Jump Time Questions

[LiminalMask]

If we assume that all jumps take one week... how do we answer the following hypotheticals?

1) A ship is making a Jump-4. Unbeknownst to the astrogator, a star (or some other large gravity object) lies along the Jump path that is not on the charts. This star is at the halfway point between origin and destination of the original jump. When the ship enters its gravity field, the jump bubble collapses and it drops out of jump. How much time has passed when this occurs?

2) A ship is making a Jump-4. Exactly halfway through the week of jump time, the Jump Drive is sabotaged and the ship drops out of Jump. Where are they along their original flight path?

On the surface, the answers seem to be "half a week" and "2 parsecs away from origin" respectively... but if ALL jumps take 1 week...?

 

[steventirey1985]

1) That deals with jump-masking, which isn't entirely agreed upon amongst Traveller players. Personally, I don't use jump masking - since your not travelling through normal space, whatever is in normal space doesn't matter during the journey. Only what is at the beginning and end of the journey matters, while you are leaving/entering normal space. At least in my opinion. But, if encountering a gravity well does cause the bubble to collapse while you are in jump space, see #2 below.

2) The ship does not reenter normal space, so it doesn't matter. If the ships jump drive is damaged/destroyed while in jump space, the jump bubble collapses, and the ship is exposed to jumpspace. This usually ends with the ship being destroyed (or at least, never heard from again).

 

[Rigel Stardin]

Jump1 = 3.25 Light Years
Jump2 = 6.5 Light Years
Jump3 = 9.75 Light Years
Jump4 = 13 Light Years
Jump5 = 16.25 Light Years
Jump6 = 19.5 Light years

Divide light years by 7 days or 168 hours...

That is how far you travel per day...

 

[far-trader]

My read of the rules says:

1) That is a misjump (bad plot on the Astrogators part). The ship drops out of Jump Space after 1 week (probably*) having traveled 2 parsecs (maybe*) along it's intended vector (or not*). The sophonts aboard may or may not be suffering from the effects of the misjump, aka Misjump Sickness.

* if the reason is to have them drop out there (i.e. referee fiat) then they do, otherwise roll for misjump per the rules of 1-36 parsecs along a random D6 path and taking a D6 weeks

2) the ship does not drop out of jump space, it is consumed by it, they are nowhere, and everywhere, ship et al utterly destroyed, everything becomes one with the universes, roll new characters

 

[Matt123]

2) Or at best (ref fiat), it creates a miss jump. Mostly tho' the ship is destroyed. It should be noted that anyone with the ability to sabotage will, usually, also know they and the ship are not likely to survive.

 

[LiminalMask]

Jump1 = 3.25 Light Years
Jump2 = 6.5 Light Years
Jump3 = 9.75 Light Years
Jump4 = 13 Light Years
Jump5 = 16.25 Light Years
Jump6 = 19.5 Light years

Divide light years by 7 days or 168 hours...

That is how far you travel per day...

Yes, this was my original thought, but I wasn't sure if Jump was strictly linear, or if it was "vanish from point A, go somewhere else for a week, come out at point B".

And thanks for reminding me that losing the Jump drive kills the ship, everyone. But I suppose I was trying to frame the question in terms of "if Jump is ended prematurely, where are you?"

 

[far-trader]

...I suppose I was trying to frame the question in terms of "if Jump is ended prematurely, where are you?"

Canon answer, it can't.

ATU answer, whatever you can imagine

...with the caveat that it WILL change the paradigm of the Traveller game/universe significantly, probably in ways you can't imagine but your players will, and insist on exploiting in ways so torturous to the ref psyche that even typing this gives me nightmares

...or not

 

[steventirey1985]

But I suppose I was trying to frame the question in terms of "if Jump is ended prematurely, where are you?"

As far as I know, a jump can not be ended prematurely by any means, with the exception being by collapsing the jump bubble. But as that destroys the ship, it doesn't really matter where you are, as everyone is dead and the ship destroyed.

Once you enter jumpspace, you have no control anymore. Since ending the jump early could give significant advantages (such as a jump-capable ship basically blinking its jump drive on then off, to instantly travel across a star system) you would figure if it was possible to prematurely end the jump that it would be mentioned somewhere. Since that is not said, one can assume that it is not possible to (voluntarily) end the jump before its scheduled time, whether that time is one week for a successful jump, or d6 weeks for a misjump.

 

[LiminalMask]

Canon answer, it can't.

ATU answer, whatever you can imagine

Yes. But let me rephrase. This is more of a "how does jump work" question than a "can I leave jump early" question. If it WERE possible to drop out of Jump at the halfway point of the week, where would you be? Again, asking purely from the standpoint of 'do jump ships go in a straight line from point A to B, or is it something else?'

Where are you during jump? Are you moving toward your destination in a line at faster than light speed? If so, is that at a constant speed? Or do you jump all the way to your destination instantly and then take 7 days to return to normal space? Do you go in some sort of curve? Or through a wibbly-wobbly timey-wimey wormhole thingie? etc. etc.

