misunderstanding in our location in space

Apparently we're rotating on the edge of the milky way galaxy. What I don't understand is, when astronomers present this as such they show a picture of some galaxy and some little mouse pointer indicating EARTH HERE. How in this multiverse could that picture possibly exist.. unless we had some kind of probe travel that distance look back and snap a pic. Sorry I can't find that photo I saw, but I'm sure it was just a picture of a similar spiral galaxy and our probable position in space.


thanks for any info



[edit on 31-5-2006 by Schizoflux]

what pic and what are you talking about

2 things.

First, light red shifts a certain amount at long distances at a fixed rate.

Secondly, using simple mathematical models, they can imput the known stars into this simulation and out pops a 3d map of all the discovered stars in our galaxy. 3d graphical representation is awesome stuff when taken to that scale.

Originally posted by Schizoflux
but I'm sure it was just a picture of a similar spiral galaxy and our probable position in space.

I believe that is what it is. And sometimes they use paintings or 3d models as well, like sardion2000 said.

Originally posted by Schizoflux
Apparently we're rotating on the edge of the milky way galaxy. What I don't understand is, when astronomers present this as such they show a picture of some galaxy and some little mouse pointer indicating EARTH HERE. How in this multiverse could that picture possibly exist.. unless we had some kind of probe travel that distance look back and snap a pic. Sorry I can't find that photo I saw, but I'm sure it was just a picture of a similar spiral galaxy and our probable position in space.

Well it's simple. We can look "through" the center of the Milky Way in the night sky. Like a cross section. We get an idea of the shape by this, and we also know we are on the edge. When you know the shape and the position we are, it doesn't take much imagination to change the angle of the view.

Looking into it from the edge.

Seems like common sense to me. But I could be wrong.

Steve

Schizoflux, It sounds like it could just be a grapical representation of the milkyway you saw.

Yeah, I don't think it's a perfect 3-d image of all charted stars... mostly because it's so hard to see all the way to the other side!

This is why we actually are not too sure if our galaxy is barred or spiral in shape !

Most of what you've seen is an artist's conception of what it would look like, or a small smattering of the brightest stars on the other side that we have detected.

If we have a general idea of where we are in this spiral galaxy, then we can select an image of another galaxy similar to ours, and put a big arrow where we would be if it was the milky way.

ussually they say artists impression

Yeah we usually use pictures of Andromeda to represent our galaxy.