[TML] White Dwarfs, Black Holes & 100 Diameters

[Jerry W Barrington]

On 10/30/07 8:26 PM, Garry Ward wrote:

> ----- Original Message -----
> From: "Jerry W Barrington" <jursamaj at yahoo.com>
> To: <tml at travellercentral.com>
> Sent: Monday, October 29, 2007 3:51 AM
> Subject: Re: [TML] White Dwarfs, Black Holes & 100 Diameters
> 
> 
>> <snip>
>> On 10/28/07 3:20 PM, Garry Ward wrote:
>> 
>>> hence my growing inclination to make jump instantaneous but make the
>>> point
>>> at which it can occur far, far, far out into the star system so that the
>>> travel time from planet to jump point and back is on the order of several
>>> days.
>> 
>> But how do you define "instantaneous" within relativity?  Simultaneity
>> depends on speed.  I suspect the only fast drive that could possibly be
>> made
>> to fit with what we know so far of physics would travel *at* light speed.
>> 
> reach jump point, flip switch, space folds, ship drops through, flash,
> you're at the destination, no week in 'jump'. Very much like the Guild
> Heighliners in Dune, travel without moving.

Ok, "no time spent in Jump" works fine.  But I assume you also mean you
arrive at the destination at the same clock time as you left.  But with
relativity, "when" is relative too.  There can be no common clock to
reference, especially if the ship is moving fast (significant fraction of
c).  And before somebody says ships have to be stationary: with respect to
what?  Motion is also relative!

>>> Gotta set aside some time to get back to the idea of the jump relative
>>> parsec based on the parallax of the distance from the primary to the jump
>>> boundary.
>> 
>> Say what?!?
> Posted the initial version of this probably about a year ago. OTU jump is
> based on the parsec which is very much earth centric since the span of a
> parsec is based on the parallax of earth's orbit. A parsec from a martian
> perspective would be different and one from a venusian perspective would
> also be different, so I came up with the idea that the jump boundary isn't
> at 100d from the planet but at the .0001 G line from the primary and that
> the "parsec" jumped would be relative to the parallax at that .0001 G line.
> 
> Yeah, it blows canon out of the water, but as I've observed before, I only
> worry about cannons when I'm doing Napoleonic Naval miniatures.

I imagine that could easily be turned into a simple function of star mass.
:)

Personally, I'd more likely say that the parsec unit just happens to be
close to the unit used by the jump drive.  Honestly, the maps play pretty
loose with the distances to real object anyway.

I like that the limit of drives in 2300AD was not a "neat" multiple of any
standard Earthly unit.

Of course CJ Cherryh has an interesting drive.  Apparently gravity doesn't
bother it much, and it can be used to change speed.  However, activating it
when attached to too big a mass can be catastrophic.  At one point in the
Chanur saga, a ship captain threatened to activate it will dock at a
station.  The result would have smeared the mass of the station and all
attached ships over a large space!

I'm rather fond of drives that use some natural limit, rather than an
arbitrary number.  Thus, you can't jump to *that* system, because the
influence of this other system is in the way.  :)



On 10/30/07 8:26 PM, Leonard Erickson wrote:

>> Say what?!?
> 
> You *do* know how the parsec is defined, don't you?

Yes, I know parallax, but I'm sure somebody will benefit from the
explanation.  :)

I understood every word in Garry's sentence, it was the sentence as a whole
I didn't understand.  And now that I understand where he's going with it,
well...  I won't be using it, but more power to him.  And that usage should
definitely drop the parsec term.  Parsec, by definition, is based on
*Earth's* parallax.



On 10/30/07 8:26 PM, Timothy Little wrote:

> Red dwarf stars would have a shorter "jump parsec" than heavier stars.
> Barnard's Star for example would have a "jump parsec" of about 1
> parsec, while Sol's would be 2.4 parsecs.  Giant stars would allow up
> to maybe 10 times the standard Traveller jump distance, so would
> probably be a great hub of long distance trade.

Would they really?  Sure, you can go a long way *from* them in 1 jump.  But
then it may take quite a route to get *to* then in the 1st place.



On 10/30/07 8:26 PM, Garry Ward wrote:

> Yep. Some of the best transfer points for long haul traffice might not have
> any inhabitable planets or native races. Really makes a sound reason for
> places like B5 (outside of pure diplomacy). Changes military tactics; you'll
> want your strike forces stationed somewhere they can jump the furtherest,
> which might very well not be close to your home world.

Likewise, how do you get the message to them telling them where to
jump/attack?  And how long does it take them to come back to be ready again?

Oh, and for the rapid cycle version, look at 2300AD's stutterwarp.