Traveller-digest       Monday, June 16 1997       Volume 1997 : Number 1430



(R)1996. Traveller is a registered trademark of FarFuture Enterprises.
All rights reserved.

The following topics are covered in this digest:

Re: Fire in Space
PE Starport / Infrastructure costs
Re: A challenge for you all!!
Re: T4 Char gen system
Re: PE Starport / Infrastructure costs
Re: T4.1 Chargen: Increasing Skill points
Psionic Institutes Errata
Re: T4.1 Char gen system
Anyone in Costa Rica who plays Traveller?
Re: Thoughts on Traveller 4.5 (?) Character Generation...
Re: Pocket Empires question
Education and T4.1 Char Gen Checklist
Marc--FS Data?
Re: Quck Physics Question
RE:BG Fire in Space
Re: Quick Physics Question

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

Date: Mon, 16 Jun 1997 13:39:45 +0100
From: anders.backman@aniware.se (Anders Backman)
Subject: Re: Fire in Space

>    Now in space you have the natural ability to deprive Fire of one of the
>elements it needs.  The ambient tempature of the universe at large is what?
>Around 3 Kelvin if memory serves?  Starve the Fire of Heat and it stops.  Once
>that's done you can go in and figure out what has been in combustion and stop
>that cold and the fire is gone.  It's that simple and that complex. ;)

Fire does not need an external heatsource except for ignition (as everybody
knows) 3K background is irrelevant to the siiue. Your assertion about the
three requirements are however accurate. Turning off the floorfield will
reduce the amount of oxygen available to the fire but only if there hasn't
started a convection system. the best solution of course is to vent the
fire into vacuum but inhabitants of the burning locale might object to
that.


/Anders Backman
Aniware AB
anders.backman@aniware.se

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

Date: Mon, 16 Jun 1997 13:11:15 +0100
From: Nick Munn <N.S.Munn@sheffield.ac.uk>
Subject: PE Starport / Infrastructure costs

I quite like PE (though I'll like it more if/when I finish writing a 
C program to handle the tedious maths for me).

There's been a lot of talk about making starport and infrastructure 
costs dependent on population; frankly, I disagree.  Here's why:

Infrastructure is an absolute quantity.  If you have too much 
infrastructure for your population, it's too expensive to maintain 
(as per rules).  If it were not so, every time the population 
increases, you'll need to increase Inf.  Too much fuss for me...

I see starports as similar, in that building a "main" starport of a 
certain class also involves building a number of sub-starports of 
lower class.  It also involves the creation of infrastructure on the 
world.  If I upgrade to a D starport from E, not only do I build a 
D-port, I produce a network of cleared landing sites all over the 
planet.  That helps my expansion, of course...

The rules for calculating EE give an infrastructure bonus to planets 
with D starports or above; I extend this to mean that upgrading a 
starport also includes an infrastructure improvement or 
restructuring, of +1 level per level of starport upgrade from E.  
Class A and B starports, once built, add to the resources score of 
the planet as per the same table.

One way of understanding the rules is that the better the resources / 
infrastructure a planet has, the better the starport is likely to be, 
when the world is discovered.  Thus, planets shouldn't receive 
inf/res bonuses for developing better starports.  My counter-argument 
is twofold: one, it allows pre-existing worlds to have more resources 
than ones which are developed in the course of a (long) game can ever 
have, and two, starports create resources.

How do I mean that?  Starports generate income through sales 
of fuel, maintenance and (A/B) construction, and indirectly through 
supporting space exploitation.  The resources of gas giants and 
planetoid belts has already been allowed for (+G +B if space travel) 
but space-based industries have not.  The key point here is:

Resources are determined by demand, and demand is determined by the 
use of technology.

In other words, uranium is not a resource at TL 0, because there's no 
demand for it.  Wood, on the other hand, is a resource from all TLs, 
which can be used more or less effectively (as detailed in PE).  An 
orbital construction industry suddenly creates a market for e.g.
lanthanum, or organic supplies (even water), which may be of almost 
no resource value up until that point.

