Star Charts/Stellar Cartography: the Sector System

[Timo]

But are they? Sulu uses the terms "Sector" (okay, he says "Section") and "Quadrant" in an apparent descending, zooming-in order in explicating that the Reliant being here is damned odd - the final term of the three is "and slowing", nailing shut the case.

As for the other TOS appearances, "Armageddon" refers to thousands of casualties in the quadrant; in a 20x20x20 ly cube, who would notice mere thousands? In "Errand", Klingons being in a specific quadrant makes it obvious they are headed for Organia, even though a sector should offer plenty of other options. "Babel" associates the quadrant with the immediate vicinity of Kirk's ship,

OTOH, "Tribbles" has Klingons considering even half a quadrant a significant volume of space. The other TOS references are sort of neutral.

Although the dialogue in ST5:TFF now tickles me: when trouble develops at Nimbus III, does Kirk feel there are other ships in that quadrant, or the quadrant that includes Earth? Or are the two one and the same? After all, as Admiral Bob specifies, the issue is not ships, but getting Kirk there. Perhaps the underlying assumption is that once Kirk gets there, he'll have all the ships he then judges he might need. Although of course he judges he needs none, as hasty action with incomplete resources will be decisive and beats procrastinating.

For the above discussion, we get "Grid" from VGR, potentially a good onscreen name for the "little q" thing.

Timo Saloniemi

 

[Henoch]

I did disclaimer "most"...

 

[Kamen Rider Blade]

I like the radial representation. Four Galaxy Quadrants (big "Q"). For your image above, 500 ly radial sections (or sub-quadrants which TOS shortened down to quadrant, little "q") gives a total size of 100,000 lys in diameter and perhaps 4 quadrants high gives 2000 ly thickness to encompass most of the galaxy. Subdivide each quadrant into 20 ly sectors to define the galaxy. Fits most of the TOS dialogs where both terms are used where quadrants seem bigger than sectors.

But our Milk Way is currently estimated to be about 1,000 ly thick with a Diameter of 100,000 ly.

If you wanted each "Sector" to be similar in Radial Length & Height before you sub-divide into Sub-Sectors, then there would be a total of 100 Sectors Diameter or 50 Sectors Radius.

Therefore each Sector would be roughly 1,000 ly Radial Length wise and roughly 1,000 ly Thickness wise.

 

[Kamen Rider Blade]

https://memory-alpha.fandom.com/wiki/Sector

The Star Trek Encyclopedia (3rd ed., p. 434) defined a sector as,

"In interstellar mapping, a volume of space approximately twenty light-years across. A typical sector in Federation space will contain about 6 to 10 star systems, although sectors toward the galactic core will often contain many more. The Milky Way Galaxy is divided into hundreds of thousands of sectors, grouped into four quadrants. Sectors are usually numbered, although in common usage they are often named for a major star or planet located in that sector."

Milky Way has a estimated Diameter of 100,000 ly, estimated Thickness of 1,000 ly
I'm making the assumption that we're using the above pattern of Sector division with each increasing layer being divided into odd numbers in sequence for each quadrant.

If each Sector had a consistent Radial Width of 20 ly and Height of 20 ly, but varying Arc Lengths based on the closer Arc Length or Further Arc Length relative to the center of the Galaxy, you'd have ALOT of Sectors to play with.

I did the math and the TNG era of dividing the Milky Way up into all those sectors would give you these stats:
The Milkway would have a Radius of 2,500 sectors and a Diameter of 5,000 sectors per 20 ly Height slice.
Each quadrant would have 6,250,000 sectors for each 20 ly Height slice with a total 312,500,000 Sectors per Quadrant assuming all 50 Height slices are factored in.
Combining all 4 quadrants, the Milky Way Galaxy would have 1,250,000,000 sectors.

https://memory-alpha.fandom.com/wiki/Category:Sectors
Given that the sector numbers in Memory Alpha seem semi-random, I can make a relatively safe assumption that they are numbered in the order "Explored" by StarFleet.