 

[Metropolitan District 268]

Well, I'm just returnign to Traveller after 30-odd (some of them VERY odd!) years away, and I've missed out on all this Canon nonsense.

When I last played Traveller, it was a loose framework of concepts and rules for players and referees to flesh out for themselves in ways that suited the adventures they wanted to play - and my Traveller universe is still like that.

My take on Jump Drive and Hyperspace is that a controlled fusion event (hence the need for all that L-hyd) pushes the ship into a quantum singularity which is outside the normal spcae-time continuum, and which distorts that continuum to a certain extent (the more powerful the drive, the greater the extent).

This distortion takes about a week of "normal" time to achieve, at the end of which the space-time continuum is distorted to such an extent that there is a second point at which it touches the singularity, and the ship exits the singularity into normal space at that point.

On this rationalisation, you do not HAVE to speculate about what is in teh "intervening" space because the ship does not actually have to pass through it. And the skill of astrogation lies in manipulating the distortion of the space-time continuum such that you arrive at the correct place, rather than in "plotting a course" at all.

Ultimately, though, we do not need to know such things unless they are going to arise in a game; at which point the ref needs to come up with an answer that suits the scenario and produce a semi-plausible answer for it.

But "right" and "wrong" answers?

Let's just consider two sixteenth century mariners, speculating that in the future there will be "ships" that sail the skies rather than the seas.

"How will they cope with strong wind?" asks an officious bystander.

"I think they'll be at the mercy of strong winds and blown wherever they take them," says the first, "so if it's too windy they won't even leave the ground".

"Oh no," says the second. "By the time they've come up with a way to make them fly, they'll have solved that problem too. In anything short of a hurricane they'll not be troubled by the wind; and it might even help them get off the ground."

Which is right?

Well, in a sense they both are. The first is describing the problems of lighter-than-air machines; and the second is describing fixed-wing aviation!



As to "what happens if you leave jump half-way" I'd suggest that an uncontrolled release of the distortion of the space-time continuum would create unpredictable reverberations which might throw you just about anywhere. In my universe it'd be a mis-jump.

 

[far-trader]

Yes. But let me rephrase. This is more of a "how does jump work" question than a "can I leave jump early" question. If it WERE possible to drop out of Jump at the halfway point of the week, where would you be? Again, asking purely from the standpoint of 'do jump ships go in a straight line from point A to B, or is it something else?'

Per Marc Miller's article in an early JTAS, yes, the path of the ship is a straight line (iirc, but that might be just implied) that maps directly to normal space with the only difference being it takes a week to travel that distance instead of years or longer.

Where are you during jump?

One of 6 alternate dimensions (1 per jump number), with another 30 that are only accessible through misjump.

Are you moving toward your destination in a line at faster than light speed? If so, is that at a constant speed?

That is less clear, or I don't recall the specifics. Presumably you don 't travel anywhere near the speed of light and so avoid all the relativistic issues. Or perhaps more likely Jump Space is such a strange dimension that such concepts as time and distance are immaterial.

Or do you jump all the way to your destination instantly and then take 7 days to return to normal space?

And how would you know that was the case rather than travel at a constant rate? It's best not to overthink it.

FWIW there is some variability in both time and distance in jumping, canonically, random, so who knows what really goes on. Much of it is left up to each ref to make up or ignore.

 

[mike wightman]

By the way somewhere it is written that a misjump lasts 1-6 weeks - roll of a d6.

 

[aramis]

If we assume that all jumps take one week... how do we answer the following hypotheticals?

1) A ship is making a Jump-4. Unbeknownst to the astrogator, a star (or some other large gravity object) lies along the Jump path that is not on the charts. This star is at the halfway point between origin and destination of the original jump. When the ship enters its gravity field, the jump bubble collapses and it drops out of jump. How much time has passed when this occurs?

2) A ship is making a Jump-4. Exactly halfway through the week of jump time, the Jump Drive is sabotaged and the ship drops out of Jump. Where are they along their original flight path?

On the surface, the answers seem to be "half a week" and "2 parsecs away from origin" respectively... but if ALL jumps take 1 week...?

1) The parabolic wormwhole was formed through J-space at the moment jump was initiated. They fall through it in 1 week. The gravity well deflected it, but it was formed at transition. They may not REALIZE it until they come out, after the week.

2) the drive's been offline since 5 minutes in. They continue to fall through that parabola until they'd normally fall out.

2a) Damage the charged and not yet fully decayed jump grid, however, and if the whole is more than 3m, the ship is toast, immediately, as J-space invades and disassociates bits and pieces. The shell dejumps at the end of the week, with anyone within 1m of the shell. Alive if their suits will last them that long.

 

[aramis]

By the way somewhere it is written that a misjump lasts 1-6 weeks - roll of a d6.

That varies by edition. MT, it's 1d6+3 days.

 

[Icosahedron]

With a caveat that I tend to disregard canon, too:

You need to decide what works best for you and your players. Perhaps instead of asking us what we do, you should be asking yourself what you want.

Do you want intervening bodies in real space to affect Jump?
If so, your ship travels in a straight line through pseudo-normal space, if not, it travels through some warp, hole or extra dimension that has only a beginning and an end.