A starport causes an increase in supply (starships and related 
services) and demand (raw materials and lifesupport).  This certainly 
merits an increase in infrastructure, but IMO also rates an increase 
in resources, since it's infrastructure which wasn't needed and 
couldn't exist before the starport and its use of new resources.

Nick



 

Dr. Nick Munn, Dept. of Information Studies, University of Sheffield
Tel. (0)114 222 2673, email n.s.munn@sheffield.ac.uk

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

Date: Mon, 16 Jun 1997 10:04:28 -0400
From: "Chris Cox" <chriscox@ix.netcom.com>
Subject: Re: A challenge for you all!!

Goran, 

Actually your challege has already been meet by several members of this list
including myself.  Bruce Johnson, has deckplans for his 200-ton Yugo Box Far
Trader "http://www.u.arizona.edu/~bjohnson/traveller.html".  Andy Akins has
plans for his Akishu Irirkhan Class 300-ton Patrol Cuiser
"http://www.netins.net/showcase/theakins/andy/trav/trav.htm".  Paul Owensby's
had deckplans for his 200-ton Guppy Class Far Trader, howerver, I can't seem
to find his web page anymore, Paul?.  Finally you can find deckplans for two
of my THUDDD entries on my web page "http://users.aol.com/yanbeck/trav.htm".

Chris Cox
"Investment banking galley slave in New York City"
(chriscox@ix.netcom.com)
The Draconis Cluster Traveller pages
(http://users.aol.com/yanbeck/trav.htm)

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

Date: Mon, 16 Jun 1997 16:06:48 +0200 (METDST)
From: Hans Rancke-Madsen <rancke@diku.dk>
Subject: Re: T4 Char gen system

Marc Miller writes: 
>Edu and degrees are "decoupled." There are many people who have the knowledge
>equivalent of a university degree or a masters or something, but because they
>don't have degrees, they cannot work in academia, or get admitted to grad
>school.

OTOH. there are child prodigies that have already finished grad school by the
time they are 18. And I would imagine that it would be possible for some
cultures to press average children into learning grad level stuff before they
are 18 (the same way some cultures make children into soldiers before their
teens). I just wondered if the system would account for high EDU stats that
way.

>I know some people with that sort of knowledge but who cannot persevere in an
>academic environment and so don't have the degree to reflect it.

Fair enough. I just thought you ought to mention that in the text to avoid 
confusion. Also, what happens if such a person later does go to Grad School?
Would it be easier for him to graduate? (some self-taught people do go to
school precisely to get a certificate that they know what they already know).

I remember a Jack Vance short story where academic standards were so
different across the interstellar community that this planet's medical
authorities gave everybody, regardless of academic credentials, a test
before certifying them to practice medicine. The flip side was that if
you passed the test, you got the authorisation even if you didn't have
any credintials at all.
 
>I was tempted to make it possible for someone to get a degree but not the 
>Edu increase, but that was a bit too cynical.

Back when I ran a Naval campaign I fiddled a bit with the char gen. I
established minimum levels of skills for various ranks (f.ex. enlisted men
usually didn't get promoted until they had at least one MOS at level 2).
For officers, being of high social status added the same to your promotion
roll as having the appropiate skills at the appropiate level (being both
good at the job AND of high social status was even better, of course). So 
Captain Erakea Wois of HIMS (His Imperial Majesty's Ship) Mukhaldim had a
noble 2nd Officer who couldn't astrogate himself out of a paper bag. Wois 
and his 1st officer weren't too hot themselves. The best astrogator was an 
insufferable bridge ensign.
 
BTW. a completely general observation about T4: I was dissapointed that you
didn't make more of an effort to differentiate between general rules and
milieu-specific rules. This includes the benefits derived from mustering
out. TAS memberships and scout ships shouldn't, IMO, be as plentiful in
Year 0 as they are in Year 1100 (I was surprised to learn that the TAS
even existed in Year 0).


