FTL impossibilities, TDR stuff

A thread of 2 messages, 17 November 1990 to 27 November 1990, in the order they were sent.

#1800 FTL impossibilities, TDR stuff

Robert P Poole · 17 November 1990

Well, folks, I talked to a local Special Relativity guru.  Guess what?  All FTL
drive systems that rely on taking a ship out of our space-time and plopping it
temporarily in some "hyperspace" or "jump space" are going to violate
relativity.  (Specifically, you will invariably get reverse time travel.)
Here's why:

FTL, by definition, gets you from A to B faster than light can do it.  Once you
get to B, you can accelerate in normal space back to A until your velocity is
near c.  Start your FTL drive again, and you will arrive back at A in your new
reference frame, moving at just under c, some time before you left.  The only
way to solve this problem is to have ONE reference frame.  That is forbidden
under Special Relativity.

If you didn't follow that argument, here it is in a different form.  Say A is
the Earth, at noon.  Using your FTL, you jump to Alpha Centauri and arrive
there at 1 pm.  Accelerate in normal space toward Earth, get near c.  You are a
real stud and can take 40 G's of acceleration or whatever.  3 pm your time, 6
pm Earth time, but your reference frame still includes the Earth of two weeks
ago.  (Don't forget that information can't travel faster than light.)  Try
using your FTL again.  Whoops!  Back at Earth two weeks before you left.

What does this all mean?  Traveller doesn't work, nothing works, you are
doomed, SFRPG's will never be realistic.

Well, I think this underscores a more fundamental problem than all the physics
problems in Traveller.  Basically, folks, most of you have lost sight of the
fact that Traveller is a GAME.  In fact, it purports to be a ROLE PLAYING game.
If you're in it for space combat, tough shit.  There are many excellent space
combat systems available.  The point is to have fun.  Granted, some of the
inconsistencies grate on people's nerves, but when you get right down to it
there is nothing you can do without violating some laws of physics.

I'm not really flaming the efforts of people to make Traveller more bearable,
but what some of you are trying to do is model reality.  You can't do it.  I've
been watching all this talk about Black Globes and reactionless thrusters, and
I just have to laugh.  As long as you don't get a free ride (i.e., getting
something for nothing), what's the problem?  Who cares about the nitty gritty
details?  _I_ know the rules are "wrong," so do you.  {shrug}

Hopefully, the people who are going to spend all their time working on TDR will
realize that they are trying to fix the more broken aspects of Traveller
(trade, weapons, etc.) without losing sight of the fact that it is an RPG.
I applaud the effort.

As for ASCII, I can see how a lot of people would want to get straight ASCII
text and print it out.  I would recommend that the people doing this use Emacs
or else use a word processor that has an ASCII output option -- you're going to
want to use some kind of formatting for all those wonderful tables.

For those who want a nicer looking presentation -- something you can put in a
flex binder and show to people, or at least have readable -- I am willing to
put in my time and convert the final results into a machine-ready form so that
the docs can be typeset.  Then it is a matter of making the PostScript files
(or whatever) publically readable.  I would also be willing to make hard copies
and send them out via snail mail to whomever is interested in having nicely
typeset docs instead of unreadable dot matrix output.  (Just send me a check to
reimburse me for reproduction costs.)

And since no one on the TDR team is interested, I am willing to help coordinate
development of software for ship design, character generation, etc., assuming
that the TDR people are going to get all the algorithms to be self-consistent,
easy to understand, and amenable to computational algorithm.  Obviously, there
will be nothing to "jabber about and argue over until it dies of inertia" if
the TDR people do their jobs right.  IF.

I gotta see this.

Robert P. Poole                       [email removed]
[address removed]                     MIT Course VIII
311B Bexley Hall                      "We make Idols of our concepts, but
[address removed]                      wisdom is born of wonder."
                                         -- St. Gregory the Illuminator

#1857 Re: (1800) FTL impossibilities, TDR stuff

Edwin Wiles · 27 November 1990 · reply to #1800

Robert P Poole said basically that FTL travel is impossible.  I will agree,
IF we add the proviso:  "With Our Current Understanding Of Physics!"

