So, I was looking at the map for Burning Empires and it has a compass rose indicating “Galactic North”. Which way is Galactic North? Is that Coreward, Rimward, Spinward, or Antispinward?
Paging Mr Moeller…
Good grief! It’s “up,” obviously.
p.
As full of sass as Paul’s answer is, that’s pretty much accurate as far as I can figure. Presumably galactic “west” is spinward and “east” is antispinward.
Yeah, the map doesn’t seem to use polar coordinates (I’m eyeballing it to be wide enough that coreward would be perpendicular to the center of the top edge, but somewhat off at the outer edges, if that makes sense… Like an uncorrected projection of Russia will have a different North in Kiev and Siberia.) So “Galactic North” is either parallel/perpendicular to the axis (you could measure a slice of galaxy with a rectangle where x is the span from top to bottom parallel to the axis of the galaxy and y is the span coreward to rimward perpendicular to the axis and get grid coordinates rather than polar ones) or it’s relative to something other than the rotational properties of the galaxy. You could define Galactic North by drawing a line from the midpoint of the axis of the galaxy to the end of a designated spiral arm and saying that any vector parallel to that line and pointing towards the arm is North, parallel and pointing towards the core is South, that the up/down axis is the closest line to the actual axis of rotation that is perpendicular to North, and that East/West is perpendicular to both of those lines.
You could do the same with another galaxy, for that matter, or with the planet Ahmilahk died on, or whatever you want. Another galaxy might be the easiest, since you could pick a real bright one and get an approximately correct value for your location if you can spot the core, the North Galaxy, and some known third factor. Even just two of three gives you a single curving line you know you’re on, which is better than nothing.
Galactic North is a real astrographic direction. It’s a right angle from coreward and spinward. When spin is in front of you, and core is right, north is up.
So, astronomers have two definitions of “Galactic North”. One, is as was said, the cross product of coreward and spinward. Another system, commonly referred to as J2000, defines “Galactic North”, essentially, as coreward. When science fiction talks about directions in a space setting, they typically use the latter system, but it isn’t universal by any means.
Hence my question, which way is “Galactic North”. It can really be defined in any number of ways, any of which are equally valid since the galaxy doesn’t have a true pole in any sense of the word since it is a disk as opposed to a sphere.
Here’s a link to Chris’Cartographic Principles’ page from his personal site.
Vega is the reference star system in the middle where the four grand quadrants intersect. If you are looking down on the galactic disc, north is the axis through vega towards the core.
Note that the scale bar is wrong on the current map on the wiki, though the grid is correct. Each grid is 200 ly to a side.
Hello!
As far as I can read in the BE book, Galactic North is the Urfan worlds (it has a big “N” nearby), before the Void. I don’t think it has anything to do with with the real Galactic North in astrogation; just an easy orientation shortcut by Mr. M. (thus, Galactic South would be the Vaylen front), but what do I know?
Greets
GGDD
Sorry guys, life caught up with me there for a moment. Galactic North is coreward, South is rimward. All orientations are along the “flat” of the galactic disk.
-Chris