      Hans Rancke
University of Copenhagen
     rancke@diku.dk
- ------------
        "The referee should determine the nature of subsequent
         events based on the individual situation."
                                _76 Patrons_, p. 8

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

Date: Mon, 16 Jun 1997 10:18:24 -0500 (CDT)
From: "Joseph E. Walsh" <ransom@connect.iconnect.net>
Subject: Re: PE Starport / Infrastructure costs

On Mon, 16 Jun 1997, Nick Munn wrote:

> Infrastructure is an absolute quantity.  If you have too much 
> infrastructure for your population, it's too expensive to maintain 
> (as per rules).  If it were not so, every time the population 
> increases, you'll need to increase Inf.  Too much fuss for me...

That was the reason we decided not to have infrastructure and starport 
costs related to Pop, actually.  There was a lot of discussion about this 
during playtesting.  In the end, Stu and I opted for the playability 
route instead of the realism route on this one.  

The game was already becoming so complex as to make each turn take a 
great deal of time and effort.  There were several suggestions on the 
table for making the game even more realistic, but adding them in made 
it much much less playable. More than half the playtesters wanted the 
game to be simpler, while less than half wanted the game to be more 
complex.  Game design isn't a democratic process, but we felt the 
playtesters who wanted it to be simpler were better representative 
of the intended audience. So, we opted for playable, attempting to strike 
a decent balance between the two extremes.

In game terms, what you're doing when you increase Infrastructure is 
coating the whole planet in improved Infrastructure, in a sense.  Thus, 
the Size factor in that cost formula. It's not necessarily a uniform coat 
of Infrastructure; maybe two continents are increased by 2 points and two 
continents aren't increased at all, giving a total, planet-wide 
Infrastructure increase of 1 (assuming uniform population distribution).  
Essentially, that's what the game is modeling.

Finally, it's a trivial task to change the formula for using Pop instead of 
Size, for those who like complex, realistic rules.  We figured anyone who 
wanted to do so could easily modify the rules to suit their own 
campaigns.  Those who just wanted to play a fun Traveller game could use 
the rules as written.


> I see starports as similar, in that building a "main" starport of a 
> certain class also involves building a number of sub-starports of 
> lower class.  It also involves the creation of infrastructure on the 
> world.  If I upgrade to a D starport from E, not only do I build a 
> D-port, I produce a network of cleared landing sites all over the 
> planet.  That helps my expansion, of course...

Yes, you've hit the nail on the head.  The rules I'm working on right now 
for city generation show this effect.  If you have a B class starport in 
the UWP, you're going to have primary, secondary, and tertiary cities with 
better starports and/or spaceports than you would if your UWP starport 
was C class.


> Class A and B starports, once built, add to the resources score of 
> the planet as per the same table.

I see where your reasoning is coming from, but actually that's not the 
case in the PE rules.  Of course, I'm not trying to discourage you from 
using your variant rule; there's nothing wrong with that.  But, under the 
rules, Resources is a fixed valuation that is based on what exists 
on-planet.  The amount of resources you can extract and use varies with 
TL.  Thus, the .1*TL part of the GWP formula.  And, since the entire GWP 
formula uses multiplication (other than the divided by C+1 part), this 
affects Infrastructure as well.  TL and Infrastructure are inextricably 
linked.  Again, the cities rules (which include detailing rules for Pop, 
Gov, LL, TL, Resources, Infrastructure, Labor, and Culture) make this 
aspect of the rules evident to a much greater degree than does PE.

In PE, the + DM's for Resources based on Starport Type are merely 
expressing the tendency of planets with higher Resources to have better 
starports.  Working it the other way changes the meaning of Resources.  
Again, though, if that's how you want your universe to work, go for it. :)


One final note:  PE's economic rules could easily have been extended to 
make a whole book all by themselves.  There are a lot of complex 
interactions in there, as well as subtle inter-dependencies and effects. 
It will take most people quite a bit of time, study, and play before they 
fully understand every nook and cranny of the system.  Some of IG's 
future products will expand on the implications of the PE Econ rules, 
making them more obvious.  

I encourage those of you who are interested in this to stop by the PE 
walk-through on IRC this Thursday.  While Stu will be going through the 
whole book, I plan to be there as well, and we both hope to spend a good 
amount of time exploring the Economics section.


- -Joe
______________________________________________________________________________
Joseph E. Walsh  |  Game Designer for Marc Miller's Traveller
_________________|  Atari 1200XL and Apple IIGS User and Programmer

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

Date: Mon, 16 Jun 1997 08:59:55 -0800
From: Richard Hough <rdhough@orca.bc.ca>
Subject: Re: T4.1 Chargen: Increasing Skill points

>I number of people have compared the fact that the stat levels
>are bigger numbers than skills and have concluded that this
>means that they have a bigger effect.  This is a false conclusion.

I beg to differ. My conclusion that attributes (ie. stats) have a bigger
effect than skills in the published T4 rules is not based on comparing the
numbers of each, it is based on actually using these rules in the game. The
trouble is that tasks and DMs do not just depend on the total number of
attribute and skill points, they also depend on their variance from the
norm, the number of times they get used, and the modifiers available. And
in all these effects, attributes beat skills.

'Way back when I first got T4 I played using the published rules. Pretty
soon everyone noticed that the high-attribute characters were just
succeeding massively at everything they tried, regardless of the difficulty
of the task or what their skills were. Everyone else was a chump by
comparison. This may or may not be realistic, but definitely harmed
enjoyment of the game. My players soon learned to make all their character
generation rolls on the Physical and Mental development table since +1 Dex
was easier and better than getting +1 in every Dex-based skill. The effect
was that all the characters became very similar and the task results
unbalanced, so I had to use one of the alternate task systems

>What is important is the range.  If you have skills from 0-6
>and stats from 100-106 the stats are no more important than
>the skill.  Both have a range of 6, you are just adding 100
>to all the roles.

You are correct, the range is important. The range, or variance as I called
it in my post, determines the difference between a "good" skill from a
"bad" skill. If the variance was small, the difference between a "good"
pilot and a "bad" pilot would be minor. However, an average skill is around
2 and varies by 2 points or so. An average attribute is around 7 and varies
by 7 or more points (player characters tend to be on the high end of this
scale). This means two "skilled" characters can vary by as much as 10
points. This is an enormous range of variation, which is not bad. What is
bad is that most of the variance is from attributes, and almost none is
from the skill.

This means that one's skill level has little effect on how "good" you are
at doing things. For example, which do you think would be a better sensor
technician; a scout trained in the use of every known sensor technolgy
backed with years of experience, or some kid who took 1 course in college?
Answer: you have no idea. You have to know their Intelligence attributes.
The variability between different characters' Int is so large is swamps any
difference in training. I am not saying Int shouldn't count, I am saying
training should be an important factor and right now it isn't.

How so? First of all, using the published rules, skills do not have a range
of 6; they have a range of 2 or 3 and the distribution of this range is
heavily skewed to the low end of the scale. Attributes have a much wider
range, and at least for player characters, they are skewed toward the high
end.

Secondly, you do not add the extra attribute points "to all the rolls",
only the ones which use the attribute, and attributes are used more often
than skills. Therefore, 1 point in a attribute beats 1 point in a skill.
And characters start off with more attribute points than skill points. The
combination is overwhelming.

Third, it's easier to get a high attribute than a high skill. Smart players
will make almost all their character development rolls on the Physical or
Mental character generation tables if you let them. The probability of
increasing Dex is 1/6 on each roll on the Physical table for most careers,
while Dex-based skills are scattered among several tables so the
probability of getting a single high skill is low. Therefore getting high
attributes is easier and more beneficial than getting high skills. This
rewards munchkins and penalizes role-players.

>The system is identical to one where you
>have skills and stats both from 0-6 and you roll against
>100+skill+stat.

Alas, it is not. You see, it's not just attribute+skill you roll against.
Many times, like in the personal pools, the table DMs, the character
generation breakpoint DMs, action points from Snapshot, breaking grapples
or 'sticky gun' hits, and in may other cases, you do not roll a task. You
roll against a basic attribute, skill, or use one as a DM. In all these
cases using attributes gives you lots more points than skills. In your
example, it's like the 100 is added only when the attribute is included and
never when the skill is used.

