(June 23, 2014 at 1:15 am)Wyrd of Gawd Wrote: Sounds legit but you're forgetting that even the most distant galaxies clump together in clusters. So galaxies are merging all over the place. We are not the center of the universe.
I don't think he was asserting that we are. However, the expansion itself is the space between galaxies expanding. I think Janna Levin put it quite well with her analogy of cities and the distance between them expanding some time ago. But I recently read some other stuff of hers and liked this:
Quote: Space is not just an abstract notion but a mutable, evolving field. It can begin and end, be born and die. Space is curved, it is a geometry, and our experience of gravity, the pull of the earth and our orbit around the sun, is just a free fall along the curves in space. From this huge insight people realized the universe must be expanding. The space between the galaxies is actually stretching even if the galaxies themselves were otherwise to stay put.
Some are on a collision course, some are merging, others are moving away faster than others from us. If you put yourself in a galaxy that was in redshift from us, we would appear to redshift from the milky way. In most any direction you look from any galaxy, the universe appears to be expanding.
Here's a really good analogy:
