mike wightman
SOC-14 10K
You would need a lot more than one x boat per link - a single misjump could spell disaster,
The Traveller Ansible (= FTL Comms)
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Spinward Flow
SOC-14 1K
A 1-bit signal is known as a "heartbeat" ... in the "I'm okay/I'm not okay" sense.
It does not convey additional USEFUL information beyond that.
Now, if you increased the number of XBoats cycling through this process, you MIGHT be able to approach 110 baud speeds (accoustic modem of the late 70s, early 80s era) ... but there's a problem. XBoats that depart in a synchronized fashion do not break out of jump into the destination system retaining that synchronized timing. At that point, you realize that any "multiplexing" of 1-bit data transfers becomes horrendously asynchronous ... meaning that all you're delivering is NOISE on the far end, rather than coherent message data arising from combinations of 0/1 single bit data transfers that appear "at random" at the destination.
So nice try ... but the logistics involved (110 XBoats getting dispatched PER SECOND continuously without end?!?) breaks the scheme all by itself of wanting to transmit 1-bit "messages" that contain any useful information.
Yeah ... NO.
That basically amounts to "induced misjump after the fact" when the starship in jump space has already been gone for a day.
If that were possible to do, then the entire Breaking Off By Jumping maneuver goes out the airlock.
- Pirates wouldn't be able to escape by jumping. The pursuers would simply need to "step on" the origin point to "yoink" the pirates back to where they jumped from.
- Fleets would not be able to retreat by jumping. Their adversaries would simply need to "step on" the origin points of retreating starships to "yoink" them back to where they tried to escape from ... only to be ambushed by their adversaries in an even more disadvantageous position (retreating starships are in a lower fuel state due to having jumped, disoriented after breakout, unprepared for suprise ambush, etc.).
That sounds like an exceptionally DUMB rule to me, that opens up all kinds of exploits and unintended consequences.
What I've read about it that it's transmitting a form of binary, so you can have a type of digital communication. Eventually.
Without addressing the XBoat issue, 110 baud is more the "fast enough" for a vast array of scenarios. That's 950K byte per day. More than enough to transmit market reports and fleet movements.
Spinward Flow
SOC-14 1K
You do realize that those 950k bytes per day is going to require ... {grabs calculator} ... 7.6 million XBoats dedicated to that single channel of communication, right?
7.6 million XBoats per day jumping will require 76-304 million tons of fuel per day (jump-1 to jump-4) just to keep that "channel open" ... which those XBoats are not going to be able to go and get themselves (for some strange reason, why aren't these things like permanently fueled when delivered from the manufacturer?).
I think you need to check your assumptions (at the door!) for that to be in any way supportable.
And it still doesn't solve the "asynchronous data transfer" problem on the other end of 168 hours +/- 10% variability for jump durations.
BackworldTraveller
SOC-13
I thought the whole point of jump-space, as originally defined, was that there was no mapping between jump space as entered and anywhere in real space other than the exit point.
i.e. you move through jump-space such that you start at A and end at B and bypass everything in between.
Both A and B have limits in real space governed by diameter of the nearer bodies - but that is it.
The advantage is that you don't ever collide on exit.
The disadvantage is that you can collide, a few micro-seconds later, with something that was passing - if your luck is really bad.
The later attempt at a downgrade from intervening masses is just nonsense under that original definition.
i.e. you move through jump-space such that you start at A and end at B and bypass everything in between.
Both A and B have limits in real space governed by diameter of the nearer bodies - but that is it.
The advantage is that you don't ever collide on exit.
The disadvantage is that you can collide, a few micro-seconds later, with something that was passing - if your luck is really bad.
The later attempt at a downgrade from intervening masses is just nonsense under that original definition.
BackworldTraveller
SOC-13
If jump-space is a plane in two dimensions, why is it aligned to the plane of the galaxy? If it doesn't interact with gravity there is nothing forcing it to be planar in any specific orientation. What is it about Mass that does interact with it? The 100R limit suggests that the induced gravity field isn't the limiting factor but something else in that mass is inextricably linked? What is the smallest size for which the 100R limit applies? Most of space in a solar system's hab zone has several billion atoms/ions in each dTon of space.