Moreover, there are fewer attributes than there are skills. This means that
the extra attribute points get added to many tasks, while skill points are
only added to a few. If you have a high attribute you are simply
overwhelmingly powerful in many, many tasks. At the same time a high skill
is practically worthless; it only applies in a few instances, and cannot
make up for a low attribute unless skills reach double digits. This was the
basis for my claim that skills should be allowed to do so.

The result is the oft-lamented "Traveller Effect", where an English
professor picks up a jump drive manual and can suddenly make drive
modifications the designers themselves can't match. Or the olympic gymnast
who completes a first-aid course and can now perform heart transplants
better than Dr. Barnaard.

Moreover, our high-Edu English professor doesn't just outperform the jump
technicians, she also blows away every highly-trained mechanic, astrogator,
biologist, gravitics technician, and so on unless they also have a high
Edu. This may be appropriate for a "Gilligan's Island"-like campaign where
the "Professor" character can perform any technical skill well, but it does
not fit my campaign.

Simply looking at the target numbers and probabilites of the task rolls
does not give you a true indication of the relative effects of attributes
and skills. When the great Task System thread was going on I originally
made a claim similar to yours, that the difference in points did not
severely affect task outcomes. I was wrong. I didn't find this out by
talking about it but by actually trying out the various task systems
proposed in typical game situations.

Do you seriously claim that a character with Dex 15 and Vac Suit 1 and a
character with Dex 7 and Vac suit 9 are equally powerful? Go through the
rule book, comparing their performance on every Dex-based task, every table
and personal pool. Yet both require an equal number of rolls during
character generation. In the current T4 rules, attributes are vastly more
powerful than skills. The effect of this is to turn characters into limited
"Dex-class", "Edu-class" and so on characters. IMHO, this is the number 1
flaw with the existing T4 rules.

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

Date: Mon, 16 Jun 1997 09:19:48 -0700 (PDT)
From: "John R. Snead" <jsnead@netcom.com>
Subject: Psionic Institutes Errata

In Psionic Institutes a number of Special Psionics are described,
Antipsionic, Battery, Eidetic Memory...  The list of such abilities
contains an entry labeled Lightning Calculation.  Unfortunately, this
particular Special is not described in the text.  Since the authors of
this book are on the list, I'm wondering if any of them could post the
description of this ability.  It's not too hard t figure out what it does,
but I'd like to see the full T4-sytle write-up. 

Btw, I really like the write-up of most of the specials, though, as with
other versions of Traveller, I wonder about just how game- breaking
Invisibility is.  It's always been Canon (at least for the Droyne), but
it's pretty powerful too. 

As a final note, Psionics is the only aspect of T4 where I prefer TNE's
method of execution.  The TNE style of psionics, w/o Psi Points and
similar nonsense is, to me, much superior to T4 psionics... 


- -John Snead jsnead@netcom.com

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

Date: Mon, 16 Jun 1997 13:03:25 -0400 (EDT)
From: CardSharks@aol.com
Subject: Re: T4.1 Char gen system

In a message dated 97-06-16 02:45:06 EDT, you write:

<< Does that mean that a character who rolls a B on EDU is allowed to assume
 > that he has already gone through Grad School? Or that he will be able to 
 > breeze through it?  >>

It means he has the "equivalent" of a grad school education. But it doesn't
guarantee admission or even completion.

Marc Miller

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

Date: Mon, 16 Jun 1997 15:22:03 -0400 (EDT)
From: Daniel Rossi <drossi@axisol.co.cr>
Subject: Anyone in Costa Rica who plays Traveller?

Here's an oddball question...

Anybody out there who plays or knows of someone that plays Traveller in
Costa Rica?

I knew someone who did about fifteen years (Craig Lowen - if you're out
there pls write) but that was a little while ago.

