Is the center of SAG * the very center there?
- Thread starter Marbat
- Start date
Pretty much... everything is rotating around that black hole.
More or less. Mostly we think of it as the center, but it's not perfectly centered if you look at the extents of the outer arms. Also, it's coordinates are a little goofy, at about "25.22, -20.91, 25899.97" (rounded to two decimal places). Since Sol is at 0,0,0, and we assume that the intention is for a straight line through the center of the galaxy "north" of it should cut straight through the true center, that would mean that Sagittarius A* sits about 25 lightyears "east" of the center. It's hard to draw conclusions about its north/south position, as it's just 25.9k north of Sol. It also sits nearly 21 lightyears "lower" than Sol.
Actually, it isn't. The question has been asked many times before, both here on the ED forums and on real-life space forums.
Let's compare Sag A* in the galaxy to the Sun (or a similar star) in a solar system. The Sun contains about 99.8% of the mass of the solar system, so saying "everything revolves around the sun" is a fair approximation of reality. Most star systems are like this. However, the million-solar-masses of Sag A* might sound like a lot, but it is seriously outweighed by the trillion-solar-masses of the rest of the stars and gas in the galaxy - not to mention dark matter (whatever that might be). Sag A* gravitationally rules only a few hundred LYs in its immediate vicinty.
As I mentioned in another thread on this topic, not only is Sag A* off-centre by a couple hundred LYs, there isn't even a force that keeps Sag A* in the centre - it just happens to be in the centre right now, and inertia is pretty much keeping it there. But if you (or some other fiendishly-minded technologically-advanced alien with a giant tractor beam) were to steal Sag A* and drag it out of the galaxy, most of the galaxy would just keep on spinning, unaware that Sag A had been taken away.
The co-ordinate x=0 line passes within 25 LY of Sag A*, but doesn't pass right through it. Which raises the question: if Sag A* isn't what has defined "the centre of the galaxy", then what is? Universal Cartographics (or whatever trans-factional scientific organization is in charge of defining the galaxy) must have picked "north" for a reason. They presumably calculated the precise centre of the galaxy (something that's rather hard for us to do here on Earth with our single point of view), and then drew a line from Sol through that centre and out the other side.
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@Sapyx
That's a great explanation.
Like a lot of others, I do get frustrated with ED from time to time. (Taken out of context, that sentence could be a very embarrassing thing to discuss publicly.)
The content gets stale because there's no real end-game and very little in the way of new content added consistently.
However, the context of all of this is so interesting and posts like yours capture my imagination all over again. Also, kind of makes me want to find the exact center and fly there.
Although having just arrived at Explorer's Anchorage, I'm not sure I'm up for more exploration at the moment. LOL
That's a great explanation.
Like a lot of others, I do get frustrated with ED from time to time. (Taken out of context, that sentence could be a very embarrassing thing to discuss publicly.)
The content gets stale because there's no real end-game and very little in the way of new content added consistently.
However, the context of all of this is so interesting and posts like yours capture my imagination all over again. Also, kind of makes me want to find the exact center and fly there.
Although having just arrived at Explorer's Anchorage, I'm not sure I'm up for more exploration at the moment. LOL
Well... I mean... who else was going to decide?
I would bet since in 3305 the galaxy is better known than ever, they were able to determine the gravitational center of the galaxy, hence the spot where the mass of the galaxy is equal north, south, west and east. Or said differently, if the galaxy was a solid disk, the point of equilibrium, where you could balance that disk on a stick, even with Sag A* 25 ly east of it.
Maybe FD even determined that spot based on the results of the stellar forge, being it only by considering the masscodes of all systems (since the rest is only generated upon first visit of the system).
If that is the case, we should be able to determine the center by ourselves. Just give each masscode a fictional weight of any number, but increasing with the letter, and you should be able to calculate the spot, which should be located at 25.22, -20.91, something. Or am I totally wrong with my rudimentary understanding of maths?
Maybe FD even determined that spot based on the results of the stellar forge, being it only by considering the masscodes of all systems (since the rest is only generated upon first visit of the system).
If that is the case, we should be able to determine the center by ourselves. Just give each masscode a fictional weight of any number, but increasing with the letter, and you should be able to calculate the spot, which should be located at 25.22, -20.91, something. Or am I totally wrong with my rudimentary understanding of maths?
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The problem here is that the game uses more than one coordinate system. The player-visible coordinate system that you just talked about has Sol as its zero-point ([0,0,0]), and Sgr A* is [25.21875,-20.90625,25899.96875] in there. I vaguely remember the engine having a galactic coordinate system (for the galactic-scale stuff) with Sgr A* as its center, but I'm not sure. Looking at the galactic region borders, they certainly don't converge over it. However, the more important one is the proc. gen. coordinate system, which is used for generating and naming the sectors we all know and love, divided into the 1280 ly cubes. That one's zero point would be at the bottom left near corner of Elite's galaxy, and Sol would be, let's see... around [49985,40985,24105] in numbers.
Of course, we are talking about Elite's galaxy, not our Milky Way. Even though the former is modeled after the latter, I like to keep the two separate. It's not a perfect replica, after all - in the years since the game released, our knowledge of it has improved considerably, but Elite's galaxy has of course remained the same.