[Lynda (OP)]

I have been reading about our universe.    Apparently, our galaxy, the Milky Way, is a spiral one and our solar system is part of one of the spirals sticking out from the centre.

Where is our galaxy in relation to the known universe?    Is it comparatively near the edge or near the middle?

In both our galaxy and the universe can anyone tell me what is in the centre?

It would be good if someone can tell me!   

[Kryptid]

As far as it is known, our Universe does not even have a center. It is possible that the Universe is infinitely large, in which case any point could be argued as the center. Also, our Universe may also be an expanding "hypersphere" of some sort. Imagine that the Universe is a balloon, and all of the stars, galaxies, you and me are imbedded in the surface of this balloon. All of these objects are confined to the balloon's surface, and cannot move into or out of the balloon (they can move around within the surface, though). The balloon's surface represents the 3-dimensional space we inhabit. Thus, it could be said that the center of the balloon is the center of the Universe. Since this center does not reside on the balloon's surface, it cannot be seen or reached by us. It resides in what we might call "hyperspace".

[LeeE]

In regard to the 'known' universe, our galaxy is a member of the Local Group http://en.wikipedia.org/wiki/Local_Group, which in turn is a member of the Virgo Supercluster http://en.wikipedia.org/wiki/Virgo_Supercluster

You might want to have a look at Large-scale structure of the cosmos http://en.wikipedia.org/wiki/Large-scale_structure_of_the_cosmos to put it in context.

We are, of course, effectively at the middle of the 'known' universe because the qualifier 'known' refers to us and the radius of what we can see from our point in space is about the same in all directions:)

The evidence suggests that there is a super-massive Black-Hole singularity at the center of our Milky Way galaxy.