Do you want every jump, no matter what, to take a week, or would you prefer to split the time if something goes wrong? It's your universe, you decide.

Personally, I devised a Jump Formula many moons ago:
t = (d+c^2)^-3 (SI units)
It matches the earliest canon before they came up with the '168 plus or minus' idea, in that each jump takes 'about a week'.

If you want to go with physics rather than canon, I'd guess that some form of extra-dimensional quantum jump would be the most likely FTL solution, taking a week regardless and having no connection with intervening space-time. If anything goes wrong, you'll drop out after a week, either at your departure point or your destination.

Of course, errors might affect the match between ship-time and Universal Time. The week is UT. The crew may think they've dropped out after only a couple of days aboard, but they still arrive at the destination on time - or the SPA open the on-schedule ship to find mouldy skeletons and gnawed bones...

 

[McPerth]

But let me rephrase. This is more of a "how does jump work" question than a "can I leave jump early" question. If it WERE possible to drop out of Jump at the halfway point of the week, where would you be? Again, asking purely from the standpoint of 'do jump ships go in a straight line from point A to B, or is it something else?'

As I understand jump (not sure if canon agrees), yes you go in a straight line from point A to point B... in the alternative dimension used for the jump. In what we call normal space, you're simply not there, so you don't move in straight line, nor in a curved one.

 

[BytePro]

...
When I last played Traveller, it was a loose framework of concepts and rules for players and referees to flesh out for themselves in ways that suited the adventures they wanted to play - and my Traveller universe is still like that.
...

Yes, this is often the best way - good Science Fiction often deals with the pure Fantasy elements this way. Thus avoiding the logical contradictions that result from providing too many particulars for a fiction.

Ex: Mongoose Traveller speaks of a 'Jump Bubble' in a 'tiny parallel universe'. Then, among several other contradictions, has gravity able to 'cause a jump bubble to collapse prematurely' after stating that the jump bubble was carried 'into the tiny pocket universe' - i.e. gravity in one universe effecting the beyond space jump bubble inside of a 'parallel universe'. :nonono:

Love the 'tiny pocket universe' - really - ship size is 'tiny'? That is one big arse 'pocket', IMO. :rofl:

Besides, I can understand the literary desire to avoid having a 'normal' universe, but what's wrong with having a 'tangential' universe every once in a while?

Rule designers don't always make good fiction authors...

 

[Xerxeskingofking]

the underneath is My Own, Personal Opinion

1) A ship is making a Jump-4. Unbeknownst to the astrogator, a star (or some other large gravity object) lies along the Jump path that is not on the charts. This star is at the halfway point between origin and destination of the original jump. When the ship enters its gravity field, the jump bubble collapses and it drops out of jump. How much time has passed when this occurs?

I'd say they either jump sucessfully to the target system, or fail to enter jumpspace as some safty system kicks in at the last second and stops them. In MTU, the Jump is a point to point affiar, so if the "Exit" point cannot form (due to unexpected grav effects), the Jump doesn't happen. they burn all thier fuel, dump the power into the hull grid...and stay right where they are.

2) A ship is making a Jump-4. Exactly halfway through the week of jump time, the Jump Drive is sabotaged and the ship drops out of Jump. Where are they along their original flight path?

agian, my take:

the "jump" is between demensions, and once in J space, any relation to normal space is meaningless. until the bubble decays and they exit at the destination, they are not anywhere in N-space.

 

[Metropolitan District 268]

Rule designers don't always make good fiction authors...

Oh BytePro, I really AM laughing my arse off at that one! :rofl:

Do you mind if I adopt it as my signature line??

 

[phavoc]

If we assume that all jumps take one week... how do we answer the following hypotheticals?

1) A ship is making a Jump-4. Unbeknownst to the astrogator, a star (or some other large gravity object) lies along the Jump path that is not on the charts. This star is at the halfway point between origin and destination of the original jump. When the ship enters its gravity field, the jump bubble collapses and it drops out of jump. How much time has passed when this occurs?

2) A ship is making a Jump-4. Exactly halfway through the week of jump time, the Jump Drive is sabotaged and the ship drops out of Jump. Where are they along their original flight path?

On the surface, the answers seem to be "half a week" and "2 parsecs away from origin" respectively... but if ALL jumps take 1 week...?

My take on this (1) If the star was halfway between the origin and destination point, you'd take the travel time, divide it by half, then add some random time variable (1-6hrs say) and that's how much time has passed. Of course you would have burned the full amount of jump fuel to get there.

(2) My understanding of the jump tech, is that even if the jump drive is sabotaged it does not make a difference. In regular traveller you have a jump grid that is charged and gets you into jump space. In MGT you have a hydrogen pocket universe which degrades over time. But in both the jump drive's usefulness is at an end once you hit jumpspace.

But assuming that sabotage WAS possible, I would say that most likely your ship would be destroyed. As a referee you could have a catastrophic act occur, such as the ship emerges from jump space at the 50% mark, damaged, you have a mis-jump, you arrive at your destination very late, etc.