This goes for any of the versions of the game. (I don't have much choice at
this point :-)

Thanks in advance for any help.


Daniel

_____________________________
A  X  I  S  O  L  S. A.
Axis Internet Solutions
http://www.axisol.co.cr

=46rom the desk of Daniel Rossi
drossi@axisol.co.cr

Worldbox CR: 2026
P.O. Box 379012
Miami, FL. 33137-9012
USA

Tel. (506) 223-1376

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

Date: Mon, 16 Jun 1997 14:10:06 -0400 (EDT)
From: FarFuture@aol.com
Subject: Re: Thoughts on Traveller 4.5 (?) Character Generation...

In a message dated 97-06-16 05:38:25 EDT, you write:

<< 
 (1) College and Advanced Degrees:
      a) Military/merchant personnel could be sent to college and advanced
schools during the course of a career. This would recommend the trend in US
military today where officers (and even NCO's) are requested/required to get
BA, BS, advanced degrees.

*** remember that anyone can get +1 Edu in the appropriate tables in chargen
during a career, as well as in muster out. This implies just what you are
saying, without defining it specifically.

       b) Characters should be able to get additional BA/S, MA/S, PhD level
degrees as long as they've got the credits and they make the rolls!

This seems to me tedious and not very adventuresome. Even for a scholar
character.

Marc

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

Date: Mon, 16 Jun 1997 12:18:11 -7
From: "Stuart L. Dollar" <sdollar@goodnet.com>
Subject: Re: Pocket Empires question

On 16 Jun 97 at 15:43, Brody  Dunn wrote:

> If I have a negative discretionary tax then does that increase my
> popularity ( Thinking about tax breaks for invaded worlds etc...)

My apologies.  This is perhaps not as clear as it should have been.

No it is not possible to have a discretionary tax which is negative.  
The only way to reduce tax below the Inf + Culture + Law is to reduce 
law and culture by the means described elsewhere in the book...

Stu
Stuart L. Dollar                sdollar@goodnet.com
- ---------------------------------------------------
Co-Designer of Products for Marc Miller's Traveller
Including the upcoming release:  Psionics Institutes 
- ----------------------------------------------------
"Resistance to Tyrants is Obedience to God."
- -Thomas Jefferson

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

Date: Mon, 16 Jun 1997 08:46:42 -0700
From: scharlto@ifsna.com
Subject: Education and T4.1 Char Gen Checklist

> Date: Thu, 12 Jun 1997 17:40:33 -0400 (EDT)
> From: CardSharks@aol.com
>
> Pursuing an ED8 certificate increases your Edu to 8.
> Going to an Academy will increase it to 9.
> Going to Univeristy gets you an A.
> Grad School gets you a B.
> Honors gets you+1 Edu.

This sounds like an improvement to me, but what happens with those lucky
souls who rolled a high EDUT to start with?  Does such a character get a
fixed plus to their rolled EDU? (+1 for the certificate, +2 for Academy, +3
for University, +4 for Grad Schhol and +1 extra for Honors, to a max of
15)?  I would think that otherwise there would be little reason for the
character with a natural 12 EDU to go to the University, except as a
prerequisite for Med School or something.

>Date: Sat, 14 Jun 1997 01:15:15 -0400 (EDT)
>From: CardSharks@aol.com
>Subject: Re: T4.1 Char Gen Checklist
>
>
>The character generation charts are now 20 pages (each a separate file) in
>Word For Windows 95. If you can read them, I will email them to you. I
want
>feedback on usability.
I would very much like a copy of this, which I would be happy to comment on
as much a possible/needed.

Thanks for the Sneak Peeks!
Steven Charlton

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

Date: Sat, 14 Jun 1997 18:01:23 +0000
From: "Kenneth Bearden" <dreamer@weck.brokersys.com>
Subject: Marc--FS Data?

> >They won't go into M0 hardback. They will be incorporated into the official
> >files. My intention is to post that as a text file somewhere (to make it
> >easier to search for your homeworld).

Marc, a question about the FS data....