Sector 001 = Earth & Vulcan Systems

Sector 89102 being the furthest sector listed & referenced on screen.

 

[Christopher]

But our Milk Way is currently estimated to be about 1,000 ly thick with a Diameter of 100,000 ly.

Well, not really. "Where No Man" aside, the galactic disk has no definable edge, and thus no definable thickness. It just gets gradually more diffuse the further out you get, like a cloud. That 1000 ly is the scale height of the old thin disk -- the distance at which its stellar density is reduced by a factor of e (about 2.718). So at 1000 ly from the center plane, the stellar population density is about 2.7 times thinner, at 2000 ly it's about 7.4 times thinner, at 3000 ly it's 20 times thinner, etc. And that's just the thin disk -- the thick disk of lower-metallicity stars has a scale height of about 4900 ly. And beyond that you have the galactic halo with its globular clusters and halo stars. The idea that the galaxy's stars are found only within a flat, narrow disk is completely wrong. The disk is just the densest concentration.

https://en.wikipedia.org/wiki/File:Milky-way-edge-on.pdf

So really, if we're talking about galactic coordinates in 3D, it should be a spherical volume, or perhaps an oblate spheroidal one.

 

[Kamen Rider Blade]

So really, if we're talking about galactic coordinates in 3D, it should be a spherical volume, or perhaps an oblate spheroidal one.

Let's stick with "Spherical Voume". It's easier on the math and we can just use the furthest distance from the Galactic Center as the Radius and form the Galactic Spherical Diameter from that.

Now I need to adjust my maps. Thanks Chris! =D

 

[Christopher]

I imagine it might be feasible somehow to use larger sectors as you get further out on the Z axis, like how counties in less populous states can be much larger than in more populous ones. I'm not sure how the geometry of that could work, unless you start with big sectors and then subdivide them more finely as you get closer to the galactic plane.

 

[Mres_was_framed!]

But are they? Sulu uses the terms "Sector" (okay, he says "Section") and "Quadrant" in an apparent descending, zooming-in order in explicating that the Reliant being here is damned odd - the final term of the three is "and slowing", nailing shut the case.

With the Enterprise so often being the "only ship in the quadrant," I think Sulu was acting surprised, lol. Not sure if this dialogue can be used to determine what is meant by quadrant or not...on the other hand, taking my joke a bit more literally, it might be reasonable to assume that a quadrant happens to be about the size of the distance that actual Star Ships are usually apart from each other

I imagine it might be feasible somehow to use larger sectors as you get further out on the Z axis, like how counties in less populous states can be much larger than in more populous ones. I'm not sure how the geometry of that could work, unless you start with big sectors and then subdivide them more finely as you get closer to the galactic plane.

Using that logic, perhaps one of the terms in use refers to areas (at least areas that are part of the Federation) that are not of uniform size but refer to a given area containing a few systems that are closely related to one another by culture or commerce. So, like a Bajoran sector, or a Mutara Sector, of whatever size needed to include those points of interest. An interesting idea

 

[Kamen Rider Blade]

I imagine it might be feasible somehow to use larger sectors as you get further out on the Z axis, like how counties in less populous states can be much larger than in more populous ones. I'm not sure how the geometry of that could work, unless you start with big sectors and then subdivide them more finely as you get closer to the galactic plane.

Assymetry is a pain in the Ass. I'd rather have Symmetrical then Assymetrical.

You look at modern maps in 2D, and it's a cluster fuck of scalling issues. I'd rather avoid those issues by using simpler systems that everybody can understand. If that means every one of my "Big Sectors" is a cube with 1,000 ly for each side. Then stack as many cubes as needed to cover both the "Thin & Thick" disks, so be it.

Us Thin Disk Milky Way Galactic folks will be in Layer 0 in terms of Height on the Big Sector (XX, YY, DD) depth scale on the Cartesian Coordinate system of Cubical blocks, but we can at least make things work out if we have to scale out all the way to 200,000 ly if need be since the center of the Milky Way Galaxy will be used as the central reference point.

 

[DEWLine]

Sidebar question: how many years to the 20th Anniversary of Star Charts' publication? Two years, and maybe five months to go, right?

 

[Kamen Rider Blade]

Christopher, who has published the most accurate canonical StarChart for the latest era in the canonical timeline?

 

[Henoch]

But our Milk Way is currently estimated to be about 1,000 ly thick with a Diameter of 100,000 ly.

If you wanted each "Sector" to be similar in Radial Length & Height before you sub-divide into Sub-Sectors, then there would be a total of 100 Sectors Diameter or 50 Sectors Radius.

Therefore each Sector would be roughly 1,000 ly Radial Length wise and roughly 1,000 ly Thickness wise.

Oops, my math sucks. I was trying to put logic to dialog, where various uses of the terms quadrants and sectors were used in TOS with no consistent meaning. These quadrants are not the obvious big four Quadrants of the galaxy until the TOS movies, so, they represent something else. Could a quadrant be something as simple as a sector subdivided into four pieces?

 

[Kamen Rider Blade]

Oops, my math sucks. I was trying to put logic to dialog, where various uses of the terms quadrants and sectors were used in TOS with no consistent meaning. These quadrants are not the obvious big four Quadrants of the galaxy until the TOS movies, so, they represent something else. Could a quadrant be something as simple as a sector subdivided into four pieces?

https://en.wikipedia.org/wiki/List_of_Star_Trek_regions_of_space#Galactic_quadrants
https://memory-alpha.fandom.com/wiki/Quadrant

Please don't get Quadrants confused with Sectors & Sub-Sectors.

Any bad use of "Quadrant" by TOS should be treated like idiots who don't understand proper UFP terminology for what a "Quadrant" is or Universal Translator error.

 

[Christopher]

Christopher, who has published the most accurate canonical StarChart for the latest era in the canonical timeline?

I'm not sure how to define "accurate" in the context of a fictional narrative where everything is invented and fits together in whatever way best serves the story. Unless you're asking which fictional map graphic is most accurate to real astrocartography. As for canonical charts, these days they're usually just based on Star Charts maps, which are relatively accurate in their depiction of star positions and galactic geography, at least to the best of our knowledge 18 years ago. So I guess the answer to your question is Geoffrey Mandel.

 

[Henoch]

Any bad use of "Quadrant" by TOS should be treated like idiots who don't understand proper UFP terminology for what a "Quadrant" is or Universal Translator error.

SPOCK: Thank you, Doctor McCoy. Moving on schedule into quadrant nine oh four. Beta Six is eight days distant.

SPOCK: (consulting PADD) Quadrant four four eight, sir.

SPOCK: Starfleet records no authorised vessel in this quadrant except ours.

KIRK (OC): I told Starfleet all we had was a boatload of children but ...we're the only ship in the Quadrant.

Yep, these guys are idiots.

 

[Timo]

Semantically, Quadrant makes at least some sense when it is 90 degrees out of the galactic disc, and basically none if it's supposed to be a subdivision of a 3D volume: dividing volumes into four is a geometric chore. But that it is a division goes without saying, and perhaps sufficiently justifies the original TOS/early TNG usage. It's a shame we don't get examples of that usage in later Trek any longer... But the double meaning of the word is very much a Trek fixture, and should remain so.

Perhaps it's an artifact of Trek pseudohistory, though? In the early days, the ships would be entitled to their own Quadrants, more or less (it really is a feature rather than a bug!), and might be hard pressed to react to anything in a different Quadrant. Later on, awareness across an entire sector would be practical, and the faster vessels could also react to more distant events, so the heroes would not limit their discussions to mere Quadrants. And the Borg are already sufficiently advanced to think in terms of Grids rather than mere Sectors.

Timo Saloniemi

 

[Mres_was_framed!]

Oops, my math sucks. I was trying to put logic to dialog, where various uses of the terms quadrants and sectors were used in TOS with no consistent meaning. These quadrants are not the obvious big four Quadrants of the galaxy until the TOS movies, so, they represent something else. Could a quadrant be something as simple as a sector subdivided into four pieces?