How deep is it? After all, the galactic disk is more than 1 parsec deep.
Does it interact with dark matter?
Is it a rotating frame? Is that rotation (if any) aligned exactly to galactic rotation?
When two galaxies collide, what happens to the associated jump-space plane?
Are there spaces within the Milky Way that have fragments of swallowed smaller galaxies jump-plane? If so, how are they aligned?
Is there jump space in inter-galactic space?
Now, where is my character with Science(Cosmology)+6 when I need him?
How deep is it? After all, the galactic disk is more than 1 parsec deep.
Does it interact with dark matter?
Is it a rotating frame? Is that rotation (if any) aligned exactly to galactic rotation?
When two galaxies collide, what happens to the associated jump-space plane?
Are there spaces within the Milky Way that have fragments of swallowed smaller galaxies jump-plane? If so, how are they aligned?
Is there jump space in inter-galactic space?
Now, where is my character with Science(Cosmology)+6 when I need him?
As I understand it, only an object larger than the fleeing ship can do this. It's one of the justifications for extremely large ships despite the limit of one spinal mount per ship regardless of size.
And, honestly, I don't like it much. But it exists, so...
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Pretty much, yeah. It is useful information, though. "When you get this warning, something extremely significant has happened on our end -- not apocalyptic, since we still sent the follow-up error-correction/validation signal -- but really big." And it's fast by Traveller standards (before the higher-order drives become available).
This isn't going to happen, and it won't be done that way.
On a 24-hour cadence you aren't going to get significant overlap, and the ships would know their own departure dates so it would be possible to discover a missing ship despite duration variance. If simultaneous pairs are sent, the worst case differential variation is 34 hours. So, with simultaneous pairs, you get confirmation within no more than 34 hours that one of the two was recalled.
By nature, this is extremely low bandwidth. If you want multi-bit signalling, use approximately parallel XBoat routes (useful for normal message traffic anyhow) that will sync up at intermediate nodes where the multiple individual bits can be collated.
Two parallel routes can give you four message states, three of which are messages:
1. No interruptions: no message
2. Interruption on route A only: Message A
3. Interruption on route B only: Message B
4. Interruption on both routes: Message C
For example:
Message A: Send all available military assets this way immediately. You'll find out why on the way here.
Message B: Run Away! All of you, run -- now! It's too late for us, we pray you can escape our fate.
Message C: The Emperor is dead, long live the Imperium!
There might be a better set -- it's a silly-late hour here.
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These questions have driven generations of in-universe researchers and philosophers to alcoholism and madness.
This is because they invariably lead to the realization that there is a G_d, and that G_d is a collective of RPG authors and players.
mike wightman
SOC-14 10K
How deep is it? After all, the galactic disk is more than 1 parsec deep.
It has no depth, it is a 2d plane, the rating of your jump drive is the distance you can be away from the plane to access it.
Does it interact with dark matter?
Does dark matter exist? Does it exist in the OTU? Is dark matter itself a manifestation of the jump plane in our universe?
Is it a rotating frame? Is that rotation (if any) aligned exactly to galactic rotation?
I would say yes, it is rotating as it solves an issue.
When two galaxies collide, what happens to the associated jump-space plane?
Do other galaxies have a jump plane or is it something unique to our galaxy thanks to Grandfather?
Are there spaces within the Milky Way that have fragments of swallowed smaller galaxies jump-plane? If so, how are they aligned?
That depends on the previous question and answer.
Is there jump space in inter-galactic space?
That depends on the previous question and answer.
It has no depth, it is a 2d plane, the rating of your jump drive is the distance you can be away from the plane to access it.
Does it interact with dark matter?
Does dark matter exist? Does it exist in the OTU? Is dark matter itself a manifestation of the jump plane in our universe?
Is it a rotating frame? Is that rotation (if any) aligned exactly to galactic rotation?
I would say yes, it is rotating as it solves an issue.
When two galaxies collide, what happens to the associated jump-space plane?
Do other galaxies have a jump plane or is it something unique to our galaxy thanks to Grandfather?