So many times in history, someone has said "not possible, the universe
doesn't allow it", it has turned out later that it WAS possible, only
our knowledge was incomplete, or the evidence misunderstood, to give
the impression that the desired ability was impossible.

I'll even admit (reluctantly :-) ) that the percentage chance of FTL
working is MUCH less than 1%, but until we know everything, we cannot
eliminate that last little bit of uncertanty.

Still, Robert has a valid point:

	DON'T GET BOGGED DOWN TRYING TO MAKE EVERYTHING "REAL".

It is sufficient if it is "close", or even as long as it is internally
consistent and not too obviously externally bogus.

Example, FTL is necessary to reduce travel times to something that can be
used within the framework of an RPG game taking place on multiple planets
around different stars.  Yes, it mucks up with our current understanding
of physics, but it is needed, so give it a mild handwave and continue on.

However, a "reactionless" drive is probably NOT necessary.  Having
only "reaction" drives puts a whole series of other problems into
fairly well understood fields.  Allowing higher efficiencies than
are now possible, through some plausible means (such as controlled
fusion), can reduce interplanetary travel times to something more
tolerable.  On the other hand, long trips leave lots of time for
fun and games like "self-improvment" (Gee! I didn't know this ship
had a shooting range!), and "capture-the-bridge" (I don't understand
*why* the Captain is soooo upset!).

> ...been watching all this talk about Black Globes and reactionless
> thrusters, and I just have to laugh. ...

Robert?  You seem to fall into the same category of people who say
"It's Just A Show!  Get A Life!"  To which I say:

	So What!  WE LIKE TRYING TO FIGURE IT OUT!

It doesn't matter if we KNOW that it isn't going to work in real life,
it's enough if we can come up with something that doesn't bend too many
rules and is internally consistent!  The question is, which rules are
we going to bend and by how much!  THAT's what we're arguing about! :-)

Which is *precisely* what the TDR development team is going to have to
do.  Decide which rules to bend and by how much.  Yes, the trade rules
and such are desparately in need of fixing, but how can you fix them when
you don't know how long it takes to get from here to there, or how much
it's going to cost you to transport that cargo over that distance?

Without having both maneuver and FTL drive pinned down, you can't figure
what is "reasonable" for cargo/costs/sizes/values/etc...  Sure, you can
come up with some pretty good formulas, but you need some constants to
plug into the formulas so that the number of useless cargos generated are
not so many that you roll dozens of times before you get one viable cargo
that doesn't even fill your cargo space!  Yet the cargos generated should
allow for the chance that bad choices will lead to financial problems.

I suppose that the first thing to do is to decide what features depend
on which others, praying that there aren't too many circular dependencies.

Here, I'll start the chart:

	Maneuver Drive ____
		^          \
		|           > Ship Design ---> Cargo Viability
	FTL Drive _________/

Before you can develop good formulas for generating cargo, you have to know
how much it costs to transport the goods and how long it takes to get there.
(Some cargos are perishable.)  Before you can know that, you have to have your
ship design methods layed out, because without that, you've no idea what your
average ship capacities are.  Before that, you have to have some idea how your
Maneuver and FTL Drives work, because they will affect what you can get away
with in Ship Design.  Before that, you have to decide just how your FTL drive
is going to work.  Like, are you required to move away from gravity wells for
it to work efficiently?  How far?  This will affect what your maneuver drive
must be capable of for your FTL drive to work.  If you're not required to move
away from a gravity well, then do you have to be outside atmosphere?  If not,
then why bother with a maneuver drive anyway?

Get the idea?  Yes, the design process is probably going to be somewhat
iterative, but if you get the basics nailed down carefully enough, the
rest shouldn't be too bad.

	    ABOVE ALL, MAINTAIN INTERNAL CONSISTENCY!

I don't think there's anything that ticks an RPGer off more, than a
game which isn't internally consistent.  Such inconsistency normally
shows up in the rules, making it hard to play.

				    Good Luck!
- - --
Preferred: [email removed]			Edwin Wiles, NetExpress Inc., Vienna, VA
Alternate: ...!grebyn!netex!elw