I was under the impression, since it was being hashed out here on the 
TML, that the FS data in the M0 harback would be revised.

Am I reading this right?  Are you still going to publish the broken 
data in the new book?

If so, I've got two questions:  (1) Why has so many people been 
trying to fix this stuff if it is not going to be fixed in the 
hardback?  (2)  Why, after all of the hubbub on the TML are you still 
going to re-publish the broken data anyway?

I can tell you, if the M0 hardback does contain the broken data, I 
certainly won't buy it, and it will be the first T4  product that I 
haven't bought.

On the other hand, if the M0 hardback contains fixed data, I probably 
will get it--judging from my track record so far of buying everything 
that IG has put out.

Make me understand.

> Despite the fact that
> around a hundred of lines had minor or not-so-minor changes in my revised
> data, all the changes will easily fit in a single page. So, probably, all
> the revision to FS would fit in 8/9 pages. This means a 4/5 errata sheet,
> more or less the size of the old MT errata. Why don't include these errata
> sheet with the hardback and future sales of the FS stock?

Carlos is right here.  I wouldn't be completely happy if the FS data 
being re-published in broken format, but I'd be OK with errata sheets 
included in each product.  If that happened, I'd probably get the 
product.

Kenneth.

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

Date: Mon, 16 Jun 1997 13:45:17 -0700 (PDT)
From: Craig Berry <cberry@cinenet.net>
Subject: Re: Quck Physics Question

> Date: Sun, 15 Jun 1997 21:32:36 PST
> From: shadow@krypton.rain.com (Leonard Erickson)
> Subject: Re: Quick Physics Question
> 
> > 1.) The station suffers a sudden, sharp deceleration, dropping it below
> > orbital velocity.  The station's orbit begins to decay.
> 
> You slow the station. Which puts it in a *higher* orbit! I'm not
> kidding. Consider that a satellite at a 100 miles up orbits earth in 90
> minutes, but the moon at 250,000 miles orbits in 29 *days*.

Not quite right, though I know what you're thinking about.  If you push
"backward" against an object in circular orbit, it slows down, which puts
it in an elliptical orbit with the original circular-orbit altitude as
apastron and a new, lower periastron.  At that new periastron (180 degrees
away from where the impulse was applied) the object will indeed be moving
*faster* than it was in its original circular orbit.

Similarly, if you push "forward" on such an object, it winds up in a
larger elliptical orbit, with a lower velocity 180 degrees away at the
new, higher apastron.

BTW, "Orbital decay" is one of the most misused concepts in SF.  An orbit
in vacuum never decays; it just repeats indefinitely, or until perturbed
by some outside force.  Only orbits near enough to a planet to feel the
outer edges of an atmosphere decay, due to the tiny but constant drag of
the atmosphere. 

> > 2.) The airlock the cargo hauler is docked to likely crumples under the
> > sudden strain, possibly opening the hauler to space and parking it partway
> > into the station itself. (Providing it holds together.)
> 
> Likely. But maybe not. The forces involved aren't *that* far from what
> might happen if a big ship "bumped" the airlock in docking. So the
> docking ring may hold, but the hull of the hauler may not. So it might
> "crumple" around the docking collar.

I would imagine that docking rings/bays would be built very tough, to
withstand just this sort of mishap.  Also, the points directly in contact
with the vessel would be at least a bit elastic, to absorb shocks.  Think
about how both (most) docks and tugboats are lined with old tires, so that
things can run into them without either crumpling.  I can't see a good
reason why this wouldn't work in space (with vac-resistant elastics, of
course).

