Quote:
Originally Posted by Turtle
OK We have to resolve this.  Neither of your two diagrams specify up or down view or which pole is which.
"Get a Straight Answer" |
No. They do not. (
and by the way, this conversation seems so oddly familiar 
)
The only things for certain the diagrams show is that rotation is going towards Cygnus from our point of view. That is to say: if you are looking at the constellation Cygnus then you are looking toward the direction the solar system is moving in terms of galactic rotation. It's the fact that Cygnus is in the northern hemisphere that settles the question of which pole leads. It is the north pole.
Quote:
Originally Posted by Turtle
The more scholarly articles I've been off hunting simply don't seem to mention the direction, but I just found this answer for counter-clockwise. I honestly thought everything rotated counter-clockwise because of conservation of angular momentum?   |
Astrnomical systems do usually rotate counterclockwise as a matter of convention. The right hand rule is usually used. If you point your thumb up then that defines the north pole. Your fingers then (not pointed straight out, but curved a bit) show the direction of rotation. Point your thumb at your face and look at the direction your fingers are pointing and it is indeed counterclockwise.
The direction of rotation usually defines the pole in this way. Looking at things from the top then (from the north—which is also convention) will show counterclockwise rotation.
The diagrams I linked obviously don't follow this convention. But, the pertinent thing is that the galactic coordinate system has Cygnus at 90 degrees which is the direction of rotation (as viewed by us). So if we are on earth's (or the sun's) north pole and looking up, we will see the general direction that we are rotating toward.
Is this much more than gibberish?
~modest
