Why X-Boat tenders

[ottarrus]

Has anyone tried to jump through the middle of a star?

There have been a lot of side references going all the way back to the LBBs about accidentally Jumping into the middle of a star. This is along the line of 'be careful and don't eff this up' advice to novice astrogators.

So far as anyone knows, there are no gravitic bodies [suns, planets, etc.] within JumpSpace. At least, nothing that has ever been reported in 10k years of interstellar travel.
OTOH, if you did encounter the euphemistic JumpSpace equivalent of 'flying into a rock-filled cloud', the odds on you being alive to report it are not good.

 

[ottarrus]

Or more simply, Earth to Mars, while Mars is exactly opposite Earth on the other side of the Sun, in a straight line.

Oh great... now the astrology types are gonna start chiming in...

 

[Nelphine]

Either way, the idea of a station being a jump target all the time (or there being a specific area of space such that a single tender can reliably handle the xboats of a single small system) fits into the standard assumptions of the otu, regardless of how it's described.

We may continue with the comparison of the OPs station design vs the otu tender design.

 

[Ol'Weedy]

Just stepping randomly into this thread because something made my neuron (yes singular - it gets lonely at times) fire.
Two things on jump masking:
Is Traveller a simulation or a game? As a game, the concept of jump masking adds little unless it is a specific plot point. Since the majority of stars in the OTU are M-class dwarfs (except, because someone at some time did the generation way wrong, there a tremendously large surplus of F class stars - but that is neither here nor there - or out there) it would be an issue in most systems, but it is inherently ignored by the rules and by every adventure I can think of.

Second: Let's pretend we're in the Solar System and jumping somewhere else: Good news, Earth is more than 100D away from the sun, so we can ignore that. And the sun is only half a degree wide, so ignoring complicated math, only a 50 degree circle of the 360 degree sky is blocked by the sun's 100D at any one time - this can potentially block some destinations some of the time and will never blank destinations far to the north or south of the ecliptic - and Traveller's universe is only 2-demsinsional so... you don't have the tools to even accurately consider masking without a 3D interstellar map. (And about that 50 degree cut of the sky that is blocked? I am lazy today, so I asked ChatGPT what percent of the sky it would block. Four times I asked, and the answers were: 25%, nonsense, 3.183%, and then nonsense again - I love AI )

Somewhere between those 3.18 and 25% numbers 'feels' about right. Can also add, that the chance of running into an unexpected gravity well on a 1 or 2 parsec jump, would be pretty negligible. I guess once you hit J6 things would get a bit harder, but how much?
It always comes back to that "Space is big. Really big..." thing.

 

[Ol'Weedy]

Here is the most important single sentence with regards to jump masking etc.


So being within 100D only matters as you are trying to leave jump space. It does not mater what is between the two jump points in our universe, because jump space is a hyperspace beyond our universe (I can dig out references to jump space being described as a hyperspace in canon). This is what the GT crowd failed to take into account and as a result we got fanon made canon.

Later on Marc says:


Twice it is stated the ship must be trying to leave jump space, nowhere does it mention in the article that ships can be pulled out of jump space by objects in our universe.

I think this is a case were an idea from a book (One of Heinlein's or Niven's, can't remember which), crossed over into vaguely defined canon.
In said book, the protagonists, were forced out of jump space by baddies using a small, semi-portable black hole. I think one of the results for a possible miss-jump, (something about you come out of j-space, but your J-drive doesn't), came directly from the story, and probably influenced the original idea. Time frame would have been within 10 years of Traveller being invented too....

 

[Condottiere]

Oh great... now the astrology types are gonna start chiming in...

If the stars are favourable, plus one to the astrogation roll.

 

[phavoc]

Has anyone tried to jump through the middle of a star?

That is categorically impossible per the rules on how jump space works. Every jump will precipitate out of jump space at 100D of an object of sufficient size.

 

[phavoc]

Here is the most important single sentence with regards to jump masking etc.


So being within 100D only matters as you are trying to leave jump space. It does not mater what is between the two jump points in our universe, because jump space is a hyperspace beyond our universe (I can dig out references to jump space being described as a hyperspace in canon). This is what the GT crowd failed to take into account and as a result we got fanon made canon.

Later on Marc says:


Twice it is stated the ship must be trying to leave jump space, nowhere does it mention in the article that ships can be pulled out of jump space by objects in our universe.

Here is the most important single sentence with regards to jump masking etc.


So being within 100D only matters as you are trying to leave jump space. It does not mater what is between the two jump points in our universe, because jump space is a hyperspace beyond our universe (I can dig out references to jump space being described as a hyperspace in canon). This is what the GT crowd failed to take into account and as a result we got fanon made canon.

Later on Marc says:


Twice it is stated the ship must be trying to leave jump space, nowhere does it mention in the article that ships can be pulled out of jump space by objects in our universe.

The 100D limit exists for entry or exit of jump space. The difference is entry to jump within 100D has varying degrees of success (or failure, depending on how you look at it) and you automatically leave jump space at entering within 100D of large enough object.

