.  Ammonia takes the top spot again.  Hmm, what about solid
methane and ammonia ice...

The numbers are from the CRC Handbook of Chemistry and Physics,
67th edition, 1986-1987, page B-447.  Great book.  Everyone
should read it at least once through :-).

As James pointed out, all materials don't have the same number
of molecules per unit volume.  Sometimes the trend is counter-
intuitive (tiny H2 molecules occupy a lot of space).  I never
did well on that chapter on attractive/repulsive forces so that's
the best answer I can give.  Remember all that stuff you learned
about ideal gases?  Trash it.  It only works well for noble gases.
All the other gases act really strange.
- --
John H. Kim
jokim@jarthur.claremont.edu
uunet!jarthur!jokim

-------- TML Message #1237 --------

Archive-Message-Number: 1237
Date: Fri, 20 Apr 90 10:03:07 BST
From: Jo Jaquinta <jaymin@maths.tcd.ie>
Subject: 1,000,000 stars level 3

	Well level three is ready. A week early at that!
	For those that haven't been following, I have been writing
a progressive system of star generation. This is not to be confused with
the system design sublist who I believe are working on generating systems
astronically accurately by committee. What I generate is straight out
of the books.
	Level three contains almost all of the elements detailed in WBH.
Because of the wealth of data, presentation becomes a problem so there
are several subsidiary programs to display it in a variety of ways. The
core of the whole system is the routines that generate the linked list
representing the system. I wholeheartedly encourage people to use these
routines to generate their own programs to present the data in the way
they find most useful. I have many projects and ideas for development
that I am very eager for people to do while I work towards release 4.
	Level four is basically an extension to provide planetary maps.
Physical, temperature, population spread and so forth. I desperately
need someone who knows landscaping fractals, preferably on a triangular
grid. It is scheduled for release on the 1 June but without fractal 
algorithms it probably won't see light until 1 July.
	Just mail me for a copy. Please report any and all bugs.
	Enjoy,
				Jo Jaquinta
				jaymin@maths.tcd.ie

-------- TML Message #1238 --------

Archive-Message-Number: 1238
Date: Fri, 20 Apr 90 00:06:58 PDT
From: gwh%ocf.Berkeley.EDU@lilac.berkeley.edu
Subject: Re: why methane is more effecient and Re: mass independent drives

Methane vs LH2:
	Chris, the reason that you can store more hydrogen in liquid methane thathan in liquid hydrogen is simple: the volume per molecule isn't that much
different, even if there are five [one C and four H] vs. two [two H] atoms in
the molecule.  Since there are twice as many Hydrogen atoms in a methane 
molecule than in a hydrogen molecule [diatomic, only way it's stable in nature]
then you get twice as much hydrogen, though it weighs a whole lot more.
	I don't feel like going into gas and liquid theory enough to justify
the above, just remember that most of everything is empty space anyway :-) and
the ping pong balls bounce about like tennis balls do.

Re: mass-independent drives
	Interesting analysis.  This whole things points out a couple of
things some friends of mine and I have known and dealt with for a long time:
	Traveller isn't science.  A lot of it is pseudoscience that looks real
good. and

	If you bend things a little you can still make sense.  For instance,
at the beginning, things like hull armour weren't a factor, and so starships
tended very strongly to have a closely similar density.  When high guard came
out, they didn't want to deal with mass, so they continued that assumption.
Presumeably the 'armour really takes up volume' assumption helped to 
counteract that, but i haven't done an analysis of it myself...
	Then, with Megatrav, suddenly we have a problem.  Our starships now
are like everything else and _weigh_ something.  Oops, wow, our drives didn't
used to take this into account.  Two choices for the designers now: either to
cheat on reality [really just realizing that there's been an innacuracy in the
rules] and keep the drives consistent; or they could revamp them totally and
risk having starships that had been made earlier not work in the new system.
They chose to assume that ships really were still close to the same density,
continuing a known reality gap, but that way we can still make ships like we
used to...
	All you have to do to correct this is to follow allong in the 
assumption that the rule is valid under...have a ship within [relatively] 
reasonable densities.  As long as you don't armour it to hell and back, it'll
work fine.  If you demand reality anyway, kluge a rule yourself and ignore
the new Fighting Ships and you might as well write Marc Miller a nasty letter
about it too :-)

[oh, final comment about ship densities... FINALLY we have starships that 
weigh more then they displace in water. :-) old ships just couldn't sink, so
using them as submarines was a bit difficult :-)]

- -george


*******************************************************************************
George William Herbert              JOAT For Hire: Anything, Anywhere: My Price
   UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-)
- -------------------------------------------------------------------------------
"Who?" the man managed.                    Whip me, Beat Me, Make me learn C...
"The Rastafarian Navy," Case said,         ++++++++++ gwh@ocf.berkeley.edu  OR
"...and all we want is a jack into your    ========== gwh@soda.berkeley.edu OR
custodial system." -neuromancer            """""""" maniac@garnet.berkeley.edu

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