I think this makes sense. I hear a lot of suggestions that quadrant in TOS is a fourth of something other than the Galaxy. For what it's worth, at the very beginning, I have heard that apparently the concept of TOS was supposed to be about a ship assigned to the "9th qudarant," which onscreen became Sector 9 in "Amok Time."

SPOCK: Thank you, Doctor McCoy. Moving on schedule into quadrant nine oh four. Beta Six is eight days distant.

SPOCK: (consulting PADD) Quadrant four four eight, sir.

SPOCK: Starfleet records no authorised vessel in this quadrant except ours.

KIRK (OC): I told Starfleet all we had was a boatload of children but ...we're the only ship in the Quadrant.

Yep, these guys are idiots.

I get the feeling that quadrant here is being used erroneously but consistently to refer to a cube of space. How big, I'm not sure. More on that below.

Semantically, Quadrant makes at least some sense when it is 90 degrees out of the galactic disc, and basically none if it's supposed to be a subdivision of a 3D volume: dividing volumes into four is a geometric chore. But that it is a division goes without saying, and perhaps sufficiently justifies the original TOS/early TNG usage. It's a shame we don't get examples of that usage in later Trek any longer... But the double meaning of the word is very much a Trek fixture, and should remain so.

Perhaps it's an artifact of Trek pseudohistory, though? In the early days, the ships would be entitled to their own Quadrants, more or less (it really is a feature rather than a bug!), and might be hard pressed to react to anything in a different Quadrant. Later on, awareness across an entire sector would be practical, and the faster vessels could also react to more distant events, so the heroes would not limit their discussions to mere Quadrants. And the Borg are already sufficiently advanced to think in terms of Grids rather than mere Sectors.

Timo Saloniemi

We don't always agree but in this case your points seem very consistent with my take on what we see on the show. Kirk says in "Amok Time" that they would be one of three Star Ships at a conference. This is the same episode that gave us "Sector 9" in canon.

Putting both your ideas together, if a quadrant is 1/4 of a sector AND is the traditional area covered by one Star Ship's patrol, then "Amok Time" puts 3 ships in the sector at the inauguration and 1 still out on patrol, each having their own "little q quadrant". Given that a few TOS episodes and numerous early TNG episodes suggest that a backup ship is about a week away (just far enough to be unable to affect the plot, lol), this situation also explains that it almost by design that so often the hero of the story serves onboard the "only ship in quadrant" close enough to save the day.

 

[Henoch]

Putting both your ideas together, if a quadrant is 1/4 of a sector AND is the traditional area covered by one Star Ship's patrol, then "Amok Time" puts 3 ships in the sector at the inauguration and 1 still out on patrol, each having their own "little q quadrant".

Sectors may be associated to Starbases. Starbase 9 is the location for Starfleet Command, Sector 9, etc. Each sector divided into four quadrants, each with its own Starship for patrol. Other Starships launch out from these Starbases on exploration missions beyond the sector (into adjoining unexplored sectors). Once the new sector fully mapped and explored, Starfleet decides to establish new colonies, invite new worlds to join the Federation, and build a new Starbase or not. The exploration Starships like the Enterprise would then move on to the next Starbase to expand the new sectors around them. This reassignment drift around to Starbases is supported by the Enterprises observed route to Starbases throughout its episodes.

 

[DEWLine]

Starfleet doesn't make decisions re: where to put colonies, invite worlds/species/star nations into the Federation, etc.. Those decisions are still reserved for Federation civilian authorities, as I recall.

Back to the mapping discussion...

 

[Mres_was_framed!]

Sectors may be associated to Starbases. Starbase 9 is the location for Starfleet Command, Sector 9, etc.

I like that idea, as it addresses, in a way, the outlier of Starbase 200 in TOS, and other oddly high for the era Starbase numbers in TNG. I wonder if sectors or Starbases could be numbered in such a way in three dimensional space that it could be interpreted as 20-0 or something similar.

Also very nice to see chart in Stardate order