The JTAS 24 article states that the "The perturbing effect of gravity preclude from exiting jump space within the same distance (100D)". As I stated previously, one can argue that jump space is curved, or non-linear because Miller never specifically states it IS linear. Other versions attempt to define it better and in more clear terms. However I think it's a relative strawman argument that argues against it simply because that's not how gravitation fields work in reality. Science illustrates (in a 2D model at least) that you have a flat plane and gravity is an inverse cone. So logically, if you come within the 100D limit of said cone, you'd be pulled out of jump space per the rules and explanation provided. And the JTAS article has a paragraph header labeled "Gravity well effects".

We can all interpret as we choose to, or utilize the edition we prefer. I like to think common sense prevails when questions of this type arise. Occam's razor works great for all versions of Traveller.

 

[Condottiere]

So, I take it that the crow has to recalculate his flight path.

 

[Sigtrygg]

The 100D limit exists for entry or exit of jump space. The difference is entry to jump within 100D has varying degrees of success (or failure, depending on how you look at it) and you automatically leave jump space at entering within 100D of large enough object.

The JTAS 24 article states that the "The perturbing effect of gravity preclude from exiting jump space within the same distance (100D)". As I stated previously, one can argue that jump space is curved, or non-linear because Miller never specifically states it IS linear. Other versions attempt to define it better and in more clear terms. However I think it's a relative strawman argument that argues against it simply because that's not how gravitation fields work in reality. Science illustrates (in a 2D model at least) that you have a flat plane and gravity is an inverse cone. So logically, if you come within the 100D limit of said cone, you'd be pulled out of jump space per the rules and explanation provided. And the JTAS article has a paragraph header labeled "Gravity well effects".

We can all interpret as we choose to, or utilize the edition we prefer. I like to think common sense prevails when questions of this type arise. Occam's razor works great for all versions of Traveller.

Nope.
Your model is wrong and only exists in our universe.
Jump space is a different universe and it is only when attempting to enter or you are trying to leave jump space that there is any connection between the two.

 

[phavoc]

Nope.
Your model is wrong and only exists in our universe.
Jump space is a different universe and it is only when attempting to enter or you are trying to leave jump space that there is any connection between the two.

I'm glad you have the definitive ruleset that others seem to be missing! Care to share quotes from it that substantiate your point?

The problem with your interpretation is that logically the 100D rule has to be invoked somehow. Using the upthread example of trying to jump through a star, it is categorically stated that trying to enter normal space from jump space within 100D of an object will force the ship to return to normal space at the 100D limit. That's the "...preclude a ship from exiting jump space..." part. So, literally using that sentence, setting your exit point to being the opposite side of the star you are currently on and at a distance of 99D would mean when you entered jump space and tried to exit at your intended location, you would be forced to emerge at the 100D limit. While one could argue that you'd gain the 1D distance on the other side of the star of where your intended exit point was (thereby jumping through the star itself), that would also mean that your ship is violating the stated rule and you'd actually gain 1D in distance due to bouncing forward. That would make no sense and seem both a spiritual and literal violation of the 100D rule.

Within the original Jumpspace article Miller states that planetary objects gravity wells have "turbulence" that affect the entry into jump space. That is confirmation that the physics I mentioned do affect jump - at a minimum it effects entry. Exit is also affected by gravity wells since you cannot exit any closer than 100D. If a ship "naturally precipitates out of jumpspace as the near the 100D limit", then the gravity well of an object does affect a ship within jump space.

You have to jump through a lot of hoops to substantiate your interpretation. I'm unaware of anything in the CT literature that definitively states it one way or the other. This is from CT, and other versions do call this out. As we are on the MGT board, the MGT v1 Core Rulebook states:

"A ship can only safely Jump when it is more than one hundred diameters distant from any object. A vessel could only Jump away from Earth when it is more than 1.27 million kilometres distant (as well as 140 million kilometres away from Sol and 300,000 kilometres away from the Moon). Gravity can cause a Jump bubble to collapse prematurely, bringing a ship back into normal space early (so if a ship tried to Jump from Earth to Mars when the Sun was between the two, the vessel would fall out of Jump space as soon as it came within one hundred diameters of the Sun." (emphasis mine).

Gaming wise the straight-line idea is hard to do and most players just disregard it. However that doesn't mean it's not there (and, arguably, has always been there). All the rulesets do appear to agree jump space is a realm outside of our normal space - yet one still is able to affect the other.

 

[Sigtrygg]

My quotes are taken from MWM's Jump Space article, GDW JTAS 24 and then reprinted MgT JTAS 2.

The article does not mention jump bubble collapse, straight line paths within our universe (stop and think about the implications of that one for a moment) or any of the other fanon made retcanon by GT and T5.

Gravity affects a ship trying to enter jump space, it affects a ship trying to exit jump space, no mention whatsoever of gravity in the universe affecting a ship in jump space.

 

[Condottiere]

So, we actually should try a microjump between Terra and Mars.

 

[Sigtrygg]

The Terrans used their early jump drive for insystem travel, and i still maintain that the type A makes a much better insystem delivery van...

 

[Nelphine]

Which is why i stand by my interpretation, while going against certain implied things (such as mgt1), is what must exist GIVEN the rules as written for things like trade and xboat tenders, and major established published adventures.

In this case, gameplay mechanics trump half implied things about potential laws of jump space.

 

[Condottiere]

It's really simple.

Just have someone in the next Mongoose sanctioned game at a convention, jump through the middle of a star.

 

[Nelphine]

I would do it just for that meme. Glorious.