> > 3.) Everybody on the station not strapped down goes flying HARD against a
> > convenient bulkhead, console, etc.
> 
> Not that hard. Remember, due to the added mass the accel goes down.
> They'll be moving at all of 3 meters per second relative to the station
> (1/5th g for 1.5 sec = 3 meters/sec)

How fast they end up moving is far less important than the magnitude of
the acceleration.  Still more important is the acceleration's direction,
and how quickly the acceleration occurs -- the "jerk factor," as some
engineers call the latter.  If the acceleration is lined up with the
station's artificial gravity, then no problems at all should occur.  If
it's perpendicular, a ramp up to 0.2g over a few seconds won't cause
people to fall over, but might well topple glassware on tables and such. 
0.2g applied instantaneously and perpendicular to station g *will* knock
standing people over and cause other general mayhem among unsecured
objects.  (For comparison, by the way, 0.2g acceleration corresponds
roughly to a magnitude 6 earthquake -- though of course in an earthquake
the direction and magnitude of the acceleration is constantly shifting
from moment to moment.)

> Well, as I noted, you missed the fact that slowing down moves you
> *outwards*, and the fact that the extra mass drops the acceleration a lot.
> 
> That first bit is one of the many contra-intuitive laws of orbital
> mechanics, and explains why docking manuevers are so automated in the
> real world. Until you are practically on top of your target manuevers
> just plain don't work the way you expect them to.

Quite true about the counter-intuitive nature of OM...hope my
clarifications make sense.

- ---------------------------------------------------------------------
   |   Craig Berry - cberry@cinenet.net
 --*--    Home Page: http://www.cinenet.net/users/cberry/home.html
   |      Member of The HTML Writers Guild: http://www.hwg.org/   
       "Every man and every woman is a star."

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

Date: Mon, 16 Jun 97 21:19:00 GMT 
From: s.johnson107@genie.com
Subject: RE:BG Fire in Space

>> Post Scriptum; Yeah Battlestar Galactica mucked up the fire
>> in space episode, but then that was always a more visual show
>> then anything else. ;)
> What do you mean??? The stock fire fight film was from a 1950's
> refinery fire!
    Yup, no thought, rhyme or reason to it, just visually exciting images.
Well... interesting at least. ;) The whole show had holes big enough to fly the
Galactica through, but it did look good.  The poured the money into special
effects and tended to neglect little details like intelligent plot and logical
background.  Typical Hollywood Sci Fi, make it _look_ good and who will care
about all the other flaws. ;)
    And mind I _liked_ BG... when I was a teenager.

Stephen

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

Date: Mon, 16 Jun 1997 17:35:02 -0500 (CDT)
From: Joseph "Chepe" Lockett <jlockett@io.com>
Subject: Re: Quick Physics Question

Quoth Leonard Erickson:
> You slow the station. Which puts it in a *higher* orbit! I'm not
> kidding. Consider that a satellite at a 100 miles up orbits earth in 90
> minutes, but the moon at 250,000 miles orbits in 29 *days*.

That's only because the "sideways" velocity needed to continuously fall
"around" the Eath becomes less the further away you are (and thus, the
weaker the Earth's gravitational pull becomes) -- Newton did an early
calculation using just this analogy.  If your theory were true, then
braking a ship or satellite to _zero_ orbital velocity would presumably
suddenly cause it to shoot straight upward, no? 

When you "brake" in orbit, you are reducing your total energy (kinetic,
due to motion, and potential, due to height).  The two are related, and so
the loss of kinetic energy causes a corresponding loss of potential
energy: you lose altitude.  Some of that loss returns as kinetic energy:
you speed up as you approach the planet, and then "pay back" the kinetic
energy to potential as your elliptical orbit brings you back to the
original height where the braking took place. 

> That first bit is one of the many contra-intuitive laws of orbital
> mechanics, and explains why docking manuevers are so automated in the
> real world. Until you are practically on top of your target manuevers
> just plain don't work the way you expect them to.

Larry Niven's "smoke ring" novels (about life in an unusual free-fall
environment) have a nice children's ditty summarizing basic orbital
mechanics which, alas, I cannot for the life of me remember.

- ----------------------------*------------------------*------------------------
 Joseph L. "Chepe" Lockett  |"Nullum magnum ingenium | GURPS fan, Amiga user,
http://www.io.com/~jlockett | sine mixtura dementiae | Shakespearean scholar,
  Email: jlockett@io.com    | fuit." -- Seneca       | actor and director.

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

End of Traveller-digest V1997 #1430
***********************************