Are there spaces within the Milky Way that have fragments of swallowed smaller galaxies jump-plane? If so, how are they aligned?
That depends on the previous question and answer.
Is there jump space in inter-galactic space?
That depends on the previous question and answer.
As I understand it, it's actually some number of parsecs thick, but is "flattened out" on maps as an approximation. I expect I'm mistaken.
mike wightman
SOC-14 10K
It's not 2d if it has a third dimension...
Is it stated to be literally 2D? The maps are, but the maps aren't the territory (to borrow a phrase).
If it is literally 2D, there ought to be much larger gaps between accessible worlds, and a lot of worlds that would seem to be accessible won't be.
Spinward Flow
SOC-14 1K
So a 101 ton craft can "step on" the departure of a 100 ton XBoat to "recall it" without warning.
... sounds legit ... 
But some explanations of jumpspace say it has layers, which is different from depth because they are discrete 2D planes, that are reachable by jumpdrives of the corresponding number.
And hop and skip drives must reach "deeper" or higher layers.
mike wightman
SOC-14 10K
You mean like the way in which quantum fields "stack"...
according to canon a jump 1 drive can misjump up to 36 parsecs...
according to canon a jump 1 drive can misjump up to 36 parsecs...
If they know the exact departure point. And you have to hit it exactly -- the 100D radius of a Type S with a 1Td drop tank is pretty small. Though in fairness, you've got almost a week to keep looking.So a 101 ton craft can "step on" the departure of a 100 ton XBoat to "recall it" without warning.
The apparent justification is that the 100D limit applies to everything, for the entire duration of the jump. (This also probably affects the location of suitable jump points -- you don't want to jump from a point that'll get run over by the planet you're leaving...)
I've already mentioned that I don't like the rule much, mostly because it can be exploited like this. But it's a fun exploit precisely because it turns something meant to make impractically-large but dramatically-satisfying ships more useful, into something that undercuts one of the core premises of the setting.
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That's a CT thing (of which I personally approve). CT misjumps are "oops, the drive malfunctioned and briefly broke the universe". Later versions have "oops, we missed the target" misjumps (hit the right system, but you're out in its Oort Cloud somewhere). Unless I'm missing something, and I probably am...
My dad used to do serious work via 150 baud acoustic-coupler modem on a thermal printer teletype-terminal.
Keep in mind - we've gotten used to low-latency high speed graphical interfaces... but back in the 90's, the graphical terminals worked by just sending an icon number, icon color, location, and label - 4× UInt8, plus a compressed 6 or 7 bit per character string. one could get a meaningful interface with that depth.
also keep in mind that, by using toggles or escape sequences one can extend the character set dynamically without expanding the bit depth.
ASCII (7 bit) is a 1-word:1-character protocol. Baudot, however, was a shift sequencing one. This meant some things require non-characters that shift what the next word or all following words mean.
Ironically, the first 32 characters of ASCII are not human readable, don't print, and are really just terminal control characters (hence the name "control characters")... and are considerably more than are really needed for modern computing. 16 is plenty for most uses... but ASCII has been extended and is grandfathered in...
Other systems use variable character depth... For example, we could posit an 8 bit encoding using 0x00 as null, 0xFF as del, and 0xFE as Shift.
One byte characters get the range 0x01 to 0xFD (1 to 253), 2 byte characters take the form 0xFE00 to 0xFEFD, 3byte as 0xFEFE00 to 0xFEFEFD, and so on.
110 baud is 13¾ characters per second at 8n0, 12 cps at 8n1 or 8y0, 11 cps at 8n2 or 8y1, 9 cps at 8y2...
however, in 7 bit... 7n0 is 15 BPS.
Heck , 6-bit teletype implementing SI/SO, one can drop the 7th ASCII bit and go 6n0 and get 18 cps in 110 baud.. (to get the upper 64 of ascii, you preface the upper set with SI (0x0F= Ctrl O) then the lower 64 equivalent, and then SO (0x0E=Ctrl N).
Note also: converting common text from 8-bit to 6-bit SO/SI is, for low-names text, a compression method.
